考虑桩–土间相互作用的分离式承台双肢空心墩拟静力试验研究

Experimental Study on Quasi-Static Test of Double-Leg Hollow Piers with Separated Pile Caps Considering Pile-Soil Interaction

摘要: 为研究桩–土相互作用条件下分离式承台双肢空心桥墩的抗震性能，以某桥梁下部结构为原型，设计并制作了能够考虑桩–土相互作用的分离式承台双肢空心桥墩缩尺模型试件，开展其低周反复拟静力试验，从破坏现象、滞回曲线、骨架曲线、延性性能、耗能能力及桩身变形特征等方面对其抗震性能进行了分析。结果表明：低周往复荷载作用下试件经历弹性、屈服和破坏三个阶段；其滞回曲线较为饱满，骨架曲线下降段平缓，位移延性系数达到4.3，表明结构具有较好的耗能能力和变形能力。相关成果可为分离式承台双肢空心桥墩的抗震设计与基础构造优化提供参考。

Abstract: To investigate the seismic performance of double-leg hollow bridge piers with separated pile caps under pile-soil interaction conditions, a scaled specimen of such a pier system was designed and fabricated based on the substructure of a prototype bridge. Quasi-static cyclic loading tests were conducted to evaluate its seismic behavior in terms of failure mode, hysteretic curves, skeleton curves, ductility, energy dissipation capacity, and pile deformation characteristics. The results show that the specimen experienced three stages—elastic, yield, and failure—under low-cycle reversed loading. The hysteretic curves were relatively full, and the descending branch of the skeleton curve was gentle. The displacement ductility coefficient reached 4.3, indicating favorable energy dissipation and deformation capacity. The findings can serve as a reference for the seismic design and foundation optimization of double-leg hollow piers with separated pile caps.