Pipe gallery foundation pit with tension and compression support

Abstract

The invention relates to a pipe gallery foundation pit with an obvious width effect, in particular to a pipe gallery foundation pit with a tension and compression support. The pipe gallery foundationpit is structurally characterized by further comprising top beams, a pile top support steel pipe, a prestressed steel strand and at least one compressed inner support pipe; the top beams are positioned at the upper end parts of retaining structures; the lower parts of the top beams are fixedly connected with the retaining structures; two ends of the pile top support steel pipe are supported on theinner sides of the top beams at the upper ends of the retaining structures on two sides respectively; the prestressed steel strand penetrates through an inner cavity of the pile top support steel pipe; two ends of the prestressed steel strand are fixed to the top beams at the upper ends of the retaining structures on the two sides respectively; two ends of each compressed inner support pipe are supported and fixed on the inner side faces of the retaining structures on the two sides in the foundation pit respectively; the compressed inner support pipes are located below the pile top support steel pipes; the compressed inner support pipe closest to the bottom of the foundation pit is a lower compressed inner support pipe; and the distance between the lower compressed inner support pipe andthe bottom of the foundation pit is 1.5-2m. The pipe gallery foundation pit has the advantages that through the double effects of pulling and pressing, the situation that the retaining structures areunstable in an inverted splayed shape can be effectively reduced or avoided, and skirting damage and arc sliding type damage of the foundation pit are avoided.

Description

Technical field[0001]The invention relates to a pipe gallery foundation pit with obvious width effect, in particular to a pipe gallery foundation pit with tension and compression support.Background technique[0002]With the continuous acceleration of the urban development process, various types of pipe gallery foundation pit projects are increasing, and they account for a large proportion of the entire project investment and construction period, which is called one of the key links in the construction of control projects. The supporting structure on both sides of the existing pipe gallery foundation pit (using row piles or continuous walls, the row piles include cast-in-place piles, steel sheet piles, and SMW construction method piles) need to be based on overall stability, stability against overturning, arc sliding, and anti-uplifting at the bottom of the pit , Anti-seepage and other stability calculations to determine the depth of the sheet pile inserted into the bottom of the pit. ...

AI Technical Summary

Problems solved by technology

The support structure on both sides of the foundation pit of the existing pipe gallery (using row piles or continuous walls, and row piles include cast-in-place piles, steel sheet piles, and SMW piles) needs to be based on overall stability, anti-overturning stability, arc sliding, and anti-uplift at the bottom of the pit. Calculation of various stability such as anti-seepage and anti-seepage to determine the depth of the sheet pile inserted into the bottom of the pit. However, due to the different construction environments, different soil structures, and soil properties, the depth of the sheet pile often occurs in the following situations : Affected by the soil structure, the design depth cannot be reached; Affected by the soil properties, although the design depth is reached, the design stability requirements cannot be met

These problems will lead to the instability of the inner kick of the foundation pit of the pipe gallery and further lead to the overall instability of the foundation pit, which will bring great safety hazards to people's lives and property, such as the instability incident of the foundation pit of the Hangzhou Metro in 2008

[0003] In order to solve the above problems, the existing technology adopts the method of internal support, that is, a plurality of support horizontal pipes are distributed in the foundation pit, such as concrete cross braces, steel pipe supports, etc., only considering the function of the internal support to push outward, but the foundation pit The embedded stability of the foundation pit is realized by the insertion depth of the support structure, that is, the balance of the sheet pile is realized by relying on the passive earth pressure provided by the soil inside the foundation pit. Most of the above are valgus on both sides or one side, that is, the lower part of the support structure is deflected inward by the external thrust, and the upper part of the support structure is deflected outward, and even the soil at the bottom of the foundation pit is turned up and deformed. Some supporting horizontal tubes are difficult to play a role in controlling instability

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