The Determining And Optimization Of Cable Force Of Concrete Cable-Stayed Bridge With Single Tower And Single Cable Plane

Cable-stayed bridge is such kind of bridge, in which bridge floor system stiff girder is primarily under compression (dense cable) or under bending moment (sparse cable);in which support system the cable is under tension and the tower is under compression. Because of the reasonable structural style ,the economical cost and elegant appearance, the prestressed concrete cable-stayed bridge obtains the widespread application in the long-span bridge.The cable is one of the key parts of cable-stayed bridge. It takes on most part of load in construction stage and in the actual use. Rational cable force can guarantee the structure safety in construction and make the structure 's internal force reasonable after construction. Through the adjustment of cable force, strueture's internal force can come out in reason. Theoretically that whatever cable-stayed bridge structure, always can find a group of force, it makes the structure in the deterministic loads, some mechanical properties of the target to achieve optimal performance. So cable force optimization problem appears. Moreover speaking of the cable-stayed bridge, we not only need pay attention to the completion state, but also take seriously to construct state. Only in this way, the bridge structure via the reasonable construction state transition to the reasonable completion state.How to determine a reasonable construction cable force of prestressed concrete cable-stayed bridge, giving prestressed concrete cable-stayed bridge can meet the safety requirements for construction, while to achieve the ideal state of stress on completion state and the design goal line, is one of the key questions in the detail design of prestressed concrete cable-stayed bridge. In a word, the determining and optimization of cable force of concrete cable-stayed bridge (final cable force,initial constrction cable force), is one of long-term research topics attracting engineers.This article carries on research on the above problem, has finished the following work:(1)Combined with analysis of the reasonable completion state, to analyze all kinds of existing methods of determining and optimization of final cable force, to find out their advantages and disadvantages and application conditions; combined with analysis of engineering project Shi Zhou Bridge,with the aid of finite element software to built a modle for anlysis of prestressed concrete cable-stayed bridge with single tower and single cable plane, to improve the minimum bending energy method by using the method of binding, to determine the final cable force (considering the influence of live load). Through comprehensive application of internal balance method, bending moment feasible region method and so on, to optimize cable force.(2)Based on the the finite element calculation principle of the cable forces on construction state, to comparison and selection the reasonable method from all kinds of existing methods of determining of initial construction cable force, combined with analysis of engineering project, considering the influence of factors, such as temperature, nonlinear, shrinkage and creep of concrete, forward iterative optimization analysis is proposed to determine the construction cable force .According to compare with the cable tension adjustment of Shi Zhou Bridge, we can see that comprehensively applying the existing methods for determining and optimization of cable force, is to avoid the limitations of a optimization method used only; with the use of finite element software to propose the man-machine interactive visualization simulation for cable tension adjustment is to improve the efficiency, has practical value.