The Space Theory And Applicant Study Of Long-span Steel-concrete Composite Bridges

After the world warâ…¡, Europe needs to restore war-damaged bridges and buildings. A lot of steel-concrete composite structure were constructed for saving the steel. After the great Kanto earthquake in 1923, Japan found that the use of composite structure prossesses good seismic performance. In consequence, the composite structure has been developed rapidly in bridges and high-rise buildings.This thesis studied the steel-concrete composite bridges, including the bridge aesthetics, space theory, model test and engineering applications and so on. This thesis are concluded as:1, Long-span Qin-arch bridge theory. Qin-arch bridge started from an old bridge type, is a new arch structure from the aesthetic point of view. The main arch, looks like piano, strings, such as slings, round curves, dynamic, will shape the U.S. unity with the mechanics, the classical and the modern arch bridge arch bridge combines, classical arch bridge and modern arch bridge perfect combination together, fully demonstrated the united states of bridge architectural beauty and mechanics beauty.Large-span arch bridge of three key technical problems, namely stability, the level of thrust problems, construction problems, the solution proposed new ideas and technology programs.2, Prestressed steel-concrete composite bridge system transformation technology. Bending reduction according to mechanics principle, development and application of composite bridge system transformation technology. Using the structure system change and the section forming process, reasonable adjust the effective section control stress, reduce the control section concrete tensile stress of the objective.3, Prestressed transfer efficiency and the method of moment AM. According to the negative bending moment influence line of the composite beam, precisely preloading, according to loading procedure concrete structure layer, based on the bending moment influence line for unloading, the fulcrum in negative moment area of concrete with compressive stress, the influence line moment modulation to improve efficiency of prestressing. Through the method of influence line for bending moment amplitude modulation to improve efficiency of prestressing.4, Development and application of composite bridge structure new system. Shenzhen rainbow bridge, mainly uses three new techniques:1) the steel-concrete composite bridge structure system,2) prestressed steel-high haunched hollow plate beam; 3) new technology of steel duct positioning method by internal-pipe.Prestressed steel-concrete composite bridge new technology and its application. With corrugated steel web PC bridge, steel truss web PC composite bridge, large cantilever PC bridge with corrugated steel webs-truss research and application, with its advanced new technology, new technology and system innovation, a new type of composite structure system will enter a new development period.Steel concrete composite structure is a high strength, high performance materials, but also a high efficient, economic construction technology. Realize the combination of bridge"light, high strength, large span, economic, beautiful"target. Achieved remarkable economic and social benefits, has broad application prospects.