某刚架拱桥荷载试验研究

Loading Test Study of a Rigid Frame Arch Bridge

为评定某刚架拱桥的实际承载能力,确定桥梁的实际运营状况并为后期的维修加固提供科学的依据,对该桥进行了现场荷载试验。荷载试验前结合桥梁专业有限元软件计算了设计标准荷载下桥梁结构各测量值的大小,荷载试验过程中对结构的挠度、应变、自振特性、冲击系数等参数进行了测试,随后将实测结果与理论分析结果进行了对比。分析结果表明:桥跨梁体实测的挠度校验系数介于0.74~0.92之间,未超出规范中1.0的限值,表明桥梁结构刚度具有一定的富余度,结构刚度实际工作性能较好。试验跨动力测试的模态与理论模态吻合较好,说明桥梁结构的刚度满足使用要求。该桥在正常使用状态下的承载能力不能满足要求,建议对该桥进行承载能力加固处理。

In order to evaluate the actual bearing capacity of a rigid frame arch bridge, determine the actual work condition of the bridge and provide a scientific basis for the maintenance and rein- forcement of the bridge, a field load test of the bridge was carried out. Each measurement value of the bridge structure under the design standard load is calculated by the bridge finite element software before the load test. The deflection, strain, natural vibration characteristic and impact coefficient of the structure were tested in the load test, and the results were compared with the theoretical analysis. The results show that： The calibration coefficient of bridge beam body test- ed in the load test is between 0.92 and 0.74, which is not beyond the limit value 1.0 of the stand ard, at the same time this indicates that the stiffness of the bridge structure has a certain afflu- ence. The modal measurement results of the test span by the dynamic test and the theoretical modal analysis are identical, which shows that the bridge structure stiffness meets the application requirement. The carrying capacity of the bridge under normal use condition can not meet rele- vant specification requirement, and it is suggested that carrying capacity of the bridge should be strengthened.