Abstract: After investigating the situation and circumstance of the side slopes along the Pan-Xi Expressway in construction period，the authors analysed the unstability mechanisMof every slough-of-side slope ，summed up the methods in existence，and especially made a study on two cases when there Was water channel in the worksite or micro structure in slope body。Accordiny，some universality advances to harnessing landslide on Xigeda strata are put forward．

Key words: Xigeda strata, unstability, construction period

摘要： 通过对西攀高速沿线边坡在施工期间情况的调查，分析了各坍塌边坡失稳的机理，总结出了其中存在的规律； 其中着重研究了当工点附近有水渠通过和坡体内存在局部构造时，对边坡的不利影响；最后对防止昔格达地层施工 期失稳提出了一些普适性的建议．

关键词: 昔格达地层, 失稳, 施工期