Excavation method of high-pressure gas expansion fracturing in connecting channel of urban subway hard rock formation

Abstract

The invention discloses an urban subway hard rock stratum connection channel high-pressure gas expansion cracking excavation method, a connection channel is excavated by adopting an upper and lower step method, and the construction sequence of the step method is as follows: upper step excavation, construction of an upper step primary support, construction of an arch mortar anchor rod, excavation of a lower step, construction of a lower step primary support and construction of a connection channel secondary lining structure; wherein the upper step is excavated by adopting a mechanical method and an assistant high-pressure gas expansion fracturing method, and the lower step is excavated by adopting a high-pressure gas expansion fracturing method. The excavation method has the advantages of high efficiency of excavation through a blasting method, safety of excavation through a mechanical method, small influence range, basically no environmental pollution, high efficiency compared with pure mechanical excavation, good safety performance, little pollution, low noise, small vibration, easiness in control and the like.

Description

technical field [0001] The invention relates to the technical field of hard rock excavation, in particular to a method for excavating by high-pressure gas expansion and fracturing of connecting channels in hard rock formations of urban subways. Background technique [0002] In recent years, with the rapid development of my country's economy and the vigorous promotion of urban construction, the traffic flow in my country's cities has increased significantly. Traffic congestion and urban environment deterioration have become common and important problems to be solved in major cities. As a safe, fast, efficient and environmentally friendly form of transportation, urban subway has become the first choice for many big cities to solve traffic problems. In the planning and design of urban subways, it is usually necessary to set up a communication channel between the up and down tunnels. The communication channel is a very important auxiliary facility, which often plays the role of ...

AI Technical Summary

Problems solved by technology

These non-blasting excavation methods have the advantages of low vibration, low noise, safety and reliability, etc., but high cost, low rock breaking efficiency, large amount of personnel and equipment, and require multiple free faces, and excavation of hard rock with a strength exceeding 50MPa , extremely inefficient or even impossible to implement

At present, the excavation of connecting passages in the hard rock strata of urban subways is mainly carried out manually, supplemented by the use of simple mechanical tools (such as pneumatic picks) for excavation, and the efficiency is extremely low

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