Method for directional energy-gathered blasting of retaining wall with low damage

Abstract

A method for directional energy-gathered blasting of a retaining wall with low damage includes the following steps of (1) drilling, (2) high-pressure water jet grooving, (3) powder charging, (4) hole sealing and (5) blasting. The method for directional energy-gathered blasting of the retaining wall with low damage has the advantages that grooving blasting, energy-gathered cartridge bag blasting and joint-cutting cartridge bag blasting can be reasonably combined, and complementary advantages are achieved. According to the method, the water jet grooving mode is used so that the defects of cutter clamping, drill holding and the like existing in a traditional mechanical indenting mode can be overcome, and considering that the sizes of jet flow seams are determined by jet flow parameters, the problem that the blasting effect is affected due to the sizes of seam grooves can be solved. An energy-gathered cartridge bag and a joint-cutting tube are utilized, the fact that the directional effect is enhanced at the same time when surrounding rock is protected is made to be possible, and the problem that the energy-gathered cartridge bag can not be accurately placed into a blasthole is also solved. After initiation of explosion, the position of grooving is cracked first, meanwhile, the joint-cutting tube has a certain buffering function and a certain guiding function, the damage of explosion stress waves and detonation gas on the surrounding rock is weakened, and therefore the purposes that surrounding rock damage is lowered and a smooth flat wall face is formed can be achieved.

Description

technical field [0001] The invention relates to the technical field of directional fracture control blasting, in particular to a low-damage directional energy-gathering wall blasting method. Background technique [0002] At present, directional fracture control blasting technology has been widely used in the tunnel excavation construction process, mainly including blasting hole cutting blasting method, shaped charge blasting method, and slotted charge blasting method. Among them, slotting blasting refers to cutting a groove of a certain depth on the axial wall of the blasthole according to the blasting cracking direction and design requirements, and then carrying out charge blasting. The stress distribution makes the explosion stress concentrate on the tip of the slot, and then realizes the directional fracture of the rock mass. However, the traditional mechanical grooving method is prone to problems such as jamming, difficulty in orientation, twisted notch, severe abrasion...

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