Construction method of an underground prestressed support structure

Abstract

The invention discloses a construction method for an underground prestressed support structure. The steps include: (1) sinking the support piles carrying the anchor cables; (2) horizontally supporting the top of the construction; (3) excavating the foundation pit until the initial excavation Set the depth, install N purlins within the range, and stretch the anchor cables to press against the N purlins; (4) Excavate the foundation pit, install the N+1 purlins, and make the anchor The cables are pressed against the N+1 purlins; (5) Complete the installation of all the purlins and pour the bottom plate; (6) Remove the purlins below the roof of the K-th floor and construct the roof of the K-th floor; (7) Remove the K-th floor For the purlins below the roof of the 1st floor, construct the roof of the K-1st floor; (8) complete the construction of the roof below the purlins of the Nth floor; (9) remove the tension on the anchor cables, and construct the roof. In this application, purlins are used to replace support members, and purlins are used as force transmission parts to form prestressed support piles, so that purlins and support piles are formed as a whole, ensuring the integrity and stability of the foundation pit support system .

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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