Coal measure strata tunnel milling digging and blasting combined construction method

Abstract

The invention discloses a coal measure strata tunnel milling digging and blasting combined construction method which includes: performing milling digging grooving on an upper step arc guide part (1), performing initial supporting after grooving of the upper step arc guiding part (1) is finished to form a stable bearing arch, performing milling digging grooving on two side walls of a lower step on a lower step left side wall part (4) and a lower step right side wall part (3), performing initial supporting, performing core earth drilling, explosive filling and initiating on an upper step core earth part (2) and a lower step core earth part (5), ventilating, deslagging, and repeating the steps until a whole tunnel is dug. The construction method fully expresses the advantages of a mechanical milling digging method and a drilling blasting method, achieves accurate forming of a tunnel outline through mechanical milling and digging, causes small surrounding rock disturbance, is good in back break control effect, good in operation environment and high in construction security, reduces back break, protects surrounding rock, improves self-bearing capacity of the surrounding rock and avoids large deformation and partial collapse.

Description

technical field [0001] The invention relates to a combined construction method of milling and blasting for tunnels in coal-measure formations, and belongs to the technical field of tunnel construction methods. Background technique [0002] The Chinese Patent Gazette disclosed the patent application number 200910305045.9 on February 3, 2010, and the invention patent titled "Construction Method for Milling and Excavating Support of Submarine Tunnel Fault Fracture Zone". This patented technology uses a milling machine to carve grooves along the tunnel contour on the upper half of the tunnel, and then mills the middle rock mass of the upper half after installing the steel grid (all done by the milling machine), and then proceeds to the lower half Excavation or blasting excavation first, reserve a 50-100cm milling layer, after the blasting, use a milling machine for contour milling. This patented technology is suitable for subsea fractured strata, and its applicable section is s...

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Problems solved by technology

[0003] The object of the present invention is to provide a combined construction method of milling and blasting for tunnels in coal-measure strata to solve the problem of drilling and blasting construction of coal-measure strata tunnels with well-developed joints in IV, V and VI grades of medium hardness or relatively soft surrounding rock mass during construction. Large blasting disturbances, severe over-excavation, continuous partial landslides, and high-risk construction problems in coal seam gas tunnels

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