Experimental Study On Mechanical Properties Of Shale Under Dynamic Loading And Analysis Of Rock Mass Vibration Reduction

In many projects are related to the rock and soil under dynamic loads, and even repeated dynamic loads, so the study of rock and soil under dynamic loads is of great engineering significance of response. In this paper, SHPB test system is used to study the single impact test and cycle impact test of shale specimens. Study on the dynamic characteristics of shale specimens, at the same time with the numerical simulation method to analyze the dynamic distribution of stress, displacement and plastic zone loads of shale, Provide some theoretical support and guidance for the stability design and safety parameter selection of rock mass. The main contents and conclusions of this paper include the following aspects:(1)Using SHPB test system of shale specimens of single impact damage under different loading rate test, and the test data are analyzed. Results show that Dynamic compressive strength and strain rate of shale specimens have obvious correlation, but with the increase of strain rate, the deformation modulus did not change much with the increase of strain rate; Tensile failure is the main failure mode of shale specimens during loading process; The absorption energy increases with the increase of the incident energy during the single shock process; The absorption energy increases with the increase of strain rate.(2) The SHPB cycle impact test was carried out on shale specimens, and the data collected were processed and analyzed. The results show that the dynamic compressive strength of shale specimens decreases with the increasing of cyclic loading; The deformation modulus decreases gradually; Average strain rate increased gradually; Damage degree increased gradually; In the process of constant amplitude cyclic loading, the energy absorption value is increased.(3) The dynamic loading process of shale specimens was simulated and analyzed by using FLAC3D numerical simulation software. The simulation results show that:The stress, displacement and plastic zone of the simulated specimen are increased correspondingly with the increase of the amplitude of the loading function at the single loading time. Along with the increasing of the loading times, the simulation test piece along the axial direction tensile stress is increasing, the compressive stress is decreasing, the maximum displacement is increasing, and the plastic zone is increasing at the Cyclic loading time.(4) Combined with the characteristics of shale rock slope dynamic load on sampling are analyzed and the effect of vibration reduction measures were put forward.