A construction method for shallow-buried long-span tunnel with small net distance and four lanes

Abstract

The invention discloses a construction method for a small-clear-distance four-lane shallow-buried large-span tunnel. The construction method comprises the steps: step S10, alternately constructing two tunnels along the longitudinal direction, wherein the alternating distance is not less than 40 m, performing the look-ahead hole long roof pipe, look-ahead grouting small guide pipe and hollow grouting anchor rod operations, grouting the surrounding rock so as to form the composite lining supporting structure; step S20, excavating and supporting the upper half section of the side pilot tunnel; step S30, excavating and supporting the lower half section of the side pilot tunnel, and performing the formworking secondary lining to the side pilot tunnel; step S40, excavating and supporting the upper half section of the intermediate hole chamber; step S50, excavating and supporting the lower half section of the intermediate hole chamber, and performing the formworking secondary lining to the intermediate hole chamber; and step S60, paving the road surface and decorating the wall. The construction method for the small-clear-distance four-lane shallow-buried large-span tunnel is applied for underground-excavating the separated two-hole tunnel in double directions in the V-level surrounding rock with seriously broken rock bodies, satisfying the tunnel construction safety, reducing the construction risk, improving the construction efficiency, and saving the construction period.

Description

technical field [0001] The invention relates to the field of engineering, in particular to a construction method for a small clear distance four-lane shallow-buried long-span tunnel used for two-way underground excavation of a separated two-cavity tunnel in V-level surrounding rocks with relatively broken rock bodies. Background technique [0002] In the prior art, due to considerations of route planning requirements and terrain constraints, it is sometimes unavoidable to adopt tunnels with a small clear distance for traffic routes. The traditional small distance tunnel has the problem of mutual influence between structural safety and construction, and measures must be taken to solve it. Due to the great technical difficulty and risk in the design of a single-hole four-lane tunnel with a small clear distance, it will be very difficult to study the structure of a four-lane shallow-buried long-span tunnel with a small clear distance and to carry out a safe and reasonable four-...

AI Technical Summary

Problems solved by technology

[0003] The existing shallow-buried long-span tunnel with small clear distance and four lanes has the following technical problems: the structural design is unreasonable, and there are certain hidden dangers in construction; the construction method and process are not standardized, resulting in low structural strength and safety stability of the tunnel

In addition, there are problems such as low construction efficiency, long construction period and high cost.

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