Method and system for tunneling extrahard rock by means of hydraulic fracturing technology and tunneling machine

Abstract

The invention relates to a method and system for tunneling extrahard rock by means of a hydraulic fracturing technology and a tunneling machine. By means of the hydraulic fracturing technology, the extrahard complete rock generates cracks, and therefore the rock integrity is lowered; according to the formation condition, the drilled hole position and the fracturing sequence of a face are designed, a drill rod stretches out of a hole to perform perpendicular punching in sequence on the face, a to-be-fractured section inside the drilled hole is sealed through a packer, high-pressure water is pumped into the to-be-fractured section, the hydraulic pressure is increased continuously, after the hole wall is fractured, cracks are expanded, and pressurizing is stopped after the cracks are expanded to the preset length, the packer together with other fracturing devices is taken out, and the tunneling machine begins tunneling. According to the method and system, the integrity of the rock within the construction range is lowered, the tool abrasion during tunneling is reduced, and the tunneling efficiency is improved.

Description

technical field [0001] The invention belongs to the technical field of tunnel construction, and in particular relates to a method and a system for assisting a tunnel boring machine to excavate extremely hard rock by using hydraulic fracturing technology. [0002] technical background [0003] Tunnel boring machine, also known as TBM (Tunnel Boring Machine), is a factory-like assembly line tunnel construction equipment integrating mechanical, electrical, hydraulic, optical, and gas systems. The maintenance and replacement of cutting tools affect the process of tunnel construction. At the same time, the consumption of cutting tools is also one of the items that account for a large proportion of the construction cost of tunnel boring machines. [0004] Tool consumption is generally measured by tool consumption rate, that is, the number of tools consumed per meter of footage or the number of tools consumed per 100m of footage. The cutter ring is the part of the cutter that direct...

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Problems solved by technology

[0004] Tool consumption is generally measured by tool consumption rate, that is, the number of tools consumed per meter of footage or the number of tools consumed per 100m of footage. The cutter ring is the part of the cutter that directly contacts the rock mass for rock breaking, so the tool consumption mainly refers to the tool ring. Consumption, when the knife ring rolls to break the rock, it will gradually wear out, the diameter will become smaller, and the top of the knife will become wider. When the wear reaches a certain level, the knife will fail because it cannot continue to be used, and the higher the strength of the rock mass, the greater the abrasiveness. The conclusion that the more severe the tool wear has been confirmed by many studies, therefore, in extremely hard and complete rock formations, the length of excavation that can be driven by each new knife is very short, requiring frequent shutdowns for maintenance and tool replacement, which consumes man-hours and Increased costs, resulting in inefficient tunnel boring machines

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