Eugen Brühwiler received his civil engineering and doctoral degrees from the Swiss Federal Instit... more Eugen Brühwiler received his civil engineering and doctoral degrees from the Swiss Federal Institutes of Technology (ETH) in Zurich and Lausanne. As a professor of Maintenance and Safety of Structures and consulting engineer, his activities include structural and fatigue safety of existing bridges using data from monitoring as well as the improvement of concrete structures using UHPFRC.
Preliminary results obtained from short term test-loading are used to illustrate possibilities of... more Preliminary results obtained from short term test-loading are used to illustrate possibilities of FEM used to calibrate complex interaction characteristics between a pile and soil in a bridge with integral abutments. The measurements are obtained during the winter season on the bridge over Ledån, Northern Sweden. The bridge is built in 2006 and used for long term monitoring within the international project supported by RFCS. The main objective of the ongoing research project is to proposed recommendations for rational analysis and design of bridges with integral abutments.
Peter Collin, born 1960, presented his PhD thesis 1992, concerning the stability of steel frames.... more Peter Collin, born 1960, presented his PhD thesis 1992, concerning the stability of steel frames. He has since been working with design and development of steel-and composite bridges.
Traffic density and vehicle weight have been increasing over time, which implies that many existi... more Traffic density and vehicle weight have been increasing over time, which implies that many existing road bridges were not designed for the high service loads and increased number of load cycles that they are subjected to today. One way to increase the traffic load capacity of non-composite steel-concrete bridges is to post-install shear connectors. This paper presents a study of a steel-concrete bridge that has been strengthened with post-installed coiled spring pins, a type of connector which can be installed from below while the bridge is still in service. The strengthening method and design procedure are presented, along with the results from field monitoring performed to evaluate the behaviour of the strengthened structure. The results from the strengthened and nonstrengthened sections show that the coiled spring pins counteract the slip and increases the degree of composite action. Finite-element models of the field tests were created in order to compare the results using different design assumptions and establish a suitable level of detail for modelling the shear connectors.
A number of older bridges are constructed with floor systems consisting of a non-composite concre... more A number of older bridges are constructed with floor systems consisting of a non-composite concrete slab over steel girders. A potentially economical means of strengthening these floor systems is to connect the existing concrete slab and steel girders to permit the development of composite action. This paper presents the results of a study examining methods for doing this using post-installed shear connectors in bridge girders. A series of tests on individual post-installed shear connectors and full-scale beams retrofitted with the post-installed shear connectors were conducted to evaluate structural behavior and develop design recommendations. Results of the research were subsequently implemented in a bridge near Hondo, Texas. This paper provides an overview of this research project and results of laboratory tests and field implementation.
This workshop aimed at spreading knowledge from researchers as well as designers, on the subject ... more This workshop aimed at spreading knowledge from researchers as well as designers, on the subject of prefabricated composite bridges. Bridges and Research from Sweden, Finland, France, USA, UK and Germany were presented and discussed.
In the design and construction of bridges, questions of sustainability, maintenance and durabilit... more In the design and construction of bridges, questions of sustainability, maintenance and durability are becoming more and more important for European road administrations, in addition to safety and serviceability issues. Therefore integral abutment bridges are becoming highly attractive to designers, constructors and road administrations, as they tend to be less expensive to build, easier to maintain and more economical to own over their life time. Bearings and joints are main sources of maintenance costs during a lifetime. These costs vanish because the bridges are joint-and bearing-free. However, this very advantage complicates the design compared to conventional bridges in some crucial respects. Combined with the fact that most European countries have only limited experience with integral bridges to date, this leads to a reluctance of road administrations to use this bridge type. Thus the main objective of the project is to experimentally and theoretically investigate the behaviour of critical points of integral abutment bridges. Regarding the soil-structure interaction, recommendations are elaborated based on monitoring results as well as previous research and monitoring campaigns. Conventional HP piles and sheet piles are investigated as a foundation. Furthermore a hinged HP connection is developed to decrease the stresses in the pile system. An investigation of the design and construction of the slab to pavement approach is also carried out to avoid major damages to the structure. Finally the most important information is condensed into the essential features in form of a 'Design guide for composite bridges with integral abutments'. EC Economic and durable design of composite bridges with integral abutments EUR 24224 Economic and durable design of composite bridges with integral abutments Interested in European research? RTD info is our quarterly magazine keeping you in touch with main developments (results, programmes, events, etc.). It is available in English, French and German. A free sample copy or free subscription can be obtained from:
A number of older bridges are constructed with floor systems consisting of a non-composite concre... more A number of older bridges are constructed with floor systems consisting of a non-composite concrete slab over steel girders. A potentially economical means of strengthening these floor systems is to connect the existing concrete slab and steel girders to permit the development of composite action. This paper presents the results of a study examining methods for doing this using post-installed shear connectors in bridge girders. A series of tests on individual post-installed shear connectors and full-scale beams retrofitted with the post-installed shear connectors were conducted to evaluate structural behavior and develop design recommendations. Results of the research were subsequently implemented in a bridge near Hondo, Texas. This paper provides an overview of this research project and results of laboratory tests and field implementation.
