A testing system to understand rock fracturing processes induced by different dynamic disturbances under true triaxial compression

Abstract

In this context, a testing system to understand rock fracturing processes induced by different dynamic disturbances under true triaxial compression was developed. The system is mainly composed of a static loading subsystem, a dynamic loading subsystem, a specimen box subsystem, and a data measurement subsystem. The static loading subsystem uses low stiffness loss frame structure technology, which greatly improves the frame stiffness in the three principal stress directions (up to 20 GN/m) and ensures the demand of the disturbance experiment in both the prepeak and postpeak stages. The disturbance loads with frequency of 0–20 Hz and stress level of 0–30 MPa were applied using large flow parallel oil source technology characterized with high heat dissipation efficiency. For the disturbance loads with frequency of 100–500 Hz and stress level of 0–30 MPa, they were realized by using high-frequency and centimeter-per-second-scale low-speed disturbance rod technology. Three rigid self-stabilizing specimen boxes were utilized to provide support for the specimen and deformation sensors, ensuring the stability and accuracy of the data obtained. To verify the performance of the true triaxial test system, disturbance experiments were conducted on granite specimens. The results show that the experimental device satisfies the requirements of original design, with an excellent repeatability and reliable testing results.