PREDICTION OF ROCK MASS QUALITY IN TARGET DEPTH FOR TAMUSU AREA OF ALXA PRE-SELECTED REGION FOR GEOLOGICAL DISPOSAL OF HIGH-LEVEL NUCLEAR WASTE

Tamusu pre-selected area of Alxa pre-selected region for geological disposal of high-level nuclear waste is located in North Alxa Block. The crust consists of Permian and Triassic granite and is stable. There are a few faults, three ductile shear zones and one ductile-brittle deformation zone in the area. And the joints are controlled by regional tectonics. The classification of ground rock mass mainly is Ⅲ, and secondly is Ⅳ. According to core logging and mechanical test, the classifications of TMS01 and TMS02 drill cores are mainly Ⅴ and Ⅲ, respectively. From comparison of rock mass quality and well logging data, obvious correlation between quality and physical parameters of rock mass is found. Therefore, the relationship between rock mass quality and resistivity is established. Combining with the quality of surface rock mass and drilling core and geophysical prospecting section, the quality of rock mass in target depth is predicted as follows:the main rock mass is grade Ⅱ and Ⅲ, and some is grade Ⅰ and Ⅳ.