南水北调中线工程白庄地裂缝成因及活动性分析

白庄地裂缝是南水北调中线工程遇到的唯一一处地裂缝地质灾害。通过勘察白庄地裂缝的分布、发育形态特征,研究煤矿开采沉陷影响、九里山断裂构造、应力解除效应、环境地质背景条件、地下水作用等因素,分析地裂缝的发育成因。结果表明,白庄地裂缝不属于采空区沉陷裂缝,其发育受九里山断裂构造控制,在其他环境地质作用的变化因素(采矿活动引起的应力释放,地下水下降,地表水下渗)诱发和激化的综合叠加作用的体现。成因分析和初步监测显示,地裂缝仍存在微弱的活动性,但总体趋于稳定。

Cause and activity analysis of the Baizhuang ground fissure for the South to North Water Transfer Project

The only one ground fissures geological disaster along the middle route of the South-to-North Water Transfer Project (SNWTP) is the Baizhuang Ground fissure. In order to analyze the causes for the fissure development, the distribution and morphological characteristics of the ground fissure were investigated. And the influence of subsidence caused by the coal mining, the fracture structure of the JiuLi mountain, the effects of the stress relief, the conditions of the environmental geological and the effects of the ground water were studied. The results showed that the ground fissures were not caused by the subsidence of the mined out area, and the development of the ground fissures was mainly controlled by the fracture structure of the JiuLi mountain. Other environmental and geological conditions (i.e., the stress release caused by mining activities, the ground water decline, and the surface water infiltration) also had a synergic effect on the ground fissures. The cause analysis and preliminary monitoring showed that the activity of the ground fissure still existed but its strength was weak, and the ground fissure activity tended to be stable as a whole.