Dam foundation one-step forming drilling blasting method by combining energy dissipation and energy collection of blast hole bottom

Abstract

Disclosed is a cushion blasting method based on a combination of hole bottom damage control and fast excavation, comprising steps: step 1. drilling in rock bodies vertical blasting holes that have collinear circle centers and are in rows; step 2. laying a cushion layer on the hole bottom of the blasting holes, the cushion layer being loose sand, rock powder or fine sand; step 3. adopting a rope to draw an energy dissipation seat to enter the blasting holes, and enabling the bottom surface of the energy dissipation seat to be placed on the cushion layer; and step 4. adding blasting powder inside the blasting holes and detonating the blasting powder after blocking it. The present invention is suitable for one-time formation of excavation for dam foundation surfaces and slope path protection layers, and has advantages such as a simple process, low cost, and a desirable excavation effect.

Description

Technical field [0001] The invention belongs to the technical field of engineering blasting, and in particular relates to a dam foundation excavation one-time forming drilling blasting technology that adopts a combination of hole bottom energy dissipation and energy gathering. Background technique [0002] The excavation quality of the foundation surface of the hydropower project and the slope protection layer of the horse road has always been the difficulty in the construction of the hydropower project. In the prior art, the traditional deep-hole bench blasting has low construction efficiency and large damage to the remaining rock mass at the bottom of the hole; horizontal pre-splitting or horizontal smooth blasting has good excavation results, but the construction efficiency is still insufficient Satisfactory. In recent years, the method of sequential initiation between holes in small steps with flexible cushions at the bottom of the hole. Due to the limited cushioning effect ...

AI Technical Summary

Problems solved by technology

In the prior art, the construction efficiency of the traditional deep hole step blasting is often very low, and the damage to the rock mass retained at the bottom of the hole is relatively large; the horizontal pre-splitting or horizontal smooth surface blasting has good excavation effect, but the construction efficiency is still not enough. satisfactory

In recent years, the sequential detonation method between holes in small steps with a flexible cushion at the bottom of the hole, due to the limited cushioning effect of the flexible cushion material on the blasting shock wave, the damage to the bottom of the hole is still relatively large, and the excavated foundation surface has a large fluctuation difference , resulting in a large amount of manual prying and excavation; at the same time, the ordinary energy-concentrating blasting using a wedge-shaped charge tank cannot achieve ideal results due to the limited energy-concentrating effect of the device.

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