A support method for a shallow-buried and large-span tunnel with a small clear distance and four lanes

Abstract

The invention discloses a support method for a shallow-buried large-span tunnel with four lanes in a small clear distance, comprising: Step S10, constructing two tunnels longitudinally staggered, the stagger distance being not less than 40m, carrying out long shed pipes at the entrance of the tunnel in advance, and small conduits for grouting in advance and hollow grouting bolt operation, which is used to strengthen the surrounding rock by grouting to form a composite lining support structure; step S20, dynamically judge the stability of the surrounding rock and the support system according to the changes in the mechanical form of the surrounding rock and support system after tunnel excavation. Reliability of the protection system, process the information obtained from construction monitoring, establish the judgment criterion, and adjust and modify the surrounding rock level, support parameters and composite support lining structure according to the judgment criterion. Implementing the support method of the present invention for a shallow-buried large-span tunnel with a small clear distance and four lanes is used to excavate a separate two-cavity tunnel in two directions in a V-level surrounding rock with a relatively broken rock body, so as to meet the safety of tunnel construction and reduce construction risks. On the other hand, it can improve construction efficiency and save construction period.

Description

technical field [0001] The invention relates to the field of engineering, in particular to a support method for a shallow-buried large-span tunnel with a small clear distance, four lanes, and a split-type two-cavity tunnel dug bidirectionally 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-lane tunnel ...

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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