Construction method of underground prestressed supporting structure

Abstract

The invention discloses a construction method of an underground prestressed supporting structure. The construction method comprises the following steps that (1), supporting piles carrying anchor cables are sunk; (2), a top horizontal support is constructed; (3), a foundation pit is excavated to a set depth for primary excavation, N enclosing purlins are installed in the range, and the anchor cables are tensioned to abut against the N enclosing purlins; (4), the foundation pit is excavated, the (N+1)th enclosing purlin is installed, and the anchor cables abut against the (N+1)th enclosing purlin; (5), all the enclosing purlins are installed, and a bottom plate is poured; (6), the enclosing purlins below the Kth layer of top plate are dismantled, and the Kth layer of top plate is constructed; (7), the enclosing purlins below the (K-1)th layer of top plate are dismantled, and the (K-1)th layer of top plate is constructed; (8), the construction of the top plate below the Nth enclosing purlin is completed; and (9), tensioning of the anchor cables is removed, and the top plate is constructed. According to the construction method, the enclosing purlins are adopted to replace supporting parts, the enclosing purlins serve as force transmission parts to form the prestressed supporting piles, so that the enclosing purlins and the supporting piles form a whole, and the integrity and stability of a foundation pit supporting system are guaranteed.

Description

technical field [0001] The invention relates to a construction method of an underground prestressed support structure. Background technique [0002] At present, in the construction process of foundation pits and underground structures, in order to reduce the cross-sectional area of ​​the supporting piles, people produce a kind of prestressed piles, which are based on the existing supporting piles, and then in the support A plurality of supports are arranged at intervals along the vertical direction on the protection pile, and the supports are extended in the horizontal direction. After the anchor cable is pressed against the support, after the anchor cable is stretched, the two ends of the anchor cable are It is fixed at both ends of the support pile, and the internal stress generated by the tension of the anchor cable is used to increase the bending resistance of the support pile, thereby increasing the strength of the support pile, thereby reducing the cross-sectional area...

AI Technical Summary

Problems solved by technology

[0003] Since the production of prestressed support piles can be completed in advance on the ground, a large number of prestressed support piles can be prefabricated in advance in batches, which can speed up the construction progress. However, in actual construction, it is found that when sinking the prestressed support piles underground , because the support protrudes in the horizontal direction, the prestressed support pile is subject to greater resistance from the soil, and since the support is generally only set on one side of the support pile, it is necessary to sink the prestressed support pile. The support pile exerts downward pressure, so the prestressed support pile often deviates from the predetermined position and tilts. In addition, when the prestressed support pile is sunk, stones or other hard impurities in the soil will cause the support to bend. Affect the tension of anchor cables, thereby reducing the strength of prestressed support piles, and affect the safety of foundation pits and underground structures during construction

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