Rock Blasting Crack Propagation and Dynamic Response of Adjacent Roadway Structure under Active Confining Pressure

In order to study the failure process of rock blasting and adjacent roadway under confining pressure, the rock rectangular plate specimen with blast hole and roadway structure is tested, and the dynamic damage process of rock is obtained by using dynamic testing technology and high-speed camera method. A rock model containing roadway and single blasting hole is established based on Holmquist-Johnson-Cook (HJC) constitutive model. The simulated results without confining pressure are compared with the test results, and the feasibility of the numerical simulation method is verified. The stress initialization method is introduced into a finite element simulation platform to simulate the rock failure process under confining pressure, and the influences of different confining pressure environments on the rock blasting crack growth and the influence of partial confining pressure coefficient (k) on the failure process of roadway structure are analyzed. The results show that, under the condition of bidirectional constant confining pressure, the inhibition effect on crack is more significant and the protection effect on roadway is better with the increase in confining pressure level. Under the condition of unidirectional confining pressure, the roadway is damaged more seriously with the increase in horizontal confining pressure, and the roadway is less prone to failure with the increase in vertical confining pressure. Under the condition of partial confining pressure, the confining pressure has obvious guiding effect on the propagation of explosive crack, and the crack will expand in the direction of the principal stress. With the increase in confining pressure, the conductivity of crack is more significant. For partial confining pressure coefficient k 1, the greater the damage degree of the left spandrel of blasting face of roadway is with the increase in k, the worse the stability of the roadway is. © 2024 China Ordnance Industry Corporation. All rights reserved.