Theoretical and Experimental Study on Damage Properties of Surrounding Rock under High-Frequency Constant Impact Load

Abstract

This paper aims to investigate the mechanics and damage properties of granite by drilling a center hole in Φ50 × 100 mm standard granite specimens under high-frequency constant impact load and then applying them to the uniaxial compression experiment through the INSTRON 1346 universal material testing machine. According to the experimental results, under constant impact load, as the center hole diameter increases, the peak stress of the rock specimen increases accordingly and the effective elastic modulus of the rock specimen decreases first and then increases gradually. In this study, by theoretical analysis of the surrounding rock damage caused under high-frequency impact load, a statistical damage constitutive model that has taken surrounding rock damage into consideration is established on the basis of the Weibull distribution. Meanwhile, the experimental curve is obtained to analyze the damage and damage radius of surrounding rock under high-frequency impact load. The results show that the surrounding rock damage and damage ratio (the ratio of damage radius to center hole radius) of rock decrease with the increase of the center hole diameter. This model that can effectively describe the damage laws of surrounding rock under impact load serves as a guide for the design and development of composite rock-drilling tools.