Design of hole pattern in static rock fracture process due to expansion pressure

摘要

The process of rock fracturing is one of important operations in quarry mining. The process can be done by controlled blasting or by soundless fracturing by Non-Explosive Expansion Material (NEEM) in hard rocks. Application of the NEEMs is so easy, safe, and very controllable but it is slow process and most of the time cost of the production by the NEEM is higher than controlled blasting method. On the other hand, usage of blasting methods (in quarry mining) are restricted in some locations or countries. Therefore, an investigation has been done on static rock fracturing by expansion process. In the research a semi-analytical and experimental model has been suggested by dimensional analysis which is based on field measurements in a granite quarry mine in Iran and a physical model (concrete block) and some numerical modeling. The model is a formula which can estimate the hole spacing in different rocks and concrete by several NEEMs and hole's diameter. Main parameters of the suggested model are NEEMs pressure, tensile strength of the intact rock, Young's modulus of the intact rock, hole's diameter, rock fracture toughness, temperature, and CaO content in the NEEM. More than twenty data have been used for verification of the suggested model which they were some data from the granite mine, some of them were from physical modeling and numerical modeling, and the others were from other researchers' experiences.