摘要
本文分长江三峡工程坝区及外围（约３１对万ｋｍ２）和长江三峡工程库首区（约３万ｋｍ２）两个层次和范围进行区域地壳稳定性评价与分区研究，在构造分区及现今地应力地场研究的基础上，运用模糊数学进行地壳稳定性量化综合评价，然后结合地质分析，进行地壳稳定性分区。长江三峡工程坝区及外围地壳稳定性评价与分区结果为：库首区地壳稳定性总体系属相对较稳定一稳定状态，三斗坪坝址区属于相对稳定地块；长江三峡工程库首区地壳稳定性评价与分区结果为：三斗坪坝址位于古老的花岗岩完整块体之上，属于相对稳定（Ⅰ）地块。从区域地壳稳定性评价看，三斗坪坝址是一个不可多得的好坝址，适宜修建巨型水利电力工程。
The scale of the Three Gorges project(TGP) on the Yangtze River ensures it will have enormous social and economic consequences. Naturally, determining the safety of TGP is an essential consideration, and conducting the assessment and zonation of regional crustal stability has a crucial role on the success or failure of TGP in the future. In this paper, the regional crustal stability takes much emphasis on tectonic stability, coordinating with crustal surface medium conditions, and considering the stability of partial rock and soil masses and of surface slope involving landslides, collapses etc. related with fracture activity. The evaluation and zonation of regional crustal stability, in this paper, is conducted in two orders and scopes: the dam region and its vincinity of TGP(about 310000km2) and the near dam region of TGP(about 30000km2). On the bases of tectonic zonation and present crustal stress field analysis, using fuzzy mathematics to do quantitative and comprehensive evaluation of crustal stability, and combining with synthetic geological study, finally, the zonation of crustal stability is conducted. The results of the assessment and zonation of the larger region are that the general crustal stability of the dam region is in less stable - stable state and that the Sandouping dam site is on the relative stable land mass; the result of the smaller region is that the Sandouping dam site is on the ancient complete granitic body belonging to the stable(Ⅰ) land mass. Therefore, from the view of assessment and zonation regional crustal stability, it is due to construct a giant hydropower station at Sandouping.
关键词
地壳稳定性
三峡工程
构造分区
坝区
地应力场
crustal stability assessment and zonation
Three Gorges Project
tectonic zonation crustal stress field
fuzzy mathematics
relative stable state
