Abstract: To investigate the effects of soil-pile interaction on the near-fault seismic response of long-span concrete-filled-steel-tubular (CFST) tied arch bridge, aiming at six kinds of widely-used pile-soil interaction simulation methods in bridge seismic analysis, the corresponding analytical models were studied and established. Nine groups of near-fault ground motion records were selected as excitation to carry out the numerical simulation analysis of the whole bridge. Based on the direct embedding method, the influence of pile-soil interaction on the seismic response of key components of arch bridge was compared and studied. The results show that the soil-pile interaction has a significant impact on the seismic response of tied arch bridge, which can increase the seismic response of key components of the bridge by more than 50%. The most adverse effect is found on the seismic internal force of arch ribs and wind braces, and the smallest impact is found on the seismic displacement of arch ribs. The influence rules of soil-pile interaction simulated by different methods on the seismic response of tied arch bridge are consistent, but the influence degree is different, which shows that these simulation methods can be used to judge the favorable or unfavorable effects of pile-soil interaction. Finally, within the scope of this study, the nonlinear effect of soil-pile interaction is limited, and using m method with less calculation to replace p-y curve method can also get ideal analysis results.

Key words: bridge engineering; CFST tied arch bridge; near-fault ground motions; soil-pile interaction; p-y curve method; comparative analysis

摘要： 为揭示桩-土作用对大跨钢管混凝土系杆拱桥近断层地震响应影响，针对桥梁抗震分析中常见的6种桩-土作用模拟方法，研究并建立了相应的分析模型，选取9组近断层地震动记录作为激励，开展了全桥数值模拟分析。以直接嵌固法为基准，对比研究了桩-土作用对拱桥关键构件地震响应的影响。研究表明：桩-土作用对系杆拱桥的地震响应具有显著影响，可导致桥梁关键构件的地震响应增大50%以上，其中对拱肋和风撑地震内力的不利影响最大，而对拱肋地震位移的影响最小；采用不同方法模拟桩-土作用对系杆拱桥地震响应的影响规律总体上一致，但影响程度不同，表明这几种模拟方法都可用于判断桩-土作用的有利或不利影响；最后在本研究范围内，桩-土作用的非线性影响有限，采用计算量更小的m法替代p-y曲线法也能得到较为理想的分析结果。

关键词: 桥梁工程；钢管混凝土系杆拱桥；近断层地震；桩-土作用；p-y曲线法；对比分析