PIER DETAILS TABLE OF CONTENTS -CHAPTER 15

TABLE OF CONTENTS – PIER DETAILS CHAPTER 15 FILE NO. TITLE DATE TABLE OF CONTENTS 15.TOC-1 15.TOC-2 15.TOC-3 15.00 Table of Contents – Chapter 15 ...............................................................31Oct2022 Table of Contents – Chapter 15 ...............................................................31Oct2022 Table of Contents – Chapter 15 ...............................................................30Oct2020 Introduction...............................................................................................30Apr2020 GENERAL GUIDELINES AND TYPE SELECTION 15.01-1 15.01-2 15.01-3 15.01-4 15.01-5 15.01-6 15.01-7 General Guidelines...................................................................................30Apr2020 General Guidelines...................................................................................30Oct2020 General Guidelines..................................................................................18May2016 Virginia Pier Cap ......................................................................................30Oct2020 Virginia Pier Cap (Special Circumstances) ..............................................30Apr2020 Type Selection..........................................................................................30Oct2020 Geotechnical Design Data Tables and Architectural Treatment for Piers ....................................................................................................30Oct2020 PIER COMPONENTS AND MISCELLANEOUS DETAILS 15.02-1 15.02-2 15.02-3 15.02-4 15.02-5 15.02-6 15.02-7 15.02-8 15.02-9 15.02-10 15.02-11 15.02-12 15.02-13 15.02-14 15.02-15 Cap/Column Clearance/Long Chord Layout ............................................30Apr2019 Cap Length Criteria ..................................................................................30Apr2020 Beam-Column Corner Reinforcing ...........................................................30Apr2020 Beam-Column Corner Reinforcing ...........................................................30Apr2020 Sample Anchor Bolt Layouts ....................................................................30Apr2020 Bottom Cap Slope and Cap Reinforcement ............................................18May2016 Cap Reinforcement .................................................................................18May2016 Seat Reinforcement..................................................................................30Apr2020 Columns ...................................................................................................30Apr2020 Columns ...................................................................................................29Oct2021 Column Ties ............................................................................................18May2016 Footing Types and Details .......................................................................31Oct2022 Drilled Shafts ............................................................................................30Oct2020 Drilled Shafts ...........................................................................................18May2016 Drilled Shafts ............................................................................................30Oct2020 SAMPLE SHEETS AND DETAILING CHECK LIST * 15.03-1 * 15.03-2 Sample Multi-Column Pier Sheet .............................................................30Apr2020 Sample Hammerhead Pier Sheet ............................................................30Apr2020 * Indicates 11 x 17 sheet; all others are 8½ x 11. PART 2 PIER DETAILS TABLE OF CONTENTS – CHAPTER 15 DATE: 31Oct2022 SHEET 1 of 3 FILE NO. 15.TOC-1 TABLE OF CONTENTS – PIER DETAILS CHAPTER 15 FILE NO. TITLE DATE SAMPLE SHEETS AND DETAILING CHECK LIST (Continued) * 15.03-3 * 15.03-4 * 15.03-5 15.03-6 15.03-7 * 15.03-8 * 15.03-9 * 15.03-10 * 15.03-11 15.03-12 Sample Hammerhead Pier Sheet ............................................................30Apr2020 Sample Wall Pier Sheet ...........................................................................30Apr2020 Sample Pile Bent Sheet ...........................................................................30Apr2020 Check List.................................................................................................30Apr2020 Check List.................................................................................................30Apr2020 Sample Virginia Pier Sheet ......................................................................30Apr2020 Sample Virginia Pier Sheet ......................................................................30Apr2020 Sample Virginia Pier Sheet ......................................................................30Apr2020 Sample Virginia Pier Sheet ......................................................................30Apr2020 Check List.................................................................................................30Apr2020 SUPERSTRUCTURE FORCES 15.04-1 15.04-2 15.04-3 15.04-4 15.04-5 15.04-6 15.04-7 15.04-8 15.04-9 15.04-10 15.04-11 15.04-12 General Information..................................................................................30Oct2020 General Information..................................................................................11Jan2011 General Information................................................................................. 17Dec2010 Example 1: Varying Height/Stiffness.......................................................11Jan2011 Example 1: Varying Height/Stiffness.......................................................11Jan2011 Example 1: Varying Height/Stiffness.......................................................11Jan2011 Example 2: Unsymmetric Spans ............................................................ 17Dec2010 Example 2: Unsymmetric Spans .............................................................11Jan2011 Example 3: Pile Bent .............................................................................. 17Dec2010 Example 3: Pile Bent ...............................................................................11Jan2011 Example 3: Pile Bent ...............................................................................11Jan2011 Example 3: Pile Bent ...............................................................................11Jan2011 SECTION 15.05 intentionally left blank PIER PROTECTION SYSTEM 15.06-1 15.06-2 15.06-3 15.06-4 15.06-5 15.06-6 15.06-7 15.06-8 15.06-9 15.06-10 General Information..................................................................................31Oct2022 General Information..................................................................................31Oct2022 General Information.................................................................................18May2016 Length of Pier Protection.........................................................................18May2016 Length of Pier Protection.........................................................................18May2016 Length of Pier Protection.........................................................................18May2016 Length of Pier Protection.........................................................................18May2016 Barrier Layout Example 1........................................................................18May2016 Barrier Layout Example 2.........................................................................30Oct2020 Barrier Layout Example 2.........................................................................30Oct2020 * Indicates 11 x 17 sheet; all others are 8½ x 11. PART 2 PIER DETAILS TABLE OF CONTENTS – CHAPTER 15 DATE: 31Oct2022 SHEET 2 of 3 FILE NO. 15.TOC-2 TABLE OF CONTENTS – PIER DETAILS CHAPTER 15 FILE NO. TITLE DATE PIER PROTECTION SYSTEM (Continued) 15.06-11 15.06-12 15.06-13 15.06-14 15.06-15 15.06-16 15.06-17 15.06-18 15.06-19 Barrier Layout Example 3 ......................................................................... 30Oct2020 Barrier Layout Example 3 ........................................................................18May2016 Barrier Layout Example 3 ......................................................................... 30Oct2020 Barrier Layout Example 4 ........................................................................18May2016 Barrier Layout Example 4 ......................................................................... 30Oct2020 Barrier Layout Example 4 ......................................................................... 30Oct2020 Barrier Layout Example 5 ......................................................................... 30Oct2020 Barrier Layout Example 5 ......................................................................... 30Oct2020 Barrier Layout Example 5 ......................................................................... 30Oct2020 PIER DETAILS TABLE OF CONTENTS – CHAPTER 15 PART 2 DATE: 30Oct2020 SHEET 3 of 3 FILE NO. 15.TOC-3 INTRODUCTION Piers transmit loads from the superstructure to the foundation. The intent of this chapter is to establish the practices and specific requirements of the Structure and Bridge Division for the design and detailing of piers and pile bents. It is expected that users of this chapter will adhere to the practices and requirements stated herein. A design waiver will be required for areas that are indicated as “minimum” standards or where the term “shall” is indicated. The designer shall be responsible for investigation, analysis and calculations necessary to secure a waiver from the State Structure and Bridge Engineer. The designer must indicate in the waiver why the standard cannot be met. References to AASHTO LRFD Specifications refer to the current AASHTO LRFD Bridge Design Specifications and current VDOT Modifications (IIM-S&B-80). NOTE: Due to various restrictions on placing files in this manual onto the Internet, portions of the drawings shown do not necessarily reflect the correct line weights, line types, fonts, arrowheads, etc. Wherever discrepancies occur, the written text shall take precedence over any of the drawn views. PIER DETAILS INTRODUCTION – CHAPTER 15 PART 2 DATE: 30Apr2020 SHEET 1 of 1 FILE NO. 15.00 GENERAL INFORMATION: Specific types of piers and details are more cost effective or necessary due to aspects of the particular bridge grade and location. In general, it is beneficial to keep cap size, column size and pile type and size the same for all piers/bents on a project and/or corridor to enable the reuse of forms and to avoid ordering small quantities. On larger projects, additional column sizes or pile types may be warranted where heights, depths or design loads vary substantially across the spans. Drainage: See File No. 22.04-2 for criteria on downspout / collector pipe placement. Multi-Column Piers: Multi-column piers are typically used where column heights are below 30 feet. Column spacing between 15 and 20 feet is generally cost effective. Cap ends shall not be rounded, but should be tapered for aesthetic purposes. Concrete Class A3 (f’c = 3,000 psi) should be used. Class A4 (f’c = 4,000 psi) may be used where warranted. The use of multi-column piers in areas where floating debris may lodge between columns should be avoided. On wide structures with more than five columns and/or cap lengths greater than 80 feet, designers should consider whether to split a multi-column pier into two piers especially where columns are short and contraction/expansion of the pier cap results in large internal forces. For piers with more than six columns and/or cap lengths greater than 100 feet, two piers are required. Hammerhead Piers: Hammerhead piers are typically used where column lengths on multi-column piers will require larger column sizes due to slenderness. Hammerhead piers are also an option where stream flow could result in debris build-up between columns of a multicolumn pier. Where stream flow is present, hammerhead piers shall be oriented parallel to the direction of flow. Small skews to the direction of flow are acceptable (0 to 5 degrees) where superstructure skew can be eliminated completely or reduced for specific design purposes. Specific design purposes include reducing skew to 10 degrees so V-load method can be used to determine cross frame forces on steel superstructure and reducing skew to 20 degrees so finite element analysis is not required. Small skews parallel to the direction of flow require concurrence of the hydraulic engineer. The design of hammerhead piers shall include a load case based on eccentric loads due to a future re-decking with half of the deck removed. Wall/Solid Piers: Wall piers are typically used where multi-column piers may be used, but stream flow will result in debris build-up between columns. Wall piers may be more cost effective than multi-column piers when collision force is taken into account. PIER DETAILS GENERAL GUIDELINES AND TYPE SELECTION