论文部分内容阅读
重庆朝天门长江大桥是主跨552m钢桁连续系杆拱桥,下层轨道横梁与主桁节点采用高强螺栓连接,为验证该节点连接的疲劳安全性能,采用1/2的大比例模型进行了节点疲劳试验。在设计寿命的200万次疲劳试验中,节点连接的高强螺栓没有出现松动,接下来的85万次疲劳破坏试验中,节点连接处的高强螺栓出现松动和失效。通过对连接板件撬力的计算,得出撬力与螺栓拉力占比例达到了34%～38%,并进一步对高强螺栓连接的内力进行计算,求得外荷载为设计疲劳荷载幅的2.5倍时高强螺栓失效,与实验结果相符合。最后总结了该类节点连接的高强螺失效原因,并归纳了破坏规律,为将来该类桥梁的设计、监测提供参考。
Chongqing Chaotianmen Yangtze River Bridge is the main span of 552m steel truss continuous tied arch bridge, the lower track beams and the main girder joints using high-strength bolts, in order to verify the node connection fatigue safety performance, the use of a large proportion of 1/2 of the node fatigue test. In the design life of 2000000 fatigue test, the node connected to the high-strength bolts without loosening, the next 850,000 fatigue failure test, the junction of high-strength bolts loosening and failure. Through the calculation of the prying force of the connecting plate, the ratio of the prying force and the bolt pulling force is 34% ~ 38%, and the internal force of the high strength bolt connection is further calculated, and the external load is calculated as 2.5 times of the designed fatigue load amplitude When high-strength bolts failure, consistent with the experimental results. Finally, the causes of failure of the high-strength spiro joints of such joints are summarized, and the failure rules are summarized, providing references for the design and monitoring of such bridges in the future.