Abstract
Based on the analysis of various in-situ measurement data collected during excavations of pumped-storage powerhouses located in deep ground, a concept that divides the excavation disturbed zones into plastic and non-plastic zones around underground openings is proposed in this study. A method to evaluate the excavation disturbed zones and the plastic zones based on measurement results of tangential stress and strain, radial interval strain, AE and joint behavior is developed. The validation of the method is carried out using real measurement data from Kazunogawa powerhouse cavern. Finally, a comparitive study is performed by changing material properties in zones defined acording to the proposed concept, and approaches to determine the rock mass mechanical properties which can predict the rock mass deformation behavior reasonably well are discussed.
