松动岩体工程特性研究——以雅砻江楞古水电站松动岩体为例

为了对松动岩体的工程特性进行系统研究，以楞古水电站厂址区边坡为例，对该边坡岩体进行了详细的地质编录和物理勘探试验，重点对节理裂隙的空间发育规律、镶嵌结构和碎裂结构岩体的发育深度及空间分布、软弱结构面发育分布规律以及边坡已有变形破坏特征这四个方面进行了系统的统计和分析，认为松动岩体是区域断裂活动和浅表生改造的结果，岩体工程效应差、变形模量低；同时结合应力测试、声波测速、高密度电磁勘探等试验成果进行分析，结果显示松动岩体具低波速（波速大部分小于3 000 m/s）、低应力（最大主应力不超过20 MPa）、强透水性（透水性系数大于10 L/（min·m·m））。认为岩体破碎主要受断层及节理裂隙影响，分析了岩体破裂松动的演化过程及特征。

Engineering Characteristics of Loose Rock Mass: Taking Loose Rock Mass of Lenggu Hydropower Station in Yalong River as an Example

In order to systematically study the engineering characteristics of loose rock masses, a detailed geological cataloging and physical prospect testing of the slope rock mass in the area of Lenggu hydropower station were carried out, and the spatial development law of joints and fissures, the development depth and spatial distribution of mosaic and cataclastic rock masses, and the weak structural planes were mainly studied. The systematic statistics and analysis were conducted on the development and distribution of rock masses and the deformation and failure characteristics of the slope. The results show that the rock mass engineering effect is poor,and the deformation modulus is low. The wave velocity of most loose rock masses is less than 3 000 m/s, the maximum principal stress is less than 20 MPa, and the permeability coefficient is greater than 10 L/(min·m·m). The evolution process and characteristics of rock mass fractures and loosening are analyzed combined with the experimental results of stress test, acoustic velocity measurement, and high density electromagnetic exploration. It is concluded that loose rock masses are the result of regional fracture activity and shallow transformation, and rock mass fractures are mainly affected by faults and joints.