为了分析桁式组合拱桥的损伤原因,建立了贵州清水大桥的三维实体有限元模型。对考虑预应力钢筋+桥梁自重工况和不计上弦预应力钢筋,只考虑斜杆预应力钢筋+桥梁自重2种工况进行了数值分析,得到了2种工况下桥梁第1主应力和第3主应力的分布情况。结果显示的损伤情况与贵州省交通科学研究所的清水大桥检测报告吻合较好,比较2种工况,初步判定不合理的预应力设计水平为造成该桥新拱脚和双竖杆部位损伤的主要原因。

Damage Mechanism Investigation of Trussed Combination Arch Bridge by FEMLIU Li-sheng1,YANG Da-peng1,WU Dai-hua1,CHENG Zhu-jiang2 (1.School of Sciences,Wuhan University of Technology,Wuhan 430070,China;2.Guizhou Communication Science Research Institute,Guiyang 550014,China)A three-dimension finite element model of Qingshui Bridge has been built for investigating the damage reason of trussed combination arch bridge.Two different conditions was considered.One was all prestressing+dead load and the other was part of prestressing+dead load.The first and third principal stress under those two conditions had been obtained by numerical analysis.The damage regions that calculated by numerical results were coincident with the investigation report by Guizhou Communication Science Research Institute.The irrational design of initial pre-stress may be a key factor that causes the damage of this bridge.trussed combination arch bridge;crack;pre-stress;FEM