高墩大跨连续刚构桥的荷载试验

摘要

In order to evaluate the actual bearing capacity of large-span rigid frame bridge with high piers,the stress state and overall deformation of the control sections under static load condition were measured in field load test.The vibration characteristics,modal response under different diving speeds and the impact action in the case of vehicle jumping were analyzed through the pulse test,the barrier-free driving test and the obstacle driving test.The research results show that the measured values of the strain and deflection of the static load test are less than the theoretical values.The bridge is close to the elastic state,the vertical stiffness meets the requirements of the code.When the driving speed is in the range of 20 ~40 km/h,there is no obvious positive correlation between the impact coefficient and the vehicle speed.The dynamic displacement of the bridge under the vehicle load is very small.There is no abnormal response of the bridge,and the structure performance can meet the requirements of the normal design of the load(Highway-I).%为评估悦乐高墩大跨刚构桥的实际承载力,在现场荷载试验中测定了静载工况下各控制截面的应力状态及整体的变形情况.通过脉动试验、无障碍和有障碍行车试验研究了该桥的自振特性、不同行车速度下的模态响应及跳车情况下的冲击作用.结果表明:静载试验的应变和挠度实测值均小于理论计算值,桥梁接近处于弹性工作状态,竖向刚度满足规范要求;行车速度在20～40 km/h范围时冲击系数与车速无明显的正相关性,桥梁整体在加载车辆作用下引起的动态位移值很小,桥梁无异常反应,结构性能满足设计荷载(公路-Ⅰ级)正常使用要求.