GENERAL GUIDELINES PART 2 DATE: 30Apr2020 SHEET 1 of 7 FILE NO. 15.01-1 GENERAL INFORMATION (continued): Wall/Solid Piers (continued): Concrete Class A3 (f’c = 3,000 psi) shall be used. Sloped (tapered/battered) walls shall not be used. Non-reinforced walls are prohibited. Wall piers shall be oriented parallel to the direction of flow. Caps are required where the width of wall is not sufficient for bearing layout (typically where two bearing lines are present). Sloped Walls (not to be used) Cap Required for Bearing Layout Cap Not Required for Bearing Layout Pile Bents: Pile bents are typically used over wetlands or bodies of water due to their lower cost and reduced environmental impact. However, they may not be suitable for tall piers. The only pile types allowed with pile bents are prestressed concrete square piles (from the BPP standards, with minimum size being 18”) or prestressed concrete cylinder piles (DBE approval is needed for cylinder piles). Plumb piles are preferred. The outside pile on both sides of the bent may be battered to improve resistance to movement due to transverse forces only where future widening is not a concern. Likewise, piles may be battered longitudinally at a fixed bent or bents to better fix the thermal center of a unit and handle longitudinal forces. Batter on piles should not exceed 1:6. Before battering piles, designers should consider whether fixing more bents can adequately handle design loads and movement. A pile bent shall not be used if more than 35’ of pile is exposed above the ground line or water line (MHT). Pile bents are often used in scourable areas. Designers must investigate both the existing ground and scoured condition as the assumed point of fixity for the piles can vary substantially. Additionally, pile driveability must be evaluated. The designers must determine if a pile can be driven deep enough so that it is stable after scour occurs. Assuming the number of piles equals the number of beam lines is a good starting point for preliminary design. Piles Plumb Piles Battered Longitudinally PIER DETAILS GENERAL GUIDELINES AND TYPE SELECTION GENERAL GUIDELINES Outside Piles Battered Transversely PART 2 DATE: 30Oct2020 SHEET 2 of 7 FILE NO. 15.01-2 VIRGINIA PIER CAP: When a joint is introduced at a pier/bent, a design waiver approved by the State Structure and Bridge Engineer is required and the Virginia Pier Cap shall be used. As part of the design waiver request, the designer must address the type of joint and, if a tooth joint is planned, the alignment of the teeth (this is particularly important for curved structures where the longitudinal movement will likely have a transverse component). Locating a tooth joint at a pier of a curved structure is strongly discouraged. See File 17.01-9 thru -13 for information pertaining to abutment type selection and jointless philosophy. The minimum embedment into the concrete integral backwall shall be 6” for steel stringers and 9” for concrete stringers. Distance between end of beam/girder and buildup (D1) shall provide a minimum of 1” clearance at maximum expansion. The buildup shall be of sufficient width to provide a minimum of 3” beyond the back of drip details with superstructure at maximum contraction and shrinkage, where applicable, (D2). The top of buildup below the drip bead shall be sloped, but the top can also be sloped full width. The top slope shall drop a minimum of 2”. The Designer shall work with the District to determine the minimum trough depth sufficient for manual cleanout. Where beam/girder depths are shallower, additional cap depth may be necessary to ensure the minimum trough depth and cross-slope are maintained. The Designer shall include anticipated construction loading in design of the pier (e.g., steel erected on one side only, steel erected on both sides with deck cast on one side only, etc.). The Designer shall include the following note in the plans: Forms for the backwall shall be attached to the girders only; the forms shall not be attached to or blocked against the cap or other backwall. The backwall and forms must be free to move in relation to the cap. Tooth joints can capture large volumes of drainage and details for conveyance of drainage to the ground and erosion control need to be carefully considered. However, tooth joints are not to be considered part of the design of or eliminate the need for bridge deck drainage systems. Any deviations from the conceptual layout or minimum dimensions indicated above require a design approval from the District Structure and Bridge Engineer. PIER DETAILS GENERAL GUIDELINES AND TYPE SELECTION VIRGINIA PIER CAP PART 2 DATE: 30Oct2020 SHEET 4 of 7 FILE NO. 15.01-4 VIRGINIA PIER CAP (SPECIAL CIRCUMSTANCES): The Virginia Pier Cap details shown above are for special circumstances (e.g., gore area on bridge where ramps merge). See previous sheet for applicable notes. WATERPROOFING MEMBRANE DETAIL FOR VIRGINIA PIER CAP: PIER DETAILS GENERAL GUIDELINES AND TYPE SELECTION VIRGINIA PIER CAP (SPECIAL CIRCUMSTANCES) PART 2 DATE: 30Apr2020 SHEET 5 of 7 FILE NO. 15.01-5 TYPE SELECTION: This flowchart is provided to aid pier type selection. It is intended to provide general guidelines and to supplement 15.01-1 thru 15.01-3. START HERE Is debris build-up a concern? Yes Use hammerhead or wall pier No Yes No Are prestressed concrete piles being considered? Use hammerhead or wall pier or multi-column pier Yes Is pier over wetland or body of water? No Use pile bent Yes Does the column position interfere with the roadway? No Yes No Yes Based on the length to point of fixity for scoured and unscoured conditions, and accounting for unsupported lengths, can the piles in a bent handle the loads? Can more piles or a larger size pile be used? No Does the required finished grade result in insufficient vertical clearance to the cap or superstructure above the roadway? Does the required finished grade result in insufficient vertical clearance to the cap or superstructure above the roadway? Use hammerhead or wall pier or multi-column pier Yes Use integral straddle bent No Yes Use straddle bent or hammerhead pier Use integral cap Use hammerhead or multi-column pier No Yes Are column heights expected to exceed roughly 30 feet? (30’ is a guide) No Use multi-column pier or wall pier In all cases, see Section 15.06 if the horizontal clearance to face of pier will be less than 30 feet from edge of traffic lane. PIER DETAILS GENERAL GUIDELINES AND TYPE SELECTION TYPE SELECTION PART 2 DATE: 30Oct2020 SHEET 6 of 7 FILE NO. 15.01-6 GEOTECHNICAL DESIGN DATA TABLES: The appropriate geotechnical design data table shall be provided either on pier and abutment sheets or on the sheet with the Substructure Layout. See File No. 23.01-8 for table to be used with pile foundations. See File No. 17.02-3 for tables to be used with spread footings or drilled shafts . ARCHITECTURAL TREATMENT FOR PIERS The decision to incorporate architectural treatment into a bridge project and the type of treatments shall be made during the preliminary design. Incorporating or removing architectural treatments from a project at a later stage could require re-design and plan changes including quantities. Including architectural treatment on piers may affect geometric items such as horizontal clearances. Designers must consider the texture relief to be sacrificial and position reinforcement to provide the minimum concrete cover required from the back of the maximum relief used to the reinforcement. Copings may need additional reinforcement to be included in plan details. Architectural treatments such as sculpted windows and wall murals have minimum dimensions that need to be considered when sizing structural members (e.g., columns) where those treatments are desired. See Chapter 5 of this manual for requirements, details and information for architectural treatment. PIER DETAILS GENERAL GUIDELINES AND TYPE SELECTION GEOTECHNICAL DESIGN DATA TABLES AND ARCHITECTURAL TREATMENT PART 2 DATE: 30Oct2020 SHEET 7 of 7 FILE NO. 15.01-7 CAP/COLUMN CLEARANCE: No portion of a cap or column on a double or triple overpass shall be within 4 feet clear of the top front face of parapet/rail extended 10 feet above the top of deck or protrude beyond the back of parapet/rail for the remaining distance to the required vertical clearance for the road classification as illustrated below. The same criterion applies to the cap or column for at-grade barriers except that that Standard BPPS series barrier may be located directly adjacent to the column. BRIDGE LAYOUT ON LONG CHORD: Use details only if pier is laid out on the long chord. Details shown here must agree with BRIDGE LAYOUT and SUBSTRUCTURE LAYOUT shown on the plans. PIER DETAILS PIER COMPONENTS AND MISCELLANEOUS DETAILS CAP/COLUMN CLEARANCE / LONG CHORD LAYOUT PART 2 DATE: 30Apr2019 SHEET 1 of 15 FILE NO. 15.02-1 CRITERIA FOR PIER CAP LENGTH: SQUARED CAP END ROUNDED CAP END Only when within hydraulic opening Notes: 1. Set location of the center of the rounded cap end as follows:  at least 6” beyond center of the extreme anchor bolt.  at least a length equal to the development length (L) for the main bars beyond the critical section. Use whichever gives the greater cap length. 2. The width of the pier seat shall be such that the edge of seat shall be at least 3” beyond the extreme point of the masonry plate and anchor bolt sleeve, where applicable, and 6” beyond the anchor bolt(s). Where masonry plate criteria controls cap width or length, the masonry plate may be clipped to provide the necessary clearance. 3. The critical section for multi-column cap bending moment (cantilever) with concentrated load(s) outside the centerline of the extreme column is the centerline of that column. For critical section for shear in cap, see AASHTO LRFD specifications, Articles 5.8.1 and 5.6.3. 4. For basic development length and modification factors, see Chapter 7, Section 2. 5. Top reinforcement shall be of sufficient length for supporting the stirrups. PIER DETAILS PIER COMPONENTS AND MISCELLANEOUS DETAILS CAP LENGTH CRITERIA PART 2 DATE: 30Apr2020 SHEET 2 of 15 FILE NO. 15.02-2 REINFORCING DETAILS AT CORNER OF BEAM AND COLUMN: The reinforcement in the corner where a beam and column intersect shall be adequate for strength (transferring 100% moment) and crack control. For an opening corner, where the moments cause tension in the inside corner, the most efficient reinforcement scheme is as shown in the following figure. This scheme shall be used to the most possible extent. Most Efficient Reinforcement for Opening Corner Other reinforcement not shown for clarity Considering constructability, the following detail can be used for the reinforcement in an opening corner. Lap splice lengths shall meet AASHTO LRFD Specifications. Alternative Reinforcement for Opening Corner Other reinforcement not shown for clarity PIER DETAILS PIER COMPONENTS AND MISCELLANEOUS DETAILS BEAM-COLUMN CORNER REINFORCING PART 2 DATE: 30Apr2020 SHEET 3 of 15 FILE NO. 15.02-3 REINFORCING DETAILS AT CORNER OF BEAM AND COLUMN (Cont’d): For a closing corner, where the moments cause tension in the outside corner, the reinforcement near the outside surfaces shall be continuous. Reinforcement for Closing Corner Considering constructability, the following detail can be used to detail the reinforcement in a closing corner. The lap splice lengths shall meet the AASHTO LRFD Specifications. Alternative Reinforcement for Closing Corner PIER DETAILS PIER COMPONENTS AND MISCELLANEOUS DETAILS BEAM-COLUMN CORNER REINFORCING PART 2 DATE: 30Apr2020 SHEET 4 of 15 FILE NO. 15.02-4 SAMPLE ANCHOR BOLT LAYOUTS: TYPICAL ANCHOR BOLT LAYOUT shall include offset dimensions for each anchor bolt from one reference point and angles. Variable tables should accompany anchor bolt layouts where necessary. Cap width, centerline bearing to centerline pier, seat width and centerline of seat to edge of seat dimensions are normally shown in the cap PLAN view. (For skewed structures. Bearing with 4 anchor bolts shown.) (For curved structures. Bearing with 4 anchor bolts shown.) PIER DETAILS PIER COMPONENTS AND MISCELLANEOUS DETAILS SAMPLE ANCHOR BOLT LAYOUTS PART 2 DATE: 30Apr2020 SHEET 5 of 15 FILE NO. 15.02-5 BOTTOM CAP SLOPE: Bottom slopes for pier cap cantilevers should generally be limited to a range between 3 : 1 and 6 : 1 with the ratio of (cap depth) to (depth at end) generally limited to a range between 2 : 1 and 1.3 : 1. Deviations from these limits should be made only in cases of unusual pier geometry or to achieve architectural effects. Slopes shall not be used where the end of cap is less than 2’-6” deep and/or slope depth is less than 12”. Slopes shall not be used on caps with rounded ends. CAP REINFORCEMENT: Top Bars: All top main cap bars shall be hooked at the ends of the cap. Use 180 degree hooks with a single layer. Use 90 degree bends with two or more layers of top main bars. Laps should be avoided. If required, laps should be