Seismic Performance

NosaCAD, ABAQUS and PERFORM-3D are widely applied for nonlinear structure analysis. NosaCAD is developed with ObjectARX, second development tool of AutoCAD, and runs in the AutoCAD environment, so that NosaCAD possesses the powerful geometric processing function of AutoCAD. NosaCAD also has a set of modules to deal with the parameters for nonlinear analysis. ABAQUS and PERFORM-3D have powerful nonlinear analysis functions. However, it would be time-consuming to establish building structure model in the CAE of ABAQUS. PERFORM-3D can only transform the elastic parameters for analysis model from EATBS or SAP2000. In this paper, two transformation modules are developed for transforming the nonlinear analysis model from NosaCAD to ABAQUS and PERFORM-3D. The generated models can be calculated in ABAQUS or PERFORM-3D directly. An example model is transformed and the nonlinear time history analysis of the model is carried out in these three pieces of software.

Reinforced concrete moment resisting structures everywhere throughout the world is in necessity of quick actions for overhauling their execution level to survive the seismic loading impacts. Failure of beam column junctions are identified as the central cause of failure in moment resisting frames during seismic loads. Successful and economical techniques are required to improve joint structural properties and ductility of structures. In present work the seismic behavior of beam column joints with Diagonal cross bracings and strengthened concrete is contemplated. Performance of beam column joints with reinforcement specifications as per IS 13920:1993 and IS 456:2000 along with diagonal cross bracings, strengthening of concrete by using glass fibers and GGBS are studied in this exertion. The outcomes in this study illustrates that the provision of additional diagonal cross bracings and strengthening of concrete shows improvement in structural properties like load carrying, energy dissipation capacities and ductility which eventually improves the seismic behavior of beam column joints.

Abstract. This study focuses on the earthquake performance of two URM buildings having typical architectural
configurations common for residential use constructed per pre-modern code in Albania. Both buildings are unreinforced clay
brick masonry structures constructed in 1960 and 1984, respectively. The first building is a three-storey unreinforced one with
masonry walls. The second one is confined masonry rising on five floors. Mechanical characteristics of masonry walls were
determined based on experimental tests conducted according to ASTM C67-09 regulations. A global numerical model of the
buildings was built, and masonry material was simulated as nonlinear. Pushover analyses are carried out to obtain capacity
curves. Displacement demands were calculated according to Eurocode 8 and FEMA440 guidelines. Causes of building failures
in recent earthquakes were examined using the results of this study. The results of the study showed that the URM building
displays higher displacement and shear force demands that can be directly related to damage or collapse. On the other hand, the
confined one exhibits relatively higher seismic resistance by indicating moderate damage. Moreover, effects of demand
estimation approaches on performance assessment of URM buildings were compared. Deficiencies and possible solutions to
improve the capacity of such buildings were discussed.

In urban areas, increase in population and scarcity of land, the horizontal development gets restricted that’s why most of the
owners, building contractors, engineers are adopting vertical development of buildings for the construction. Natural hazard like
earthquake affects the stability of such structures. Performance of structures in different areas of Northern part of India, during
the earthquakes, is reviewed. The earthquake caused damage to heritage structures as well as modern buildings. Both masonry
and reinforced concrete buildings showed poor performance. Previous studies reveal that major failures of structures occurred
due to improper design procedures. Therefore, it is need of time to analyses & designs such hazard resisting structures so as to
save human life and avoid property damage. The behavior of a building during earthquakes depends critically on its overall
shape, size and geometry. Nonlinear pushover analysis has been used to evaluate the seismic performance of three buildings with
four different plans having same area and height. The results of effects of plan aspect ratio on seismic response of buildings have
been presented in terms of displacement, base shear. Behaviour parameters of the analyzed moment resisting frames also
calculated.

In the recent earthquakes, concrete structures have been severely damaged or collapsed, which has raised questions against the seismic adequacy of existing buildings. These existing reinforced concrete buildings need to be evaluated to determine the capacity to resist seismic loads. The behavior of a building during earthquakes depends critically on its overall shape, size and geometry. Conventional approach to earthquake resistant design of buildings depends upon providing the building with strength, stiffness and inelastic deformation capacity which are great enough to withstand a given level of earthquake-generated force. This is generally accomplished through the selection of an appropriate building configuration and the careful detailing of structural members. In this research, nonlinear pushover analysis has been used to evaluate the seismic performance of three buildings with three different plans having same area and height. This method determines the base shear capacity of the building and performance level of each part of building under varying intensity of seismic force. The results of effects of different plan on seismic response of buildings have been presented in terms of displacement, base shear and plastic hinge pattern.

