Energy-based Cable Force Calculation And Cantilever Construction Process Optimization Research For Hybrid Beam Cable-stayed Bridges

The main girder of the hybrid girder cable-stayed bridge is composed of two different materials,steel and concrete.The combination of the two materials gives full play to the advantages of their respective material properties and has good economical and aesthetic effects.However,while improving the mechanical properties,it also increases the difficulty in the design and construction control of the hybrid beam cable-stayed bridge.At present,there are few literatures about the optimization of the construction process of the hybrid girder cablestayed bridge,especially the single-tower asymmetric hybrid girder cable-stayed bridge,and many cable-stayed bridge cable force calculation methods also have their own shortcomings.Therefore,the research on cable force calculation of hybrid beam cable-stayed bridge and optimization of main girder construction process has certain engineering practical significance.Based on the research background of Shaozhou Bridge in Shaoguan,Guangdong,this paper establishes the finite element model of the bridge with Midas Civil and BDCMS,and performs cable force calculation and construction process optimization for the bridge based on the calculation results of the two finite element software.The main research work of the thesis includes:1)Summarize the structural characteristics of hybrid girder cable-stayed bridges and the current research status of cable-stayed bridges at home and abroad,and introduce the calculation methods of cable forces in the completed bridge state and construction state.2)Based on the minimum bending energy method and the zero displacement method,the cable force combination in the completed state of the cable-stayed bridge is calculated,and the force and displacement of the bridge under different cable force combinations are analyzed.A cable force optimization method based on the combination of the minimum bending energy method and the genetic algorithm is proposed,and the reasonable bridge cable force is obtained,and then the construction tension cable force is obtained by the formal installation iteration method.3)Combined with the cantilever construction process of the main girder of the hybrid girder cable-stayed bridge,five construction procedures of the standard girder section of the main girder are proposed,and the cyclic construction process of each beam section is simulated and checked,and the structure of the hybrid girder cable-stayed bridge under different procedures is analyzed and compared.In response,the optimal construction procedure is selected after comprehensive consideration,and it is verified that the optimal construction procedure can not only make the force and alignment of the bridge in the construction stage and the bridge completion stage more reasonable,but also save a lot of construction time.