西南某水电站深风化现象及其机理浅析

对西南某电站坝区谷底存在的深风化现象，通过系统的地质测绘、钻孔资料及EH-4连续电导率成像系统勘探结果与室内测试分析，分析深风化现象特征与分布，并对这种深风化、软化现象的形成机制进行了初步探讨。研究结果表明，坝区谷底为多期侵入活动改造的古老岩体，不同期次岩体接触面因结合力较弱成为挤压破碎带，后期的构造活动使该破碎带岩体在中等围压下进一步破碎，并经中更新世以来的长期风化与软化形成现今的深风化囊。对其进行有针对性的处理，并不妨碍该坝作为低堆石坝的坝址。

Preliminary Analysis of Mechanism and Phenomena of Deep Weathering in Some Hydroelectric Station, Southwest of China

Standing to phenomena of deeply weathering at the bottom of the dam area valley in some hydroelectric station,southwest of China,by the systematic geologic surveying,the data of borehole,the result of EH-4 e1ectrical conductivity image-forming system and indoor tests analysis,the deeply weathering phenomenon characteristics and its distribution are analyzed,and preliminary discussion on the genetic mechanism of the deeply weathering and softening is made.The results of study enunciate,there is ancient rock mass which is reformed by the intrusive activity many times at the bottom of the dam area valley,because of the weak cohesion bonds the dissimilar epoch contact plane of the rock mass become the compressive rupture zone,later tectonic movements make the rock mass of compressive rupture zone further broken up under medium confinement pressure,since middle Pleistocene epoch long-term weathering and yielding,current deep weathering bag has been formed.With the fitting processing,the phenomena of deeply weathering don't hinder the dam as the address of low rockfill dam.