Cost Optimization Design Of Anchor System Under Construction Control Of Cantilever Arch Bridge

Long-span reinforced concrete arch bridge has good seismic performance and durability,and is one of the most competitive design schemes in mountain environment.Cantilever pouring method can save site and break through mountain terrain restrictions more easily.In theory,it can form a "perfect match" with the design scheme.However,the choice of anchor location for this method is usually limited.In many cases,the use of ultralong buckles and anchor cables cannot be avoided.In order to ensure the working efficiency of the fastening cable,the inclination angle of the fastening cable should not be too small,and the height of the tower should be correspondingly increased,which will bring about huge consumption of temporary structural materials such as the tower and the fastening cable.Therefore,how to find reasonable design parameters of anchorage system so as to avoid unreasonable consumption of temporary structural materials on the premise of ensuring construction safety is an optimization design problem worthy of attention.Based on the engineering background of Shatuo Bridge,this paper studies the optimization design of the design parameters of cable-stayed suspension system.The main work includes:(1)According to the construction process of cantilever concrete arch bridge,the parametric model of the construction process is established by using the "unit life and death technology" in ANSYS.At the same time,the calculation formula for determining the reasonable construction cable force by the stress balance method is deduced,and the corresponding calculation program is compiled by MATLAB.(2)The tower height and the vertical distance of the anchor point of the buckle cable are selected as the main design control variables,the cost of the anchor system of the tower is selected as the objective function,the construction safety restrictions such as the stress range of the arch ring,the stability requirements of the tower and the cable force sensitivity are fully considered,and the joint optimization is carried out by using the interactive environment of MATLAB and ANSYS.(3)In view of the different tower positions and the different unit price ratio of cable and tower,this paper respectively discusses their influence on the optimization calculation results and convergence speed.The optimization analysis shows that the optimization calculation can significantly reduce the cost of the temporary structure.With the increase of the distance from the tower to the arch foot,the tower height tends to increase.When the price ratio of cable to tower material is larger,the optimal design tower height is larger.As for the convergence of the algorithm,the change of distance has little influence on the convergence speed and the algorithm has good convergence.The change of the unit price ratio between the cable-stayed and the tower has a great influence on the convergence speed of the algorithm.With the increase of the cable-stayed material price,the convergence speed gradually slows down.