Integral abutment bridges are bridges without any expansion joints, and their largest benefits ar... more Integral abutment bridges are bridges without any expansion joints, and their largest benefits are the lower construction-and maintenance costs. In order to build longer integral bridges it might be necessary to allow plastic hinges to be developed in the piles. Lateral thermal movements are the major reason to plastic deformations, and since temperature variations are cyclic it has to be proved that low-cycle fatigue will not occur. A simulation of the pile strain spectra should be able to take into account the strains caused by temperature variations and traffic loads. Such a model has been created from real temperature data and traffic loads measured by Bridge-Weigh-In-Motion technology. Monte Carlo simulations have been performed in order to simulate daily and annual temperature changes as well as the varying traffic loads. Piles strains have been calculated, and their fatigue effect has been evaluated.
This paper deals with prefabricated composite bridges with full-depth precast decks. For steel-co... more This paper deals with prefabricated composite bridges with full-depth precast decks. For steel-concrete composite bridges, a new shear connection and its design provisions were suggested by extensive experiments and finite element (FE) analyses. The shear connection for precast decks was investigated to consider the effects of bedding layer, filling material in shear pockets and group arrangement. For the integrity of the precast decks, longitudinal prestressing was introduced and design guidelines for the magnitude of prestress were proposed. It is necessary to keep the joints compressive during the service life of the bridge to prevent cracking and leakage at the joints. Bonding strength was neglected in the design. In order to take full advantage of precast slabs, the concept of incremental prestressing was adopted for continuous prestressed concrete (PSC) girders. Based on the experimental research on joints and connections, several model tests were performed to verify the suggested design guidelines. There are several applications using precast decks not only for steel bridges and but also for concrete ones. Among them, design characteristics and enhanced details for construction were introduced for two bridges.
Peter Collin, born 1960, presented his PhD thesis 1992, concerning the stability of steel frames.... more Peter Collin, born 1960, presented his PhD thesis 1992, concerning the stability of steel frames. He has since been working with design and development of steel-and composite bridges.
In integral abutment bridges clamped abutment piles are in addition to a compressive normal force... more In integral abutment bridges clamped abutment piles are in addition to a compressive normal force subjected to bending load cycles from daily and yearly temperature variations. Through experiments with full-scale specimens representing a clamped pile it is shown that a steel pipe pile loaded in bending can withstand several hundred load cycles at strain ranges greater than 6 times the yield strain with almost full load bearing capacity. By means of an example it is shown that by permitting pile strains greater than the yield strain, in contrast to most present design codes, integral abutment bridges can be erected with a span length up to 500m and a prospected service life of 120
The effects of different weld geometries on the mechanical properties of undermatched welds in hi... more The effects of different weld geometries on the mechanical properties of undermatched welds in high strength steel have been studied experimentally. Static tension-and hardness tests have been performed on 30 individual test specimens. Three parameters were chosen to be studied; width-to thickness relation, undermatching level and the ratio between the width of the weld and the thickness of the steel plate (relative thickness). The conclusion is that the weld width and volume has a strong influence on the strength of the joint, this is due to constraint. Fractures were achieved in the base metal for joints undermatched as much as 23 %. These seemingly surprising results are explained theoretically using incremental plasticity theory.
