钢筋混凝土T梁旧桥极限承载能力研究

Study on Ultimate Bearing Capacity of an Existing RC T-girder Bridge

通过外观检测、特殊检测和静力荷载试验等常规试验来获得承载能力检算系数,进而间接评定在役旧桥的极限承载能力,虽然具有一定的可靠性,但与结构真实的极限承载能力之间存在一定的误差。通过对一座钢筋混凝土T型截面简支梁旧桥进行破坏试验,获得其真实抗弯极限承载能力,并与特殊检测和静力荷载试验间接得到的评定结果进行对比。结果显示,通过破坏试验得到的抗弯极限承载力大于特殊检测评定以及静力荷载试验评定的结果,实际可运营的车辆荷载也大于设计车辆荷载,虽然此桥病害较为严重,但其极限承载能力尚满足运营要求。

The check-calculation coefficient of bridge load-bearing capacity can be obtained by routine test such as appearance inspection,special inspection and load test to assess the ultimate bearing capacity of existing bridges indirectly.This method is reliable on the evaluation of old bridges,but there is error between the evaluation result and the real ultimate bearing capacity of bridges to some extent.Through a destructive test for a RC simply supported T-shaped girder bridge,the true ultimate flexural capacity is obtained,and compared with the evaluation results by special inspection and static load test indirectly.The result shows that（1） the true ultimate bearing capacity obtained by the destructive test is larger than those obtained by special inspection and static load test,the available vehicle loads are significantly larger than the designed vehicle load;（2） although the bridge has serious cracking,the actual bearing capacity could still meet the demand of design loads.