The aim of this present study is to find out the possible effective earthquake mitigation system by adopting steel bracings for the low, medium and high raise buildings. Also the study highlights the building performance by obtaining the natural time period and the corresponding results shows that the reinforced concrete building with steel bracing system performs better than any other normal building under severe earthquake zones of India. Based on the study undertaken the project aims to determine the extent of possible changes in the seismic performance of low medium & high rise RC framed buildings. This research involves the various analysis techniques to determine the lateral forces ranging from purely linear to non-linear inelastic analysis. The entire process of modeling, analysis and design of all the primary elements for all the models are carried out by using ETABS 2016 nonlinear version software and its software implementation. In India the Standardized method of analysis is followed by using a code – IS1893 (Part 1):2002 – " Criteria for Earthquake resistant design of structures " .

The basic aim of this study is to investigate the nonlinear performance of a ten story special moment resisting frame (SMRF). The elements are designed based on the 1997 edition of the Uniform Building Code for seismic zone 2A. The global and local nonlinear behaviors of the frame are studied under several earthquake ground motions. For this purpose, an inelastic dynamic analysis is performed using three artificial time histories functions generated using SIMQKE_GR program. Nonlinear Static "Pushover" Analyses using various invariant lateral load patterns was also performed. The seismic performance of the structure is determined on the basis of its damage state under an earthquake ground motion. For this purpose, inelastic dynamic and nonlinear static analyses are used to calculate the damage state "drift profiles and inter-storey drifts". Damage Index from the nonlinear time history analysis is compared with those obtained by pushover analysis procedure. In general, the case study explores variations in the results; it was found that estimates of building response from the nonlinear static analysis are generally insensitive to the pattern of lateral load used to perform the pushover analysis. On the other hand, it was found that building structure's dynamic response characteristics depend strongly on the load path, properties of the structure and the characteristics of the ground motion.

Outrigger braced structures has efficient structural form consist of a central core, comprising braced frames with
horizontal cantilever ”outrigger” trusses or girders connecting the core to the outer column. When the structure is loaded
horizontally, vertical plane rotation of the core is restrained by the outriggers through tension in windward column and
compression in leeward column. The effective structural depth of the building is greatly increased, thus augmenting the lateral
stiffness of the building and reducing the lateral deflections and moments in core. In effect, the outriggers join the columns to the
core to make the structure behave as a partly composite cantilever. By providing eccentrically braced system in outrigger frame by
varying the size of links and analyzing it. Push over analysis is carried out by varying the link size using computer programs, Sap
2007 to understand their seismic performance. The ductile behavior of eccentrically braced frame is highly desirable for structures
subjected to strong ground motion. Maximum stiffness, strength, ductility and energy dissipation capacity are provided by
eccentrically braced frame. Studies were conducted on the use of outrigger frame for the high steel building subjected to
earthquake load. Braces are designed not to buckle, regardless of the severity of lateral loading on the frame. Thus eccentrically
braced frame ensures safety against collapse.

Buckling-restrained braces (BRBs) have proven to be very effective in improving the seismic performance of existing and new structures. They provide strength, stiffness and add energy dissipation to the structure. However, being BRBs characterized by a low post-elastic stiffness, their use may lead to residual deformations hindering the building's reparability and to excessive cumulative ductility demand possibly compromising the residual capacity of BRBs. To overcome these drawbacks, BRB frames (BRBFs) can be coupled with moment-resisting frames (MRFs) to form dual systems. If properly designed, MRFs acting as backup frames allow the control of the residual drifts and the optimization of the performance of the BRBs. The contribution of this study is to provide insights into the performance and residual capacity of BRBFs-MRFs dual systems and to shed light on the influence of the main BRB's design parameters. To this end, a nondimensional formulation of the equation of motion is introduced for a single degree of freedom system, and an extensive parametric study is performed for a set of natural ground motion records with different characteristics and scaled to various intensity levels. This allows the investigation of a wide range of configurations, considering different levels of the relative strength and ductility demand of BRBFs and MRFs, and obtains useful information for their design. Finally, two case study frames, modeled as two-dimensional nonlinear multi-degree of freedom systems, are analyzed, and the results were compared to those obtained from the nondimensional formulation to show the capabilities and the limitations of the adopted methodology and of the SDOF approximation.

