不同地震作用下弧形排布抗滑桩及边坡稳定性分析

Stability Analysis of Arc-arranged Anti-sliding Piles and Slope under Different Earthquake Actions

以九寨沟某特大桥高边坡为研究对象,研究不同地震作用下弧形排布抗滑桩和边坡的动力特性和稳定性。结果表明,抗滑桩连系梁中部桩顶水平位移大于两端;坡腰处的地震加速度的增长速率趋势减弱,但整体数值基本随边坡高度的增加而增大;弧形排布抗滑桩第一主应力均出现在连系梁两侧,而抗滑桩本身第一主应力较小;弧形抗滑桩能适用于0. 1g、0. 2g汶川波和0. 2g阪神波,而在其他工况弧形排布抗滑桩连系梁混凝土本身出现开裂;边坡土体主应变较大值主要出现在各台阶底部,且在弧形排布抗滑桩前部土体有最大主应变;唐山波在时程上加速度幅值起伏波动远大于汶川波和阪神波,边坡水平波动响应也大;唐山波下抗滑桩桩顶的整体水平位移远大于阪神波和汶川波。

Taking the high slope near a bridge in Jiuzhaigou as study object, the dynamic characteristics and stability of the arc-arranged anti-sliding piles and the slope under different seismic actions are analyzed. The results show that,( a) the horizontal displacement of the middle pile top of pile coupling beam is larger than that of the two ends;( b) the growth rate of seismic acceleration at slope waist has a trend of weakening, but the overall value basically increases with the increase of slope height;( c) the first principal stress of anti-sliding piles appears on both sides of the coupling beam, while the first principal stress of pile itself is smaller;( d) these piles can withstand the actions of 0. 1 g and 0. 2 g Wenchuan earthquake waves and0. 2 g Hanshin wave, but in the action of other earthquakes, the concrete of coupling beam is cracked;( e) the main strain of slope soil is mainly at the bottom of each step, and there is the maximum main strain in the front soil of anti-sliding piles;( f)in time history, the fluctuation of acceleration amplitude of Tangshan wave is much larger than that of Wenchuan wave and Hanshin wave, which results in a large response of slope horizontal fluctuation;and( g) the overall horizontal displacement of pile top under Tangshan wave is much larger than that of Hanshin wave and Wenchuan wave.