Construction process for prestress support in deep foundation pit

Abstract

The invention relates to a construction process for a prestress support in a deep foundation pit. The construction process specifically comprises the following steps: (1) cleaning a site and constructing and paying off; (2) construction preparation; and (3) constructing enclosure engineering: a prestress is applied in an enclosure mode by means of triaxial stirring pile water sealing, a cast-in-situ bored pile, a biaxial stirring pile, a stiffening anchor rod pile, anchor spraying and a semi-detached waist rail, wherein the step (3) specifically comprises the following steps: sequentially joining and alternately performing triaxial stirring pile water sealing, cast-in-situ bored pile enclosing and biaxial stirring pile matched with earthwork excavation and transportation; firstly, performing construction of the cast-in-situ bored pile, wherein two stirring pile drivers move in opposite directions to reduce construction cold joints, and 3-5 days after construction of the biaxial stirring piles, following up and inputting the mixture into a drilling machine for performing construction of the cast-in-situ bored pile; after construction of the cast-in-situ bored pile, excavating earthwork, and then continuously excavating earthwork after constructing the stiffening anchor rod pile, and performing anchor spraying and the semi-detached waist rail; and repeating the construction flowsin the steps till integral construction of a to-be-constructed super deep foundation pit is finished. The construction process efficiency is high, the safety of the foundation pit is ensured, and theconstruction period is shortened.

Description

technical field [0001] The invention relates to the technical field of building construction, to the technical field of deep foundation pit excavation construction, and in particular to a construction technique for prestressed support in deep foundation pits. Background technique [0002] With the development of economy and society, human beings have more and more demands on the construction of high-rise buildings and long-span bridges. Deep development. Ultra-tall buildings will inevitably require ultra-deep foundation pits as a guarantee. [0003] At present, the support engineering of deep foundation pit has become an important sub-item of high-rise building construction engineering. Since the earthwork of the foundation pit has not been excavated, the foundation pit support construction is developed in a completely concealed and semi-concealed state. Technology is heavily and widely studied in the engineering community. Especially in the construction in the central ar...

AI Technical Summary

Problems solved by technology

[0005] 1) It is prone to collapse and deformation of the excavated foundation pit;

[0006] 2) When digging a deep foundation pit, there are often potential safety hazards in adjacent buildings, underground structures and pipelines;

[0007] 3) The traditional underground diaphragm wall construction method requires large investment, low safety factor, and high construction noise. It requires a wide construction site and is not suitable for construction in urban centers; in traditional deep foundation pits supported by reinforced concrete When the concrete support construction is completed and the curing strength reaches the design requirement value, the soil can be excavated. There is no intersection between the support construction and the earthwork excavation process

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