Hard rock tunnel construction method

Abstract

The invention discloses a hard rock tunnel construction method. The hard rock tunnel construction method comprises the following steps that an arrangement mode of drill bits of an electric pulse rockdrill is designed according to the shape of a tunnel face needing to be drilled, wherein the high-voltage electrode and the low-voltage electrode of the drill bits have a preset distribution so as toperform rock break on the tunnel face through the pulse discharge effect of the high-voltage electrode and the low-voltage electrode, and the overall distribution area of the high-voltage electrode and the low-voltage electrode is larger than or equal to the cross-sectional area of a shell of the electric pulse rock drill; and the electric pulse rock drill is adopted to perform rock breaking construction on the tunnel face. When the tunnel face is subjected to rock breaking, outlines excavated by the drill bits can completely contain the shell of the electric pulse rock drill, thus over-breakand under-break can be avoided, and the stability of a tunnel supporting structure system is ensured. Meanwhile, due to the fact that the electric pulse rock drill performs rock breaking by utilizingthe pulse discharge effect, the drill bits do not need to rotate in the rock breaking process of the tunnel face, so that the wear amount of the drill bits is small, and the rock breaking efficiency is high.

Description

technical field [0001] The invention relates to the technical field of rock crushing, and more specifically, relates to a hard rock tunnel construction method. Background technique [0002] In the construction of mining, hydropower, geological exploration, civil engineering, transportation and petroleum engineering, it usually involves the construction of breaking rocks, and the construction cost is directly affected by the efficiency of rock breaking. The rock breaking methods commonly used in the prior art include mechanical Rock breaking and dynamite blasting to break rock. [0003] On the one hand, with the continuous deepening of the depth and breadth of human resource exploitation, the acquisition of crude oil, natural gas and geothermal energy in the future will require unconventional wells such as deep wells and ultra-deep wells, and traditional mechanical drilling methods are used to drill hard rocks. Or in ultra-deep wells, the drill bit is easy to wear, the drill...

AI Technical Summary

Problems solved by technology

[0003] On the one hand, with the continuous deepening of the depth and breadth of human resource exploitation, the acquisition of crude oil, natural gas and geothermal energy in the future will require unconventional wells such as deep wells and ultra-deep wells, and traditional mechanical drilling methods are used to drill hard rocks. Or in ultra-deep wells, the drill bit is easy to wear, the drilling efficiency is low, and the rock-breaking drilling is more difficult

[0004] On the other hand, when using the traditional drilling and blasting method for rock-breaking construction, due to the large distance between the drilling center of the rock drill and the edge of the shell of the rock drill, if it is necessary to ensure that the drilling direction of the rock drill is parallel to the axial direction of the excavated tunnel, the second drilling The excavation profile will be smaller than the first excavation profile, resulting in a gradual decrease in the excavation radius, affecting the quality of the tunnel, and also causing a large amount of under-excavation

However, if it is necessary to keep the tunnel profile unchanged, there will be a certain angle between the drilling direction and the hole axis when drilling peripheral holes, which will cause the excavation profile to spread outward in the radial direction, resulting in a large amount of overbreak

This not only has a serious impact on the stability of the tunnel support structure system, but also greatly increases the construction cost of the tunnel due to the increased slag discharge and backfilling workload.

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