Physical Simulation Experiment on the Rock Breaking Efficiency of Pulse Type Controllable Shock Wave.

Given that conducting controllable shock wave tests in actual rock formations underground in coal mines affects coal mine production with the parameters required for equipment design and incurs significant costs, a series of ground tests were conducted separately. First, the impact of energy storage on rock breaking efficiency was analyzed. Then, physical simulation experiments were conducted on the differential efficiency of controllable shock waves on high-strength cement, sandstone, granite, solid granite, and limestone. Results show that (a) for high-strength cement, the energy storage of 50 kJ is driven by pulse power, and the energy converter uses a metal wire with a length of 120 mm and a diameter of 1.6 mm to convert energy. (b) For sandstone, after a single impact on the sample, due to the lack of confining pressure and outer protection, the physical model sample was directly exploded, and the cracking effect was very good. (c) For granite, the experimental results of three energy levels of 50, 70, and 100 kJ have basically verified that the energy storage of the pulse power driving source with an energy of 100 kJ can achieve the result of fracturing material mode. (d) For solid granite, endoscopic exploration was conducted on the drilling holes and adjacent guide holes where impact was implemented. (e) For limestone strata, when the energy storage design of the pulse power drive source is 100 kJ, the existing metal wire electric explosion energy conversion efficiency and three impacts can meet the cutting seam requirements of most coal seam roofs.