Horizontal inner support at capping beam elevation of foundation pit supporting and protecting system and construction method thereof

Abstract

The invention discloses a horizontal inner support at a capping beam elevation of a foundation pit supporting and protecting system and a construction method thereof. The structure of the horizontal inner support comprises a capping beam (1) and a supporting rod piece (2), wherein a reinforcement cage is arranged in each of the capping beam (1) and the supporting rod piece (2); the reinforcement cage is formed by binding longitudinal carrying non-prestressed reinforcements with transverse stirrups; a plurality of longitudinal sleeves run through the capping beam (1) and the supporting rod piece (2); a steel strand (6) is arranged in each longitudinal sleeve; all the steel strands (6) are stretched and anchored by anchors (8); the construction method has the key points that when the reinforcement cage of the capping beam (1) and the reinforcement cage of the supporting rod piece (2) are placed, the longitudinal sleeves with the steel strands (6) are arranged on the reinforcement cages, and each steel strand (6) is stretched after the strength of concrete reaches stretching strength; the structure and the construction method of the horizontal inner support are capable of both ensuring enough bearing capacity and anti-deformation capability and saving steel materials, and are convenient for subsequent demounting.

Description

technical field [0001] The invention relates to the field of civil engineering, in particular to a horizontal internal support at the elevation of the top beam of a foundation pit support system and a construction method thereof, and more specifically, to a horizontal internal support at the elevation of the top beam in the foundation pit support system. Structural and construction methods of post-tensioned unbonded prestressed concrete horizontally inwardly braced. Background technique [0002] With the continuous and in-depth development of urbanization, in order to effectively improve the utilization rate of land, it has become a trend for buildings to develop into underground space. The scale of building foundation pit excavation is also increasing, and the excavation depth is also deepening, so the foundation pit support system has also received more attention. The foundation pit support system consists of retaining wall structure (including pile row type and wall type...

AI Technical Summary

Problems solved by technology

[0003] As part of the foundation pit support system, the above-mentioned top beams and supporting rods must firstly meet sufficient bearing capacity, and secondly, they need to have better resistance to deformation. For example, the top beam needs to resist horizontal bending displacement and the supporting rods need to resist Vertical bending displacement, and finally the top beam and the supporting rods need to be easily disassembled, which creates the following contradiction: if sufficient bearing capacity and deformation resistance are required, the reinforcement ratio of the concrete structure must be increased, and due to the structural The reason is that the cross-sectional area of ​​the top beam and supporting rods is relatively large, so the amount of steel bars is naturally more, but more steel bars will not only increase the cost of consumables, but also bring many difficulties to disassembly

When disassembling the horizontal inward support, in order to avoid damaging the surrounding construction main structure, large machinery cannot be used, only small machinery or even manpower can be used to disassemble, which is troublesome and laborious, and delays the construction period

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