located near area(s) of maximum positive moment. With two or more layers of top reinforcement, additional bar series are required (each successively shorter) to provide the required clear distance between bends. Cap dimensions shall be reevaluated if more than five layers are required. Bottom Bars: Multi-column piers: Lowest bottom main cap bars in corners of stirrups shall be extended into cantilever. Others in lowest row and bars in other bottom rows may be terminated at interior end of cantilever (i.e. column side) except where additional bars require extension to meet shrinkage and temperature requirements. Laps should be avoided. If required, laps should be located near area(s) of maximum negative moment. See File No. 15.03-1 for example. Hammerhead piers: Laps should be avoided. At a minimum, bottom main cap bars shall be placed in the corners of stirrups, consist of #6 bars or larger and meet shrinkage and temperature requirements. PIER DETAILS PIER COMPONENTS AND MISCELLANEOUS DETAILS BOTTOM CAP SLOPE AND CAP REINFORCEMENT PART 2 DATE: 18May2016 SHEET 6 of 15 FILE NO. 15.02-6 CAP REINFORCEMENT (Continued): Shrinkage and Temperature Bars: For area and spacing requirements for shrinkage and temperature reinforcement, see AASHTO LRFD specifications, Article 5.10.8. Stirrups: Use #4 stirrups unless the spacing required is less than 4” (in which case #5 stirrups should be used). When two #5 stirrups do not satisfy the steel required, three stirrups in one plane may be used. When the stirrup area becomes excessive, the cap depth should be reevaluated. Vertical legs of stirrups should be distributed across the cap width (Example 1). Two vertical legs may be placed between two adjacent main bars where the distance between main bars is greater than or equal to 5” (Example 2). Two vertical legs shall not be about the same main bar (Example 3). Where designers are concerned with high torsion and splitting forces in pile bent caps (e.g. bents with staggered battered piles), stirrups may be arranged as shown in Example 4 where one stirrup encloses all the main bars and one or more stirrups provided on the interior. Prohibited Acceptable EXAMPLE 1 Prohibited Pile Bent EXAMPLE 2 Acceptable EXAMPLE 3 PIER DETAILS PIER COMPONENTS AND MISCELLANEOUS DETAILS CAP REINFORCEMENT Pile Bent EXAMPLE 4 PART 2 DATE: 18May2016 SHEET 7 of 15 FILE NO. 15.02-7 PART SECTION THRU WALL / SOLID PIER WITHOUT CAP PART SECTION THRU PIER CAP MAIN REINFORCEMENT < 6” TO TOP OF SEAT PART ELEVATION PART SECTION MAIN REINFORCEMENT ≥ 6” TO TOP OF SEAT PART SECTION PART SECTION SPLIT PADS PIER DETAILS PIER COMPONENTS AND MISCELLANEOUS DETAILS SEAT REINFORCEMENT PART 2 DATE: 30Apr2020 SHEET 8 of 15 FILE NO. 15.02-8 Columns: Vertical reinforcement (PV series) in columns shall equal at least 1% of the gross concrete area of the column except for wall/solid piers. The minimum vertical reinforcement in wall/solid piers may be reduced to 0.5% of the gross concrete area as indicated on the following sheet. Maximum reinforcement shall be limited to 8% of the gross concrete area. Vertical reinforcement extending into pier caps shall not be hooked. Pier caps shall be deep enough to allow adequate development length of the PV series without using hooks. The minimum spacing between the vertical reinforcement from AASHTO LRFD specifications, Article 5.10.3.1, shall be provided between spliced bar sets with bars spliced side by side. Radial splicing to provide the required spacing for additional bars shall only be permitted where tied to inner hoops to maintain position. Side by Side Radial Splicing For spiral and tie requirements, see AASHTO LRFD specifications, Article 5.10.4. Circular columns shall be designed as tied columns. However, the confinement steel shall be continuous spirals (#3 reinforcing bars minimum) or welded wire fabric. The pitch of the spiral shall be taken as the required spacing for ties. Multi-Column Piers: The minimum column diameter shall be 3’-0”. Where columns larger than 3’-0” are required, they shall be selected in 6” increments from 3’-0” to 5’-0”. For diameters greater than 5’-0”, 12” increments shall be used. The use of A4 (f’c =4,000 psi) concrete should be considered when its use will result in a reduction in column diameter. The minimum bar size for vertical reinforcement is #9. Use ten (10) #9 bars for 3’-0” diameter column unless strength requirements indicate a larger area is needed. Hammerhead Piers: Main vertical reinforcement shall be detailed such that maximum concrete lifts will not exceed 30 feet. The use of hollow column sections requires additional details for inspection including elevation markings on the interior, access ladders, lighting and power supply. PIER DETAILS PIER COMPONENTS AND MISCELLANEOUS DETAILS COLUMNS PART 2 DATE: 30Apr2020 SHEET 9 of 15 FILE NO. 15.02-9 Columns (Cont’d): Wall/Solid Piers: The minimum wall thickness shall be 2’-6” unless a design approval request is submitted to and approved by the District Structure and Bridge Engineer. AASHTO LRFD specifications Article 11.2 states solid wall piers are designed as columns for forces and moments acting about the weak axis and as piers for those acting about the strong axis. Article 5.7.4.2 states a reduced effective area may be used when the cross-section is larger than that required to resist the applied loading for bridges in Seismic Zone 1. Current ACI 318 10.3.1.2 limits the reduced effective area to one-half the gross area. The minimum vertical reinforcement in wall/solid piers shall not be less than 0.5% of the gross concrete area. The area of vertical reinforcement provided shall not be less than required by Article 5.7.4.2 using a reduced effective area and as required to satisfy AASHTO LRFD limit state design. As such, the minimum area of vertical reinforcement extending from the footing into the wall for a wall thickness of 2’-6” is equivalent to #7 bars @ 8” each face where applicable. Horizontal reinforcement in the wall shall not be less than #4 bars @ 12”. Vertical Reinforcement to Allow for Spread Footing Elevation Adjustments: When using spread footings, design the pier for additional column height up to 3 feet to allow the bottom of footing elevation to be lowered if the foundation material at the plan elevation does not meet the design bearing resistance. Detail the reinforcement accordingly. The amount of additional column height to account for depends on the geotechnical conditions. The pier design must account for both the planned footing elevation and the lower footing elevation, since in some situations the design with shorter columns may control. Add the following note to the pier sheet(s) if the maximum additional column height is other than the 3 feet that is described in 401.03(b): “Bottom of footing elevations shall not be lowered by more than _ feet.” PIER DETAILS PIER COMPONENTS AND MISCELLANEOUS DETAILS COLUMNS PART 2 DATE: 29Oct2021 SHEET 10 of 15 FILE NO. 15.02-10 COLUMN TIES: For spiral and tie requirements, see Article 5.7.4.6 of the AASHTO LRFD specifications. The column sections to the right depict additional tie arrangements adhering to the requirement of Article 5.10.6.3 that no vertical bar or bundle shall be more than 24” measured along the tie from a restrained bar or bundle. In the first example (top), the dimensioned bars are less than 24” from a restrained bar and do not require an additional tie. Comparing the second example (middle) to the first, the column dimensions were increased and the dimensioned bars now exceed 24” requiring an additional tie. Instead of adding two additional ties along the transverse face, one was added and the original tie position was moved so that all bars are less than 24” from a restrained bar. Comparing the third example (bottom) to the second, the column dimensions remain the same, but the number of vertical bars is one less in each longitudinal face. The dimensioned bars are less than 24” from a restrained bar and do not required an additional tie. PIER DETAILS PIER COMPONENTS AND MISCELLANEOUS DETAILS COLUMN TIES PART 2 DATE: 18May2016 SHEET 11 of 15 FILE NO. 15.02-11 FOOTING TYPES AND DETAILS: Minimum footing depth shall be 3’-0” except for footings with square prestressed concrete piles where the minimum footing depth shall be increased as indicated in File No. 15.02-11. Footing dimensions for each column (including pile layout where applicable) at a multi-column pier should be identical. With stepped footings, the shorter column length is stiffer and draws more load. The longer column carries less load, but is more slender. The required footing sizes should have similar dimensions and one footing size used. Footing dimensions should be kept the same between all similar types of piers except on larger projects where design loads, geometry or geotechnical requirements vary substantially across the spans or where specific need exists (e.g. minimum footing size is necessary to provide required clearance for sheet piling during construction). In these situations, footing sizes should be grouped. Top of footings shall be a minimum of 12” below existing ground or finished grade. Top of footings for overpasses shall be a minimum of 12” below the invert of adjacent ditch or top of fill slope. When a pier protection barrier (BPPS) is required, the 12” minimum shall be increased to 2’-6” to avoid interference with the BPPS footing. For stream crossings, footing shall be located at a depth to provide for safety against scour. Shrinkage and temperature reinforcement, as defined in AASHTO LRFD 5.10.6, is not required for side faces of buried footings less than 5’-0” in depth. For buried footings 5’-0” or deeper, provide #5 bars at 12” spacing on each face and in each direction. Spread footing: A spread FOOTING PLAN is shown on File No. 15.03-2 for a hammerhead pier. FOOTING PLAN for a multi-column pier is similar. A TYPICAL Pile footing: For a hammerhead pier or multi-column pier where piles are used in the footing, rest the bottom reinforcement mat on top of the piles. This allows the entire mat of reinforcing steel to be tied off and lowered onto the pile group. See File No. 15.03-1 for an example of a TYPICAL FOOTING PLAN for a multi-column pier using steel piles. A FOOTING PLAN for a hammerhead pier is similar. For wall piers with piles, the footing reinforcement is likely to be tied in place as lowering a long narrow flexible mat on top of the piles may not be feasible. Reinforcement should be detailed at the bottom of the footing allowing the designer to take advantage of the full footing depth for moment and shear calculations. Due to the low number and size of bars typically required, conflicts with pile spacing could exist, but slight field adjustments can be made. Additional bars shall be detailed over the piles transversely and longitudinally. PIER DETAILS PIER COMPONENTS AND MISCELLANEOUS DETAILS FOOTING TYPES AND DETAILS PART 2 DATE: 31Oct2022 SHEET 12 of 15 FILE NO. 15.02-12 DRILLED SHAFTS: General: Drilled shafts have a high axial and lateral capacity and may be economical where large numbers of steel or prestressed piles would be required. When weathered rock prevents conventional pile driving a sufficient distance below the scour elevation, drilled shafts may be a solution. Since there is no significant vibration during construction, drilled shafts can be used when there is risk of disturbing existing structure(s) by pile driving. Drilled shafts often do not require a footing (i.e. columns can be individually supported by a drilled shaft). Concerns to consider when determining whether drilled shafts are appropriate include lack of redundancy, quality is sensitive to construction procedure and the presence of groundwater can make construction difficult. The minimum concrete cover for main vertical (principal) reinforcement and ties and spirals is 1” more than for pier columns. See current IIM-S&B-80. Radial splicing to provide the required minimum spacing for additional bars shall only be permitted where tied to inner hoops to maintain position. See File No. 15.02-9 for similar details in columns. Vertical reinforcing bars from shaft projecting into footing or column shall be detailed 6” longer than needed to allow for shaft elevation tolerances. Drilled Shaft Directly Supporting Column: When a single column is individually supported by a drilled shaft, the drilled shaft diameter shall be a minimum of 6” greater than the column diameter. However, the vertical reinforcement in the drilled shaft shall align with the position of the vertical reinforcement in the column, i.e. the cover for the vertical reinforcement will be at least 3” more in the drilled shaft than in the column. SECTION A-A SECTION C-C SECTION B-B SECTION D-D PART ELEVATION PIER DETAILS PIER COMPONENTS AND MISCELLANEOUS DETAILS DRILLED SHAFTS PART 2 DATE: 30Oct2020 SHEET 13 of 15 FILE NO. 15.02-13 DRILLED SHAFTS (Continued): Drilled Shafts Supporting Footing: When drilled