Force Analysis Of The Static Test Model Designed For Long-Span Continuous Steel Truss Arch Bridge

The type of steel truss arch bridge is not very common in our country, and the long span over 500 m can be counted on one′s fingers. But Chongqing Chaotianmen Changjiang River Bridge ,which is during the stage of construction now, being a three-span continuous semi-supported and tied steel truss arch bridge, is arranged with the length of the main bridge to 932 m. The span of the main bridge is 190+552+190 m. The two decks of bridge include two lanes for light railway,eight lanes load for the level of roadⅠand two rows load for persons with the width of 2.5 m. The upper and lower layers of ties are arranged. With so many characteristics such as long-span,special live load and unique style of bridge structure,Chongqing Chaotianmen River Bridge is the top one because of it′s span in the world among the same type of bridges.The finished example of this type of bridge is quite sparse and there is little mature experience used for reference. In addition,the thought of the design is very fashionable.All the reasons above lead to the necessary of the further and moer careful study on the structure′s performance in safety during the construction stage and use stage by means of model test,in order to ensure the safety. Taking the advantage of the similarity between testing model and actual project,the problems can be noticed early concealing in not only design but also in construction.This article, which takes the model′s static test of Chongqing Chaotianmen Changjiang River Bridge as the project back ground and uses large-scale finite element software MSC.Marc 2005r3, carries on the spatial analysis simulation by setting up the emulating model of test bridge according to the actual construction process. Its purpose is to direct the adding of compensating load and the test scheme for harmful member and displacement exactly during the static model test,and to do some further study on the force of the long-span continuous steel truss tied arch bridge under the state of construction and use after completion.By contrast of the finite element analysis data and the practice test data in bridge, it proves that the method using the finite element spatial analysis to simulate the construction process according to the construction order is feasible and the analyses way by means of influence line is effective. The accurate and reliable analogue result can be used to guide the load and test plans for the model project properly. And the research may provide some valuable experience for similar bridges.