THE CAUSE OF FORMATION AND ENGINEERING GEOLOGICAL PROPERTIES OF HYDROTHERMAL ALTERED ROCK IN GRANITE MASS FOR GUANGZHOU PUMPED STORAGE POWER STATION

摘要

The clay-grouting altered granite which formed due to hydrothermal alteration is rarely to be seen in the engineering construction of water conservancy and hydropower.lt is understood that the altered granite formed under special geological condition based on the study of the cause and distribution regulation of the altered granite body at the site of Guangzhou pumped storage power station(GPSPS).There are several alteration types in the granite mass, one of them is montmorillonization.The montmorillonite in monttnorillization altered granite can swelling when it absorbs water that makes the compact-structure granite loose.calving and disintegrate Into sandy-gravel soil which is a kind of soft belt in the granite mass.The support of altered rock and its impact to the substructure work,especially to the large span underground powerhouse and high pressure tunnel and manifold are analyzed and discussed with respect to the integrity and strength of the rock mass and based on the engineering geological characteristics of the altered granite in this paper.