深切峡谷地区地壳浅表层地应力状态变化分析

An analysis on variation of crustal stress states at the shallow part of upper crust in deep-cut valley region

本文以三峡水库引水工程秦岭特长隧洞水压致裂地应力测量为例,在野外地质调查、室内超前预测分析、现场和室内测试等的基础上,对深切峡谷地区地壳浅表层地应力状态进行了系统分析,结果表明深切峡谷地区地壳浅表层分为应力降低区、应力增高区和原始应力区,原始应力区(即构造应力面)的深度大致等于地应力测点周围山体和沟谷之间的相对高差.

Taking the hydr-fracturing geo-stress measuring of Qinling long deep buried tunnel in the water diversion planning project from Yangtze River to Weihe River as an example, on the basis of field geological investigation, of flee pre-forecast analysis, in-situ and office measuring and so on, the crustal stress states at the shallow part of upper crust in deep-cut valley region are systematically analyzed in this paper. The results show that there are crustal stress reduction zone, crustal stress concentration zone and primary crustal stress zone in the shallow part of upper crust in deep-cut valley region, and that the depth of primary crustal stress zone （or tectonic stress plane） is about the relative height difference between the summit of mountain and the bottom of valley near a geo-stress measuring site.