Energy Behavior of Sandstone Containing Weak Filling Joints with Multiple Angles under Dynamic Splitting Loads

Abstract

The impact of weak filling joints with multiple angles on the energy dissipation mechanism is significant for surrounding rock engineering to prevent and mitigate disasters. In the present study, the sandstone samples containing weak filling joints were prefabricated, and dynamic splitting tests were conducted under three nominal loading rates with a modified Split Hopkinson Pressure Bar system. The effects of nominal loading rates and joint angles on time-based curves and energy-based curves were investigated systematically. The test results indicated that the nominal loading rate and joint angle had remarkable influences on energy dissipation characteristics. The sample containing a larger joint angle preferred brittle failure, whereas the sample with a smaller joint angle failed with a plastic feature. Moreover, the reflection energy decreased as the joint angle increased, which was opposite to the evolution tendencies of transmission energy and absorption energy. The transmission energy and absorption energy had different sensitivities to changes in joint angle and nominal loading rate. The exponential function could excellently describe the dependence of transmission energy, reflection energy, and absorption energy on joint angles. With the incremental joint angle, the energy reflection ratio had a contrary tendency to the energy transmission ratio.