顺向坡岩层倾向与坡向夹角对斜坡稳定性的影响

 顺向坡是岩质斜坡中稳定性最差、最易变形破坏的斜坡类型，顺向坡岩层倾向和坡向夹角的上限与岩质密切相关。为了分析不同岩质顺向坡岩层倾向与坡向夹角对斜坡稳定性的影响，建立考虑侧限顺层平面型斜坡的稳定性计算模型。考虑斜坡侧向边界阻滑效应，结合直剪试验岩桥贯通理论计算侧向阻力，以T2b2和T2b3分别作为软、硬岩代表，分析不同岩质顺向坡岩层倾向和坡向夹角变化对斜坡稳定性影响的敏感程度，最终给出顺向坡岩层倾向和坡向的上限夹角。结果表明：在考虑侧限时，硬质岩岩层倾向与坡向夹角变化对斜坡稳定性影响的敏感程度高于软质岩，取30°为顺向坡岩层倾向与坡向夹角的上限较合适。通过三峡库区库首至巴东段滑坡统计，验证分析结果的合理性。结论为经验判断顺向坡危险性提供了依据，也可作为区域滑坡危险性评价等工作中坡体结构划分的参考。

INFLUENCE OF INTERSECTION ANGLE BETWEEN TREND OF SLOPE AND STRATA ON STABILITY OF BEDDING SLOPE

Bedding slope is the most unstable and most easily deform and fail for all kinds of rock slopes. The upper limit of intersection angle between trend of slope and strata is closely related to rock hardness of bedding slope. In order to analyze the influence of intersection angle between trend of slope and strata on the stability of bedding slope，stability calculating model of bedding landslide is built. Considering the lateral resistance of bedding landslide，according to rock bridge transfixion theory of shear test，the T2b2 and T2b3 rocks are selected as the representatives of soft and hard rocks respectively to analyze the sensitive degree of influence of different intersection angles between trend of slope and strata of bedding slope on slope stability. Finally，the upper limit of angle between the trend of slope and strata for bedding landslide is determined. It is indicated that the slope stability of hard rock is more sensitive than that of soft rock when the intersection angle between the trend of slope and strata changes. It is reasonable that upper limit of the angle for a bedding landslide is 30°. The conclusion is verified by landslides between head of reservoir to Badong in the Three Gorgers Reservoir. The analytical results are very important to analyze the stability of bedding slope and to divide slope structures in potential landslide mapping.