A blasting method used in road mining

Abstract

The invention discloses a blasting method applied to access road type extraction. The dynamic tensile strength of rock is lower than the dynamic compressive strength of a filling body; after a peripheral hole is detonated, at the junction part of the ore rock and the filling body, a blasting stress wave generates a reflected tension wave and a transmission compression wave at two medium interfacesdue to different wave impendences of the filling body and the ore rock; and through calculating the distance between the peripheral hole and the filling body, the blasting parameter of a tunnel faceis determined, so that a stress wave peak value of the transmission compression wave produced at the two medium junction part through the stress wave generated by blasting is lower than the dynamic compressive strength of the filling body. The filling body is ensured to keep perfect without being damaged, and meanwhile, the strength of the produced reflected tension wave is larger than the dynamiccompressive strength of the rock, so that a rock breaking effect is improved. Through the method provided by the invention, an ore body in anaccess road can be ensured to be sufficiently blasted, andfillers at one side or two sides of the access road can be ensured to keep perfect without being damaged by the blasting stress wave.

Description

technical field [0001] The invention belongs to the technical field of mining, and relates to a multi-step approach method of backfilling mining method, in particular to a method for improving blasting quality in the approach method. Background technique [0002] When adopting multi-step approach mining method or open-field and then-fill mining method, because filling is carried out after the first-step mining is completed, during the second-step and third-step mining processes, the blasting stress wave generated by the blasting of the blast hole near the side of the filling body It will cause damage to the filling body and collapse, resulting in ore dilution. At the same time, the damage of the filling body will reduce its support to the surrounding rock of the upper and lower walls of the empty area, affecting the safety of the second and third steps of mining. Especially in the downward approach mining method, due to the small mining section, if the blasting parameters ar...

AI Technical Summary

Problems solved by technology

If the distance is too large, the rock at the junction of the filling body and the rock cannot be fully broken due to insufficient stress wave intensity, forming large pieces or hanging sides, resulting in ore loss and a threat to the safety of mining.

If the distance is too short, the intensity of the transmitted stress wave generated at the junction is too large, which will inevitably exceed the strength of the filling body and cause the filling body to be damaged, causing the filling body to cause the side of the filling body to fall off and cause secondary damage caused by the filling material mixed with ore. In severe cases, there may even be a large amount of collapse of the filling body, which will lead to safety accidents in the stope

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