Influence of the Disturbance in the Orthogonal Direction on the Kaiser Effect Using Discrete Element Method
When a rock sample is subjected to cyclic loadings, acoustic emission (AE) events increase sharply when the peak stress value applied previously is attained. This phenomenon is called Kaiser effect (KE). One important application of the KE is to determine the in situ stress, the knowledge of which is critical for the design work for underground engineering. Compared to the traditional methods, the acoustic emission (AE) method based on KE is done in the laboratory with special loadings on the rock cores and thus very economical. However, one fundamental question needs to be answered is the influence of the damage introduced by many factors during the period of the coring and samples preparation and so on. In this paper, we explore the influence by a series of loadings on samples in the direction perpendicular to the direction of the previous peak stress. Cyclic uniaxial compressions on the rectangular specimen and cyclic Brazilian tests were carried out based on the contact model in the particle flow code. The results demonstrate that, the disturbance in the orthogonal direction cannot influence Kaiser effect of the rock sample.