This paper discusses the application of a novel framework for the simulation of the seismic response of a school building in Sankhu, Nepal, which was damaged by the 2015 Gorkha earthquake. This framework uses a recently proposed methodology to estimate the backbone curve for every bay of the building. It then combines these curves to obtain the force-vs.-displacement response for every floor along two perpendicular horizontal directions, which is used to calibrate a box-type model of the building. The proposed methodology is validated with the data obtained by the authors from the instrumentation of the four-story school building during a reconnaissance a month after the earthquake. The comparison with the field data indicates that the proposed framework can simulate the seismic response of the actual structure, and capture their damage patterns and dynamic properties.

This study focuses on the development of a statistical model for buildings with infilled reinforced concrete frames. The cornerstone of this study is the nonlinear numerical model of a school building in Nepal. The model is developed based on the ASCE 14-17 guidelines, and it is extensively validated with field data. Then, it is used in a series of parametric studies conducted to identify the influential material parameters, and in incremental dynamic analyses conducted to provide data for the calibration of the statistical model. The three-staged least square statistical modeling approach is employed to relate the influential material parameters and ground motion intensity measures with important response quantities related to the peak and residual first story drift ratios.

One of the lateral load opposing frameworks in multi-storey structures is Steel brace frame. The resistance of the structure which enhances against horizontal forces by expanding its stiffness and stability is Steel bracing system in RC multi-storey building is conservative, simple to set up, involve less space and give obliged quality and inflexibility. Flat slab reinforced buildings have exhibit many dominances over conventional type of beam column building. However, the effectiveness of structure in flat slab construction is inferior in performance under earthquake loading. Flat slab requires the simple formwork which usually result in an economical construction. In present study, a G+9 storey building is analysed for seismic zone IV as per IS 1893: 2002 using ETABS software. Flat slab is used by providing drop panels and peripheral beam. For all models parameters are kept constant. The effect of the distribution of the steel bracing along with the flat slab RC frame on the seismic performance of the building is studied. The performance of the building is evaluated in terms of storey displacement, storey shear, story drifts and slab stresses. The percentage reduction in lateral displacement along X direction is tabulated. By providing drop panels the slab stress is reduced on structure compared to RC bare frame. Hence it is concluded that the use of steel bracing with flat slab in construction resists the lateral forces for many vulnerable conditions.

In the recent earthquakes, concrete structures have been severely damaged or collapsed, which has raised questions against the seismic adequacy of existing buildings. These existing reinforced concrete buildings need to be evaluated to determine the capacity to resist seismic loads. The behavior of a building during earthquakes depends critically on its overall shape, size and geometry. Conventional approach to earthquake resistant design of buildings depends upon providing the building with strength, stiffness and inelastic deformation capacity which are great enough to withstand a given level of earthquake-generated force. This is generally accomplished through the selection of an appropriate building configuration and the careful detailing of structural members. In this research, nonlinear pushover analysis has been used to evaluate the seismic performance of three buildings with three different plans having same area and height. This method determines the base shear capacity of the building and performance level of each part of building under varying intensity of seismic force. The results of effects of different plan on seismic response of buildings have been presented in terms of displacement, base shear and plastic hinge pattern.

Reinforced concrete moment resisting structures everywhere throughout the world
is in necessity of quick actions for overhauling their execution level to survive the
seismic loading impacts. Failure of beam column junctions are identified as the
central cause of failure in moment resisting frames during seismic loads. Successful
and economical techniques are required to improve joint structural properties and
ductility of structures. In present work the seismic behavior of beam column joints
with Diagonal cross bracings and strengthened concrete is contemplated.
Performance of beam column joints with reinforcement specifications as per IS
13920:1993 and IS 456:2000 along with diagonal cross bracings, strengthening of
concrete by using glass fibers and GGBS are studied in this exertion. The outcomes in
this study illustrates that the provision of additional diagonal cross bracings and
strengthening of concrete shows improvement in structural properties like load
carrying, energy dissipation capacities and ductility which eventually improves the
seismic behavior of beam column joints.

