Analysis of the Damage Characteristics and Energy Dissipation of Rocks with a Vertical Hole under Cyclic Impact Loads

Abstract

This study systematically investigates the failure patterns, energy dissipation, and fracture behavior of rock specimens containing a vertical hole under impact loads. First, an improved damage calculation equation suitable for the analysis of rock specimens with a vertical hole is obtained based on the one-dimensional stress wave theory and the interface continuity condition. After that, the Hopkinson pressure bar (SHPB) device was used to conduct cyclic impact tests with different impact pressures and impact modes (impact pressures with equal amplitude and unequal amplitude). The experimental results suggest that, under the equal-amplitude high pressure and unequal-amplitude pressure, the degree of damage of the rock significantly increased, the bearing capacity greatly reduced, and the rock gradually transitions from having good ductility to experiencing brittle failure. The cumulative specific energy absorption value gradually increases with the increase in the cyclic impact. Compared to that of the equal impact condition, the degree of damage to the rock is more severe for the case of equal-amplitude high pressure and unequal impact, and the failure mode undergoes a transformation from transverse tensile failure to transverse tensile failure-axial splitting failure combination and axial splitting failure. Through the analysis of rock energy changes and rock failure patterns during cyclic impact, it will be helpful to predict and control the fracture caused by local stress concentration during excavation, thus can reduce the cost of support and reinforcement in excavation and improve the stability of surrounding rocks.

Effects of Water and Cyclic Loading on Ultrasonic and Mechanical Properties of Sandstone: An Experimental Study

“…It should be noted that the dissipated energy ratio is larger than the elastic energy ratio after peak strength because of the crack growth. Previous studies have shown that during the process from the elastic stage, plastic stage to the failure stage in the stress-strain curve, there is always energy exchange with the outside world, and energy is constantly released to the outside world to maintain dynamic balance [39]. Through the experimental results of sandstone with different water content under cyclic loading, the water can weaken the sandstone underneath the Bohai Sea.…”

Influence of Base-Angle Bolt Support Parameters and Different Sections on Overall Stability of a Roadway under a Deeply Buried High Stress Environment Based on Numerical Simulation

“…In addition, the cyclic impact load generated by roadway mining will also accelerate the fragmentation of the base-angle area and other locations, increasing the difficulty of support in this area. Dai et al [10][11][12][13] studied the mechanical and energy dissipation characteristics of granite under a cyclic impact load, providing a theoretical basis for base-angle area support from the mechanical and energy perspectives. Moreover, Krykovskyi et al [14] carried out research on the strengthening effect of grouting the rock bolt onto weak surrounding rock, which enriched the strengthening theory of bolt support.…”

Damage and Failure Characteristics of Surrounding Rock in Deep Circular Cavern under Cyclic Dynamic Load: A True Triaxial Experiment Investigation

“…Considering the high cost of in situ tests, many achievements have been made in the study of surrounding rock failure mode through laboratory tests. Dai et al [15] analyzed dynamic characteristics, damage characteristics, and energy dissipation and failure modes of rock with a single hole under cyclic impact load by using Split Hopkinson Pressure Bar (SHPB). Cheon et al [16] used CT technology to detect the failure of surrounding rock and distinguish damaged and failure areas.…”