Spatial distribution of excavation induced damage zone of high rock slope

Abstract

The excavation induced damage zone (EDZ) can significantly influence the overall performance of an excavated slope. Determining the spatial distribution characteristics of the EDZ is very important to both design and construction of high rock slope. Based on the case study of the excavation of high rock slope at the Xiluodu Hydropower Station in Sichuan province of China, spatial distributions of EDZ of the slope surface and berm were determined using sonic logging and cross-hole sonic tests. The results showed that the vertical damage depth increases non-linearly from the inner side to the outer flank of the berm, whereas the horizontal damage scope increases non-linearly from the bottom to the top of the slope. The maximum horizontal damage scope and the maximum vertical damage depth are found to be at the outer flank of the berm. To reproduce and predict the EDZ for high rock slope excavation with Dynamic Finite Element Method, a modified tensile–compressive damage model was introduced into the simulation of the EDZ of Xiluodu high rock slope. Four other frequently used damage models were used as comparisons. The results demonstrate that the damage zone obtained by the modified tensile–compressive damage model agreed with observations better than the other four existing blasting damage models.