This presentation/paper will extend the gradient inelastic (GI) beam theory and the respective flexibility-based (FB) element formulation to account for shear failures in reinforced concrete members. Shear failures are brittle-thus, providing no warning-and often catastrophic, which is the main reason why recent codes include guidelines to avoid this type of failures. However, there are still, in several parts of the world, older reinforced concrete (RC) framed structures, which include shear-critical and flexure-shear-critical elements, such as RC columns and walls. Prediction of the damage and failure of these elements under combined axial-flexural-shear loading conditions is essential to assessing the seismic performance of those older RC structures. Recently the GI beam theory and its associated FB element formulation were introduced to describe flexural failures, by eliminating strain localization phenomena (a major deficiency of many analysis frameworks) and providing response objectivity, i.e. mesh convergent responses. However, shear effects have yet to be addressed. This presentation/paper addresses this challenge by introducing higher order cross-section deformation fields within a 3D beam theory together with a 3D damage plasticity concrete model. The higher order fields generate realistic shear strain distributions, while the 3D damage plasticity model is capable of capturing the 3D stress/strain interactions in the concrete response. Through-the-depth equilibrium is employed over the cross-section to account for confinement effects. Strain localization is prevented through a set of gradient nonlocality relations between material and macroscopic section deformations over the member length. The developed formulation is implemented in the OpenSees structural analysis software. The predictions of the developed GI beam formulation with shear effects are compared with experimental data for a shear-flexure-critical RC column.

In India, unreinforced brick masonry and reinforced cement concrete are the go-to technologies when it comes to construction of modern residential buildings, with the design applications ranging from one-story nuclear family houses to multi-story apartment buildings housing several families. However, each major natural disaster in India has exposed several 'chinks in the armour' linked to both of these widely employed construction techniques. Enter confined masonry. Confined masonry offers a substitute to both, unreinforced brick masonry and reinforced concrete framed residential buildings for applications in disaster prone areas of the world while keeping the cost under check and optimizing the structural performance. Confined masonry has evolved over the last century through an informal process based on its satisfactory performance in past, mostly in countries with high seismic activity like Indonesia, Mexico and Turkey. It is used for both non-engineered and engineered construction as its field applications range from one-story single-family dwellings to six-story apartment buildings. Some countries have even adopted design provisions and construction guidelines for confined masonry in their building codes. The success and implementation of building technologies is totally dependent on the local conditions like the availability and cost of building materials, the skill level of construction labour and the availability of construction tools and equipment. The fact that confined masonry construction looks similar to reinforced frame construction with masonry infill walls and that it uses the same components, i.e., masonry infills, tie-beams and tie-columns, helps in an easy transition to adopt confined masonry. Although confined masonry construction practice doesn't require any advanced construction equipment or an extra skillset, it is necessary to lay emphasis on the quality of the construction for its satisfactory performance. Hence, to optimize the quality of confined masonry structures, this thesis employs the use of a modern easy-to-learn-and-use structural software known as ETABS.

