湖北省阳新县基岩滑坡变形因子及其破坏模式

Deformation factors and failure modes of bedrock landslides in Yangxin County,Hubei Province

斜坡变形受众多因子综合控制,不同因子的敏感性与作用规律在变形过程中差异明显。以湖北省阳新县顺层基岩滑坡为研究对象,通过正交试验结合离散元数值模拟的方法,研究多个影响因子对应顺层滑坡变形的敏感性并确立主导因素,随后基于响应面拟合主导因素与滑坡不同部位变形程度间的量化关系,揭示主导因素交互作用对滑坡变形破坏模式的影响规律。结果表明,在研究区内坡度与岩层倾角分别为影响顺层滑坡变形的主导与次主导因素,滑坡的变形破坏模式受控于二者的交互作用。在中-陡倾顺层滑坡中,当坡度小于岩层倾角时,滑坡变形主要集中在坡顶,且变形程度随岩层倾角的增加而增大,表现出滑移-弯曲的变形破坏模式;在缓倾顺层滑坡中,当坡度大于岩层倾角时,滑坡坡脚位移较坡顶显著,其坡脚变形程度随坡度的增加而增大,以滑移-拉裂变形为主。研究成果可为该类滑坡的防治工作提供参考。

The deformation of slopes is comprehensively controlled by many factors,and the sensitivity and action rules of different factors are obviously different in the deformation process.This article takes the bedding landslide in Yangxin County,Hubei Province as the research object.Through orthogonal experimental design combined with 3DEC(distinct element method,DEM),the sensitivity of multiple influencing factors to the deformation of bedding landslides is studied,and the dominant factors are established.Then,based on the response surface method to fit the quantitative relationship between the dominant factors and the deformation degree of different parts of the landslide,the influence law of the interaction of dominant factors on the deformation and failure mode of landslides is revealed.The study of the slope in the Yangxin County area shows that the slope and the strata dip are the dominant and secondary dominant factors affecting the bedding landslide,and the interaction between the two has a significant impact on the slope deformation.In the medium-steep bedding landslide,when the slope is less than the angle of rock,the slope deformation mainly concentrates on the slope top,and the degree of deformation increases with increasing rock dip,showing the slip-bending deformation failure mode.In a gently dipping bedding slope,when the slope is larger than the angle of rock,the displacement of the slope toe is more significant than that of the slope top,and the deformation degree of the slope toe increases with increasing slope,showing the slip-rupture deformation failure mode.This study can provide guidances for the prevention and control of such landslides.