The Theory Of Non-Isotropic Breaking Rock By Water Jets And Its Application

Gas disaster is always one of the main disasters to threaten the security of coal mine in the coal exploitation. Although the scholar in home and abroad do a lot of trial work in gas extraction, it affect a little at present. It is considered that the gas pre-extraction measure in coal bed is one of the most effective methods to prevent the gas disaster. With the depth of coal bed increase, the permeability decrease. Consequently it affects the extraction rate and efficiency. So it become the key link solving the gas extraction in low-permeability coal beds to insure in coal mine security and enhance production efficiency. With the development of society economy and the increscent requirement for energy sources, the gas source exploitation and its using become more and more attention. The most coal field of china is all low-permeability coal beds, so it has important society value and economy efficiency to have the research of gas extraction in low-permeability coal beds.After in-depth researches for years, Taiyuan University of Technology puts forward a basal research idea and theory to enhance the effect of gas extraction in low-permeability coal bed by drilling and cutting seams with high pressure water jet. The paper minutely deduces the boundary equation of circular submersed inordinate jets, accomplishes the theory, numerical computation and testing studies of the cracked mechanism of inhomogeneous material under the high water jets, have investigated the correlative law of drilling and cutting seams with high pressure water jet in coal bed in test, obtain a result of largely enhancing coal gas extraction. The main research work is:1. Using the motion equation (the N-S equation), the continuity...