This paper studies on the characteristics of strength and deformation of brittle rock under different compression condition by experimental tests. A lot of experimental tests for the Xiangjiaba sandstone are carried out under different compression condition, including uniaxial compression, triaxial compression, uniaxial monocyclic compression and uniaxial loading and unloading. Base on the experimental test results of the Xiangjiaba sandstone, the strength and deformation of brittle rock are analyzed, and some comparative analysis for the mechanics characteristics of brittle rock are carried out. The compute results show that, the peak strength of brittle rock is increased with the confining stress, and close to a linear relationship. Its also show that, the peak strength is not increased under the monocyclic compression, neither for the loading and unloading condition.

It is very important to make reasonable construction procedure during excavating the underground powerhouse. The factors that influence the multi-layered excavation of the underground powerhouse are analyzed in this paper. And the typical multi-layered scheme is made considering of these factors. Further research shows that for the underground powerhouse that is as large as Shuibuya and Dachaoshan project, the scheme of multi-layered excavation and construction procedure can be made referring to the typical multi-layered scheme. But for those super-large underground powerhouses, some benches which are too high must be further divided based on the typical scheme. And some temporary access tunnels must be designed on appropriate benches in order to make relevant benches have no less than two working faces. Thus the speed of excavation can be improved.