shafts support a footing, the drilled shaft bars must be fully developed into the footing. Typically, large bar sizes and minimum footing depth require the main drilled shaft reinforcement to be hooked. If turned outward, these hooked bars will interfere with removing the temporary steel casing used to form drilled shafts. If turned inward, these hooked bars may interfere with the tremie tube and/or collar(s) during concrete placement when the clear opening in the drilled shaft reinforcement cage is less than 1’-3”. Where clear distance between hooks is greater than or equal to 1’-3”, hooks shall be oriented toward the interior and main vertical reinforcement spliced away from the top of drilled shaft (Case 1). Where clear distance between hooks is less than 1’-3”, splice main vertical reinforcement at the top of drilled shaft and rotate the main vertical reinforcement hooks to provide 1’-3” clear where feasible (Case 2). CASE 1 CASE 2 Radial VIEW A-A (CASE 1 ) Rotated VIEW B-B (CASE 2) PIER DETAILS PIER COMPONENTS AND MISCELLANEOUS DETAILS DRILLED SHAFTS PART 2 DATE: 18May2016 SHEET 14 of 15 FILE NO. 15.02-14 DRILLED SHAFTS (Continued): Drilled Shafts Supporting Footing (continued): Where there is insufficient room to rotate the hooks to provide the minimum 1’-3” clear opening (bar overlap), the configuration is considered too tight for field implementation or it is desirable to open up spacing, some hooks may be rotated so the ends fall outside the reinforcement cage, but within the limits of the temporary steel casing. Rotate the remaining hooks on the interior to provide the minimum 1’-3” clear opening and relatively even spacing between hook ends. VIEW B-B (CASE 2 ALTERNATE) Where the minimum 1’-3” clear opening cannot be obtained by methods discussed in Case 2, options include increasing drilled shaft diameter and increasing footing depth. With sufficient footing depth, main vertical drilled shaft bars can be developed without hooks (Seismic Zone 1 only). With sufficient footing depth, hooks can also be staggered beyond the minimum development length, but must clear the top reinforcement mat (see PART ELEVATION). Where staggered hooks are used, alternate the position of adjacent bars. PART ELEVATION Where permanent casing will be used, hooks shall be turned outward. Details similar to those shown in this section (ELEVATION and VIEW) shall be provided on the plan sheets to show the intended layout of the hooks. Drilled Shafts – Spacing, Tolerance, Embedment, Edge Distance: Drilled shaft spacing and tolerance shall be in accordance with VDOT Special Provision for Drilled Shafts and AASHTO LRFD Specifications with VDOT Modifications, current IIM-S&B-80. Projection (embedment) in caps/footings: 6” into footing with reinforcement projecting to obtain development as required by the design Edge distance: The distance from the side of any shaft to the nearest edge of the footing/cap shall not be less than 12”. PIER DETAILS PIER COMPONENTS AND MISCELLANEOUS DETAILS DRILLED SHAFTS PART 2 DATE: 30Oct2020 SHEET 15 of 15 FILE NO. 15.02-15 STATE FEDERAL AID SHEET STATE ROUTE ROUTE PROJECT NO. PROJECT 39'-0" VA. 27'-6" 88 0088-099-101, B635 10 11'-6" 2'-6" 3 spa. @ 7'-0" = 21'-0" 4'-6" 7'-0" C L Rte. 88 Notes: o 1' -7" 1' -7" 80 When finishing concrete between and beyond pads, float surface to drain fromC L pier to edges of cap. C L Pier 1 and line thru centers of bearing Welded wire fabric may be substituted for spiral reinforcement in pier columns, maintaining an equivalent area of reinforcement, subject to approval by the Bridge Engineer. For anchor bolt sleeve details, see bearing details on sheet 11. Sta. 12+00.00 7 C L Girder 1 3-PN0501 C L Girder 2 C L Girder 3 C L Girder 5 C L Girder 4 C L Girder 6 1'-6" 1'-6" PLAN OF CAP typ. typ. Symmetrical about this line except as shown for seat elevations 36 x 2-PS0501 12 spa. @ 5‚" = 3'-8" = 5'-3" 19 spa. @ 5" = 7'-11" 1'-7" Elev. 186.73 Elev. 186.58 Elev. 186.44 Elev. 186.29 1'-7" 3'-2" 2 Elev. 186.80 1'-7" 2' -9" 14 C L anchor bolt sleeve 11 1" 10 7-PC0801 3" typ. 9 2-PC0502 C L Pier 1 4' -0" 2'-11" 4-PC0803 6" pitch typ. typ. 7'-1" 3-PC0803 4-PC0804 typ. 9-PF0503 4'-3" typ. typ. 4 " 4" 3' -3" 19 3" typ. 17-PF0502 typ. 5'-9" 12 13 PC0803 5'-9" PC0804 14-PF0504 - 13 spa. @ 10" = 10'-10" C L Pier 1 4" typ. 20 SECTION A-A Scale: ƒ" = 1'-0" 19 13-PF0601 typ. 11‡" HP 10 x 42 typ. 21 Elev. 160.80 typ.16 PF0601 END VIEW 8'-6" ELEVATION PB03 series Anchor bolt sleeve typ. PF0502 80 2„ " 2' -1" 999-99_010. dgn 4'-3" 4" typ. 20 C L Column 3 8 spa. @ 11ƒ" = 7'-10" 17 PS0501 3'-0" o / C L Column 2 4" PF0903 typ. PC0502 3'-0" o / 12" typ. C L Column 1 10-PV0902 10-PV0903 8'-0" typ. PV0901 - Column 1 PV0902 - Column 2 PV0903 - Column 3 PB0301 - Col um n 1 PB0302 - Col um n 2 PB0303 - Col um n 3 15'-1" PC0801 4" 2 = 2' -7 " Elev. 182.74 Elev. 182.42 Elev. 182.11 5' -4" typ. 4" typ. = 2'-6" 3 spa. @ 10 " A 7-PC0805 10-PV0901 6 spa. @ 5" PC0805 2 PN0501 15 1'-7" A Elev. 185.99 4" Elev. 186.15 3'-2" Elev. 186.87 4" 2 C L Rte. 88 at C LPier 1 8 4' -0" 6" 4 spa. @ 11" typ. 3 x 2-PS0502 2 spa. @ 11" = 1'-10" o C L Pier 1 13-PF0601 6" typ. PV09 series 12 spa. @ 7" = 7'-6" 2„ " 1'-3" typ. 127 The Strength Limit State controls the pile design. TYPICAL SECTION OF COLUMN 1' -6" 122 (Tons/pile) 11‡" C L L Pier 1 5 C L girder TYPICAL ANCHOR BOLT LAYOUT Scale: ƒ" = 1'-0" 3' -0" 110 Minimum Tip Elevation 3' -0" 170 Pier 1 23 Estimated Tip Elevation 11' -6" Factored Axial Resistance 17-PF0502 Substructure Unit 3†" Nominal Axial Resistance Measured During Driving (Tons/pile) 1' -6" PILE DATA TABLE o / 0" 3' 16 spa. @ 8" = 10' -8" 22 Scale: ƒ" = 1'-0" COMMONWEALTH OF VIRGINIA DEPARTMENT OF TRANSPORTATION 5" typ. 3'-0" 3'-0" 1'-3" typ. STRUCTURE AND BRIDGE DIVISION C L column SAMPLE MULTI-COLUMN PIER SHEET TYPICAL FOOTING PLAN PIER DETAILS PIER 1 PF0503 and PF0504 steel reinforcement omitted for clarity VDOT S&B DIVISION RICHMOND, VA STRUCTURAL ENGINEER 1 Scale: …" = 1'-0" unless otherwise noted Scale: ‚" = 1'-0" c 2020, Commonwealth of Virginia PART 2 No. Description Revisions Date Designed: SJB ........... SJB Drawn: ................ SGB Checked: ............ Date Plan DATE: 30Apr2020 SHEET 1 of 12 Apr. 2020 999-FILE NO. 15.03-1 STATE FEDERAL AID SHEET STATE 72'-8" ROUTE ROUTE PROJECT VA. 58 68'-8" NO. PROJECT 0058-041-116, B607 16 Telegraph Rd. Constr. B L C L Beam 1 C L Beam 2 C L Beam 3 C L Beam 4 90 3 spa. @ 9'-4" = 28'-0" C L Beam 5 o Notes: C L Beam 6 C L Beam 7 When finishing concrete between and beyond pads, float surface to drain fromC L pier to edges of cap. C L Beam 8 2' -0"2' -0" 7 4-PN0501 4'-8" R = 1'-3" typ. R = 2'-0" typ. For closure diaphragm details, see sheet 12. Dowels can be adjusted to miss PS0401 bars. 1'-7" C LPier 1 PV0601 PH0501 3… " typ. 34'-4" 4'-8" 1' -3" 34'-4" 3 spa. @ 9'-4" = 28'-0" PN0502 Dowel keyway typ. 2'-0" 2'-0" typ. typ. 1'-8" typ. Sta. 12+00.00 Line thru centers of bearing and Face of wall 5 R = 1'-3" Dowels typ. between beams 7 eq. spa. = 5'-4" PLAN OF CAP o ty p. Telegraph Rd. Constr. B L 34'-0" 60 C LPier 1 69 x 2-PS0401 - 68 spa. @ 12" = 68'-0" Elev. 125.92 7„ " PC0502 EF Elev. 126.05 Elev. 125.93 SECTION A-A Scale: " = 1'-0" Elev. 125.21 6-PC0601 6-PC0601 PC0502 EF Elev. 124.99 B Elev. 125.81 Elev. 125.67 Elev. 125.57 4 Elev. 125.45 2 5" PC0502 EF 3" typ. 2 Elev. 125.33 3' -0" C LPier 1 PS0401 2'-0" 5 spa. @ 8" mi n. l ap min. lap 1' -4" = 2' -0" 2 spa. @ 12" Vari es 2‚" PC0502 C LPier 1 ƒ" 13 " rubber tip 3 layers of fabric impregnated with hot bitumen 9" typ. 10 PH0501 PV0601 106.00 1‚" o / x 2'-0" CRR Class I plain dowel 12" B 16 2'-7" 20 2'-7" 103-PF0601 EF & 103-PV0601 EF - 102 spa. 8" = 68'-0" 6 999-99_016. dgn 12" PF0502 2' -9" m i n. 6" 15 2' -9" 2'-9" 11 4" PV0601 1apped with PF0601 typ. 4" typ. = 3'-4" 4-PN0501 3 spa. @ 9" = 2'-3" 1 " PV0601 EF lapped with PF0601 EF typ. 4" A 13 spa. @ 11" = 11' -11" A 14-PH0501 EF and 14-PN0502 each end 4" 4-PN0501 3 spa. @ 12" = 3'-0" 2'-0" PC0601 3" 14 mi n. l ap 3' -11„ " 4'-0" 2'-6" 3…" typ. PF0504 20 12" 71'-2" PF0403 DOWEL DETAIL Not to scale C L piles C LHP 12 x 53 PF0504 bott. 9" Sta. 12+00.00 9" Telegraph Rd. Constr. B L 90 o 2' -7" 21 PFO502 C LPier 1 PF0502 typ. @ each pile C L piles 1'-8" 3 spa. @ 10" 1'-8" 4" 6' -6" 2' -0"2' -0" 1' -8" C L HP12 x 53 1' -8" = 5' -10" 7 spa. @ 10" PF0403 typ. @ each pile 8-PF0504 top 1' -3" 4" 9-PF0502 bottom 8 spa. @ 9" = 6'-4" typ. between piles PF0601 1' -6" 73'-2" PF0502 bott. 17 3' -0" ELEVATION 4" = 2'-6" 1'-3" 1'-3" 4'-0" 6'-6" 4" SECTION B-B 3'-11" 3'-11" 1'-3" 4 spa. @ 7'-10" = 31'-4" 4" typ. Scale: " = 1'-0" 4 spa. @ 7'-10" = 31'-4" PF0502 top 22 79 spa. @ 11" = 72'-5" Driving test pile FOOTING PLAN PILE DATA TABLE 3 spa. @ 10" = 2'-6" SAMPLE WALL PIER SHEET PIER DETAILS Substructure Unit Pier 1 Nominal Axial Factored Resistance Axial Measured During Resistance Driving (Tons/pile) (Tons/pile) 210 136 COMMONWEALTH OF VIRGINIA DEPARTMENT OF TRANSPORTATION 23 Estimated Tip Elevation Minimum Tip Elevation 91 95 STRUCTURE AND BRIDGE DIVISION PIER 1 PART 2 The Strength Limit State controls the pile design. VDOT S&B DIVISION RICHMOND, VA STRUCTURAL ENGINEER No. Scale: ‚" = 1'-0" unless otherwise noted 1 c 2020, Commonwealth of Virginia Description Revisions Date Designed: SJB ........... SJB Drawn: ................ SGB Checked: ............ Date Plan DATE: 30Apr2020 SHEET 4 of 12 Apr. 2020 999-FILE NO. 15.03-4 DETAILING CHECK LIST FOR PIERS / BENTS 1 Show Plan of Cap, Elevation, End View and (Typical) Footing Plan at a scale of 3/8” = 1’-0”, but no smaller than 1/4” = 1’-0”. Show remaining details at a scale of 3/4” = 1’-0”, but no smaller than 1/2” = 1’-0”. 2 Slope cap from end-to-end when seat heights of 4” or more can be avoided. Slope bottom of cap parallel to top of cap. Minimum pad heights should be 1” at the edge of pad (or 1½” if using dowel detail) and cap elevations should be established on this basis. For hammerhead with sloping cap, provide elevation of top of column on both sides of column. For all other sloping caps, provide elevation at top of column on the higher side of each column. 3 When cap is horizontal, the top of cap elevation should be established 1” below the lowest pad (or 1½” if using dowel detail) and dimensioned in the elevation view. 4 Where “arriving” and “departing” beam/girders result in calculated differences in pad elevations, the difference is to be applied as follows: difference = 1/8” : apply to bolster thickness. difference > 1/8” to 1/2” : apply to bearing height. difference > 1/2” : apply to pad elevations or to superstructure members taking aesthetics into consideration. 5 The anchor bolt layout is to be shown in plan view. If dimensions vary, add table. 6 Include DOWEL DETAIL for piers/bents with prestressed beams and fixed closure pours. 7 Length of PN bars should be determined to obtain a Class A splice with top PC bar. 8 For a symmetrical pier cap, reinforcing steel may be shown in half of cap and pier labeled “Symmetrical about this line except as shown (for superelevation) (etc.).” 9 Use minimum of 3”. 10 Use minimum of 1” unless bearing layout requires larger cap. 11 Space bars to clear anchor bolts or anchor bolt sleeves and to allow ample room for concrete vibrators. To alleviate spacing problems, consider adding another row of bars. 12 Hooks in stirrups should be shown at bottom of cap so as to preclude any possible interference with anchor bolts and shall be placed away from exterior corners. 13 Dimension must allow for fabrication tolerances for stirrups. 14 Length of main column reinforcement shall extend to within 2” of the lowest layer(s) of top main cap bars. 15 Use Class B splice for main column reinforcement lap with footing bars. 16 Provide bottom of footing elevation to the hundredth of a foot (i.e. not tenths). PIER DETAILS SAMPLE SHEETS AND DETAILING CHECK LIST CHECK LIST PART 2 DATE: 30Apr2020 SHEET 6 of 12 FILE NO. 15.03-6 DETAILING CHECK LIST FOR PIERS / BENTS (Continued) 17 Footing-to-column bars shall be hooked in footing. These bars shall have 90 degree hooks. However, 180 degree hooks shall be used in footing when 90 degree hooks result in conflict with pile locations. Bars are to rest on bottom mat of main footing reinforcement and shall provide the minimum embedment length into footing. See File Nos. 07.02-2 and -3. Embedment length shall be not less than basic development length for compression. 18 Where seat reinforcement is required per File No. 15.02-6, provide typical detail. Space bars to miss anchor bolts and anchor bolt sleeves. 19 Main footing bars shall be hooked. One direction shall have 90 degree hooks, and the other direction 180 degree hooks to prevent conflicts at the footing corners. Bars shall be located above piles. 20 In the top of footings, in each direction, provide #5 bars at 12” maximum spacing, or a greater amount of steel if required by design. 