209国道许家湾滑坡的成因及治理对策

结合许家湾滑坡灾害点的地质背景资料和现场勘察结果，从滑坡区的地貌、区域地质构造、地层岩性、土壤特性、水文地质特征以及人类工程活动等方面分析滑坡成因机制。指出同向多层次结构的边坡类型、山高坡陡及地表水汇集走廊的地貌特征、发育多组密集节理的区域地质构造、软硬互层的地层岩性、土体的残余强度特性等是滑坡形成的内因；而人为削坡、强降雨和破坏植被营造水耕梯田等人类活动所造成的流水浸蚀，是滑坡形成的诱发空子。基于滑坡稳定性的定量计算，确定了采用抗滑挡土墙、格构式地梁和垫梁组成抗滑系统，并布置了由树枝笼渗沟构成的排水系统等工程治理措施。现场监测结果表明滑坡治理措施卓有成效。

Formation Cause Analysis of Xujiawan Landslide in the No.209 Ntaional Road and Its Treatment

Combining with the geology background information an d the field survey of Xujiawan landslide, the causes of the landslide formation ar e analyzed from geomorphology, hydrogeology, geological structure, stratum, soil properties and human engineering activity The results show that the factors, such as the slope type with the same direction, the geomorphologic characteristi c with steep slope and funneling the surface water, stratum of interactive rock and soft soil, the geological structure of multilayer joint planes, characterist ic of residual shear strength of soil, etc , are the mainly geological factors The cutting slope, water erosion due to rainstorm, vegetation breakage and pa ddy terrace, are the inducements Based on the calculation of quantitative eval uation on its stability, the engineering measures of stabilizing the landslide a re carried out This measures include a braced system consisted of anti slide r etaining wall, case foundation beam and beam cushion, and a drainage system cons isted of seepage drains formed by bunch of tree branch The results of field o bservation indicate the effect of landslide treatment is satisfactory