某空腹式双曲拱桥承载力现场测试与分析

Field test and analysis for bearing capacity of spandrel double-curvature arch bridge

为检验在役双曲拱桥的承载能力与动力特性,对某净跨为36 m空腹式双曲拱桥进行了静载试验、动载试验及空间有限元分析。测试结构的静态应变、动态应变、挠度、自振频率、振型及加速度等结构反应,计算得出冲击系数。将实测结果与有限元结果进行对比分析,结果表明：应变校验系数为0.5~0.9,结构具有较好承载力。实测的各阶频率及相应振型与有限元计算结果比较吻合,桥梁整体竖向刚度较好。

To examine the bearing capacity and dynamic responses of existing double-curvature arch bridge structures, static loading and dynamic loading tests and space finite element analysis on a hollow double-arch bridge with a span of 36m were conducted. The static and dynamic strains, deflections, natural frequencies, vibration modes and accelerations of the bridge were tested. The impact coefficients were calculated in accordance with the dynamic strains. The test results were compared with the finite element calculation results. It is indicated that the bridge has a favourable bearing capacity and vertical stiffness when the testing coefficient of the strain ranges between 0.5 and 0.9 ; when the measured frequencies and modes of natural vibration approximate to the finite element calculation results （theoretical values）.