Analysis of blasting characteristics of interbedded rock mass based on particle expansion method

Abstract

In engineering, blasting is often used to achieve engineering purposes. Still, more studies are limited to a single rock layer, and there are few details on complex rock layers, such as interbedded rock bodies. This paper analyses the effects of the blasting environment, layer thickness, and inclination angle on the blasting effect from the levels of reflected stress, cracking state, and contact resultant force with the help of the particle expansion method. It is found that: (i) The blasting environment and layer thickness greatly influence the blasting effect, while the inclination angle has a minor influence. (ii) When the layer thickness in a hard rock environment is less than seven times the radius of the crushing zone, the reflective stress near the contact surface increases with the layer thickness, conversely, it decreases. (iii) For hard rock environments with layer thicknesses up to 3 times the radius of the crushing zone, the number of cracks increases with layer thickness at a rate of 68% per meter, conversely, it decreases at a rate of 6.5% per meter. For soft rock environments with layer thicknesses up to 1 times the radius of the crushing zone, the number of cracks decreases at a rate of 112% per meter with layer thickness. It increases at a rate of 10% per meter for layers between 1 and 2 times the radius of the crushing zone. (iv) The average contact resultantforce increases at a rate of 15.4% per meter when the layer thickness gradually increases to 10 times the radius of the crushing zone for hard rock environments and decreases at a rate of 51.7% per meter when the layer thickness increases to 1.5 times the radius of the crushing zone for soft rock environments, and converges if the layer thicknesses continue to increase for both soft rock and hard rock environments.