Crack Analysis Of Rock And Numerical Analysis On Some Parameters Considering Damage In Smooth Blasting

Smooth Blasting is a relative succeed technology of blasting in practices, this technology's characteristic is that the excavate surface is smooth and level, blasting vibration of wall rock is relatively low and the stability is more high , adopt this technology we can improve the quality of blasting, realize more security, economy and scientific excavating.At present, in the design and construction of smooth blasting, considering few influence that main blast hole' first blast damage to rock of smooth blasting parameters. In high strength rock, because the influence of damage obvious to can obtain better result of smooth blasting; however, in the low intensity rock, it is difficult to obtain better result of smooth blasting. In fact, the result that the smooth blasting is often relatively bad in the low intensity rock, exceed digging. The main reason is: The main blast hole' first blast damage to rock of smooth blasting is highly, make mechanics nature parameter of rock take place heavy change, but in design and construction the damage is few consider, the consequence is single hole' charge quantity excessive, the rock is destroyed overly and exceeded dug.Crack mechanism of smooth blasting is analyzed in theory using fracture mechanics and damage mechanics method, deduct the parameters of smooth blasting considering the main blast hole' first blast damage to rock of smooth blasting.Numerical simulation'technology is as a kind of effective means to study about real world, already given largely function to go deep into knowing rock blasting phenomenon and produce mechanism, improving theoretical research level, instructing engineering design and project practice. Using the dynamic finite element program ANSYS/LS-DYNA, combine project reality, has compared various kinds of computing technologies of damage parameter, the different mechanics parameters of rock before blasting and after blasting is studied by adopting the test method, the damage parameter of quantization is confirmed. Explosion pressure is simplified as the triangle loading, the rock body is considered as the elastic-plastic body, model simplify for 2D issue, by numerical simulation for rock smooth blasting take account of damage and take no account of damage and numerical simulation for rock smooth blasting take account of damage in different smooth blasting spacing and differentburden, after comparing the effective stress in each model. To draw: In keeping hole explode pressure, borehole diameter, burden no change, considering damage the spacing of borehole should increase in smooth blasting and not be greater than 15.5 times of borehole diameter; In keeping hole explode pressure, borehole diameter, spacing no change, considering damage the burden of borehole should increase in smooth blasting and not be greater than 21 times of borehole diameter. After adjusting parameter according to numerical simulation result, the spacing equal to 13 times smooth blasting borehole diameter, the burden equal to 20 times smooth blasting borehole diameter, obtain the good result in project, it is proved the feasibility of adopting the numerical analysis method to study the blasting parameters.