秦巴山区浅层滑坡内动力地质成因分析

以秦巴山区安康市汉滨区洪山镇淀沟浅层滑坡为例，通过区域宏观构造、边坡细观结构、岩石微观构造等多种尺度详细剖析浅层滑坡的变形破坏特征及内动力地质成因。研究表明:秦巴山区浅层滑坡的成因机理与内动力地质条件密不可分。滑坡多发育于软弱变质岩区，受区域构造活动影响，褶皱、断层等宏观构造在区内连续、交错分布，造成岩石内部的矿物发生变形、拉长、剪断等，形成韧性剪切带，并产生大量微裂隙，多期次岩脉填充交切，使岩体性质更加劣化。当应力超过岩石强度时，内部片层状结构发生弯曲、折断、压裂等一系列微观变形，是变质岩主要的变形破坏方式。区内断层与滑坡斜交，岩层及褶皱枢纽产状与滑坡坡向同向同倾，也为滑坡的形成提供了良好的孕灾条件。这种相对脆弱的地质环境再受到人类活动和降雨等外动力因素影响，极易引发浅层滑坡，进而对附近居民及建筑物产生严重威胁。 

ANALYSIS ON INTERNAL DYNAMIC GEOLOGICAL GENESIS OF SHALLOW LANDSLIDE IN QIN-BA MOUNTAIN AREA

Taking the Diangou shallow landslide in Qin-Ba Mountain Area as an example, deformation destruction characteristics and internal dynamic geological genesis are analyzed in detail and multi-scale through regional macrostructure, side slope microstructure and rock microstructure. The study results show that the formation mechanism of shallow landslides in Qin-Ba Mountain Area is closely related to the internal dynamic geological conditions. Landslides usually developed in weak metamorphic areas and affected by regional tectonic activities. Folds, faults and other macro-structures were continuously and crossly distributed in the area which resulted in the deformation, elongation and shear of minerals in the rock, forming a ductile shear zone and a large number of micro-cracks. The filling and intersecting of multi-stage cracks made the rock mass more deteriorated. When the stress exceeded the rock strength, a series of micro-deformation occurred in the internal lamellar structure, such as bending, breaking and fracturing, which are the main deformation and failure modes of metamorphic rocks. The oblique crossing of faults and landslides, the same direction and inclination of the rock layers and folds with the slope aspect, providing a good forming condition of landslide. This relatively fragile geological environment affected by external factors, such as human activity and heavy rain, can easily lead to shallow landslides. It would be serious threats for nearby residents and constructions.