三峡库区消落带滑坡稳定性分析中的力学问题

Mechanical problems in slope stability analysis for the water-level-fluctuation zone of Three Gorges Reservoir

针对三峡库区消落带特殊的地质环境,在系统分析作用于滑坡体上的力系以及滑坡体受力状态随库水位变化而变化的规律的基础上,研究了水库消落带库水位周期性变化对岩石变形特性演化规律的影响,提出了旱季(天然状态)、雨季(暴雨或长期降雨状态)、旱季+175m库水位、雨季+175m库水位、旱季+地震、雨季+地震、旱季+175m库水位+地震、雨季+175m库水位+地震、旱季+库水位由175m下降至145m、雨季+库水位由175m下降至145m等10种典型计算工况及其相应的作用荷载体系,建立了三峡库区水库消落带滑坡稳定性分析评价方法。其研究成果为探索处于三峡库区水库消落带地质环境的稳定性分析评价方法和确定三峡库区库岸边坡整治工程设计方案奠定了基础。

In view of the particular geological environment in the water-level-fluctuation zone of Three Gorges Reservoir, and on the basis of the systematic analysis of the forces acted on the slope, and the influence of water level fluctuation on the slope stability along reservoir area, this paper studies the effect of the cyclic water pressures on the deformation characteristics of rock, and puts forward the loading system for ten typical design conditions including dry season （natural state）, rainy season （rainstorm or rain for a long period of time）, dry season ＋ reservoir level （175 m）, rainy season ＋ reservoir level （175 m ） ＋ earthquake, rainy season＋ earthquake, dry season ＋ reservoir level （175 m） ＋ earthquake, rainy season ＋ reservoir level （175 m） ＋ earthquake, dry season ＋ reservoir level lowered from 175 m to 145 m, rainy seasons＋ reservoir level lowered from 175 m to 145 m. A comprehensive analytical evaluation system of the slope stability in the water-level-fluctuating zone of Three Gorges Reservoir Area is proposed on the basis of the static limit-equilibrium method. The research results can serve as the foundation for the analytical evaluation method of the stability of the geological environment in the water-level-fluctuation zone of Three Gorges Reservoir and to constitute the engineering design plan for slope stability control in the reservoir area.