新安江水电站坝基析出物成因分析

Study on Formative Mechanism of Exudates from the Dam Foundation of Xinánjiang Water Power Station

通过对新安江水电站坝基析出物的实地调查和室内分析研究,得出析出物的形成主要是在还原环境下,地下水对坝基岩层、帷幕体和坝体混凝土的淋滤分解的结果,与页岩的软泥化关系不密切.析出物中的主要成分铁、锰等是来自塘家坞砂岩、由于该砂岩中铁锰含量不高,地下水对基岩等的化学潜蚀缓慢.30多年来析出物的总排出量不多.故对坝基岩石强度影响不大.

After detailed field and laboratory study, it is known that exudates from the dam foundation of Xin'anjiang Water Power Station result from eluviation and decomposition of bedrock, curtaingrouting, and concrete, caused by groundwater under the reduction environment, but not closely related to shale softening-argilbzation. Elements such as Fe and Mn in the exudates mainly come from Tangjiawu sandstone. Because the sandstone is not rich in Fe and Mn, and groundwater erodes the rock and dam foundation very slowly, the amount of the exudates in the past 30 years is very small, therefore there is no obvious influence on the mechanical strength of the bedrock under the dam foundation.