Optimization Of Self-expanding Packing Body And Model Blasting Experiment

Drilling and blasting is the most widely used and effective rock breaking method in current rock excavation projects.Blast hole filling is one of the key procedures in drilling and blasting operations,and it is an important means to improve the blasting quality and ensure the safety of blasting operations.Due to the lack of suitable packing materials and packing technology,the current blasting construction has little or no blast hole filling operation,resulting in low blasting energy utilization rate,poor blasting effect and serious blasting hazard.Based on this,this paper uses the expansion pressure characteristics of the expansion agent in the confined space after encountering water to design a self-expanding packer.The self-expanding packer preparation optimization and model blasting experiments are carried out.The specific work is as follows:(1)Based on the expansion mechanism of the expansion agent and the blast hole packing mechanism,a self-expanding packing body is designed,and the anti-sliding ability(expansion pressure and friction)and shear resistance(shear strength)of the self-expanding packing body are designed)And other stuffing performance tests.(2)Aiming at the problems of high temperature and pressure in the hydration reaction of the self-expanding packing body,the cooling and pressure-bearing experiments of adding refrigerant and explosion protection tube inside the packing body were carried out,and the cooling type and refrigerant ratio in the packing body were determined And the structure of the stuffing body cooling device,and the performance of the stuffing body was measured.(3)Conducted explosion experiments of blasting equipment under the action of selfexpanding stuffing bodies,and tested the wires of four types of detonation equipment of electric detonators,digital electronic detonators,detonators and detonating cords directly through the surface of the self-expanding stuffing body And the explosion performance after passing the explosion protection tube.(4)Based on two types of rock breaking methods,electric blasting and industrial explosive blasting,through high-speed photographic tracking,a model blasting effect comparison experiment of different packing materials was carried out,and the effect of the self-expanding packing body on the rock breaking effect was analyzed.The self-expanding packing body developed in this paper has 10 times the frictional force with the hole wall after the hydration reaction,the shear strength is about 1..21 MPa,and the retention time of the blasthole is 1.5 times longer than the river sand,indicating that the selfexpanding packing The body can achieve high-pressure,high-strength,and high-airtight blasthole filling,which can prolong the time for explosive gas to act on the rock and improve the rock-breaking effect.The explosion test of blasting equipment verified that the cooling and pressure-bearing device of the self-expanding packing body can ensure the safe transmission of the explosion-transmitting equipment and increase the field practicality of the self-expanding packing body.