基于关键块体理论的岩体稳定性分析方法及其在三峡工程中的应用

针对三峡工程船闸边坡、地下厂房等岩石工程建设中面临的复杂岩体结构块体稳定性问题,阐述了引进岩体关键块体理论解决工程实际问题的关键技术及过程。以关键块体理论为基础,提出任意形状块体的体积计算、凹形块体几何构型以及考虑一般水压模式条件下的块体水载荷计算等一系列方法,实现了复杂岩体地质结构面切割条件下的关键块体识别及多种载荷组合下的关键块体稳定性评价,并应用于三峡船闸边坡及三峡地下厂房等多个工程部位岩体稳定性分析与支护评价。三峡船闸边坡施工期数百个块体几何构型及稳定性分析结果表明关键块体稳定性分析结论与现场实际块体出露特征和稳定状态总体相符。所提出的基于关键块体理论的岩体稳定性分析方法具有较好的针对性和实用性,可为其他工程岩体稳定性分析提供理论依据。

Series Methods of Analyzing Rock Mass Stability Based on Key Block Theory and Their Applications to Three Gorges Project

Some key technologies of applying the key block theory in engineering practice are presented to address the stability issue of complex rock blocks involved in the construction of ship lock slope and underground power house of the Three Gorges Project (TGP). Such technologies include the calculation of block volume with any shape, the geometric configuration of a particular type of concave block, and the calculation of water pressure under the general distribution loading condition. By applying these methods to the rock stability analysis and reinforcement evaluation in the shiplock slopes and the underground powerhouse of TGP, key blocks can be identified under the condition of cutting of complex rock mass geological discontinuities, and the stability of key blocks under various load combinations can be evaluated. Applications to the geometric configuration and stability analysis of hundreds of blocks in the construction period of the ship lock slope excavation of TGP demonstrate that the results of stability analysis are roughly consistent with the actual characteristics of exposed blocks and their stability state on site. In conclusion, the methods of rock mass stability analysis based on key block theory proposed in this paper are of good pertinence and practicability, and offer theoretical basis for the rock stability analysis of other projects.