万(州)-梁(平)高速公路K34～K59段滑坡成因分析

万(州)-梁(平)高速公路K34-K59段滑坡十分发育，是重庆境内滑坡灾害最为严重的一段。该区地质条件复杂，岩体中缓倾角结构面、软化夹层发育，在外界因素触发下，即可形成岩层向临空面松弛滑移的依附面。1999年12月-2003年9月，该路段发生滑坡灾害23处，增加工程投资2亿多元，对高速公路的建设造成很大的危害和威胁，并拖延了工期，给国民经济建设带来严重的影响和损失。文章依据工程地质勘察结果，从该滑坡的地质环境及变形特征分析，对其形成机制做了深入研究，为今后类似滑坡的防治提供参考。近年来，在高等级公路的建设中，线形要求严格，在山区及丘陵地区往往需要采用开挖方式通过，由于建设中的不合理工程活动，新滑坡的产生以及老滑坡的复活可能性大增。致使滑坡灾害日趋严重。通过对影响岩质路堑边坡稳定性因素分析，说明了这些影响因素与边坡稳定性的关系。文章认为特殊的地质构造及易滑地层的广泛分布，是滑坡大量出现的地质基础。大量降雨入渗，不合理的人为工程是滑坡的诱发因素。各种情况表明，在今后一定时期内，人类活动可能成为滑坡的主要影响因素。

Genetic mechanism analysis for landslides between 34 to 59 kilometers of the Wanzhou- Liangping expressway

There are many landslides between 34 to 59 kilometers of the Wanzhou-Liangping expressway, and this section is the most hazardous section of the highway in Chongqing City. The local geological conditions are complicated, and rock mass contains many gently dipped structure planes and soft intercalations,which can form attaching faces of sliding towards the free surface triggered by the external factors. Twenty-three hazardous landslides occurred in this area from December 1999 to September 2003, which cost more than 200 million RMB of extra investment, and building phase of the expressway was prolonged, all of which produced serious damages to the national economic development.According to the result of the engineering geological investigation, from the analysis of the geological environment and deformation characteristics, the mechanism of landslide formation was studied deeply. The results of study promoted the deep recognition of the landslide, and provided preference for the prevention of similar landslides. Engineering excavations are often used in highway construction at mountainous area.It is easy to lead new landslides and revive o1d landslides. Landslides have taken place more seriously day by day in recent years dueing to unreasonable engineering activities. By analyzing on the factors influencing rock cut slope stability, the paper introduced the relations between influence factors and slope stability for reference. This paper considered that special geological structure and the layers apt to slip are the geological base of the landslides, and heavy rainfall,seepage and illogic excavation are the main triggering factors of the landslide hazard. It is suggested that the human activities may be the main factor causing landslide to occur in a relatively long-term future.