Abstract: The effect of cutting and blasting affects the efficiency of underground mining operations.In the process of underground mining of an iron ore,there is a problem that the effect of the slotting blasting without cutting well process is not good.Starting from the traditional blasting process,first test the swelling coefficient of the ore particles in the squeezed state,then optimize the blasting parameters through numerical simulation,and finally verify the calculated results by comparing the field blasting effect.It was found that adjusting the blasting resistance line from 1.2 m to 1 m can overcome the problem of insufficient compensation space in the traditional blasting technology.Numerical simulation found that the effective stress value of the furthest unit point in the direction of the resistance line during the blasting process is greater than 61.3 MPa of the dynamic compressive strength of the ore.At the same time,the stress wave generated during the squeezing blasting process has a squeezing effect on the ore,meeting the test requirements.The ore crushing expansion coefficient is less than 1.333,meeting the blasting compensation space requirements.The traditional line of resistance calculation formula is not suitable for slotting blasting without well,and the compensation coefficient K0 should be considered.After the blasting parameters were revised,a good blasting effect was achieved.This test provides theoretical and data basis for mining construction technology of slotting blasting without cutting well in underground mining.

Key words: slotting blasting without cutting well,optimization of blasting parameters,coefficient of bulk increase,resistance line,numerical simulation