地震作用下弧形抗滑桩加固边坡的动力响应及稳定性分析

Dynamic Response and Stability of Arc Anti-slide Piles in Slope Reinforcement under Earthquake

基于弧形结构在抗压承载方面的优势,以九寨沟某边坡实际工程为依托,研究地震作用下不同弧形排布形式的抗滑桩加固边坡的动力响应特性和边坡的稳定性。结果表明:边坡坡面各监测点的X向水平位移均随着地震加速度幅值的增加而增大;弧形排布抗滑桩能承担并分担边坡土体下滑力,使边坡整体水平位移减小,有效地限制边坡上方土体的滑移,减少地震作用下边坡发生失稳的风险;对边坡位移的约束作用上,表现为:弧形排布抗滑桩>直杆排布抗滑桩>反向弧形排布抗滑桩;不同边坡坡面位置处的地震加速度均随着边坡高程的增加而增大,呈现出一定的放大效应,且这种放大效应随着边坡高程的增加而越来越明显;汶川地震波(0.3 g)作用下弧形排布抗滑桩连系梁和汶川地震波(0.2 g)作用下反向弧形排布抗滑桩连系梁的混凝土已经出现拉裂,无法满足结构抗震承载能力的要求,对此需进行结构尺寸的调整。

Based on the advantages of arc structure in compression bearing,this paper studies the dynamic response characteristics and stability of the slope strengthened by anti-slide piles with different arc arrangement under earthquake by taking a slope project in Jiuzhaigou Valley as the case.The results show that the X-direction horizontal displacement of each monitoring point on the slope increases with the increase of seismic acceleration amplitude;the arc arrangement anti-slide pile can bear and share the sliding force of the slope soil to make the overall horizontal displacement of the slope smaller,which effectively limits the sliding of the upper slope soil and reduces the risk of slope instability under the action of earthquake;the constraint of slope displacement is shown as follows:arc arrangement of anti-slide piles>straight rod arrangement of anti-slide piles>reverse arc arrangement of anti-slide piles;the seismic acceleration at different slope positions increases with the increase of slope elevation,showing a certain amplification effect,and the amplification effect becomes more and more obvious with the increase of slope elevation;the concrete of coupling beam of arc-shaped anti-slide pile under Wenchuan earthquake wave(0.3 g)and of reverse arc-shaped anti-slide pile under and Wenchuan earthquake wave(0.2 g)have showrf tension cracks,which does not meet the requirements of seismic bearing capacity of the structure,and needs adjustment of structure size.