Construction optimization of spatial arch bridges based on inverse hanging and RGA method

Form -finding and construction process are complex for spatial arch bridge. To facilitate the design and construction of spatial arch bridge, an algorithm with combination of inverse hanging and real -coded genetic algorithm (RGA) method is proposed. The experimental device suitable for inverse hanging experiment of spatial arch bridge is firstly proposed. The experimental results are compared with the numerical results to validate the accuracy of proposed form -finding algorithm. The validated results indicated that the error which is mainly caused by measure error is below 5 %. Then, the form -finding algorithm and RGA is combined to perform construction optimization for planar and spatial arch bridge. With the proposed optimization algorithm, the form -finding of spatial arch bridge is completed and the optimization of installation order of hangers can be performed based on the form -finding results. The tensioning force corresponding to different installation sequences is significantly different (546 kN and 177 kN). By using RGA, the max stress of arch is significantly decreased and generally below 100 MPa. The RGA is efficient in optimize the installation sequence. The control value of tension force of all hangers can be computed by using the RGA and reverse construction simulation. The nonlinear effect and the influence of geometrical size on tensioning force can be automatically considered. The results of this study indicate that the proposed algorithm is an efficient and accurate method for the construction optimization of spatial arch bridges.