Yanqi River Bridge Status And The Construction Phase Suspender Force Optimization

Based on Hengyang Yanqi bridge,this thesis investigates the optimum preliminary tensions of the suspenders at reasonable status of completed bridge,and studys how to determine and adjust the preliminary tensions of the suspenders at the construction stage. This dissertation has mainly dealt with the following respects:1 .It designs a structural analysis program for static response of linear system, which made of truss element or beam element or combined. The program is validated by some classical examples. Then explains how to build the computational model of the Yanqi bridge detailedly.2.The constrained minimum energy method is chosen to found the mathematical model that determine the optimum preliminary tensions of the suspenders at reasonable status of completed bridge,with the whole deformation energy of the arch rib and the beam as the objective function, the displacement of the appointed node,the bending moment of the appointed section,the limit tensions of the suspenders as the constrained condition.3.It reviews the theory of optimization algorithm,and modifys the program based on the constrained variable metric method to fit solving the large-sized mathematical model.4.Compares the preliminary tensions of suspenders got by the constrained minimum energy method with it offered by the designing institute, concluding that the result through the constrained minimum energy method is superior to the result offered by the designing institute.5.It uses the step-by-step method to tension the suspenders,and determines to tension the suspenders for the first time to the level that half of the final tensioning,and adjusts the preliminary tensions of the suspenders by the influence matrix method when tensioning the suspenders for the second time, realizing the aim that tensioning the suspenders to the design level by tensioning the suspenders for only two times. So this method provides the theory evidence for the construction control.