为了深入研究矩形截面且空心薄壁桥墩的延性抗震性能,对4个模型墩在恒定的轴压和循环反复水平荷载作用下进行了拟静力试验。探讨了薄壁墩在压、弯、剪共同作用下的破坏形态、位移延性和耗能能力,考虑轴压比、配箍率2个参数对结构极限承载力和延性性能的影响。试验结果表明:模型墩的破坏形式为弯曲破坏,位移延性系数介于3.61-5.56之间;配箍率是影响桥墩延性抗震性能的主要因素,随其值的增加位移延性系数增大,箍筋能显著提高试件的延性和耗能能力;随着轴压比的提高,试件的承载力有所降低,后期变形能力减小,抗震性能越来越差;建立了具有8个控制点的恢复力模型,并给出了各控制点的计算公式。
For the sake of researching antiseismic ductility of rectangular cross-section and hollow thin-walled piers,pseudo-static test for four specimens of such piers were performed under constant axial load and cyclically reversed horizontal load.The failure modes,effect of ductility and dissipated energy under the combined action of press,bending and shear were discussed,considering the effect of axial compression ratio and stirrup ratio on the ultimate strength and ductility of the specimens.The result shows that(1) Failure mode of specimen is bending failure and their ductility factor falls between 3.61 and 5.56;(2) stirrup rate takes the main responsibility for antiseismic ductility of piers,displacement ductility factor improves with increasing of the stirrup ratio,and stirrup could greatly improve the capacity on ductility and energy dissipation;(3) ultimate bearing capacity,later stage deformation capacity and antiseismic performance decline with the increase of axial compression ratio.The restoring force model which has eight characteristic points were built and the calculation formulas for the characteristic points were presented.