某钢筋混凝土弯箱梁桥承载力评估

Bearing Capacity Evaluation of a Reinforced Concrete Curved Box Girder Bridge

为了研究连续箱梁桥承载力及裂缝开展情况,评定桥梁的各项指标,为桥梁的运营养护提供可靠资料,采用现场加载试验及有限元数值模拟分析相结合的方法,基于静载试验测定各工况下桥梁应力和变形,利用动载试验测定桥梁自振特性及车辆对桥梁的冲击系数。对比实测值与有限元计算结果得出结论,该桥梁卸载后的残余位移和应变满足相关规范要求,结构动刚度能满足正常使用要求,桥梁正常使用条件下的车辆冲击效应满足设计要求。裂缝开展方面满足相关规范最大裂度的限值要求,该桥梁承载力不满足设计要求。建议对该桥梁上部结构进行加固补强,以满足正常运营条件。

In order to study bearing capacity and crack development of continuous box girder bridge under test load,to evaluate the bridge indexes in detail,and to provide reliable information for the operation and maintenance of the bridge,a combination of field load test method and finite element numerical simulation analysis is used,the stress and deformation of the bridge under each working condition are measured based on static load test,and combined with dynamic load test,the self⁃vibration characteristics of the bridge and the effect of vehicle impact on the bridge are determined.Finally,the measured values are compared and analyzed with the finite element results,it is concluded that the residual displacement and strain of the bridge after unloading meet the requirements of the relevant codes,the dynamic stiffness of the structure can meet the normal use requirements,the effect of the bridge under normal use conditions meets the design requirements,the crack development meets the maximum crack limit of the relevant codes,the comprehensive assessment of the bearing capacity does not meet the design requirements.It is recommended that the bridge superstructure should be strengthened to meet the normal operation conditions.