21 For minimum pile embedment, see AASHTO LRFD Specifications, Article 10.7, with VDOT Modifications, current IIM-S&B-80. Note the H-piles depicted on File Nos. 15.03-1 and -3 are shown for seismic Zone 1 with no uplift and intermittent uplift respectively. 22 Provide the appropriate geotechnical design data in tabular format if not combined with abutment data and provided near front of the plan assembly. For additional information, see File No. 15.01-7. 23 Minimum tip elevations are required for pile foundations. 24 Where architectural treatment(s) is used, provide limits of architectural texture, coping widths, texture grid scales, relief, treatment position and other necessary details as applicable. See Chapter 5 of this manual for requirements, details and information for architectural treatment. PIER DETAILS SAMPLE SHEETS AND DETAILING CHECK LIST CHECK LIST PART 2 DATE: 30Oct2020 SHEET 7 of 12 FILE NO. 15.03-7 STATE FEDERAL AID SHEET STATE ROUTE ROUTE PROJECT VA. 58 0058-041-116, B629 29 Top of trough Elev. 407.52 4" PH0501 EF 2 spa. @ 4" = 9" NO. PROJECT 41-PH0503 spa. @ 10" = 33'-4" Top of seat/pad, typ. Bottom of trough Elev. 406.50 4" typ. H Waterproofing membrane Notes: Top of trough Elev. 406.33 See sheet 26 for plan of cap and pier elevation. Drainage trough cantilever at low side Epoxy-Resin Type EP-3B shall be the prime or base coat. Type EP-3T shall be the finish coat. Epoxy-Resin materials shall comply with Section 243 of the Specifications. typ. Top of seat/pad, typ. 1' -6" PH0501 EF 3 spa. @ 5" = 1'-3" 5" See sheet 27 for anchor bolt details and cap reinforcement details. Surface preparation, mixing, application and curing shall be in accordance with Section 416 of the Specifications as applicable to Type EP-3 Epoxy-Resin. The application of sand on the wet surface will not be required. 3-PH0502 Bottom of trough Elev. 403.67 59-PV0402 and PV0403 spa. with PS06 bars H Bottom of trough Elev. 403.67 PIER CAP PARTIAL ELEVATION 5" AT0501 EF 4" 4" 3" typ. AT0501 EF 2 spa. @ 4" = 9" 1 Constr. joint 5" 12 AT0502 1 3" typ. AT0501 4 spa. 3" typ. typ. @ 5" = 1'-10" PS0505 Bottom of trough Elev. 403.67 PC0602 4" typ. SECTION J-J 7-AT0501 4" 5" PH0501 EF 2 spa. @ 4" = 9" PH0501 EF 2 spa. @ 4" = 9" 12 typ. 1' -3" J PH0503 6" typ. AT0502 PH0502 2 spa. @ 10" = 1'-8" 2" cl. typ. 2'-3" 15 Scale: 1" = 1'-0" 2" 1'-9" 12 1 J PH0501 EF 3 spa. @ 5" = 1'-3" PV0402 5'-0" PC0602 PC1101 DRAINAGE TROUGH CANTILEVER DETAIL typ. 1' -9" PV0403 16 1" typ. 6 spa. 9" = 4'-6" 3" typ. Scale: 1" = 1'-0" Top of trough C L stainless steel inserts and bolts 1" 1" typ. PS0603 17 2' -10… " Tooth expansion joint PS0604 Permissible construction joint 999-99_029. dgn Bottom of backwall Surface to recieve VDOT Epoxy Resin Waterproofing full length of pier Pier 4 SECTION H-H End of Virginia Pier Cap ‚" continuous fabric reinforced sheet neoprene Detail I 3' -0† " PC0603 C L Scale: ƒ" = 1'-0" Integral backwall Integral backwall 2" cl. Stainless steel PL „" x 2" x 4'-8" Bottom of trough Elev. 403.67 …" o stainless steel insert …" o Stainless steel bolt Line thru center of bearings at Span d 1" ‚" continuous fabric reinforced sheet neoprene on low side of trough EF 6" 2" WATERPRROFING MEMBRANE DETAIL 16 Drainage trough cantilever omitted for clarity Line thru center of bearings at Span e Scale: 1" = 1'-0" Bottom of trough at bridge exterior TROUGH WATERPROOFING DETAIL 16 COMMONWEALTH OF VIRGINIA DEPARTMENT OF TRANSPORTATION Not to Scale STRUCTURE AND BRIDGE DIVISION DETAIL I SAMPLE VIRGINIA PIER SHEET PIER 4 SECTIONS AND MISC. DETAILS Not to Scale PIER DETAILS PART 2 VDOT S&B DIVISION RICHMOND, VA STRUCTURAL ENGINEER 1 Scale: " = 1'-0" unless otherwise noted No. c 2020, Commonwealth of Virginia Description Revisions Date Designed: SJB ........... SJB Drawn: ................ SGB Checked: ............ Date Plan DATE: 30Apr2020 SHEET 11 of 12 Apr. 2020 999-FILE NO. 15.03-11 DETAILING CHECK LIST FOR VIRGINIA PIER 1 Show Plan of Cap, Elevation, End View and (Typical) Footing Plan at a scale of 3/8” = 1’-0”, but no smaller than 1/4” = 1’-0”. Show remaining details at a scale of 3/4” = 1’-0”, but no smaller than 1/2” = 1’-0”. 2 Slope cap from end-to-end when seat heights of 4” or more can be avoided. Slope bottom of cap parallel to top of cap. Minimum pad heights should be 1” at the edge of pad and cap elevations should be established on this basis. For sloping cap, provide elevation at top of column (and cap) on both lower and higher sides. 3 Provide drainage trough and pad/seat elevations in tabular format. 4 Length of PN bars should be determined to obtain a Class A splice with top PC bar. 5 Label the location of centerline/baseline as shown on the title sheet. For a symmetrical pier cap, reinforcing steel may be shown in half of cap and pier labeled “Symmetrical about this line except as shown (for superelevation) (etc.).” 6 Use minimum of 3”. 7 Use minimum of 3’-2” unless bearing layout requires larger cap. 8 Length of main column reinforcement shall extend to within 2” of the lowest layer(s) of top main cap bars. 9 Space bars to clear anchor bolts or anchor bolt sleeves and to allow ample room for concrete vibrators. To alleviate spacing problems, consider adding another row of bars. 10 Hooks in stirrups should be shown at bottom of cap so as to preclude any possible interference with anchor bolts and shall be placed away from exterior corners. 11 Dimension must allow for fabrication tolerances of stirrups. 12 The anchor bolt layout is to be shown in plan view. If dimensions vary, add table if needed. 13 Where seat/pad reinforcement is required per File No. 15.02-6, provide typical detail(s) with size and spacing of reinforcing steel. 14 Show Cap End View complete with size and spacing of nose reinforcing steel at a scale of 1/ ” = 1’-0” unless space is insufficient to show adequate details. 2 15 Show Pier Cap Partial Elevation of trough complete with location of waterproofing membrane and trough reinforcing steel at a scale of 1/2” = 1’-0” unless space is insufficient to show adequate details. Waterproofing membrane shall be located at the low side(s) of trough as shown in File No. 15.01.4 and -5. 16 Show miscellaneous details, e.g. DRAINAGE TROUGH CANTILEVER DETAILS, TROUGH WATERPROOFING DETAILS and WATERPROOFING MEMBRANE DETAILS. 17 Include standard sheet(s) in the plan assembly for appropriate joint type. For specific requirements and guidelines for completing those standard detail sheets, refer to the Notes to Designer for the particular standard contained in Part 3 of this manual. PIER DETAILS SAMPLE SHEETS AND DETAILING CHECK LIST CHECK LIST PART 2 DATE: 30Apr2020 SHEET 12 of 12 FILE NO. 15.03-12 GENERAL INFORMATION: Forces on the superstructure are transferred to the substructure through the bearings. Bearing design, joint design, unit length (i.e. length of continuous spans between joints) and subsurface conditions affect pier design and a holistic approach is required to ensure the bridge functions properly. Expansion bearings transmit forces to the substructure due to movement of the bearing. Fixed bearings are attached to the substructure to prevent movement between the superstructure and the substructure. However, the substructure may deflect based on its stiffness and the force transferred from the superstructure. The substructure must be designed for the forces from any type of bearing. Grade (vertical profile) effects can typically be ignored in design. Wind and Braking Forces on Superstructure: Wind forces on the superstructure and live load can have both a transverse and longitudinal component. These forces are computed for various skew angles of wind perpendicular to the longitudinal direction of the bridge. Thus 0 degree skew angle is perpendicular to the bridge and consists of the largest transverse force wind pressure. 0 Degree 30 Degree 60 Degree Wind on Superstructure and Live Load Braking Force (Traction) consists of only a longitudinal force on a straight bridge, but will have a transverse component on a curved bridge due to centrifugal force. Longitudinal forces and transverse forces are typically distributed among the number of bearings fixed in that direction. For example, on a straight four-span bridge with fixed bearings at Pier 2 and guided expansion (slotted) bearings at the abutments and Piers 1 and 3, Pier 2 should conservatively be designed for all the longitudinal force. Piers 1, 2 and 3 should be designed for their portion of the transverse force (i.e., one-half span back and one-half span up station). The design of Piers 1 and 3 would include longitudinal temperature and shrinkage forces, where applicable, and Pier 2 any unbalance force as discussed below. Temperature (Expansion, Contraction) and Shrinkage Forces (where applicable): Expansion/contraction of the superstructure develops forces which are transferred to the substructure through the bearings. Bridges with concrete superstructures must also be designed for shrinkage. A shrinkage coefficient of 0.0003 may be used except for segmentally constructed bridges. For typical multi-beam/girder prestressed concrete superstructures not integral with the substructure, the shrinkage coefficient can be considered to include superstructure creep effects. PIER DETAILS SUPERSTRUCTURE FORCES GENERAL INFORMATION PART 2 DATE: 30Oct2020 SHEET 1 of 12 FILE NO. 15.04-1 GENERAL INFORMATION (Continued): Temperature (Expansion, Contraction) and Shrinkage Forces (where applicable): The total design movement at each bent/pier shall be 0.65 times the design thermal movement range. The design thermal movement range shall be obtained from AASHTO LRFD specifications, Table 3.12.2.1-1 using the moderate climate range for steel superstructures (120 °F) and the cold climate range for concrete superstructures (80 °F). See current IIM-S&B-80. Therefore, +/- 78 °F should be used to determine temperature forces for pier/bent design for steel superstructures and +/- 52 °F for concrete superstructures. A 52 °F contraction combined with shrinkage will control for concrete superstructures. Where elastomeric expansion bearings are used, the maximum elastomeric shearing resistance shall be used to determine temperature and shrinkage forces. On a two-span continuous symmetric structure with fixed bearings at the pier, the temperature and shrinkage (where applicable) force would be zero at the pier. With unsymmetric spans, an unbalanced force will exist due to the unbalanced expansion lengths and/or bearing design. Similarly for three or more span continuous symmetric structures with fixed bearings at the middle pier(s), the thermal center (neutral point) can be considered the center. However, relative stiffness between piers may shift the thermal center of a bridge and/or create unbalanced forces at fixed piers. When pier/bent heights differ by more than 25 percent between piers/bents within a continuous structural unit, the designer shall take into account the effects of substructure stiffness when determining the expansion length at any point (including joints) and the forces to be resisted at any substructure unit. Pier height is measured from the top of footing to the top of cap. For pile bents, height is measured from the assumed point of pile fixity to the top of cap. See Example 1. When the summation of span lengths left or right of a fixed pier differ more than 25 percent, the designer shall take into account the effects of unsymmetric spans when determining the expansion length at any point (including joints) and the forces to be resisted at any substructure unit. See Example 2. The design of pile bents is further complicated in that the magnitude of the temperature and shrinkage (where applicable) forces directly affects the location of the assumed point of fixity for the pile along with varying geotechnical conditions at each location. See Example 3. Pier programs typically apply load factors internally. The load factors for force effects for Uniform Temperature, TU, and Shrinkage, SH, in the strength limit state depend on whether I g or Ieffective was used to derive forces and are the same for both. Designers shall ensure that the appropriate load factors from AASHTO LRFD Article 3.4.1 are used in pier program runs for TU and SH. All three examples use simplified analysis in conjuction with the gross moment of inertia for the pier columns. As such, a load factor of 0.5 and 1.0 would be used for strength and service limit states respectively for both TU and SH for load combinations within the pier program. Since the load factors are the same, TU and SH are considered together in the examples and the combined force is intended to be input as TU in the pier program. Bridges with curved girders, skews greater than 20 degrees, integral piers, and/or column/pile lengths varying by more than 50 percent between extremes within an individual pier/bent should be modeled using a finite element analysis program to determine overall structure behavior due to thermal and other loads before designing piers, bearings or joints. PIER DETAILS SUPERSTRUCTURE FORCES