利用大型岩质滑坡形成的环境条件及重力圧密原理分析滑面形态与强度参数

USE OF LANDSLIDE FORMATION ENVIRONMENT INFORMATION AND PRINCIPLE OF GRAVITY COMPACTION FOR LARGE-SCALE ROCK LANDSLIDE SLIP SURFACE SHAPE AND STRENGTH PARAMETERS

大型、特大型岩质滑坡,因其体积大,范围大,且多位于高山峡谷地区,用勘探方法虽能较准确的查明滑带的位置、形态,但因极恶劣的地形条件,绝大部分在初步研究阶段,由于缺少勘探资料而不能确定滑面位置,因而也难以获得滑面的强度参数。本文从大型岩质滑坡形成的初始环境地质条件：地形条件,地貌条件,岩性条件,构造条件,河流形态,斜坡坡体结构和变形破坏特征,结合滑坡形成后的形态特征,以反馈研究的方式,分析确定大型岩质滑坡滑面的位置及形态特征,在获得滑坡滑面位置的基础上,分析、计算滑面上覆岩体重量在滑面上产生的正应力（压应力）;在获取部分滑带土的基础上,用滑坡体重力在滑面上产生的正应力,以重力压密原理在室内开展相匹配的试验,进而获得各地段相应的物理指标,在室内开展相匹配的强度试验,获得强度参数,建立滑带土孔隙比、含水量与摩擦系数、内聚力的关系,用试验获得的关系式,结合重力压密试验得到的不同部位的含水量,去分析、研究滑面的强度参数,采用传递系数法、摩根斯坦法开展相应的稳定性分析,得到的稳定性系数均大于1.2,与滑坡当前的变形动态较吻合。

Large-scale and super large-scale rock landslides are not only huge in size and range,but also mostly located in mountains and valleys.Usually,site exploration can be used to determine landslide slip zone location and shape accurately.However,with extremely difficult terrain conditions and mostly at the preliminary study stage,the landslides slip surface location could not be determined accurately because of lacking of exploration data and thus strength parameters are hard to get also.This paper used the initial geological conditions for the formation of large rock landslide.They include terrain conditions,topography,lithology,structural conditions,river morphology,slope body structure and deformation damage structure,combined with slide morphological characteristics after its forma-tion,used feedback approach and analyzed large rock landslide slip surface location and morphological characteristics.Based on the information of the location of the landslide slip surface,this paper analyzed and calculated normal stress（compressive stress） generated on the slip surface by the weight of the rock body covered the slip surface.Based on the acquired slip zone soil samples,using normal stress generated on the slip surface by landslide body weight force,this paper conducted matching laboratory tests using principle of gravity compaction to get the corresponding physical indicators on various areas.This paper also conducted matching lab tests of strength,and got strength parameters,and established the slide-zone soil void ratio,water content relationship with friction coefficient and cohesion.With the relationship established from tests,combined with gravity compaction tests result of the water content at different parts,this paper analyzed and studied the slip surface strength parameters.Transfer coefficient and Morgenstern law were used to calculate the stability of landslide coefficient under natural condition,and calculated values greater than 1.2,which accorded with current distortion trends of landslides.