Charging construction method for contour blasting

Abstract

The invention provides a charging construction method for contour blasting. The method comprises the following steps of: drilling a contour hole according to the blasting design; binding explosive cartridges and a detonating cord on a fixing sheet; wrapping one part of explosives in contact with the fixing sheet by a water-absorbing expansion layer at the inner side of the water-absorbing expansion layer to form a charging structure; placing the whole charging structure in the contour hole, and when the charging structure is placed in the contour hole, enabling the part of explosives wrapped with the water-absorbing expansion layer to be directly opposite to and close to reserved rock mass; injecting enough water into the contour hole to enable the water-absorbing expansion layer to absorbwater for expansion, thereby pushing the charging structure to to-be-excavated rock mass far away from the reserved rock mass, and ensuring that gaps among the expanded water-absorbing expansion layer, the explosive cartridges and the inner wall of the contour hole are filled with the water; and filling the contour hole with borehole debris or gun mud and completing blocking of the contour hole.According to the method, the blasting damage to the reserved rock mass can be effectively controlled, the blasting crushing effect of the to-be-excavated rock mass can be improved, and the explosive energy utilization rate can be significantly increased.

Description

technical field [0001] The invention belongs to the technical field of engineering blasting, and in particular relates to a charge construction method for contour blasting. Background technique [0002] In various rock mass projects such as traffic engineering construction, water conservancy and hydropower construction, and mining mining, rock drilling and blasting technology has been applied unprecedentedly. Blasting technology is the main means of rock mass excavation and ore mining. In geotechnical engineering blasting, a part of the energy of explosive explosion is used to destroy the medium to achieve the purpose of engineering excavation or mining. However, most of the energy generated by explosive blasting is transmitted through the surrounding retained rock mass in the form of seismic waves and air shock waves. Rock mass or building structures cause vibration and damage, and even lead to serious damage, affecting the construction and operation safety of the project. ...

AI Technical Summary

Problems solved by technology

Traditional smooth blasting and pre-splitting blasting generally use spaced charges, and bamboo strips are used to bind explosive rolls at intervals to form an overall charge structure and put it into the blast hole. This charge method will eventually form an eccentric uncoupled charge structure. The damage in the hole is uneven, the rock mass near the explosive is severely damaged, and the rock mass far away from the explosive is slightly damaged

For contour blasting, the radial uncoupled charge coefficient is generally greater than 1.5. Although there are bamboo slices as spacers in the radial direction near the preserved rock mass, they are still seriously damaged due to the proximity to the explosives. The rock mass to be excavated is relatively slightly damaged, which is very unfavorable for improving the excavation and forming effect of the contour surface, controlling and retaining the blasting damage of the rock mass and strengthening the crushing of the rock mass to be excavated

Aiming at the unfavorable eccentric uncoupled charge structure of contour blasting, Chinese patent CN200910059196.0 discloses a smooth blasting construction method of front eccentric uncoupled charge. The distance from the binding pad, the charge string close to the side of the light blasting body is slowly put into the blast hole. This construction method installs the bracket before charging the charge. For the size of the blast hole in drilling and blasting, the charge string after the bracket is installed It is easy to get stuck when loading into the blast hole, especially when the charge string is slowly put into the blast hole on the side close to the light explosive body, it is difficult to construct

More importantly, when excavating more complex contour surfaces in actual blasting construction, it is difficult to adjust the eccentric uncoupled charge structure according to the relative position of the light blast body and the retained rock mass, and it is impossible to ensure that the charge string is always close to the light blast during charge. one side of the body, making it difficult to function effectively

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