大跨径斜拉桥荷载试验的温度效应

Temperature Effect of Load Test forLong Span Cable-stayed Bridge

以河(源)惠(州)(东)莞高速公路龙川至紫金段枫树坝大桥(主跨320m双塔单索面预应力混凝土斜拉桥)为工程实例,建立了midas模型,分析在整体升降温及温度梯度下桥梁结构关键断面的应力变化。静载试验前,进行了温度试验。试验结果表明,空载情况下温度下降1℃,塔柱及负弯矩断面的应变值分别减少9με、10με。根据温度试验结果,对静载试验的实测应变值进行了修正,修正值约为满载值的14.9%~30.1%。

Taking Fengshuba Bridge of Longchuan-Zijin Section of He(Yuan)-Hui(Zhou)-(Dong)Guan Expressway(a prestressed concrete cable-stayed bridge with two towers and a single cable plane with a main span of 320m)as an engineering example,a Midas model has been established,the stress changes of key sections of the bridge structure under the overall temperature rise and fall and temperature gradient have been analyzed.Before the static load test,a temperature test has been carried out.The test resultshave shown that the temperature drops by 1℃and the strain value decreases by 9,10μεunder no-load conditions.According to the results of the temperature test,the measured strain value of the static load test is corrected,and the correction value is about 14.9%~30.1%of the full load value.