‫ﭘﮋوﻫﺸﻲ‬ ‫ﻳﺎدداﺷﺖ‬ « ‫ﮔﺮاﻣ‬ ‫ﻣﺤﺴﻦ‬ ‫ﻲ‬ ) 1 ( ‫ﺳ‬ ‫ﻴ‬ ‫ﻋﻠ‬ ‫ﺪ‬ ‫ﻴ‬ ‫ﻛﺎﺑﻠ‬ ‫ﺮﺿﺎ‬ ‫ﻲ‬ ) 2 ( ‫ﭼ‬ ‫ﻜﻴﺪه‬ ‫ﭘﺎﻧﻞ‬ ‫از‬ ‫اﺳﺘﻔﺎده‬ ‫روزاﻓﺰون‬ ‫ﺗﻮﺳﻌﻪ‬ ‫و‬ ‫ﺗﺮوﻳﺞ‬ ‫ﻫﺎي‬ 3D ‫ﻛﺸﻮر‬ ‫ﺳﺎﺧﺘﻤﺎﻧﻲ‬ ‫ﺻﻨﻌﺖ‬ ‫در‬ ) ‫ﺳـﺮﻋﺖ‬ ‫ﻫﻤﭽﻨﻴﻦ‬ ‫اﺟﺮا،‬ ‫ﺳﻬﻮﻟﺖ‬ ‫و‬ ‫ﺑﻮدن‬ ‫ﺳﺒﻚ‬ ‫ﺑﻪ‬ ‫ﺗﻮﺟﻪ‬ ‫ﺑﺎ‬ ‫ﺻﺮﻓﻪ‬ ‫و‬ ‫ﻧﺼﺐ‬ ‫ﺑﺎﻻي‬ ‫اﻧﺮژي‬ ‫ﻣﺼﺮف‬ ‫در‬ ‫ﺟﻮﻳﻲ‬ [1] ( ‫رﻓﺘﺎر‬ ‫ﺑﺮرﺳﻲ‬ ‫ﻛﻪ‬ ‫ﺷﺪه‬ ‫ﻣﻮﺟﺐ‬ ‫دﻧﻴﺎ،‬ ‫ﻟﺮزه‬ ‫زﻣﻴﻦ‬ ‫ﻓﻌﺎل‬ ‫ﻛﻤﺮﺑﻨﺪﻫﺎي‬ ‫از‬ ‫ﻳﻜﻲ‬ ‫روي‬ ‫ﻛﺸﻮر‬ ‫ﮔﺮﻓﺘﻦ‬ ‫ﻗﺮار‬ ‫و‬ ‫ﻟﺮزه‬ ‫اﻳ‬ ‫اي‬ ‫ﻟﺮزه‬ ‫ﻣﻬﻢ‬ ‫ﭘﺎراﻣﺘﺮﻫﺎي‬ ‫ﺗﻌﻴﻴﻦ‬ ‫و‬ ‫ﺳﻴﺴﺘﻢ‬ ‫ﻦ‬ ‫ﺑﺎﺷـﺪ‬ ‫ﺑﺮﺧـﻮردار‬ ‫ﺧﺎﺻـﻲ‬ ‫اﻫﻤﻴﺖ‬ ‫از‬ ‫آن،‬ ‫اي‬ . ‫ﻟـﺮزه‬ ‫ﻧﻴﺎزﻫـﺎي‬ ‫ﺑـﺮآورد‬ ‫در‬ ‫ﺗﺤﻠﻴـﻞ‬ ‫روش‬ ‫در‬ ‫ﺳـﺎزه‬ ‫اي‬ ‫ﻣﻲ‬ ‫ﮔﺮﻓﺘﻪ‬ ‫ﻧﻈﺮ‬ ‫در‬ ‫ﺳﺎزه‬ ‫اﻻﺳﺘﻴﻚ‬ ‫اول‬ ‫ﻣﻮد‬ ‫ﺷﻜﻞ‬ ‫ﺑﺎ‬ ‫ﻣﺘﻨﺎﺳﺐ‬ ‫ﺟﺎﻧﺒﻲ‬ ‫ﻧﻴﺮوﻫﺎي‬ ‫ﺗﻮزﻳﻊ‬ ‫ﻏﻴﺮﺧﻄﻲ،‬ ‫اﺳﺘﺎﺗﻴﻜﻲ‬ ‫ﺷﻮد‬ ‫؛‬ ‫در‬ ‫ﺳـﺎﺧﺘﻤﺎن‬ ‫واﻗﻌـﻲ‬ ‫ﻋﻤﻠﻜﺮد‬ ‫ﺑﺮرﺳﻲ‬ ‫اﻣﺎ‬ ‫ﻧ‬ ‫زﻟﺰﻟﻪ‬ ‫ﻫﻨﮕﺎم‬ ‫ﻣﻜﺎن‬ ‫ﺗﻐﻴﻴﺮ‬ ‫ﺗﻌﻴﻴﻦ‬ ‫ﺿﻤﻦ‬ ‫ﺗﺎ‬ ‫اﺳﺖ‬ ‫ﻏﻴﺮﺧﻄﻲ‬ ‫دﻳﻨﺎﻣﻴﻜﻲ‬ ‫ﺗﺤﻠﻴﻞ‬ ‫اﻧﺠﺎم‬ ‫ﻴﺎزﻣﻨﺪ‬ ‫اﺛـﺮ‬ ‫در‬ ‫ﭘﺎﻧـﻞ‬ ‫و‬ ‫ﻗﺎب‬ ‫در‬ ‫ﺷﺪه‬ ‫اﻳﺠﺎد‬ ‫واﻗﻌﻲ‬ ‫ﻧﻴﺮوﻫﺎي‬ ‫ﺑﻴﺸﻴﻨﻪ،‬ ‫ﻫﺎي‬ ‫زﻣﻴﻦ‬ ‫ﻟﺮزه‬ ‫ﮔﺮدد‬ ‫ﻣﺸﺨﺺ‬ ، . ‫ﻧﺘﺎﻳ‬ ‫از‬ ‫اﺳﺘﻔﺎده‬ ‫ﺑﺎ‬ ‫اﺑﺘﺪا‬ ‫ﻣﻘﺎﻟﻪ،‬ ‫اﻳﻦ‬ ‫در‬ ‫ﻃﺒﻘﻪ‬ ‫ﻳﻚ‬ ‫ﻗﺎب‬ ‫ﻳﻚ‬ ‫ﺗﺤﻠﻴﻞ‬ ‫ﺞ‬ ‫ي‬ ‫ﻣﻘﺎﻳﺴﻪ‬ ‫و‬ ‫ﭘﺎﻧﻞ‬ ‫ﺑﺎ‬ ‫ﺷﺪه‬ ‫ﭘﺮ‬ ‫ﻓﻮﻻدي‬ ‫ي‬ ‫ﻧ‬ ‫ﺑﺎ‬ ‫ﺗﺤﻠﻴﻞ‬ ‫ﻧﺘﺎﻳﺞ‬ ‫ﺘﺎﻳﺞ‬ ‫ﺗ‬ ‫ﻣﻮرد‬ ‫اﻧﺘﺨﺎﺑﻲ‬ ‫ﻫﺎي‬ ‫اﻟﻤﺎن‬ ‫و‬ ‫ﻣﺪﻟﺴﺎزي‬ ‫ﺻﺤﺖ‬ ‫آزﻣﺎﻳﺸﮕﺎﻫﻲ،‬ ‫ﻣﺪل‬ ‫ﺑﻪ‬ ‫ﻣﺮﺑﻮط‬ ‫ﻣﻮﺟﻮد،‬ ‫ﺄ‬ ‫ﮔﺮﻓﺖ‬ ‫ﻗﺮار‬ ‫ﻳﻴﺪ‬ . ‫ﻗﺎب‬ ‫ﺳﭙﺲ‬ ‫ﻫـﺎي‬ 3 ، 5 ‫و‬ 10 ‫ﭘﻮﺷـﺶ‬ ‫ﺑـﺎ‬ ‫ﻃﺒﻘـﻪ،‬ ‫دﻫﺎﻧﻪ‬ ‫ﻣﺨﺘﻠﻒ‬ ‫ﻫﺎي‬ ، ‫ﺑﻬﺒـﻮ‬ ‫ﺑﺮاي‬ ‫ﭘﺎﻧﻞ‬ ‫دﻫﺎﻧﻪ‬ ‫ﻳﻚ‬ ‫از‬ ‫اﺳﺘﻔﺎده‬ ‫ﺧﺎﺗﻤﻪ‬ ‫در‬ ‫و‬ ‫ﮔﺮﻓﺘﻪ‬ ‫ﻗﺮار‬ ‫ﺗﺤﻠﻴﻞ‬ ‫ﻣﻮرد‬ ‫ﻧﺎﻏﺎن‬ ‫و‬ ‫ﻃﺒﺲ‬ ‫اﻟﺴﻨﺘﺮو،‬ ‫رﻛﻮردﻫﺎي‬ ‫ﺗﺤﺖ‬ ‫ﭘﺎﻧﻞ،‬ ‫ﺗﻮﺳﻂ‬ ‫د‬ ‫ﺳﺎزه‬ ‫اي‬ ‫ﻟﺮزه‬ ‫رﻓﺘﺎر‬ ‫اﺳﺖ‬ ‫ﺷﺪه‬ ‫ارزﻳﺎﺑﻲ‬ ‫ﻣﻨﺎﺳﺐ‬ ‫اﺻﻠﻲ،‬ ‫اﻋﻀﺎي‬ ‫ﻫﺎي‬ ‫ﺗﻨﺶ‬ ‫ﻛﺎﻫﺶ‬ ‫و‬ ‫ﺷﺪه‬ ‫ﺗﺤﻠﻴﻞ‬ ‫ﻫﺎي‬ . ‫واژه‬ ‫ﻛﻠﻴﺪي‬ ‫ﻫﺎي‬ ‫ﭘﺎﻧﻞ‬ 3D ، ‫ﻏﻴﺮﺧﻄﻲ،‬ ‫دﻳﻨﺎﻣﻴﻜﻲ‬ ‫ﺗﺤﻠﻴﻞ‬ ‫ﻟﺮزه‬ ‫رﻓﺘﺎر‬ ‫ﭘﺎﻧﻞ،‬ ‫و‬ ‫ﻗﺎب‬ ‫ﺗﺮﻛﻴﺐ‬ ‫اي‬ .

