岩体渗透结构类型的划分及其渗透特性研究

CLASSIFICATION OF PERMIABILITY STRUCTURE TYPES OF ROCK MASS AND ITS PERMIABILITY CHARACTERISTICS

划分岩体渗透结构类型是水利水电工程地质勘察和渗透性评价的重要内容。从岩体结构的控渗作用出发,分析了控制岩体渗透特征的主要因素,即岩性、断裂构造、风化卸荷作用及岩溶作用;提出了岩体渗透结构类型的划分原则,即考虑岩体的各向异性特征。根据岩体的宏观渗透特征,即渗透介质及主要途径,将岩体渗透结构类型划分为5类:散体状渗透结构、层状渗透结构、带状渗透结构、网络状渗透结构、管道状渗透结构。结合工程实例,给出了小浪底渗透结构为层状及带状、三峡工程坝址区岩体渗透结构为散体状、网格状及带状。

Classification of rock mass permeability structure types is the important content for geological exploration of water resources and hydropower engineering and evaluation of permeability. Based on the seepage controlling effects of rock mass structures, key factors that control permeability characteristics of rock mass are analyzed. They are lithology, faulted structure, weathering and unloading and karst effect. Principle of dividing rock mass permea- bility structure types are put forward. The anisotropic characteristics of rock mass is considered. According to the macroscopic permeability characteristics of rock mass, the permeability structures are classified into five types. They are discrete mass permeability structure, layered permeability structure, zonal permeability structure, netlike permeability structure and duct -like permeability structure. The classification method is applied to actual engi- neering cases. The classified results of permeability structure types of rock mass at the Xiaolangdi Project and the Three Gorges Project dam sites are present. The results show that reasonable identification of permeability structure types of rock mass is of the most significance for seepage control and drainage design of water resources and hydro- power engineering.