Excavation construction technology for subway station foundation pit in upper-soft lower-hard ground

Abstract

The invention discloses an excavation construction technology for a subway station foundation pit in upper-soft lower-hard ground. The excavation construction technology is characterized in that a middle support structure is arranged in the middle of the constructed subway station foundation pit; a retaining structure of the constructed subway station foundation pit comprises an upper-part retaining structure, a middle-part retaining structure and a lower-part retaining structure; a lower-part foundation pit is divided into an upper foundation pit and a lower foundation pit; the middle support structure comprises a plurality of dug piles; the dug piles are concrete-filled steel pipe piles; and each concrete-filled steel pipe pile comprises a steel pipe support pillar, a middle joint structure and a lower joint structure. The excavation construction of the subway station foundation pit comprises the following steps: A, synchronous construction of the middle support structure and the upper-part retaining structure; B, excavation of an upper-part foundation pit; C, construction of the middle-part retaining structure; D, excavation of the upper foundation pit; and E, excavation of the lower foundation pit. The excavation construction technology is simple in step, reasonable in design, simple and convenient in construction and good in using effect, and ensures that the excavation construction process of the subway station foundation pit in the upper-soft lower-hard ground can be simply, conveniently and quickly completed and is safe and reliable.

Description

technical field [0001] The invention belongs to the technical field of subway station construction, and in particular relates to a construction technique for excavating a foundation pit of a subway station in an upper-soft and lower-hard stratum. Background technique [0002] The subway station is an important building in the urban rail transit network. It is a place for passengers to take off, transfer and wait. The cover-excavation method is a new engineering construction method adopted when the underground engineering needs to cross obstacles such as roads and buildings. Specifically, after the ground is excavated to a certain depth, the top is closed, and the rest of the substructure is in the closed area. Construction under the roof. The main structure can be done forward or reversed. When using the cover-excavation method to construct a subway station in upper hard and lower soft ground, the construction is more difficult. For example, when constructing the Wusi Squ...

AI Technical Summary

Problems solved by technology

But now, when excavating subway station foundation pits in upper hard and lower soft ground, especially for the excavation construction of subway station foundation pits with large-diameter excavated piles in the middle of the inner side, there are few construction materials that can be used for reference, and the construction is difficult

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