Abstract:
Static crushing agent (SCA) has the advantages of good safety, no harmful gas and no vibration. It is widely used in rock crushing engineering of mine or underground engineering. Aiming at the roadway side expansion project and environmental conditions of a mine in Shanxi Coking Coal, the suitable type of static crushing agent was selected. The mechanical parameters of roadway surrounding rock and the expansion performance of SCA were tested by laboratory test, numerical simulation and field engineering test. The fracturing law of SCA on roadway side rock under multi-row drilling conditions was studied, and the reasonable fracturing drilling parameters and row spacing distribution were obtained. The construction technology of static crushing agent grouting method was proposed. The results show that the smaller the hole spacing is, the better the crushing effect of SCA is, and the shorter the crushing time is. Under the premise of ensuring the crushing effect, it should also be combined with the construction efficiency of the production team 8 h shift system, and it is recommended to use the 300 mm drilling row spacing arrangement; the numerical simulation analysis obtained the stress distribution and fracture propagation law of the multi-row borehole fracturing process. The research results show that multi-row borehole SCA fracturing can safely and efficiently deal with the fracturing engineering of free surfaces such as side expansion, bottom lifting and roof cutting in coal and rock roadways.