Study On The Mechanism And Application Of VCR Undercutting + Side Collapse

In recent years,with the rapid economic development,major mines have sought new breakthroughs in increasing production capacity and reducing costs.The traditional well-forming technology was eliminated,and the deep-hole blasting technology(parallel hole cutting and group-hole ball-shaped blasting into a well)came into being,but due to the influence of geological conditions and rock drilling equipment,there are still problems in actual construction.Based on the research background of"Makong Iron Mine Large Diameter Deep Hole Stope Cutting Patio",this paper systematically studied two major technologies through field research,blast theory analysis,blast funnel test,numerical simulation and on-site blast test.:(1)VCR cutting and blasting technology is used to solve the pit cut,(2)Lateral caving technology is used to solve the shape of the pit.The work carried out and the specific results are as follows:(1)In-depth investigation of the geological situation of the mining area and the current low efficiency and high unit consumption of blasting wells,and a more comprehensive summary of the factors affecting the efficiency of blasting wells,laying the foundation for the condensation of subsequent research ideas.(2)Based on Livingston blasting funnel theory,design and carry out a blasting funnel experiment with 100mm aperture,using the mining software 3dmine in data processing,and analyzing the data to obtain the 2.1kg spherical medicine pack.The best medicine embedding depth is 1.26m,the best Proportional burial depth 0.98kg/m~3;based on this,the theoretical calculation determines the blasting parameters of the spherical spherical charge.(3)According to the detonation theory,rock blasting theory and stress wave attenuation law,the radius of the smashing circle and fissure circle formed by the coupling spherical pellet with the diameter of 150mm and the diameter of the charge of 150mm are exploded in the rock body.The calculation result is:the radius of the crushing ring is 278mm,and the radius of the fissure ring is832mm.(4)On the basis of the blasting funnel experiment,the parameters of blasting well formation were theoretically calculated according to the blasting rock mechanism,VCR cut blasting mechanism and lateral caving mechanism,and the delamination height,blast hole spacing,millisecond time,loading The drug parameters provide a targeted basis for the selection of the parameters of the blasting well test program.(5)According to the theoretically designed spherical charge package cutting scheme,using ANSYS/LS-DYNA nonlinear finite element analysis software,and using elastic mechanics models to dig deep hole blasting into three types of pure VCR method:in-line,triangle and diamond The numerical simulation study of the slot method was carried out,and the relevant parameters such as the time of blasting stress wave superimposition,the maximum value of the stress wave superimposition of the adjacent blast holes and the maximum moving speed of the unit were obtained in the three cutting methods.The success rate of the groove to form an effective cut cavity is better,and it has a greater advantage in the production process.(6)VCR undercutting+lateral collapse well test was conducted in the large-diameter deep hole test quarry of Makeng Iron Mine.After three blasting tests,a cutting patio of 3m×3m×14.3m was successfully formed.Compared with the original well plan,fire engineering Material consumption is reduced by 43.68 yuan/m~3,and unit consumption is reduced by 3.278 kg/m~3.The driving efficiency has been improved by 1.3~1.5m/shift.