大跨度连续刚构桥荷载试验研究

Load Test Research on Large-Span Continuous Rigid Frame Bridge

因考虑构件模拟的相似度和合理性,常规桥梁结构计算很难真实得出实际的承载能力。通过荷载试验了解某大桥主桥在试验荷载下的工作状态,并和有限元分析计算得到的理论值对比,确定本桥的强度和刚度是否符合规范要求。以一座三跨连续刚构桥为例,确定各工况合理加载效率,详细分析现场实际试验结果及各工况校验系数,对荷载试验在评定桥梁承载力的作用中进行综合评价。在静力荷载作用下的强度和刚度都符合相关规范要求;主桥结构振动的前五阶固有模态频率都高出相应的理论计算频率;设计下的冲击系数理论值大于动荷载作用下的冲击系数实测值。结果表明主桥在荷载试验下,它的承载能力和工作性能满足设计要求。

Considering the similarity and rationality of component simulation, it is difficult for conventional bridge structure calculation to obtain the actual bearing capacity. Through the load test, the working state of the main bridge of a bridge under the test load is understood, and compared with the theoretical value calculated by the finite element analysis to determine whether the strength and stiffness of the bridge meet the requirements of the specification. Taking a three-span continuous rigid frame bridge as an example, the reasonable loading efficiency of each working condition is determined. The actual test results and the calibration coefficients of each working condition are analyzed in detail, and the load test is comprehensively evaluated in evaluating the bearing capacity of the bridge. The strength and stiffness under static load meet the requirements of relevant specifications;The first five natural modal frequencies of the main bridge structure vibration are higher than the corresponding theoretical calculation frequencies;The theoretical value of impact coefficient under design is greater than the measured value of impact coefficient under dynamic load. The results show that the bearing capacity and working performance of the main bridge meet the design requirements under the load test.