Numerical Simulation Of Uncoupling Charge Blasting

Uncoupling charge blasting is the major technical measures for presplitting and smooth blasting, and is the main means to form smooth rock wall and protect excavation face. On the basis of extensive reading literatures published in home and abroad, the principle of uncoupling charge blasting is expounded, and the properties of parameter determination in air and water uncoupling charge blasting are analyzed.3D single hole and 2D diplopore are modeled numerically using LS-DYNA, and the stress process of uncoupling charge blasting is reappearanced, and the stress cloud and time process curve of stress and displacement of blasting are educed. Pressure and breakage of hole wall in air and water uncoupling charge blasting are analyzed, and the functional relation of borehole pressure and uncoupling coefficient is educed. The difference of stress decay rate in air and water is compared; and axis stress in diplopore simultaneous blasting is analyzed.The numerical simulate results showed that for the rock with its ultimate compressive strength is more than 76MPa, the borehole can be protected effectively in air and water uncoupling charge blasting when the uncoupling coefficient K=2,3,4 and the detonator diameter is 5cm. The Borehole pressure showed exponential decay with the increase of uncoupling coefficient, and the decay in water is lower than in air. The tensile stresses of blast axis are no less than 4.2MPa when K=3, L=10-15d, and the detonator diameter is 5cm.