GENERAL INFORMATION PART 2 DATE: 11Jan2011 SHEET 2 of 12 FILE NO. 15.04-2 Bridge Layout: To obtain a satisfactory and efficient bridge design, the distribution of wind and traction forces needs to be balanced against the temperature and shrinkage demands. If too many piers are fixed, the temperature and shrinkage forces for the fixed piers will disproportionally control design. If too few are fixed, the wind and traction forces will disproportionally control design. Joint type and size, where applicable, should be determined considering the overall bridge or unit temperature and shrinkage modeling. Where temperature and shrinkage forces in the exterior piers/bents of a unit are too large or control column/pile size, various methods may be used to reduce forces. Increasing the elastomer thickness for elastomeric bearings or switching to slip bearings with low friction coefficients can lower design forces. Oversizing or slotting holes in fixed bearing sole plates can lower design forces by allowing some movement before engaging and facilitate fit-up during erection for steel superstructures. For pile bents, predrilling and placing select backfill around the pile once it is in place can lower the assumed point of fixity by increasing the pile flexibility and reducing the temperature/shrinkage forces. Adding a joint should only be done when all options are exhausted. PIER DETAILS SUPERSTRUCTURE FORCES GENERAL INFORMATION PART 2 DATE: 17Dec2010 SHEET 3 of 12 FILE NO. 15.04-3 EXAMPLE 1: Hammerhead pier on spread/pile footing of varying height This example consists of a 4-span continuous prestressed Bulb-T bridge with semi-integral abutments. Elastomeric bearings are used and dimensions shown in the calculation table are those from the final bearing designs. The preliminary hammerhead pier design uses a 5’-0” by 11’-0” column with circular ends. The superstructure typical section consists of 5 beam lines. Skew = 0°. Sample calculations for the temperature loads are provided below and on the following sheet. Note that the thermal center of the bridge was determined by an iterative process (i.e. adjusting the position of the thermal center until opposing forces balance) and is located 14 feet to the left of Pier 2. Elastomeric deformation, ∆elast, was also determined by an iterative process for each expansion pier (i.e. adjusting the value until the summation of the elastomeric deformation and pier deflection equals the total movement required). Variables and equations: ∂ = coefficient of thermal expansion/contraction for normal weight concrete = 0.000006 per °F ∆T = Temperature change, °F = 0.65 x 80 °F = 52 °F L = Length from thermal center of bridge, feet Lelast = Length of elastomeric bearing pad, inches W elast = Width of elastomeric bearing pad, inches Gmax = maximum elastomeric shearing resistance (range = 95 to 130 psi) = 0.130 ksi Example continued on next sheet PIER DETAILS SUPERSTRUCTURE FORCES EXAMPLE 1: VARYING HEIGHT/STIFFNESS PART 2 DATE: 11Jan2011 SHEET 4 of 12 FILE NO. 15.04-4 EXAMPLE 1: Hammerhead pier on spread/pile footing of varying height (cont’d.) Variables and equations (continued): Nopads = No. of elastomeric bearings (for PS beams continuous for LL, count both bearing lines) = 10 telast = Total thickness of internal and external elastomeric layers (total pad height – shims), inches ∆elast = Assumed/actual elastomeric deformation in direction of expansion/contraction, inches Pelast = Force created internally in elastomeric pad for assumed/actual deformation, kips = Lelast x W elast x Gmax x Nopads x ∆elast / telast Hss = Top of cap to top of footing (pier on pile or spread footing), feet f’c = Column (pile for pile bent) concrete strength = 3,000 psi Ec = Modulus of elasticity for concrete, psi = wc1.5 x 33 x f’c0.5 = 1451.5 x 33 x 30000.5 = 3,156,000 psi Ic = Uncracked moment of inertia for column(s) (piles for pile bent), in4 = [72” x (60”)3 / 12] + [π x (30”)4 / 4] = 1,932,200 in4 PSS = Force required to deflect substructure required distance at fixed pier/bent, kips = 3 x Ec x Ic x ∆temp / (HSS x 12)3 ∆SS = Substructure deflection in direction of exp./contraction, inches = Pelast x (HSS x 12)3 / (3 x Ec x Ic) ∆temp = Total movement required at pier/bent including shrinkage [prestressed superstructure], inches = (∂ x L x ∆T x 12) + (0.0003 x L x 12) Sample calculation: With longer spans and shorter (stiffer) piers on the left of Pier 2, assume the thermal center of the bridge is 8.5 feet left of Pier 2. The required movement at Piers 1 and 3 will be a combination of pier deflection and pad distortion. Pier 2 is fixed and the pier must deflect the required movement. The abutments have two rows of piles and are assumed rigid, so the elastomeric pad must distort the required distance. Using the values found in the calculation table on the following sheet, the numbers for Pier 1 are: ∆temp = (∂ x L x ∆T x 12) + (0.0003 x L x 12) = (0.000006 x 98.5 x 52 x 12) + (0.0036 x 98.5) = 0.723” Try ∆elast = 0.600” Pelast = Lelast x W elast x Gmax x Nopads x ∆elast / telast = 26 x 10 x 0.130 x 10 x 0.600 / 2.152 = 94.2 kips ∆SS = Pelast x (HSS x 12)3 / (3 x Ec x Ic) = 94.2 x (13.5 x 12)3 / (3 x 3,156 x 1,932,200) = 0.022” Example continued on next sheet PIER DETAILS SUPERSTRUCTURE FORCES EXAMPLE 1: VARYING HEIGHT/STIFFNESS PART 2 DATE: 11Jan2011 SHEET 5 of 12 FILE NO. 15.04-5 EXAMPLE 1: Hammerhead pier on spread/pile footing of varying height (cont’d.) Sample calculation (continued): ∆elast + ∆SS = 0.600” + 0.022” = 0.622” < ∆temp = 0.723” Since the summation of ∆elast and ∆SS does not equal ∆temp, try ∆elast = 0.698” Pelast = Lelast x W elast x Gmax x Nopads x ∆elast / telast = 26 x 10 x 0.130 x 10 x 0.698 / 2.152 = 109.6 kips ∆SS = Pelast x (HSS x 12)3 / (3 x Ec x Ic) = 109.6 x (13.5 x 12)3 / (3 x 3,156 x 1,932,200) = 0.025” ∆elast + ∆SS = 0.698” + 0.025” = 0.723” = ∆temp Perform a similar iterative calculation process for Pier 3. Directly compute Pelast for both abutments and PSS for Pier 2. Calculation table (thermal center assumed 8.5 feet left of Pier 2): L Lelast W elast telast ∆elast Pelast Hss Abutment A 220.1 26 16 3.924 1.617 111.4 N/A Pier 1 98.5 26 10 2.152 0.698 109.6 13.5 Pier 2 8.5 N/A N/A N/A N/A N/A 37.9 Pier 3 115.5 26 10 2.152 0.456 71.6 38.7 Abutment B 220.1 26 16 3.924 1.617 111.4 N/A PSS N/A N/A 12.1 N/A N/A ∆SS N/A 0.025 0.062 0.392 N/A ∆temp 1.617 0.723 0.062 0.848 1.617 The summation of the shaded columns, ∆elast and ∆SS, must equal the total movement required, ∆temp. 111.4 kips + 109.6 kips = 221.0 kips > 12.1 kips + 71.6 kips + 111.4 kips = 195.1 kips The thermal center of the bridge is further from Pier 2 in the direction of Abutment A. Recalculate with the thermal center of the bridge 14.5 feet from Pier 2. Calculation table (thermal center assumed 14.5 feet left of Pier 2): Location Abutment A Pier 1 Pier 2 Pier 3 Abutment B L 214.1 92.5 14.5 121.5 226.1 Lelast 26 26 N/A 26 26 W elast 16 10 N/A 10 16 telast 3.924 2.152 N/A 2.152 3.924 ∆elast 1.573 0.651 N/A 0.480 1.661 Pelast 108.4 102.2 N/A 75.3 114.4 Hss N/A 13.5 37.9 38.7 N/A PSS N/A N/A 20.7 N/A N/A ∆SS N/A 0.024 0.106 0.412 N/A ∆temp 1.573 0.679 0.106 0.892 1.661 The summation of the shaded columns, ∆elast and ∆SS, must equal the total movement required, ∆temp. 108.4 kips + 102.2 kips = 210.6 kips ≈ 20.7 kips + 75.3 kips + 114.4 kips = 210.4 kips Note that the resulting temperature and shrinkage force at Pier 1 is 102.2 kips while 75.3 kips at Pier 3. Although Pier 2 is fixed, it is expected to deflect 0.106” to the right and the temperature and shrinkage force is 20.7 kips. Design requirements for all three piers will be relatively balanced as Pier 2 will be designed for a small temperature and shrinkage force, but all the longitudinal wind and braking force. Pier 1 has a larger temperature and shrinkage force, but shorter column length than Pier 3. PIER DETAILS SUPERSTRUCTURE FORCES EXAMPLE 1: VARYING HEIGHT/THICKNESS PART 2 DATE: 11Jan2011 SHEET 6 of 12 FILE NO. 15.04-6 EXAMPLE 2: Multi-column pier on spread footings with unsymmetric spans This example consists of a 3-span continuous steel bridge with joints at both ends. Elastomeric bearings will be used and dimensions shown in the calculation table are those from the final bearing designs. There is a longitudinal joint along the route centerline and the piers left and right of the joint are separate structures. The preliminary multi-column pier designs consist of two 4’-0” diameter columns left of the longitudinal joint and three 4’-0” diameter columns right. The superstructure typical section consists of four beam lines left of the longitudinal joint and five right. 4,000 psi concrete is used in this example as it was required for the column design. Skew = 0°. Fixed bearings at both piers are used in this example. Fixing the bearings at only one pier is an option. However, different joint types were required at each abutment due to the unsymmetric expansion/contraction and applying all the longitudinal superstructure forces to one pier was found to require larger column sizes. Sample calculations for the temperature loads are provided below and on the following sheet for the structure right of the longitudinal joint. Note that the structure left of the longitudinal joint should be modeled separately to determine forces. Variables and equations: ∂ = coefficient of thermal expansion/contraction for steel = 0.0000065 per °F ∆T = Temperature change, °F = 0.65 x 120 °F = 78 °F Example continued on next sheet PIER DETAILS SUPERSTRUCTURE FORCES EXAMPLE 2: UNSYMMETRIC SPANS PART 2 DATE: 17Dec2010 SHEET 7 of 12 FILE NO. 15.04-7 EXAMPLE 2: Multi-column pier on footings with unsymmetric spans (cont’d.) Variables and equations (continued): L = Length from thermal center of bridge, feet Lelast = Length of elastomeric bearing pad, inches W elast = Width of elastomeric bearing pad, inches Gmax = maximum elastomeric shearing resistance (range = 95 to 130 psi) = 0.130 ksi Nopads = No. of elastomeric bearings (for PS beams continuous for LL, count both bearing lines) = 5 telast = Total thickness of internal and external elastomeric layers (total pad height – shims), inches ∆elast = Assumed/actual elastomeric deformation in direction of expansion/contraction, inches Pelast = Force created internally in elastomeric pad for assumed/actual deformation, kips = Lelast x W elast x Gmax x Nopads x ∆elast / telast Hss = Top of cap to top of footing (pier on pile or spread footing), feet f’c = Column (pile for pile bent) concrete strength = 4,000 psi Ec = Modulus of elasticity for concrete, psi = wc1.5 x 33 x f’c0.5 = 1451.5 x 33 x 40000.5 = 3,644,000 psi Ic = Uncracked moment of inertia for column(s) (piles for pile bent), in4 = 3 x π x (24”)4 / 4 = 781,700 in4 PSS = Force required to deflect substructure required distance at fixed pier/bent, kips = 3 x Ec x Ic x ∆temp / (HSS x 12)3 ∆SS = Substructure deflection in direction of exp./contraction, inches = Pelast x (HSS x 12)3 / (3 x Ec x Ic) ∆temp = Total movement required at pier/bent [steel superstructure, no shrinkage], inches = ∂ x L x ∆T x 12 Calculation table (Right of longitudinal joint): Thermal center determined to be 63.75’ left of Pier 2 Location Abutment A Pier 1 Pier 2 Abutment B L 241.25 112.50 63.50 231.18 Lelast 18 22 24 22 W elast 18 22 24 22 telast 4.434 2.147 2.522 4.804 ∆elast 1.468 0.375 0.220 1.407 Pelast 69.7 55.0 32.7 92.1 Hss N/A 30.3 29.3 N/A PSS N/A N/A N/A N/A ∆SS N/A 0.309 0.166 N/A ∆temp 1.468 0.684 0.386 1.407 The summation of the shaded columns, ∆elast and ∆SS, must equal the total movement required, ∆temp. 69.7 kips + 55.0 kips = 124.7 kips ≈ 32.7 kips + 92.1 kips = 124.8 kips PIER DETAILS SUPERSTRUCTURE FORCES EXAMPLE 2: UNSYMMETRIC SPANS PART 2 DATE: 11Jan2011 SHEET 8 of 12 FILE NO. 15.04-8 EXAMPLE 3: PILE BENT Pile bents and drilled shafts have an additional consideration when compared to columns on spread or pile footings. The geotechnical conditions at each location require modeling and the magnitude of the forces directly affects the location of the assumed point of fixity for the pile/shaft. This example consists of a 10-span continuous prestressed Bulb-T bridge with semi-integral abutments at both ends. Elastomeric bearings will be used. Due to the length of the bridge elastomeric bearings with a PTFE sliding surface will be used at the abutments. The preliminary pile bent designs consist of 24” square prestressed concrete piles with seven piles per bent. Skew = 0°. Applying all the longitudinal forces to Bent 5 will likely be infeasible. Fixing three piers may provide an efficient design. This example spreads the load further by fixing five piers as shown below. Check to ensure that the piles can handle the forces generated by forcing them to displace for temperature and shrinkage. Slip bearings exist at both abutments and should not be part of the unit modeling. Passive pressure will develop at both abutments, but can be neglected since EPS is used behind the backwall. Example