Weak surrounding rock, tunnel intersection and arc-shaped pilot tunnel construction method

Abstract

The invention discloses a weak surrounding rock, tunnel intersection and arc-shaped pilot tunnel construction method. The method is characterized by consisting of the following steps: (1) excavating and supporting a mouth of a transverse hole; (2) constructing an advancing large pipe roof; (3) excavating and supporting a body of the transverse hole; (4) performing transverse hole inverted arch construction and bottom plate construction; (5) performing intersection door opening construction; (6) performing direct top brushing type excavation and supporting on an arc-shaped pilot tunnel; (7) mounting and supporting an upper guide arch frame of a front hole; (8) disassembling the temporary support of the arc-shaped pilot tunnel; (9) excavating and supporting the front hole by a step method; (10) constructing lining reinforced concrete on the body of the transverse hole; (11) excavating and supporting the front hole and adding a temporary inverted arch; (12) constructing a front hole inverted arch and adding a temporary cross brace; (13) constructing an inverted arch on the intersection front hole; (14) constructing lining reinforced concrete on the intersection; and (15) shifting to normal construction of the front hole. The arc-shaped pilot tunnel construction section is smaller than the front hole excavating section; the potential safety hazards of the arch change of the weak surrounding rock are avoided; the temporary work amount is small; the construction efficiency is high; the transverse hole at the intersection does not climb; and the stressed effect of the special-shaped arch frame of the front hole is good.

Description

Technical field [0001] The invention relates to a construction method of an arc-shaped pilot pit at the intersection of a soft surrounding rock tunnel. Background technique [0002] With the development of my country's national economy and technology, my country's transportation and other infrastructure construction has ushered in a new peak of development, and railways, highways and other transportation projects have developed rapidly. In the current railway, highway and other projects, in order to meet the needs of site, construction period and environmental protection, a large number of cross tunnels are used in tunnel construction. In the construction of the cross section of the tunnel, the excavation of the later construction tunnel often causes the disturbance of the surrounding rock and structure of the first construction tunnel, which affects the stability of the first construction tunnel, and even leads to the structural instability and destruction of the first construct...

AI Technical Summary

Problems solved by technology

In the construction of the cross tunnel section of the tunnel, the excavation of the later construction hole often causes the disturbance of the surrounding rock and structu...

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