不同箱室波形钢腹板PC箱梁力学性能分析

Mechanical performance analysis of corrugated steel webs(CSWs)PC box girder with different cell numbers

为了优化桥梁设计,探索了适合二车道波形钢腹板组合箱梁的箱室数目;基于某二车道波形钢腹板刚构桥箱室的设计参数,利用有限元软件进行建模,分析了4种工况下单箱单室至单箱五室波形钢腹板PC箱梁的底板跨中截面中点位移、跨中截面外侧波形钢腹板的等效剪应力、翘曲正应力及自振频率.研究结果表明:对于二车道波形钢腹板的组合箱梁,虽然增加箱室的数量在一定程度上有利于提高预应力效率、减小外侧钢腹板的剪应力,但是对于偏载下翘曲正应力和自重均有不利影响.最后利用简易公式法及主成分分析法,给出了二车道单箱箱梁合理的箱室数目.

To optimize the design of girder bridge,the proper cell number of the two-lane CSWs PC box girder was investigated.Based on the two-lane CSWs PC box girder bridge design parameter,the mechanical behaviors of single-room girder box with single cell to five cells were analyzed under four different load conditions by finite element analysis(FEA).The mid-span displacement in the bottom flange,the von-Mises shear stress in both corrugated web sides,the normal warping stress and the natural frequency of the box girders were obtained.The results show that multiplying cell numbers can increase the prestressing efficiency and decrease the von-Mises shear stress in both corrugated web sides in some cases.However,with the cell number increasing,the normal warping stress under eccentric load and the dead weight of the girder are increased dramatically.By simple formula method and principal component analysis method,the proper cell number for the two-lane CSWs PC box girder is suggested.