深厚覆盖层岩组划分及主要工程地质问题

深厚覆盖具有结构松散、岩性不连续，在水平和垂直方向有较大变化、成因类型复杂、物理力学性质呈较大不均匀性的特点。深厚覆盖层可按其成因、物质组成、结构特征及厚度变化等作为岩组划分的依据。宝兴水电站坝址覆盖层按此依据可划分为６大岩组。

Classification of deep and thick overlying rock group and their main engineering geological problems

The deep and thick overlying layers have the features of loose structure, discontinuous rock properties, large changes in horizontal and vertical directions, complicated formation types, great uneven physical and mechanical properties. The classification of rock group for the deep and thick overlying layer could be based on their formation, matter composition, structure features and the thickness changes. The overlying in the dam site of Baoxing Hydropower Station could be divided into six rock groups on the basis of the above mentioned conditions.