膨胀土公路滑坡的形成过程和机理

以国道G316线安康至汉阴段K25膨胀土公路滑坡为例,介绍了滑坡的地质环境条件,阐述了该膨胀土公路滑坡的形态、滑面滑床特征和变形特征以及气象水文、地形地貌和人类工程活动等,内外营力对该滑坡的影响。采用非饱和土强度理论,对滑坡的形成过程和机理进行了详细分析,得出开挖路堑是该滑坡产生的直接原因。其形成过程及机理为:开挖—非饱和滑带土浸水软化,抗剪强度降低或丧失—坡面隆起、坡顶开裂和坡脚剪切破坏—剪切破坏区向上发展与后缘张裂隙贯通—滑面贯通、滑坡产生。 

The formation and mechanism of an expansive soil highway landslide

With an example of K25 expansive soil highway landslide of G316 national highway(from Ankang to Hanyin),this paper introduced firstly geological condition of the landslide and then expounded the landslide configuration,characteristics of slip surface and slip bed,and the influence of climate,hydrological geological condition,landform and human engineering activities on this highway landslide.Unsaturated soil intensity was used to analyze particularly the formation process and mechanism of landslide and excavating was verified to be the main and direct cause of this landslide,and the results show that the course of the landslide includes five steps: excavating,unsaturated slip zone soil intenerated and shear strength decreasing or losing,slope surface upheaval and slope top crazing and shearing failure of slope foot,shearing failure area develops and connects with open crack of the back part of landslide,land-sliding formation.