Rapid construction method of weak surrounding rock large-section multi-arc tunnel

Abstract

The invention discloses a rapid construction method of a weak surrounding rock large-section multi-arc tunnel. According to the invention, in tunnel construction, the main tunnel on one side of the multi-arc tunnel and the place of a partition wall are synchronously excavated; the tunnel excavation is implemented by using a double side-wall heading method; then, a primary support and the partition wall are constructed before the secondary lining of the tunnel; and finally, the main tunnel on the other side of the multi-arc tunnel is excavated by using a single side-wall heading method, and a corresponding support structure is built. Compared with the traditional multi-arc tunnel construction method, the construction method disclosed by the invention does not need to cut through a middle guide tunnel and build the partition wall before excavating the main tunnels on the two sides, thereby greatly accelerating the construction of the multi-arc tunnel, shortening the construction period and properly lowering the construction cost.

Description

technical field [0001] The invention relates to a tunnel construction method, in particular to a rapid construction method for a large-section multi-arch tunnel with weak surrounding rock. Background technique [0002] The multi-arch tunnel has many advantages, such as a large degree of freedom in the selection of the opening position, a small footprint of the lead wire, convenient bridge-tunnel connection, beautiful appearance, and convenient operation and management. In recent years, the multi-arch tunnel structure has been widely used in engineering practice. Its main construction methods are: [0003] (1) Pilot tunnel first excavation method [1、2] . The method is to excavate and penetrate the central pilot tunnel at the position where the partition wall is located in the multi-arch tunnel, and then build the central partition wall from the middle of the central pilot tunnel to the openings at both ends of the tunnel. Excavation of side tunnels and construction of corr...

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Problems solved by technology

[0006] Generally speaking, in the current construction of multi-arch tunnels, the construction method of excavating the central pilot tunnel first, then building the central partition wall, and then excavating the main tunnel is mainly adopted. The excavation is divided into many blocks and the construction speed is slow, which seriously affects The construction progress of multi-arch tunnels cannot meet the requirements of rapid construction of multi-arch tunnels. As a result, multi-arch tunnels are generally only suitable for short tunnels with a length of less than 500m.

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