汶川地震震裂的斜坡岩体结构特征

Features of shattered rockmass structure of slopes by the Wenchuan earthquake

汶川震区震后斜坡地质灾害频发,其中岩体震裂松动是引起震后次生地质灾害的主要原因。以震裂岩体结构精测为基础,结合现场回弹测试与声波探测,震裂岩体具有结构面显著张开、无充填或者少量充填和岩体架空等宏观特征,同时具有回弹强度低、大范围的低波速带和强渗透性等变形特性。坡表岩体的回弹强度在20～30MPa,波速值集中在2000～3000m/s,完整性系数在0.15～0.5,完整性较差,渗透性基本上属于强透水、严重透水段。以波速值为主要划分依据,将震裂岩体分为严重震裂岩体、中等震裂岩体、轻度震裂岩体三个等级。

Slope geological disasters takes place constantly at long period after earthquake by WenChuan earthquake,and the shattered rockmass is the main reason for cause the secondary geological disasters.Some detection means such as precise measurement、rebound testing、acoustic testing were used in site,the shattered rockmass has the characteristics such as open structural planes、fillings less or no、overhead rockmass and so on,then it has the deformation characteristics such as low rebound strength、large range of low wave velocity and strong permeability.Rebound strength of slope surface is between 20 ~ 30 MPa,wave velocity value common less than 3000m/s,concentrated in between 2000 ~ 3000m/s,integrity coefficient was between 0.15 and 0.5,integrity is poorer,permeability is basically high、serious.The partitioning standards of shattered rockmass is based on wave velocity value,divided into three communities: severe shattered rockmass、medium shattered rockmass and slight shattered rockmass.