某岩溶区公路岩土滑坡形成机理与治理

Formation mechanism and treatment of landslide of a highway in karst area

灰岩区复杂的岩体和土体条件引发频繁的滑坡,严重影响了岩溶区高速公路的建设和运营。以某高速工程典型的岩土双区滑坡为例,进行岩溶区滑坡机理研究,结果表明,岩土体及地形是内因,路堑开挖是外因,强降雨是诱因,滑坡机制概括为开挖应力释放—降雨推移(Ⅰ区土体)—牵引(Ⅱ区岩体)。通过极限平衡法的滑坡稳定性分析,卸载后滑坡达到了基本稳定,但是在降雨工况下,滑坡依然处于不稳定状态。针对这种滑坡特殊成因,采用以抗滑桩为主的综合分区治理滑坡方案,处治效果良好,具有降低造价,加快施工进度等优势。

Complex geotechnical conditions of dual zone in limestone area cause frequent landslides,seriously affectingthe construction and operation of highway in karst area.With the typical landslide of dual zone in a highwayproject as example,the study of the mechanism of landslide indicated that the rock-soil mass and the landformare the internal causes,Studying on a high-speed dual-zone geotechnical engineering typical landslide Case.Bystudying the mechanism that the the cutting excavation is the external cause,the heavy rainfall is the inducement.The mechanism of landslide was summarized as follows:displacement by rainfall(soil in zoneⅠ)and traction(rock in zoneⅡ).Analysis of the landslide stability by using the limit equilibrium method showed that the landslidewas basically stable after unloading,but in case of rainfall the landslide remained unstable.Aiming at such particulargenesis of the landslide,the integral zoning control scheme based mainly on slide-resistant piles wasadopted.The treatment produced good effect,and had advantages of low construction cost and fast constructionschedule.