Optimization of Construction Process and Determination of Intermediate Cable Forces for Composite Beam Cable-Stayed Bridge

This paper presents a comprehensive study of the Xiangsizhou Bridge, a double-tower double-cable steel-concrete composite girder cable-stayed bridge located in Pingnan, Guangxi, China. A finite element model of the full-bridge spatial truss system was established using a dual main beam simulation of the steel-concrete composite girder. To obtain the initial reasonable bridge state, the minimum bending energy method was employed, followed by optimization of the state using the unknown load coefficient method to attain the final reasonable completion state. This paper proposes an innovative construction scheme for the erection of the main girders, which is designed to address the issue of excessive tensile stresses in the bridge deck slabs that can arise in conventional construction schemes. This scheme can save about 4 months of construction time and shorten the construction cycle of main beam erection by 60%. Furthermore, the study derived and verified a formula for the intermediate cable force during the construction process, which demonstrated its effectiveness. This study provides practical value for the design and construction of similar bridges.