Construction method for foundation pit pile-anchor support system adjacent to existing underground structures

Abstract

The invention discloses a foundation pile-anchor supporting system for a close existing underground structure and a construction method of the system. The supporting system comprises front-row steel pipe piles, rear-row steel pipe piles, rear-row vertical prestressed anchors, a front-row pile top beam, a rear-row pile top beam, transverse connecting reinforcements, front-row anchorages, rear-row anchorages, cushion blocks, tapered iron pieces, front-row prestressed anchors and wales. Through the vertical prestressed anchors arranged in the rear-row steel pipe piles, occupancy in underground space can be reduced greatly, and limited ground surface and space within building lines are fully utilized. The vertical prestressed anchors are anchored to the good ground, usage of the rear-row steel pipe piles can be reduced greatly, good anchorage force is provided, the front-row prestressed anchors are used for anchoring and stabilizing the rock stratum, and overturning resistance of the overall structure is improved. By the aid of the rear-row vertical prestressed anchors and the prestressed anchors arranged in the front-row steel pipe piles, factor of safety against overturning of the supporting system is enhanced effectively, construction cost is lowered, and construction period is shortened.

Description

technical field [0001] The invention belongs to the technical field of civil engineering foundation pit support, and in particular relates to a foundation pit pile-anchor support system for adjacent existing underground structures and a construction method thereof. Background technique [0002] In recent years, with the acceleration of urban construction, land resources have become increasingly scarce, and the available space on the ground and underground has become less and less. Many proposed buildings are forced to be built next to and very close to existing buildings. , so while making full use of the land, it also causes the following problems: [0003] 1. Since the foundation pit of the newly started building is adjacent to the existing building, it is difficult to choose the slope support method for the foundation pit of the new building. Neither slope excavation nor soil nail wall support nor pile anchor support can be used. . [0004] 2. If the traditional pile (w...

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Problems solved by technology

[0006] In order to solve the above-mentioned traditional pile (wall) anchor support, the width of the soil after the pit is limited, the angle of the anchor cable is large, the support effect is not good, and some foundation pits cannot be constructed with anchor cables at all, resulting in excessive deformation of the foundation pit or construction. difficult or impossible to anchor, etc., the present invention seeks to find a method that can not only overcome the limitation of external space, but also have better support effect, and the consumption of engineering materials is relatively small, the construction cost is relatively low, and the construction period is relatively short. A foundation pit pile-anchor support system and its construction method for adjacent existing underground structures with relatively high technical and economical efficiency

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