Single-free-surface combined blast hole broaching blasting method

Abstract

The invention discloses a single-free-surface combined blast hole broaching blasting method. The method comprises the steps that a blasting center hole and a plurality of circles of combined blast holes around the blasting center hole with different distances are arranged, the blast holes are charged in a sectioned mode and independently controlled to detonate, all the blast holes are subjected tosubsection delay blasting from bottom to top according to the explosive sections, and the delay blasting of the same section of explosive is completed by all the combined blast holes in a mode from inside to outside by taking the center blast hole as a starting point within blasting delay of the two sections of explosive in the center blast hole. According to the method, the combined delay initiation between the blast holes and in the blast holes is adopted, so that a common blasting funnel is formed, the broaching blasting effect is guaranteed, the action time of the pressure of the blastinggas in the combined blast holes is prolonged, more energy can be applied to the subsequent rock pushing and throwing, the explosive quantity of a single section of blasting can be greatly reduced, and the defect of large vibration of a traditional cut blasting in the same section is avoided.

Description

technical field [0001] The invention belongs to mine blasting technology, and in particular relates to a single free surface combined blast hole slotting blasting method. Background technique [0002] The blasting condition of only one free surface is often encountered in trench blasting and raise excavation blasting projects in underground mines. Affected by the construction accuracy of the drilling rig, the blastholes in the deep hole cut blasting inevitably have different degrees of deflection. The common cutting blasting method is to combine several blastholes into combined blastholes and blast at the same segment, and use the interaction between the explosion stress wave and the blasting gas between the combined blastholes to form a common blasting funnel. However, since there is only one free surface , and the single-stage blasting charge is large, the cutting blasting method often causes strong vibration effects, which adversely affects the surrounding rock mass and ...

AI Technical Summary

Problems solved by technology

Affected by the construction accuracy of the drilling rig, the blastholes in the deep hole cut blasting inevitably have different degrees of deflection. The common cutting blasting method is to combine several blastholes into combined blastholes and blast at the same segment, and use the interaction between the explosion stress wave and the blasting gas between the combined blastholes to form a common blasting funnel. However, since there is only one free surface , and the single-stage blasting charge is large, the cutting blasting method often causes strong vibration effects, which adversely affects the surrounding rock mass and facilities and equipment

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