遂德高速公路边坡滑坡稳定性分析及治理研究

Study on Stability Analysis and Treatment of Slope Landslide along Suining-Deyang Expressway

本文依托遂德高速尖梁子隧道项目,针对Z3K101+080 m~Z3K101+340 m左侧边坡滑移问题,研究了水文地质条件对边坡土体滑移的影响。通过地质勘探查明边坡土质、滑床及滑体厚度,利用反算法求得边坡土体抗剪强度,进而分析边坡稳定性,并提出防治方案。研究结果表明:坡体开挖后产生的较大临空面造成坡脚应力集中,边坡土体滑移牵引后部土体发生滑动,造成边坡形成牵引式变形破坏;通过对比3个主滑断面的反算结果,结合实际边坡变形情况,依据最不利条件计算坡脚残余滑力,得出边坡上部山体处于欠稳定状态,而原处置方案无法抵抗山体土体滑移,最终采用桩板墙的防护方案进行治理。通过应用桩板墙边坡支护方案,并监测边坡变形可知,挡墙水平位移最大值为9.4 mm,在规范允许范围内,该方案的可行性和可靠性可以为同类工程提供指导。

Based on the Jianliangzi tunnel project of Suining-Deyang Expressway,and in view of the left slope sliding problem from Z3K101+080 m to Z3K101+340 m,this paper studies the impact of hydro-geological conditions on the slope soil sliding.The slope soil quality,slide bed and slide mass thickness are identified through geological exploration,the shear strength of slope soil is obtained by means of inverse calculation,then the slope stability is analyzed and the control scheme is proposed.The results show that:a large free surface generated after the slope excavation caused stress concentration at the toe of slope,and the sliding of slope soil led to the sliding of soil behind,which resulted in retrogressive deformation failure of the slope.By comparing the inverse calculation results of the three main sliding sections,according to the actual slope deformation and based on the least favorable conditions,the residual sliding force at the toe of slope is calculated.It is concluded that the mountain on the upper part of the slope was in an unstable state,the existing treatment scheme could not resist the sliding of mountain soil,finally the sheet-pile wall protection scheme was adopted for treatment.By applying the sheet-pile wall slope protection scheme,and monitoring the slope deformation,it can be seen that the maximum horizontal displacement of the retaining wall is 9.4 mm,and within the allowable range of specifications,the feasibility and reliability of the scheme can serve as guidance for similar projects.