A Construction Method for the Replacement of Trough Supports in Single-Arch Super-Large-span Subway Stations in Composite Strata

Abstract

The invention belongs to the technical field of design and construction of tunnels, underground engineering and urban rail transportation and particularly relates to a construction method for a composite stratum single-arch super long-span subway station through groove broaching and support substitution. The construction method is characterized in that an excavated section adopts three-layer three-part layered construction, specifically, side pilot tunnels on the two sides are constructed on the upper layer of the station at first, then a middle pilot tunnel is constructed, and the side pilot tunnels and the middle pilot tunnel are all manually excavated and constructed by adopting a bench method and are staggered at a distance of 15-20 m; two-layer construction is conducted on the lower portion of the station, middle groove broaching is conducted at first in a two-layer construction mode, a middle temporary support is established after middle groove construction is completed, then symmetrical edge groove broaching construction is also conducted in a two-layer mode, and temporary vertical support substitution and groove broaching are conducted so as to ensure the effect that an arch structure and arch foot surrounding rocks are stable; and secondary lining is sequentially conducted finally. The construction method for the composite stratum single-arch super long-span subway station through groove broaching and support substitution is suitable for construction of composite stratum single-arch super long-span station tunnels and underground structures, the structural stability is good, and the construction efficiency is improved.

Description

Technical field [0001] The invention belongs to the technical field of tunnel and underground engineering and urban rail transit design and construction, and in particular relates to the construction of large-scale underground structures such as shallow-buried and under-excavated single-arch subway stations or tunnels in composite stratum by adopting trough support substitution method method. Background technique [0002] With the rapid development of my country's urban rail transit industry, various types of geological conditions and corresponding structural types and construction methods have been encountered during the construction of subway stations. In recent years, a large number of large-span station tunnels and large-span multi-line tunnels with different structures have appeared in the metro construction in cities such as Chongqing, Qingdao, Dalian, and even Guangzhou. The excavation section of the station tunnel is generally 150~250m 2 , The shape is flat, usually the ...

AI Technical Summary

Problems solved by technology

The above methods all need to set up a large number of horizontal and vertical temporary supports to achieve step-by-step reduction in height and span, and each step of excavation is quickly closed and step by step forms a ring, so that in the case of subsequent blasting in rock formations, the following It is difficult to keep temporary supports, and it is more likely to cause major safety accidents due to blasting damage to supports; at the same time, the setting of horizontal and vertical temporary supports seriously affects the construction space and construction progress, and the work efficiency is extremely low. Large-scale mechanized construction cannot be realized, and the project volume is abandoned very big

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