【作者】 张聪； 王跻锟； 冯忠居； 王富春； 王溪清；

【Author】 ZHANG Cong;WANG Ji-kun;FENG Zhong-ju;WANG Fu-chun;WANG Xi-qing;School of Highway,Chang’an University;

【机构】 长安大学公路学院；

【摘要】 为探究强震区近断层桥梁桩基础的时程响应特征,采用振动台试验,选取不同地震动峰值加速度的人工合成5010波,探究了不同地震动峰值加速度作用下桩顶与桩底的加速度、桩顶的位移、桩身弯矩的时程响应特征以及桩基损伤。试验结果表明:不同地震动峰值加速度作用下,桩顶加速度最大值出现的时刻明显滞后于桩底,最多达2.45s。桩顶水平方向位移最大值随地震动加速度峰值的增大逐渐增大,水平位移较早达到最大值,桩基础桩身弯矩最大值逐渐增大。桩身弯矩沿深度方向表现出双峰分布,峰值位于软硬土过渡带及土岩过渡区。地震动峰值加速度大于0.40g后,桩基基频显著下降,桩基础出现了损伤。强震作用下断层发育区桩基础抗震设计时,可选取桩身弯矩与顶位移双参数控制指标,进而确保桩基具有足够的抗震能力。更多还原

【Abstract】 To investigate the time-history response characteristics of bridge pile foundations near faults in strong seismic zones,shaking table tests were conducted using artificially synthesized 5010 waves with varying peak ground motion accelerations.The study explored the time-history response characteristics of pile top and pile bottom accelerations,pile top displacement,pile body bending moment,and pile foundation damage under different peak ground motion accelerations.The test results show that under different peak ground motion accelerations,the dynamic responses of the pile foundation such as accelerations at the pile top and bottom,displacement at the pile top,and bending moments along the pile-exhibit distinct variations,reflecting the influence of seismic intensity on pile behavior.The peak acceleration at the pile top occurs significantly later than at the pile bottom,with a maximum delay of up to 2.45 seconds.Meanwhile,the maximum horizontal displacement at the pile top gradually increases as the peak ground acceleration rises.The horizontal displacement reaches its maximum value earlier,while the pile foundation’s maximum bending moment gradually increases.The bending moment along the pile exhibits a "double peak" pattern,with maximum values occurring near the interfaces between soft and hard soil layers,as well as between soil and rock.When the peak seismic acceleration exceeds 0.40 g,the fundamental frequency of the pile foundation significantly decreases,indicating damage to the structure.Therefore,in designing seismic resistance for pile foundations located in fault-affected strong earthquake zones,it is advisable to use dual control parameters-pile body bending moment and pile top displacement to ensure adequate seismic performance.更多还原