The composite structures have experienced a significantly increasing application in China,in which the steel-concrete composite structure is the most widely used, and the concrete composite structure is applied more a...The composite structures have experienced a significantly increasing application in China,in which the steel-concrete composite structure is the most widely used, and the concrete composite structure is applied more and more. This paper reviewed briefly the development history of composite structure in bridge engineering in the last seven decades,introduced the state-of-the art of composite structures including the beams, columns and arches, and presented some discussions. It can be found that the traditional steel-concrete composite structures, such as steel beam-concrete deck slab, and concrete-filled steel tube(CFST) arch bridge, have been applied continuously and studied in-depth, and the corresponding design theory system is constantly improved. At the same time, the new composite structures such as corrugated steel web(truss rod)-concrete composite beams, CFST composite beams, hybrid girders in the cable-stayed bridges, CFST piers and pylons, Melan arches, etc., have been developing rapidly. Nevertheless, certain novel configurations exhibit insufficient evaluation of constructability and lifecycle costs. Some research results and technical experience have not been fully reflected in the relevant specifications, and need to be supplemented and improved in the future revision of the specifications. The behaviors and performance of steel-concrete composite structures lies between that of steel structures and concrete structures. In research and application, they may be understood better by tracing back the origination of structures. For some composite structures with same components, their performances may also have quite large difference due to the contribution of each component. For concrete composite structures consisting of different concrete materials, the degree of the difference in material properties is a structure that should be considered as a concrete composite structure and also a problem that needs further research. In engineering, it is commonly to strengthen or stiffen a structure locally,hybrid structures should be distinguished from it.展开更多
In the case of composite girders, an effective cooperation of both parts of the section is influenced by deformability of connectors. Limited flexural stiffness of welded studs, used commonly in bridge structures, doe...In the case of composite girders, an effective cooperation of both parts of the section is influenced by deformability of connectors. Limited flexural stiffness of welded studs, used commonly in bridge structures, does not provide full interaction of a steel beam and a concrete slab. This changes strain distribution in cross-sections of a composite girder and results in redistribution of internal forces in steel and concrete element. In the paper partial interaction index defined on the basis of a neutral axis position, which can be used for verification of steel-concrete interaction in real bridge structures rather than in specimens is proposed. The range of the index value changes, obtained during load testing of a typical steel-concrete composite beam bridge, is presented. The investigation was carried out on a motorway viaduct, consisting of two parallel structures. During the testing values of strains in girders under static and quasi-static loads were measured. The readings from the gauges were used to determine the index, characterizing composite action of the girders. Results of bridge testing under movable load, changing position along the bridge span is presented and obtained in-situ influence functions of strains and index values are commented in the paper.展开更多
基金sponsored in part by the National Natural Science Foundation of China(52278158,52078136)Postdoctoral Science Foundation of China(2023T160138)+1 种基金Key Project of the Education and Scientific Research of Fujian Province for Young Teachers(JZ240040)Fujian University of Technology Talent Foundation(GY-Z23239,GY-Z21220)
文摘The composite structures have experienced a significantly increasing application in China,in which the steel-concrete composite structure is the most widely used, and the concrete composite structure is applied more and more. This paper reviewed briefly the development history of composite structure in bridge engineering in the last seven decades,introduced the state-of-the art of composite structures including the beams, columns and arches, and presented some discussions. It can be found that the traditional steel-concrete composite structures, such as steel beam-concrete deck slab, and concrete-filled steel tube(CFST) arch bridge, have been applied continuously and studied in-depth, and the corresponding design theory system is constantly improved. At the same time, the new composite structures such as corrugated steel web(truss rod)-concrete composite beams, CFST composite beams, hybrid girders in the cable-stayed bridges, CFST piers and pylons, Melan arches, etc., have been developing rapidly. Nevertheless, certain novel configurations exhibit insufficient evaluation of constructability and lifecycle costs. Some research results and technical experience have not been fully reflected in the relevant specifications, and need to be supplemented and improved in the future revision of the specifications. The behaviors and performance of steel-concrete composite structures lies between that of steel structures and concrete structures. In research and application, they may be understood better by tracing back the origination of structures. For some composite structures with same components, their performances may also have quite large difference due to the contribution of each component. For concrete composite structures consisting of different concrete materials, the degree of the difference in material properties is a structure that should be considered as a concrete composite structure and also a problem that needs further research. In engineering, it is commonly to strengthen or stiffen a structure locally,hybrid structures should be distinguished from it.
文摘In the case of composite girders, an effective cooperation of both parts of the section is influenced by deformability of connectors. Limited flexural stiffness of welded studs, used commonly in bridge structures, does not provide full interaction of a steel beam and a concrete slab. This changes strain distribution in cross-sections of a composite girder and results in redistribution of internal forces in steel and concrete element. In the paper partial interaction index defined on the basis of a neutral axis position, which can be used for verification of steel-concrete interaction in real bridge structures rather than in specimens is proposed. The range of the index value changes, obtained during load testing of a typical steel-concrete composite beam bridge, is presented. The investigation was carried out on a motorway viaduct, consisting of two parallel structures. During the testing values of strains in girders under static and quasi-static loads were measured. The readings from the gauges were used to determine the index, characterizing composite action of the girders. Results of bridge testing under movable load, changing position along the bridge span is presented and obtained in-situ influence functions of strains and index values are commented in the paper.