continued on next sheet PIER DETAILS SUPERSTRUCTURE FORCES EXAMPLE 3: PILE BENT PART 2 DATE: 17Dec2010 SHEET 9 of 12 FILE NO. 15.04-9 EXAMPLE 3: PILE BENT (cont’d.) The assumed point of fixity (POF) is dependent on the geotechnical data at each bent location and is sensitive to the horizontal force exerted on the piles. In the sketch below, the points of fixity for the piles are derived by modeling the geotechnical data in the L-Pile compute program for the calculated forces. This is an iterative process in which POF’s are assumed, forces calculated and then entered into L-Pile. The new POF’s resulting from the L-Pile run are input back into the model and the process repeated until closure. Sample calculations for the temperature loads in the scoured condition are provided below and continued on the next sheet for the sketch above. Variables and equations: ∂ = coefficient of thermal expansion/contraction for normal weight concrete = 0.000006 per °F ∆T = Temperature change, °F = 0.65 x 80 °F = 52 °F L = Length from thermal center of bridge, feet Lelast = Length of elastomeric bearing pad, inches W elast = Width of elastomeric bearing pad, inches Gmax = maximum elastomeric shearing resistance (range = 95 to 130 psi) = 0.130 ksi Nopads = No. of elastomeric bearings (for PS beams continuous for LL, count both bearing lines) = 10 telast = Total thickness of internal and external elastomeric layers (total pad height – shims), inches ∆elast = Assumed/actual elastomeric deformation in direction of expansion/contraction, inches Pelast = Force created internally in elastomeric pad for assumed/actual deformation, kips = Lelast x W elast x Gmax x Nopads x ∆elast / telast Hss = Top of cap to assumed point of fixity for piles (pile bent), feet f’c = Column (pile for pile bent) concrete strength = 5,000 psi Example continued on next sheet PIER DETAILS SUPERSTRUCTURE FORCES EXAMPLE 3: PILE BENT PART 2 DATE: 11Jan2011 SHEET 10 of 12 FILE NO. 15.04-10 EXAMPLE 3: PILE BENT (cont’d.) Variables and equations (continued): Ec = Modulus of elasticity for concrete, psi = wc1.5 x 33 x f’c0.5 = 1451.5 x 33 x 50000.5 = 4,074,000 psi Ic = Uncracked moment of inertia for column(s) (piles for pile bent), in4 = 7 piles x [24” x (24”)3 / 12] = 193, 536 in4 PSS = Force required to deflect substructure required distance at fixed pier/bent, kips = 3 x Ec x Ic x ∆temp / (HSS x 12)3 ∆SS = Substructure deflection in direction of expansion/contraction, inches = Pelast x (HSS x 12)3 / (3 x Ec x Ic) ∆temp = Total movement required at pier/bent including shrinkage [prestressed superstructure], inches = (∂ x L x ∆T x 12) + (0.0003 x L x 12) Calculation table (Scoured): Location Bent 1 Bent 2 Bent 3 Bent 4 Bent 5 Bent 6 Bent 7 Bent 8 Bent 9 L 277.0 195.5 114.0 32.5 49.0 130.5 212.0 293.5 375.0 Lelast 25 22 N/A N/A N/A N/A N/A 22 25 W elast 19 15 N/A N/A N/A N/A N/A 15 19 telast 5.279 4.043 N/A N/A N/A N/A N/A 4.043 5.279 ∆elast 0.422 0.255 N/A N/A N/A N/A N/A 0.252 0.349 Pelast 49.3 27.1 N/A N/A N/A N/A N/A 26.8 40.8 Hss 35.5 39.1 41.1 36.3 37.2 50.3 56.0 46.0 43.2 PSS N/A N/A 16.5 6.8 9.6 10.3 12.1 N/A N/A ∆SS 1.612 1.181 0.837 0.239 0.360 0.958 1.557 1.903 2.405 ∆temp 2.034 1.436 0.837 0.239 0.360 0.958 1.557 2.155 2.754 The summation of the shaded columns, ∆elast and ∆SS, must equal the total movement required, ∆temp. Bent 5 must be designed for the unbalanced temperature and shrinkage force. (49.3 + 27.1 + 16.5 + 6.8) kips = 99.7 kips ≈ (9.6 + 10.3 + 12.1 + 26.8 + 40.8) kips = 99.6 kips Note that the thermal center of the structure is 49 feet to the left of the actual midpoint of the bridge (Bent 5). The bearings were originally designed assuming expansion from the actual midpoint of the bridge. An argument may be made that the bearings at Bents 8 and 9 need to be re-designed so that telast > 2 x the anticipated movement in one direction with the appropriate load factors for deformation. See current IIM-S&B-80. After re-design of the bearings, the temperature and shrinkage forces would need to be recalculated. However, the original design did not account for flexibility of the substructure and since the deformation of the elastomeric pad is much less than originally designed for, the bearing designs are O.K. by inspection. Bearing re-design to take advantage of substructure flexibility is not recommended in this case as smaller bearings with less thickness would increase the already large forces on Bents 1 and 9. Example continued on next sheet PIER DETAILS SUPERSTRUCTURE FORCES EXAMPLE 3: PILE BENT PART 2 DATE: 11Jan2011 SHEET 11 of 12 FILE NO. 15.04-11 EXAMPLE 3: PILE BENT (cont’d.): The location of the thermal center of the bridge is of particular importance in this jointless bridge example. A design waiver was approved for this structure as it exceeds the selection criteria on File No. 20.01-1 for semi-integral bridges. To minimize any negative effects due to additional movement at Abutment B, the piles at Bent 5 were battered to ensure that the thermal center is as close to the actual center of the bridge as possible. The updated calculation table with Bent 5 as the thermal center is provided below. Calculatation table (Scoured – Bent 5 battered) Location Bent 1 Bent 2 Bent 3 Bent 4 Bent 5 Bent 6 Bent 7 Bent 8 Bent 9 L 326.0 244.5 163.0 81.5 0.0 81.5 163.0 244.5 326.0 Lelast 25 22 N/A N/A N/A N/A N/A 22 25 W elast 19 15 N/A N/A N/A N/A N/A 15 19 telast 5.279 4.043 N/A N/A N/A N/A N/A 4.043 5.279 ∆elast 0.496 0.319 N/A N/A N/A N/A N/A 0.210 0.303 Pelast 58.1 33.8 N/A N/A N/A N/A N/A 22.3 35.5 Hss 35.5 39.1 41.1 36.3 37.2 50.3 56.0 46.0 43.2 PSS N/A N/A 23.6 17.1 TBD 6.4 9.3 N/A N/A ∆SS 1.898 1.477 1.197 0.599 0 0.599 1.197 1.586 2.091 ∆temp 2.394 1.796 1.197 0.599 0 0.599 1.197 1.796 2.394 The summation of the shaded columns, ∆elast and ∆SS, must equal the total movement required, ∆temp. Bent 5 must be designed for the unbalanced temperature and shrinkage force. (58.1 + 33.8 + 23.6 + 17.1) kips = 132.6 kips > (6.4 + 9.3 + 22.3 + 35.5) kips = 73.5 kips Unbalanced force = 132.6 kips – 73.5 kips = 59.1 kips The non-scoured condition must also be modeled to ensure that the reduced lengths to the assumed POF do not control design. The non-scoured results are not provided for this example. PIER DETAILS SUPERSTRUCTURE FORCES EXAMPLE 3: PILE BENT PART 2 DATE: 11Jan2011 SHEET 12 of 12 FILE NO. 15.04-12 GENERAL INFORMATION: AASHTO LRFD Specifications, Article 11.7.2.1, requires “Where the possibility of collision exists from highway and river traffic, an appropriate risk analysis should be made to determine the degree of impact resistance to be provided and/or the appropriate protection system.” This section specifies the general practices and requirements regarding pier protection for vehicular collision. Pier protection for vessel collision shall conform to the requirements specified in AASHTO LRFD Specifications, Article 3.14. For consistency, Edge of traffic lane will be used for other interchangeable terminologies in this chapter, see the following sketch and Reference Clarification. Reference Clarification: The point of reference for the 30’-0” measurement is to the edge of permanent traffic thru lane indicated in the adjacent sketch as Edge of traffic lane and Edge of traveled way (roadway). For New Construction or Bridge Replacement: The requirement for pier protection shall adhere to the following hierarchy: 1. Locate pier > 30’-0” from edge of traffic lane where feasible to mitigate vehicular collision. 2. Design pier for collision force as specified in AASHTO LRFD Specifications, Article 3.6.5 if a. Design year Average Daily Truck Traffic (ADTT) in one direction is ≥ 400 for undivided roadways and ≥ 1200 for divided roadways; or b. In discussion with the L&D/Traffic Engineer, either (i) or (ii) applies (i) History of crashes exists; or (ii) Where fill slopes and vertical alignment makes recovery not possible (nontraversable) for vehicles. (In situations in which the embankment slopes significantly downward, a vehicle could encroach closer to the pier and farther from the through traveled way and the clear zone might not be adequate.) When a pier is designed for collision force, different types of piers (File No. 15.01-1) shall be compared to achieve the most cost effective and sound engineering solution. For example, a wall pier may be more cost effective than multi-column pier when collision force is taken into account. Pier protection may be used in lieu of designing for collision forces if the resulting pier design is more expensive compared to providing pier protection. (Cost of pier protection shall include the barrier required, transition section, standard terminal and/or impact attenuator. Cost for designing a pier for vehicle collision shall include additional cost for pier designed for vehicle collision and guardrail when pier is within roadway clear zone.) PIER DETAILS PIER PROTECTION SYSTEM GENERAL INFORMATION PART 2 DATE: 31Oct2022 SHEET 1 of 19 FILE NO. 15.06-1 For Existing Bridge Piers located less than 30’-0” from edge of traffic lane: For bridge widening projects, the requirement for pier protection shall adhere to the following hierarchy. For all other projects in which the existing pier(s) will remain in service, including road projects that affect the roadway underneath the bridge, application of the hierarchy is at the discretion of the District Bridge Engineer. 1. Determine whether site conditions qualify for an exemption from pier protection in accordance with AASHTO LRFD Specifications, Article C3.6.5.1. 2. If site conditions do not qualify for an exemption, evaluate whether the pier can resist the collision force as specified in AASHTO LRFD Specifications, Article 3.6.5 if a. Design year ADTT in one direction is ≥ 400 for undivided roadways and ≥ 1200 for divided roadways; or b. In discussion with the L&D/Traffic Engineer, either (i) or (ii) applies (i) History of crashes exists; or (ii) Where fill slopes and vertical alignment makes recovery not possible (nontraversable) for vehicles. (In situations in which the embankment slopes significantly downward, a vehicle could encroach closer to the pier and farther from the through traveled way and the clear zone might not be adequate.) 3. If the pier cannot resist the collision force, use a bridge pier protection system (BPPS standards). Additional Requirements: A bridge pier protection system (BPPS Standards) shall always be used when standard MB-7F traffic barrier is required by traffic design, in which case, design of pier for collision force is not required for new construction or structural evaluation is not necessary for existing piers. Straddle bents shall be designed for collision force as well as protected with a bridge pier protection system (BPPS Standards). Maintenance of Traffic, which temporarily routes traffic close to a pier during a fixed construction contract duration, does not require bridge pier protection system (BPPS). Temporary pier protection shall conform to requirements for protection of other fixed objects. Pier protection using barrier has the following requirements (AASHTO): 1. Crashworthy ground mounted, Test Level 5. 2. 54” high barrier when located within 12’-0” from the pier being protected. 3. 42” high barrier when located ≥ 12’-0” and < 30’-0” from the pier being protected. NOTE: The 12’-0” is set from the face of pier to the face of barrier curb while the 30’-0” is set from the face of pier to the edge of traffic lane. The Structure and Bridge Division has developed standards to meet the barrier requirements noted above. These standards are included in Part 3 of this manual. If any part of the protected pier is located within 12’-0” from the face of barrier curb, 54” high barrier, Standard BPPS-1A and BPPS-2A, shall be used for the full length. The barrier transition from 42” to 54” and the 42” terminal barrier are additional if needed. PIER DETAILS PIER PROTECTION SYSTEM GENERAL INFORMATION PART 2 DATE: 31Oct2022 SHEET 2 of 19 FILE NO. 15.06-2 Additional Requirements (continued): The face of the barrier curb shall align with the guardrail offset for the roadway classification where sufficient clearance is available. The minimum distance from the edge of traffic lane to the face of the barrier curb shall be 2’-0”. The preferred minimum distance from the face of the barrier curb is 5’-0” to the face of the protected pier to keep out of the zone of intrusion. Barrier shall be aligned parallel to the edge of traffic lane. Drainage should be taken into account for long pier protection barriers. The absolute minimum distance from the edge of traffic lane to the face of a pier column or pier stem is 4’-0”. 