Eugen Brühwiler received his civil engineering and doctoral degrees from the Swiss Federal Instit... more Eugen Brühwiler received his civil engineering and doctoral degrees from the Swiss Federal Institutes of Technology (ETH) in Zurich and Lausanne. As a professor of Maintenance and Safety of Structures and consulting engineer, his activities include structural and fatigue safety of existing bridges using data from monitoring as well as the improvement of concrete structures using UHPFRC.
Preliminary results obtained from short term test-loading are used to illustrate possibilities of... more Preliminary results obtained from short term test-loading are used to illustrate possibilities of FEM used to calibrate complex interaction characteristics between a pile and soil in a bridge with integral abutments. The measurements are obtained during the winter season on the bridge over Ledån, Northern Sweden. The bridge is built in 2006 and used for long term monitoring within the international project supported by RFCS. The main objective of the ongoing research project is to proposed recommendations for rational analysis and design of bridges with integral abutments.
Peter Collin, born 1960, presented his PhD thesis 1992, concerning the stability of steel frames.... more Peter Collin, born 1960, presented his PhD thesis 1992, concerning the stability of steel frames. He has since been working with design and development of steel-and composite bridges.
Traffic density and vehicle weight have been increasing over time, which implies that many existi... more Traffic density and vehicle weight have been increasing over time, which implies that many existing road bridges were not designed for the high service loads and increased number of load cycles that they are subjected to today. One way to increase the traffic load capacity of non-composite steel-concrete bridges is to post-install shear connectors. This paper presents a study of a steel-concrete bridge that has been strengthened with post-installed coiled spring pins, a type of connector which can be installed from below while the bridge is still in service. The strengthening method and design procedure are presented, along with the results from field monitoring performed to evaluate the behaviour of the strengthened structure. The results from the strengthened and nonstrengthened sections show that the coiled spring pins counteract the slip and increases the degree of composite action. Finite-element models of the field tests were created in order to compare the results using different design assumptions and establish a suitable level of detail for modelling the shear connectors.
A number of older bridges are constructed with floor systems consisting of a non-composite concre... more A number of older bridges are constructed with floor systems consisting of a non-composite concrete slab over steel girders. A potentially economical means of strengthening these floor systems is to connect the existing concrete slab and steel girders to permit the development of composite action. This paper presents the results of a study examining methods for doing this using post-installed shear connectors in bridge girders. A series of tests on individual post-installed shear connectors and full-scale beams retrofitted with the post-installed shear connectors were conducted to evaluate structural behavior and develop design recommendations. Results of the research were subsequently implemented in a bridge near Hondo, Texas. This paper provides an overview of this research project and results of laboratory tests and field implementation.
This workshop aimed at spreading knowledge from researchers as well as designers, on the subject ... more This workshop aimed at spreading knowledge from researchers as well as designers, on the subject of prefabricated composite bridges. Bridges and Research from Sweden, Finland, France, USA, UK and Germany were presented and discussed.
In the design and construction of bridges, questions of sustainability, maintenance and durabilit... more In the design and construction of bridges, questions of sustainability, maintenance and durability are becoming more and more important for European road administrations, in addition to safety and serviceability issues. Therefore integral abutment bridges are becoming highly attractive to designers, constructors and road administrations, as they tend to be less expensive to build, easier to maintain and more economical to own over their life time. Bearings and joints are main sources of maintenance costs during a lifetime. These costs vanish because the bridges are joint-and bearing-free. However, this very advantage complicates the design compared to conventional bridges in some crucial respects. Combined with the fact that most European countries have only limited experience with integral bridges to date, this leads to a reluctance of road administrations to use this bridge type. Thus the main objective of the project is to experimentally and theoretically investigate the behaviour of critical points of integral abutment bridges. Regarding the soil-structure interaction, recommendations are elaborated based on monitoring results as well as previous research and monitoring campaigns. Conventional HP piles and sheet piles are investigated as a foundation. Furthermore a hinged HP connection is developed to decrease the stresses in the pile system. An investigation of the design and construction of the slab to pavement approach is also carried out to avoid major damages to the structure. Finally the most important information is condensed into the essential features in form of a 'Design guide for composite bridges with integral abutments'. EC Economic and durable design of composite bridges with integral abutments EUR 24224 Economic and durable design of composite bridges with integral abutments Interested in European research? RTD info is our quarterly magazine keeping you in touch with main developments (results, programmes, events, etc.). It is available in English, French and German. A free sample copy or free subscription can be obtained from:
A number of older bridges are constructed with floor systems consisting of a non-composite concre... more A number of older bridges are constructed with floor systems consisting of a non-composite concrete slab over steel girders. A potentially economical means of strengthening these floor systems is to connect the existing concrete slab and steel girders to permit the development of composite action. This paper presents the results of a study examining methods for doing this using post-installed shear connectors in bridge girders. A series of tests on individual post-installed shear connectors and full-scale beams retrofitted with the post-installed shear connectors were conducted to evaluate structural behavior and develop design recommendations. Results of the research were subsequently implemented in a bridge near Hondo, Texas. This paper provides an overview of this research project and results of laboratory tests and field implementation.
