薄壁空心钢箱混凝土墩抗震性能参数分析

Parameter Analysis of Seismic Performance of Hollow Thin-walled Steel-box Concrete Pier

为了研究薄壁空心钢箱混凝土墩的抗震性能,借助OpenSees软件建立有限元模型进行分析计算,将计算结果与试验结果进行比较以验证模型的有效性。在此基础上,建立薄壁空心钢箱混凝土桥墩模型,分析了不同轴压比、长细比、截面空心率、截面含钢率、混凝土抗压强度以及钢材屈服强度对该类型桥墩滞回曲线、刚度退化曲线以及滞回骨架曲线的影响规律。结果表明:薄壁空心钢箱混凝土墩具有良好的抗震性能;轴压比和长细比对薄壁空心钢箱混凝土墩的抗震性能影响较大,建议薄壁空心钢箱混凝土墩轴压比控制在0.5左右,并且在合理范围内尽量减小长细比;截面空心率和截面含钢率对薄壁空心钢箱混凝土墩的抗震性能有一定影响;在一定范围内,增大空心率与含钢率可提高桥墩抗震性能;材料强度等级对薄壁空心钢箱混凝土墩的抗震性能影响相对较小,削弱混凝土强度并增大钢材屈服强度可小幅提高其抗震性能;研究成果对薄壁空心钢箱混凝土墩在工程实践中的应用具有一定的指导意义。

In order to clarify the seismic performance of hollow thin-walled steel-box concrete pier,the finite-element software OpenSees was used to establish finite element model and the calculation results were compared with the test results to verify the validity of the model.On the basis of the work above,the hollow thin-walled steel-box concrete pier models were established,the changing laws of hysteresis curve,stiffness degradation curve and hysteresis skeleton curve of those models were analyzed with different axial compression ratio,length-diameter ratio,hollow ratio and steel ratio of the section,compressive strength of concrete and yield strength of steel.The results show that the hollow thin-walled steel-box concrete pier has good seismic performance.The axial compression ratio and length-diameter ratio have great influences on the seismic performance of hollow thin-walled steel-box concrete pier.It is suggested that the axial compression ratio of hollow thin-walled steel-box concrete piers should be controlled at about 0.5and the length-diameter ratio should be minimized within a reasonable range.The section hollow ratio and section steel content have certain influence on the seismic performance of hollow thinwalled steel-box concrete piers.Within a certain range,increasing the hollow ratio and steel content can improve the seismic performance of pier.The influence of material strength grade on the seismic performance of hollow thin-walled steel-box concrete pier is relatively small.The seismic performance of hollow thin-walled steel-box concrete pier can be improved slightly by weakening the compressive strength of concrete and increasing the yield strength of steel.The research results have certain guiding significance for the application of hollow thin-walled steelbox concrete pier in engineering practice.