Prefabricated supporting pipe piece inverted 'T'-shaped excavation method and temporary supporting structure adopted by urban shallow buried large-section tunnel

Abstract

The invention belongs to the technical field of urban underground engineering and particularly relates to a prefabricated supporting pipe piece inverted 'T'-shaped excavation method and a temporary supporting structure adopted by an urban shallow buried large-section tunnel. The temporary supporting structure comprises prefabricated temporary vertical supporting pipe pieces and temporary transverse supporting pipe pieces, wherein the middle partition wall of an upper left step is formed by splicing and erecting the temporary vertical supporting pipe pieces; an inverted arch of the upper left step is formed by splicing and erecting the temporary transverse supporting pipe pieces; an inverted arch of an upper right step is formed by splicing and erecting the temporary transverse supporting pipe pieces; and each temporary vertical supporting pipe piece is provided with a grouting hole. According to the prefabricated supporting pipe piece inverted 'T'-shaped excavation method and the temporary supporting structure adopted by the urban shallow buried large-section tunnel, the temporary supporting structure does not drop to the bottom by adopting temporary vertical supports, and the temporary vertical supports are closed with temporary transverse supports to form an innovative inverted 'T'-shaped excavation method; and an upper step is divided into the upper left step and the upper right step for two-step excavation, and an area of the one-time remolding to a tunnel face soil body is reduced. The construction method provided by the invention has the advantages of simple step, strong operability as well as remarkable economic benefit and social benefit and saves the land.

Description

technical field [0001] The invention belongs to the technical field of urban underground engineering, in particular to an inverted "T"-shaped excavation method and a temporary support structure for an urban shallow buried large-section tunnel using prefabricated support segments. Background technique [0002] With the development of the city, the surface roads can no longer meet the increasing vehicle traffic, only the construction of underground roads to alleviate. How to construct shallow buried large-section tunnels safely and efficiently in urban core areas with high traffic pressure, narrow ground space and complex surrounding environment, it is particularly critical to choose an appropriate excavation method. For excavating large-section tunnels, there are currently excavation methods such as the step method, CD method, CRD method, and double-side-wall pilot pit method. Areas with poor strata have potential safety hazards; however, the CRD method and the double-side-w...

AI Technical Summary

Problems solved by technology

For the excavation of large-section tunnels, there are currently excavation methods such as the step method, CD method, CRD method, and double-side pilot pit method. They have their own advantages and disadvantages. There are potential safety hazards in areas with poor strata; however, the CRD method and the double-side-wall pilot pit method excavate more sections of the tunnel face, the construction space is smaller, and the amount of temporary support construction and demolition is large, which greatly reduces the construction efficiency; The construction of side wall pilot pit method is safe, but the speed is slower and the cost is higher

In addition, the above-mentioned existing construction methods all need to construct temporary vertical middle partitions or temporary inverted arches, especially when building large-section tunnels. In concrete construction, all temporary supports must be removed before secondary lining construction in the later stage. Not only is the construction efficiency low, but it also causes environmental pollution in the tunnel and a large amount of material waste, which is not suitable for the concept of green construction and energy saving.

Images