2’-0” minimum distance from edge of traffic lane to face of barrier curb 1’-8” barrier width at base 4” distance from back of barrier to back of barrier footing 4’-0” = minimum distance from edge of traffic lane to face of pier column/stem In this case, the back of barrier footing would be cast against the pier column/stem face. This requires the pier footing to be sufficiently depressed to clear the barrier footing. Where traffic is on both sides of the pier and at differing elevation, top of pier footing elevation shall be based on the lower roadway elevation. PIER DETAILS PIER PROTECTION SYSTEM GENERAL INFORMATION PART 2 DATE: 18May2016 SHEET 3 of 19 FILE NO. 15.06-3 LENGTH OF PIER PROTECTION: The length of pier protection system shall be determined as follows. Notation: PO – Intersection of the centerline of pier and the edge of the overpass bridge deck. PA – Controlling point, either of PA1/PA3 or PA2, whichever is approached first in the direction of traffic. For one-directional traffic, it is on the run-on end. For two-directional undivided traffic, it is on the run-on end for the traffic adjacent to barrier, meanwhile on the run-off end for the opposite traffic. PB – Controlling point, either of PB1/PB3 or PB2, whichever is approached first in the direction of traffic. For one-directional traffic, it is on the run-off end. For two-directional undivided traffic, it is on the run-off end for the traffic adjacent to barrier, meanwhile on the run-on end for the opposite traffic. Where: PA1 and PB1 or PA3 and PB3 are the intersection of edge of traffic lane and edge of deck depending on the orientation of deck. PA2 and PB2 are the intersection of edge of traffic lane and a line through PO perpendicular to edge of traffic lane. One-directional traffic PIER DETAILS PIER PROTECTION SYSTEM LENGTH OF PIER PROTECTION PART 2 DATE: 18May2016 SHEET 4 of 19 FILE NO. 15.06-4 LENGTH OF PIER PROTECTION (continued): Two-directional undivided traffic For one-directional traffic on one side of the pier (including two-directional divided traffic): The minimum length of pier protection system shall be the sum of the following components: 1) 30’ on run-on end to PA (plus barrier transition and terminal section as needed); 2) Projected distance between PA and PB; 3) 5’ from PB on run-off end. For two directional undivided traffic on one side of the pier: The minimum length of barrier protection shall be the sum of the following components: 1) 30’ on run-on end to PA (plus barrier transition and terminal section as needed). PA is determined using direction of traffic adjacent to barrier; 2) Projected distance between PA and PB; 3) 30’ from PB on run-on end (plus barrier transition and terminal section as needed). PB is determined using direction of traffic opposite to the traffic adjacent to barrier. When traffic is on both sides of the pier, the noted requirements apply to both sides. PIER DETAILS PIER PROTECTION SYSTEM LENGTH OF PIER PROTECTION PART 2 DATE: 18May2016 SHEET 5 of 19 FILE NO. 15.06-5 LENGTH OF PIER PROTECTION (continued): For a curved alignment, PO shall be projected in a radial direction to the curved edge of traffic lane as shown in the following two figures. Edge of traffic lane is convex to the centerline pier. Edge of traffic lane is concave to the centerline pier. PIER DETAILS PIER PROTECTION SYSTEM LENGTH OF PIER PROTECTION PART 2 DATE: 18May2016 SHEET 6 of 19 FILE NO. 15.06-6 LENGTH OF PIER PROTECTION (continued): For hammerhead piers, if any point along the pier arm has a vertical clearance less than 16’-6”, use edge of deck to determine PA and PB, otherwise use face of pier stem to determine PA and PB. For instance, in the following figure, the lines parallel to the edge of deck through Points PC1 and PC2 may be used to replace the edge of deck for the purpose of determining the length of barrier. Also PC1 or PC2 may be used to replace PO for determining the length of barrier for all the applicable cases. For straddle bents, the length of barrier shall be determined with the following scheme. PIER DETAILS PIER PROTECTION SYSTEM LENGTH OF PIER PROTECTION PART 2 DATE: 18May2016 SHEET 7 of 19 FILE NO. 15.06-7 The following examples illustrate what types of pier protection system and what lengths shall be used. EXAMPLE 1: Traffic is on one side of the pier and the C L pier and C L roadway are parallel. The 3-column pier consists of 4’-0” diameter columns with 18’-0” column spacing. The columns are designed for the collision force. Clearances from the edge of traffic lane to pier column are as shown. ST’D GR-2 guardrail is required by roadway design. Since the pier columns are designed for the collision force and MB-7F is not required by roadway design, pier protection is not required. The ST’D GR-2 guardrail is installed according to roadway design. PIER DETAILS PIER PROTECTION SYSTEM BARRIER LAYOUT EXAMPLE 1 PART 2 DATE: 18May2016 SHEET 8 of 19 FILE NO. 15.06-8 EXAMPLE 2: One-directional divided traffic is on one side of the pier and the CL pier and C L roadway are parallel. The 3-column pier consists of 4’-0” diameter columns with 18’-0” column spacing. ADTT in one direction is 500. The columns are designed for the collision force. Clearances from the edge of traffic lane to pier column are as shown. MB-7F traffic barrier is required by roadway design. Even though the pier columns are designed for the collision force, pier protection is required as MB-7F traffic barrier is required by roadway design. The distance from the edge of traffic lane to the face of barrier curb is 2’-0” and also coincides with the guardrail offset for the roadway classification involved. The clearance from the face of barrier curb to the face of pier column: 4’-0” – 2’-0” = 2’-0”, which is < 12’-0”. Therefore a 54” barrier is required and Standards BPPS-1A and -2A will be used. PIER DETAILS PIER PROTECTION SYSTEM BARRIER LAYOUT EXAMPLE 1 PART 2 DATE: 30Oct2020 SHEET 9 of 19 FILE NO. 15.06-9 EXAMPLE 2 (continued): Because the edge of deck is perpendicular to the edge of traffic lane, PA is PA1 which coincides with PA2. PB is PB1 which coincides with PB2. The length of 54” barrier is: Lbarrier = 30’-0” + (4’-6” + 18’-0” + 18’-0” + 4’-6”) + 5’-0” = 80’-0” Add 13’-0” terminal section for guardrail and 6’-0” transition section from 42” to 54” on run-on side. Add LAYOUT OF BARRIER FOR PIER PROTECTION to standard sheet. Show length for 54” high barrier and 42” to 54” transition section as well as 42” terminal section. Add lengths to PLAN and ELEVATION, stations to PLAN on standard sheet. LAYOUT OF BARRIER FOR PIER PROTECTION PIER DETAILS PIER PROTECTION SYSTEM BARRIER LAYOUT EXAMPLE 2 PART 2 DATE: 30Oct2020 SHEET 10 of 19 FILE NO. 15.06-10 EXAMPLE 3: One-directional traffic is on north side and two-directional undivided traffic is on south side of the pier. The 3-column pier consists of 4’-0” diameter columns with 18’-0” column spacing. The existing pier is located less than 30’-0” from the edge of traffic lane. ADTT in one direction is 500 at the north side and 450 at the south side. Clearances from the edge of traffic lane to the pier columns are as shown. Since the pier is located less than 30’-0” from the edge of traffic lane and ADTT > 400, structural evaluation is required. The analysis shows that the pier cannot carry the collision force. So pier protection is required on both sides of the pier. The face of barrier curb is set 2’-0” from the edge of traffic lane to match the guardrail offset for the roadway classification involved. The clearance from the face of barrier curb to the face of pier column: North side: 14’-0” – 2’-0” = 12’-0” South side: 6’-0” – 2’-0” = 4’-0” The shortest distance from the face of barrier curb to the pier on north side = 12’-0”, therefore a 42” barrier is sufficient for north side and Standards BPPS-3A and BPPS-4A will be used. The shortest distance from the face of barrier curb to the pier on south side < 12’-0”, so a 54” barrier is required for south side. PIER DETAILS PIER PROTECTION SYSTEM BARRIER LAYOUT EXAMPLE 3 PART 2 DATE: 30Oct2020 SHEET 11 of 19 FILE NO. 15.06-11 EXAMPLE 3 (continued): North side: Since there is one-directional traffic on the north side, PA2 is approached first on the run-on end (PA2 is PA) and PB2 is approached first on the run-off end (PB2 is PB). The length of 42” barrier is: Lbarrier = 30’-0” + 39’-0” + 5’-0” = 74’-0” South side: There is two-directional traffic on the south side. PA1 is approached first on WB traffic direction for lane adjacent to barrier (PA1 is PA) and PB2 is approached first on EB traffic direction (PB2 is PB). The length of 54” barrier is: Lbarrier = 30’-0” + 55’-0” + 30’-0” = 115’-0” Add 7’-3” terminal section for guardrail on run-on end at the north side. Add 7’-3” terminal section for guardrail and 6’-0” transition barrier from 42” to 54” at both ends at the south side. Add LAYOUT OF BARRIER FOR PIER PROTECTION to standard sheet. Show length for 42” high barrier and terminal section on the north side. Show length for 54” high barrier and terminal section as well as transition from 42” to 54” on the south side. Add lengths to PLAN and ELEVATION, stations to PLAN on standard sheet. PIER DETAILS PIER PROTECTION SYSTEM BARRIER LAYOUT EXAMPLE 3 PART 2 DATE: 18May2016 SHEET 12 of 19 FILE NO. 15.06-12 EXAMPLE 3 (continued): LAYOUT OF BARRIER FOR PIER PROTECTION PIER DETAILS PIER PROTECTION SYSTEM BARRIER LAYOUT EXAMPLE 3 PART 2 DATE: 30Oct2020 SHEET 13 of 19 FILE NO. 15.06-13 EXAMPLE 4: Two-directional undivided traffic is under an existing straddle bent. One-directional traffic is outside of the straddle bent at the south side. ADTT in one direction is 420. The straddle bent is 45o skewed to the edge of traffic lane. The columns have a diameter of 4’-0”. The center to center distance between the columns is 68’-0”. The width of straddle beam is 4’6”. Clearances from the edge of traffic lane to the columns are as shown. The analysis for the existing columns indicates that the columns can resist the collision force. Pier protection is still required for both columns of the straddle bent as they are < 30’ from the edge of traffic lane. For the purposes of this example, the minimum 2’-0” distance from the edge of traffic lane to the face of barrier curb also coincides with the guardrail offset for the roadway classification involved. The width of barrier footing is 2’-0”. The face of barrier curb is set 2’-0” from the edge of traffic lane to match the guardrail offset for the roadway classification involved. The clearance from the face of barrier curb to the face of columns: North side under the straddle bent: 14’-0” – 2’-0” = 12’-0” South side under the straddle bent: 6’-0” – 2’-0” = 4’-0” Outside of the straddle bent: 6’-0” – 2’-0” = 4’-0” PIER DETAILS PIER PROTECTION SYSTEM BARRIER LAYOUT EXAMPLE 4 PART 2 DATE: 18May2016 SHEET 14 of 19 FILE NO. 15.06-14 EXAMPLE 4 (continued): The shortest distance from the face of barrier curb to the column on north side under the straddle bent = 12’-0”, therefore a 42” barrier is sufficient and Standard BPPS-3 will be used. The shortest distance from the face of barrier curb to the column on south side under the straddle bent and outside of the straddle bent < 12’-0”, so a 54” barrier is required for the south side. The length of barrier under the straddle bent is determined as shown in the above figure for twodirectional traffic. Lbarrier_in = 30’-0” + 4’-0” + 30’-0” = 64’-0” The length of barrier outside of the straddle bent is Lbarrier_outside = 30’-0” + 4’-0” + 5’-0” = 39’-0” Add 13’-0” terminal section for guardrail on both of ends of 42” high barrier at the north side under the straddle bent. Add 13’-0” terminal section for guardrail and 6’-0” transition barrier from 42” to 54” on both ends of 54” high barrier at the south side under the straddle bent. PIER DETAILS PIER PROTECTION SYSTEM BARRIER LAYOUT EXAMPLE 4 PART 2 DATE: 30Oct2020 SHEET 15 of 19 FILE NO. 15.06-15 EXAMPLE 4 (continued): Add 13’-0” terminal section for guardrail and 6’-0” transition barrier from 42” to 54” on the run-on side of 54” high barrier at the outside of the straddle bent. Add LAYOUT OF BARRIER FOR PIER PROTECTION to standard sheet. Show terminal section and lengths for 42” high barrier. Show terminal section and lengths, and 6’-0” barrier transition for 54” high barrier. Add lengths to PLAN and ELEVATION, stations to PLAN on standard sheet. LAYOUT OF BARRIER FOR PIER PROTECTION PIER DETAILS PIER PROTECTION SYSTEM BARRIER LAYOUT EXAMPLE 4 PART 2 DATE: 30Oct2020 SHEET 16 of 19 FILE NO. 15.06-16 EXAMPLE 5: Two-directional undivided traffic is on one side of the existing pier. The roadway is on a curved alignment. ADTT in one direction is 200. There were several vehicle crashes in this location. Dimensions of the bridge deck and pier are as shown. Clearances from the edge of traffic lane to the columns are as shown. Although ADTT in one direction is < 400, because of crash history, structural evaluation for the pier is required. The analysis of the pier columns indicated that the columns cannot resist the collision force. Therefore pier protection is required. The face of barrier curb is set 2’-0” from the edge of traffic lane to match the guardrail offset for the roadway classification involved. The shortest distance from the f