Study On The Effect Of Blasting Vibration On Rock And Freezing Pipes In Bedrock

In the construction of coal mine shaft, more and more coal mining enterprisechoose to use the freezing method. The influence of blasting vibration on freezingpipes is inevitable if the method of blasting is employed for excavation. So the studyof the influence of blasting vibration on freezing pipes is of great importance both intheory and practice.The numerical simulation method of dynamic FEM is employed to study theinfluence of the excavation of blasting vibration on freezing pipes under different pipediameter, different explosive charge; different distance. The distribution of stress andvibration velocity of freezing pipes and rock mass is presented and analysed: thecircumferential peak stress is greater than radial peak stress; the circumferential stressof the freezing pipes is similar in different position; the circumferential stress in thefront center of the rock is biggest; the vibration velocity in the front center of thefreezing pipes and rock is biggest. The diameter-velocity curve, the charge-velocitycurve and the distance-velocity curve are created. The stress and vibration velocity offreezing pipes and rock mass is bigger with bigger diameter, bigger charge and shorterdistance. The results are reasonable comparing to the theories.The maximum shear stress of the freezing pipes is at the interface when thefreezing pipes getting though different formations. The shear stress of the freezingpipes become stable apart from the interface. The shear stress is smaller when thefreezing pipes in the rock with higher elastic.