Study On Vibration Response Law Of Freezing Pipe And Rock In Freezing Shaft Bedrock Section Under Blasting

With the application of drilling and blasting technology in saturated shaft construction,it is inevitable that the vibration effect of freezing pipe and rock in freezing shaft bedrock section under blasting.It often has significant security issues of shaft construction due to fractured freezing pipe under blasting.Therefore,it is that much deeper studying vibration response law of freezing pipe and rock in freezing shaft bedrock section under blasting,which has very important theoretical guidance significance and engineering application value for ensuring the shaft construction safety and speeding shaft construction progress.On the background of the specific coal mine engineering,the vibration response law of freezing pipe and rock in freezing shaft bedrock section under blasting was studied by means of combing the theoretical analysis,the indoor experiment and numerical simulation.Fristly,it was analyzed that the propagation and attenuation law of explosive stress wave in rock and the reflection,refraction and scattering law of plane p-wave on the interface between freezing pipe and rock,which was based on stress wave theory.It is obtained that the plural form of stress field and displacement field of freezing pipe and rock.Secondly,it was conducted that mechanical performance experiment of negative temperature saturated sandstone through uniaxial compression experiment of negative temperature saturated sandstone.It is obtained that basic mechanical parameters of negative temperature saturated sandstone which could provide theoretical parameters for numerical simulation.The result indicated that uniaxial compressive strength and elastic modulus of negative temperature saturated sandstone increase with the decrease of temperature and poisson's ratio of negative temperature saturated sandstone decrease with the decrease of temperature.Finally,it was studied that vibration response law of freezing pipe and rock in freezing shaft bedrock section under different explosive quantity,different distance and different temperature through numerical simulation.The result indicated that node radia vibration velocity is greater than node tangential vibration velocity and element maximum tensile stress is greater than maximum compressive stress in different reference position(meeting blasting plane,vertical plane and back blasting plane).The nole vibration velocity and element maximum principal stress increasewith the increase of temperature and explosive quantity,decrease with the increase of distance in different reference position(meeting blasting plane,vertical plane and back blasting plane).The node radia vibration velocity is greater than node tangential vibration velocity and element maximum tensile stress is greater than maximum compressive stress in rock around freezing pipe.Because of the existence of freezing pipe,it is affected that vibration law of node vibration velocity and element maximum principal stress in rock.