碎粒型结构面特征及物理力学参数优化分析

某水电站坝区两岸的勘探平洞揭示了百余条挤压破碎带,兼具挤压错动和风化蚀变双重特征,其组成以碎粒岩为主,空间分布不均。作为一种软弱结构面,其工程地质特征及物理力学参数对坝区岩体利用和枢纽建筑物布置具有重要影响。通过现场调查及物理试验,分析统计了其发育分布特征、物理性质;结合现场碎粒型结构面的抗剪强度试验,获得了抗剪强度参数,根据点群趋势,分别按优定斜率法和最小二乘法取值。为避免因某些薄弱单元的累进性破坏而危及工程岩体的整体安全,建议使用优定斜率法成果的下限值作为试验成果标准值。

Characteristics and Optimization Analysis on Physico-mechanical Parameters of Structural Plane Containing Particles

More than 100 compresso-crushed zones have been revealed in the exploratory adits on both sides of the dam area of a hydropower station. These zones composed mainly of particles have the double characteristics of extrusion dislocation and weathering alteration, and the spatial distribution is uneven. As a kind of weak structural plane, their engineering geological characteristics and physical and mechanical parameters have great influence on the utilization of rock mass and the layout of pivotal structures in dam area. Through the field investigation and physical experiment, their distribution and physical properties were analyzed statistically. Combining with the shear strength test of structural plane containing particle, the shear strength parameters are obtained. According to the group trend, specific parameters are acquired, respectively according to the optimal slope method and least square method; In order to avoid endangering the overall safety of the engineering rock mass caused by progressive failure of some weak units, the lower limit value of the optimal slope method is recommended as the standard value of the experimental results.