Wedge-shaped underholing blast hole arrangement method suitable for deep-buried tunnel blasting excavation

Abstract

The invention discloses a wedge-shaped underholing blast hole arrangement method suitable for deep-buried tunnel blasting excavation. The wedge-shaped underholing blast hole arrangement method comprises the steps that a single-hole blasting test is conducted on a deep-buried tunnel excavation tunnel face; the maximum main stress direction on the excavation tunnel face is determined according to rock mass crack distribution around blast holes; and wedge-shaped underholing blasting blast hole arrangement is determined according to the maximum main stress direction. By arranging the wedge-shapedunderholing blasting blast holes in the maximum main stress direction on the excavation tunnel face, rock mass blasting cracks are advantageously expanded and broken, the using amount of explosives for underholing blasting is decreased, the underholing effect is improved, and designed tunnel excavation footage driving cycle is guaranteed.

Description

technical field [0001] The invention relates to the technical field of deep rock mass blasting, in particular to a method for arranging wedge-shaped cutting blastholes suitable for blasting and excavation of deeply buried tunnels. Background technique [0002] At present, the excavation of deep tunnels in hydropower, transportation, mining and other engineering fields is becoming more and more frequent, and the drilling and blasting method is the main method for rock mass excavation of deep tunnels. During the blasting and excavation of underground tunnels, the blastholes arranged on the excavation face are often divided into three categories: cut holes, caving holes and peripheral holes according to the different working principles, layout methods and related parameters. The cut hole is the first blast hole on the excavation face. The cut hole first blasts a cavity on the excavation face to create a new free surface for the blasting of the subsequent blast hole. Therefore,...

AI Technical Summary

Problems solved by technology

[0004] The purpose of the present invention is to provide a method for arranging wedge-shaped blastholes suitable for blasting and excavation of deep-buried tunnels, so as to solve the problem that existing wedge-shaped cutting blasting methods do not consider the influence of ground stress on blasting and cracking of rock mass, resulting in rock mass fragmentation Insufficient, the blasting slag is not easy to throw out, and the cutting effect is poor

Images