Numerical study of AE and DRA methods in sandstone and granite in orthogonal loading directions  

作　　者：Xu-hua REN Hai-jun WANG Ji-xun ZHANG 

机构地区：[1]College of Water Conservancy and Hydropower Engineering,Hohai University,Nanjing 210098,China

出　　处：《Water Science and Engineering》2012年第1期93-104,共12页水科学与水工程（英文版）

基　　金：supported by the National Natural Science Foundation of China (Grant No. 50978083);the Fundamental Research Funds for the Central Universities (Grants No. 2009B07714 and 2010B13914) in China;the Innovation Project for Graduate Students of Jiangsu Province (Grant No. CX10B_215Z)

摘　　要：The directional dependency of the acoustic emission （AE） and deformation rate analysis （DRA） methods was analyzed, based on the contact bond model in the two-dimensional particle flow code （PFC2D） in two types of rocks, the coarse-grained sandstone and Aue granite. Each type of rocks had two shapes, the Brazilian disk and a square shape. The mechanical behaviors of the numerical model had already been verified to be in agreement with those of the physical specimens in previous research. Three loading protocols with different loading cycles in two orthogonal directions were specially designed in the numerical tests. The results show that no memory effect is observed in the second loading in the orthogonal direction. However, both the cumulative crack number of the second loading and the differential strain value at the inflection point are influenced by the first loading in the orthogonal direction.The directional dependency of the acoustic emission （AE） and deformation rate analysis （DRA） methods was analyzed, based on the contact bond model in the two-dimensional particle flow code （PFC2D） in two types of rocks, the coarse-grained sandstone and Aue granite. Each type of rocks had two shapes, the Brazilian disk and a square shape. The mechanical behaviors of the numerical model had already been verified to be in agreement with those of the physical specimens in previous research. Three loading protocols with different loading cycles in two orthogonal directions were specially designed in the numerical tests. The results show that no memory effect is observed in the second loading in the orthogonal direction. However, both the cumulative crack number of the second loading and the differential strain value at the inflection point are influenced by the first loading in the orthogonal direction.

关 键 词：Kaiser effect deformation rate analysis PFC2D orthogonal loading directions in situ stress measurement 

分 类 号：P588.121[天文地球—岩石学] TP393.14[天文地球—地质学]