In this study a seismic performance assessment of school buildings, which have been built in accordance with template unreinforced masonry school projects in Turkey, has been conducted. For this purpose, the most widely used three template projects have been selected. The seismic performances of these buildings have been evaluated for various earthquake levels. This evaluation has been carried out in compliance with the Turkish earthquake code entered into force in 2007. The effects of material strength and plan features on the performance of masonry school structures have been investigated within the scope of this study. It has been concluded that school buildings with template design are far from satisfying the required performance criteria. For spectral acceleration of 0.80 g, which is expected in a 475 year period in the seismic Zone 1, the average exceedance ratio for life safety performance limit is more than 80% considering different material strengths. Upon evaluation of the...

Padang is the capital of West Sumatra Province, close to three earthquake sources such as the Megathrust Zone, the Mentawai Fault, and the Great Sumatra Fault on the mainland. Due to the fact that the impact of the earthquake can create a tsunami event in the future, the government needs to prepare shelters for vertical evacuation. About 65 existing buildings have been selected as vertical evacuation buildings, but there is no clear information on their seismic performance. This research proposes a complete assessment of the existing RC building by considering soil characteristics such as the predominant period and Vs30 from microtremor observations. A selected 3 stories of a school building located in the earthquake red zone (Vs30 < 150m/s and predominant period T > 1.5s), less than 1 Km far from the shoreline, was considered in this paper. Based on the seismic index evaluation of the building, the X direction is smaller than the seismic demand (0.8) for the first and second floors (unsatisfactory). For the first, second and third floor, the Y direction has a larger seismic index than the seismic demand. Therefore, the performance is satisfactory for the first to the third story. Based on the required inspection, the building is unsatisfactory for the X-direction. Therefore, it needs to be strengthened. We propose a re-size of the RC for the building column to improve the ductility. The proposed size for the column is 50 x 60 cm. From the re-seismic evaluation, a satisfactory seismic index for the X and Y direction can be obtained.

This paper proposes a computationally efficient approach to simulate the seismic performance of masonry-infilled reinforced concrete (RC) frames. The proposed framework utilizes diagonal struts to simulate the effect of the masonry panels. The struts are calibrated once the anticipated failure mechanism has been identified and the backbone curve has been estimated using a set of recently developed analytical equations. The experimental results from the shake-table tests of a 2/3-scale, two-bay, three-story frame are used to validate the proposed methodology. The comparison with the experimental data indicates that the proposed framework can capture the basic features of the structural behavior including the initial and post-yield stiffness, as well as the peak and residual strength. Moreover, the comparison with the widely used guidelines in ASCE 41-06 indicates that the proposed methodology is considerably more accurate.

This research aims to extend the known ductile end diaphragm concept to make it applicable for bidirectional earthquake excitation, using unbonded braces as the ductile fuses. Irregular (i.e. skewed) bridge superstructures are also covered to determine if the ductile diaphragm concept could be used in skewed bridges. Two retrofit schemes are investigated in detail to search the best geometrical layout (to maximize the dissipated hysteretic energy) of the ductile diaphragms with unbonded brace end diaphragms. Closed form solutions are sought for practical design purposes. Behavioral characteristics of the proposed retrofit schemes are quantified with an emphasis on hysteretic energy dissipation. Results from many numerical examples show that the bidirectional loading, the loading ration, and the skew angle have pronounced effect on the end diaphragm’s inelastic behavior.
Keywords: Seismic performance, Bidirectional-resistant ductile end diaphragms, Unbonded braces, Retrofitting, Steel bridges, Skewed bridges, Hysteretic models, Irregular structures, Hysteretic energy dissipation, Inelastic behaviors

