Study On Optimization Method Of Cable Force For Long-span Steel Truss Cable-stayed Bridges

The cable force directly affects the internal force state of the cable-stayed bridge,and the mechanical performance of cable-stayed bridge will be significantly different because of the different cable forces.The optimization calculation of cable force is an important content in the design and construction of cable-stayed bridge,and it can improve the mechanical performance of cable-stayed bridge.Based on a long-span steel truss cable-stayed bridge,this paper studies the cable force optimization algorithm of cable-stayed bridges and the solution method of tensile forces during construction.The main research work of this paper includes:1.The optimization methods of cable force and the common methods for determining the reasonable construction state of cable-stayed bridge are summarized,which provides reference for the work of this paper.2.The cable force optimization method based on the influence matrix and mixed particle swarm optimization method is proposed to determine the ideal completed state of the cablestayed bridge.The establishment of optimization model and the solution of the optimization problem of this method are discussed in detail.Comparing with the completed states obtained by the traditional cable force optimization methods,the method proposed in this paper has obvious advantages.3.The common methods for determining the reasonable construction state of cablestayed bridges are summarized in this paper.The cable force optimization method is introduced in the forward analysis process of the traditional backward-forward analysis method to form the backward-forward optimization analysis method,which improves the calculation efficiency and calculates the tensile forces of the cable-stayed bridges during construction.Using this method to analyze the project that this paper relies on,which achieves good results.4.The two construction schemes of side-span jacking,mid-span double-segment cantilever assembly and double cantilever assembly are proposed.Based on the previous research results,the reasonable tensile forces of the two schemes during construction are determined,and the construction stages of the cable-stayed bridge that this paper relies on are calculated respectively.By comparing and analyzing the internal force and deformation state of the tower,beam and cable of these two schemes during construction,the optimized construction scheme is obtained.