Experimental Analysis Of Blasting Loads On Rock Mass Containing Discontinuity Planes

Because discontinuity structural planes in rock mass affect stress wave propagation and fracture expansion in the process of rock blasting, with or without discontinuity planes has great discrepancy. And often the blasting effects are controlled by discontinuity planes in rock mass. On the basis of theoretical analysis, a series tests are conducted, the testing results are analyzed by using numerical simulation of AUTODYN 2D.The thesis can be helpful for personnel who interests in dynamic properties of blasting loads on rock mass that contains discontinuity planes.First, the mechanical properties of rock mass containing discontinuity planes are theoretically analyzed by using fluctuating theory. The distribution of rock damage under blasting forces is discussed. Then the damage areas containing discontinuity planes can be determined through Mohr strength theory. The preferred damage directions under one and two group discontinuity planes are studied. Finally relevant simulating tests are carried on according to the analyzing result, and the theories are verified further.Through the ultrasonic pulse transmission testing under blasting load on rock samples containing discontinuity planes, the relationship between characteristics of bedded rock damages and ultrasonic properties are established. Also damaged rocks are carefully observed and examined, the damage distribution under blasting forces are primarily determined.The numerical simulation results showed clearly the process of rock damage of bedded rocks under blasting forces.In conclusion, the thesis focused on two aspects: firstly the spacing and angles of discontinuity planes in rock mass under blasting forces are theoretically analyzed and experimentally verified. Secondly, damage characteristics and distribution laws of bedded rocks under blasting forces are presented.