Numerical Simulation And Experimental Research On The Impact Of Gas Driven Raw Rock Particles To Break Hard Rock

In recent years,as the country vigorously develops infrastructure construction,urban transportation,Sichuan-Tibet railway construction,underground excavation,and subsea tunnel excavation,hard rock excavation difficulties have generally been encountered.Most of the hard rock and other bad formations that can pass through with auxiliary methods are mostly TBM roadheaders.In order to make TBM roadheaders suitable for hard rock construction projects,under the premise of ensuring the cutting ability and efficiency of the roadheader,The new technology is attached to the TBM roadheader to assist in rock breaking.Existing rock breaking devices consume huge energy,and there are few studies on rock breaking using low-pressure gas.Highly efficient conversion of gas energy to a single large mass particle,and then the proto-rock particles are applied to the rock mass,which can better reduce energy loss and improve the efficiency of proto-rock particles impacting and breaking the rock.In order to study the impact of the proto-rock particles on the rock-breaking device and the influencing factors of the device-breaking rock by the gas with low energy loss.From the energy point of view,the SHPB experimental method is used to study the relationship between the energy density per unit volume of granite failure and the failure state of the rock sample.Clarify the structure of the original rock particle impact rock breaking device.The SHPB experiment is used to obtain the capacity of the compressed gas stored in the research device for the energy dissipation per unit volume of rock failure;the device is used to change the proto-rock particle impact cavity to perform the rock-breaking experiment to obtain the optimal proto-rock particle impact cavity length of 2g,3g,4g,5g proto-rock particles Respectively 20 cm,15cm,10 cm,5cm;using high-speed camera experiments to obtain 2g,3g,4g,5g proto-rock particle impact velocity,study the energy of the device,and get the device energy conversion rate of 28-40%,and the greater the storage pressure of the device,The energy conversion rate is low,and the energy loss is large.The device is used to conduct rock-breaking experiments on different influencing factors,namely the quality of the original rock particles and the pressure of the device.It is obtained that the rock has a better rock-breaking effect as the quality of the original rock particles and the pressure of the device increase;Cross experiments are carried out to obtain the dissipated energy of rock failure under different influencing factors.LS-DYNA numerical simulation software parameters are used to carry out rock-breaking simulation research to study the rock-breaking state in the process of rock-breaking by the impact of raw rock particles;the impact velocity of raw rock particles under different pressure conditions measured by the high-speed camera is used as the LS-DYNA numerical simulation software Parameter to study the energy dissipation of different proto-rock particle masses and proto-rock particle speeds on rock breaking.Comparing and analyzing the energy dissipation of experiment and numerical simulation under different influencing factors,it is obtained that under different influencing factors,the energy dissipation of rock failure has the same trend.