Reinforced concrete moment resisting structures everywhere throughout the world is in necessity of quick actions for overhauling their execution level to survive the seismic loading impacts. Failure of beam column junctions are identified as the central cause of failure in moment resisting frames during seismic loads. Successful and economical techniques are required to improve joint structural properties and ductility of structures. In present work the seismic behavior of beam column joints with Diagonal cross bracings and strengthened concrete is contemplated. Performance of beam column joints with reinforcement specifications as per IS 13920:1993 and IS 456:2000 along with diagonal cross bracings, strengthening of concrete by using glass fibers and GGBS are studied in this exertion. The outcomes in this study illustrates that the provision of additional diagonal cross bracings and strengthening of concrete shows improvement in structural properties like load carrying, energy dissipation capacities and ductility which eventually improves the seismic behavior of beam column joints.

In this study a seismic performance assessment of school buildings, which have been built in accordance with template unreinforced masonry school projects in Turkey, has been conducted. For this purpose, the most widely used three template projects have been selected. The seismic performances of these buildings have been evaluated for various earthquake levels. This evaluation has been carried out in compliance with the Turkish earthquake code entered into force in 2007. The effects of material strength and plan features on the performance of masonry school structures have been investigated within the scope of this study. It has been concluded that school buildings with template design are far from satisfying the required performance criteria. For spectral acceleration of 0.80 g, which is expected in a 475 year period in the seismic Zone 1, the average exceedance ratio for life safety performance limit is more than 80% considering different material strengths. Upon evaluation of the...

Openings in walls greatly influence the stiffness and strength of reinforced concrete (RC) shear walls. Several parameters influence the reduction in strength and stiffness, such as size, shape, and location of the opening, reinforcement around the opening, and failure mode of walls (flexural or shear critical). The influences of each opening parameter on the structural performance of RC walls are still poorly understood. The objective of this study is to experimentally investigate the effect of two parameters—opening size and additional reinforcement around the opening using six reinforced concrete wall specimens. They were tested under a novel test setup capable of applying pure shear cyclic loading. In addition, a simplified analytical model is proposed to calculate the initial stiffness of RC wall with a single opening. Results showed that the reduction in strength follows a linear pattern with the increase in opening size. However, the initial stiffness follows a nonlinear pattern associated with a large drop in stiffness for the big opening size. In addition, the additional reinforcement around the opening had improved maximum strength but had an insignificant influence on the initial stiffness of RC walls. Finally, the proposed analytical model for initial stiffness was verified with the test results and was depicted close agreement with the test.

Abstract Unreinforced masonry (URM) buildings are one of the most common type of constructions in developing countries, due to their reduced cost and ease of fabrication. However, the traditional non-engineered nature of these buildings combined with the poor mechanical performance of their structural materials pose a major threat to their earthquake performance, often resulting in heavy damage and losses. This study investigates the possibility of improving the response of typical URM buildings in developing countries, using a novel low-cost fibre reinforced elastomeric isolators (FREIs) developed with recycled rubber (RR). Detailed three-dimensional finite element analyses were carried out on the fixed-base (FB) and base-isolated (BI) configurations of the prototype building subjected to a set of strong recorded ground motions, considering both the design basis earthquake (DBE) and maximum considered earthquake (MCE). The numerical model of the URM building was developed using non-linear shell elements and bilinear springs that respectively simulated the hysteretic behavior of masonry walls and RR-FREIs. Numerical results show a significant reduction in both the accelerations and inter-story drifts of the BI configuration when compared to the response of the FB building. The global elastic response and corresponding enhanced seismic performance of the BI building under DBE confirm the effectiveness of the proposed base isolation system in protecting non-engineered URM buildings from seismic events with medium-to-high intensity.

This paper describes the most important aspects of the second part of a cold formed steel member connections research that is currently being done at the Universidad Nacional de Colombia. In this second stage the behaviour of two different connections are studied,, that is, extended continuity plates connection and side plates connection. This study looks at the results of a finite element analysis of the models, experimental testing on models (cyclic and monotonic tests), analysis and comparison between theoretical and experimental results, hysteretic curves of the connections, approximate calculation of energy dissipation coefficient for structures that use the types of connections studied, and finally, the application of whole results to cold formed steel frames design when these connections are used.