钢桁架桥梁荷载试验分析

Load Test Analysis of Steel Truss Bridge

为准确掌握桥梁结构运行状况,对某三桁式下承式钢桁架梁进行荷载试验,对各测试点的挠度及应变数据进行分析,主桥应变校验系数介于0.76~0.93,各挠度校验系数介于0.88~0.92,各测点应变、挠度校验系数小于1,且相对残余均小于20%,表明试验跨结构刚度满足设计要求,并在弹性工作状态。桥梁实际的竖向整体动刚度达到设计要求,结构动力性能较好。实测冲击系数均小于理论计算冲击系数,表明该桥桥面平整度较好,车辆冲击作用小,满足行车要求。

In order to accurately grasp the operation status of the bridge structure,the load test of a three-truss downbearing steel truss girder was carried out,and the deflection and strain data of each test point were analyzed,and the strain check coefficient of the main bridge was between 0.76~0.93,the deflection verification coefficient was between 0.88~0.92,the strain and deflection verification coefficients of each measurement point were less than 1,and the relative residual was less than 20%,indicating that the stiffness of the test cross-structure met the design requirements and was in a flexible working state.The actual vertical overall dynamic stiffness of the bridge meets the design requirements,and the structural dynamic performance is better.The measured impact coefficients are all smaller than the theoretical calculated impact coefficients,indicating that the bridge deck flatness is good,the vehicle impact effect is small,and it meets the driving requirements.