Integral abutment bridges are bridges without any expansion joints, and their largest benefits ar... more Integral abutment bridges are bridges without any expansion joints, and their largest benefits are the lower construction-and maintenance costs. In order to build longer integral bridges it might be necessary to allow plastic hinges to be developed in the piles. Lateral thermal movements are the major reason to plastic deformations, and since temperature variations are cyclic it has to be proved that low-cycle fatigue will not occur. A simulation of the pile strain spectra should be able to take into account the strains caused by temperature variations and traffic loads. Such a model has been created from real temperature data and traffic loads measured by Bridge-Weigh-In-Motion technology. Monte Carlo simulations have been performed in order to simulate daily and annual temperature changes as well as the varying traffic loads. Piles strains have been calculated, and their fatigue effect has been evaluated.
This paper deals with prefabricated composite bridges with full-depth precast decks. For steel-co... more This paper deals with prefabricated composite bridges with full-depth precast decks. For steel-concrete composite bridges, a new shear connection and its design provisions were suggested by extensive experiments and finite element (FE) analyses. The shear connection for precast decks was investigated to consider the effects of bedding layer, filling material in shear pockets and group arrangement. For the integrity of the precast decks, longitudinal prestressing was introduced and design guidelines for the magnitude of prestress were proposed. It is necessary to keep the joints compressive during the service life of the bridge to prevent cracking and leakage at the joints. Bonding strength was neglected in the design. In order to take full advantage of precast slabs, the concept of incremental prestressing was adopted for continuous prestressed concrete (PSC) girders. Based on the experimental research on joints and connections, several model tests were performed to verify the suggested design guidelines. There are several applications using precast decks not only for steel bridges and but also for concrete ones. Among them, design characteristics and enhanced details for construction were introduced for two bridges.
Peter Collin, born 1960, presented his PhD thesis 1992, concerning the stability of steel frames.... more Peter Collin, born 1960, presented his PhD thesis 1992, concerning the stability of steel frames. He has since been working with design and development of steel-and composite bridges.
In integral abutment bridges clamped abutment piles are in addition to a compressive normal force... more In integral abutment bridges clamped abutment piles are in addition to a compressive normal force subjected to bending load cycles from daily and yearly temperature variations. Through experiments with full-scale specimens representing a clamped pile it is shown that a steel pipe pile loaded in bending can withstand several hundred load cycles at strain ranges greater than 6 times the yield strain with almost full load bearing capacity. By means of an example it is shown that by permitting pile strains greater than the yield strain, in contrast to most present design codes, integral abutment bridges can be erected with a span length up to 500m and a prospected service life of 120
The effects of different weld geometries on the mechanical properties of undermatched welds in hi... more The effects of different weld geometries on the mechanical properties of undermatched welds in high strength steel have been studied experimentally. Static tension-and hardness tests have been performed on 30 individual test specimens. Three parameters were chosen to be studied; width-to thickness relation, undermatching level and the ratio between the width of the weld and the thickness of the steel plate (relative thickness). The conclusion is that the weld width and volume has a strong influence on the strength of the joint, this is due to constraint. Fractures were achieved in the base metal for joints undermatched as much as 23 %. These seemingly surprising results are explained theoretically using incremental plasticity theory.
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