某铁路运煤专线简支梁静载试验分析

Static Load Test Analysis of a Simply Supported Beam in a Railway Coal Special Line

【目的】以某在役运煤专线(3×16)m简支梁为研究背景,测试其在静荷载作用下的静应变、静应力及静位移,由此分析桥梁结构在静荷载作用下的工作状态及其安全性能。【方法】应用桥梁有限元分析软件Midas Civil建立该桥有限元模型进行静力求解,经计算本次试验跨确定加载工况为跨中截面加载,在现场开展静载试验分析。【结果】通过对该桥第二跨和第三跨梁进行静载试验,在荷载工况加载下,各控制截面测点应变校验系数在0.47~0.57之间,变形校验系数均在0.55~0.61之间。第三跨实测挠度最大为1.61 mm,换算到中-活载后为3.15 mm。【结论】在试验荷载作用下,控制截面各测试点上的应变未出现异常变化,最大静应变和最大静位移均在规定的范围内,实测值的变化规律和理论分析结构基本保持一致,应变校验系数、变形校验系数和实测最大挠度值换算到中活载后均小于《铁路桥梁检定规范》中的规定值,满足规范要求,说明桥梁竖向刚度良好。

[Purposes]The static strain,static stress and static displacement of a simply supported beam(3×16)m of an in-service coal special line were tested under static load,and the working state and safety performance of the bridge structure under static load were analyzed.[Methods]The bridge finite element analysis software Midas Civil was used to establish the finite element model of the bridge for static solu-tion.The loading condition of the test span was determined as mid-span section loading by calculation,and static load test analysis was carried out on site.[Findings]Through the static load test of the second and third span beams of the bridge,under the load condition,the strain calibration coefficient of each control cross section measuring point is between 0.47 and 0.57,and the deformation calibration coeffi-cient is between 0.55 and 0.61.The maximum measured deflection of the third span is 1.61 mm,which is 3.15 mm after conversion to medium-live load.[Conclusions]Under the effect of the test load,the strain on each test point of the control section has not changed abnormally,and the maximum static transformation and maximum static displacement are within the specified range.The variation law of the measured value is basically consistent with the theoretical analysis structure.The strain calibration coefficient,the deformation calibration coefficient,and the measured maximum deflection value are less than the specified value in the“Railway Bridge Verification Specification”after conversion to the medium-live load.which meets the re-quirements of the specifications,indicating that the vertical stomach of the bridge is good.