Coupling Analysis Of Rational Completion Stage And Rational Construction Stage Of Space Twist Cable-Stayed Bridge

Now, there are many research results in determination of cable-stayed bridges rational completion stage, rational construction stage and the optimal control of construction. However, there are still a lot of problems in the application. Base on the project of major body of Liang Ji Canal bridge, which is located on Tai bai Road West, Jining City, Shandong Province, and the paper has done many studies in the following several aspects.They include:the inconsistency of rational completion of cable-stayed bridge determined in cast-in-place construction stage with is completed through numerous system switchs; and my further study is the interaction between the rational completion stage of cable-stayed bridges which through numerous system switchs and rational construction stage, the conventional idea that the inner force in balance of completion stage determined in cast-in-place construction stage abandoned, considering the coupling effect of the rational construction stage and the rational completion stage, and the coupled method for determining rational construction stage and rational completion stage is introduced. Conclusion shows:the method ensures cable tension, the beam and the tower bending moment, support reaction, can achieve rational completion stage at the same time, avoiding the inconsistency of actual stress state and the theory of the rational completion stage. The most important, which the conventional approach can not consider, is the coupling effect of the rational construction stage and the rational completion stage.By analyzing the effect on rational completion stage, rational construction stage by temperature; Considering China's "Guidelines for Design of Highway Cable-stayed Bridge" (JTG/TD65-01-2007) and the project of the actual situation, the mainly deals with the annual temperature changes, daily temperature changes, the cable difference the temperature form the beam and the tower, the main tower body cross-bridge to the temperature gradient. Daily temperature changes significantly affect rational construction stage. Daily temperature changes has a greater influence on the length of closure of long-span steel box girder,particularly in the summer in Northern China, and construction control should be given full consideration; The annual temperature changes, the cable difference the temperature form the beam and the tower more significantly affect the rational completion stage. In cable-stayed bridges design it should be fully considered. For the space twist cable-stayed shaped bridges, the main tower body cross-bridge to the temperature gradient more significantly affects the rational completion stage, So in cable-stayed bridges design it should be fully considered.The method of determining the non-stress cable length is researched. Comprehensive consideration the factors affecting the length of the non-stress cable, detailed research and analysis of each factor. Practical calculation method of the non-stress cable length is introduced. The practical calculation method is more precise than the method of Chinese Highway Cable-stayed Bridge Design Standard Specifications. The method will be to provide more scientific methods of calculating the length of non-stress in the future.For camber settings, in addition to considerations on the norm, the problem that the car load on the main beam produces long-term creep deformation also should be considered; When tensioning, not only concrete strength be required, but elastic modulus and age also be required.For the leaning tower of cable-stayed bridge, universal pre-deviation formula of the leaning tower is introduced, which provides a reference for construction of leaning tower of cable-stayed bridges.