Pile foundation underpinning structure traversing group pile foundation and construction method thereof

Abstract

The invention provides a pile foundation underpinning structure traversing a group pile foundation and a construction method of the pile foundation underpinning structure. The pile foundation underpinning structure comprises an existing bearing platform structure and existing piles. The existing bearing platform structure is horizontally supported by the tops of all the existing piles, and the multiple existing piles are arranged. The outer portion of the existing bearing platform structure is wrapped with an underpinning bearing platform. The underpinning bearing platform comprises a primarypouring bearing platform and a secondary pouring bearing platform. The primary pouring bearing platform is located above the secondary pouring bearing table. The outer side of the existing bearing platform structure is wrapped with the primary pouring bearing platform. A plurality of underpinning piles are symmetrically and vertically arranged on the two sides of the bottom of the primary pouringbearing platform. The pile foundation underpinning structure can be used for existing pile foundation underpinning construction in the process of an underground structure traversing the group pile foundation, through secondary pouring of the bearing platform, it is ensured that midspan rebars on the lower side of the underpinning bearing platform are uniformly arranged in a pass-through manner, and meanwhile the defect that the durability of later planting ribs cannot be guaranteed or the detection difficulty is large is overcome; compared with a traditional method, the method is safer; and meanwhile, the existing pile foundation and the existing bearing platform are cut in advance, and the pile foundation load is prevented from being directly transmitted to a new structure.

Description

technical field [0001] The invention belongs to the field of geotechnical engineering, in particular to a pile foundation underpinning structure passing through pile group foundations and a construction method thereof. Background technique [0002] With the acceleration of urbanization in my country, more and more urban underground structure construction projects conflict with existing pile foundations. Due to the dense distribution of pile foundations in pile group foundations, the traditional pile foundation underpinning technology cannot guarantee the penetration of the main stress reinforcement on the underside of the new underpinning cap, and the mid-span part where the cap load acts is also the internal force concentration of the underpinning structure Point, security is difficult to guarantee. [0003] Moreover, in the construction of traditional underpinning structures, it is often difficult to guarantee the quality of the rebar planting between the new cap and the ...

AI Technical Summary

Problems solved by technology

Due to the dense distribution of pile foundations in pile group foundations, the traditional pile foundation underpinning technology cannot guarantee the penetration of the main stress reinforcement on the underside of the new underpinning cap, and the mid-span part where the cap load acts is also the internal force concentration of the underpinning structure point, security is difficult to guarantee

[0003] Moreover, in the construction of traditional underpinning structures, it is often difficult to guarantee the quality of the rebar planting between the new cap and the existing cap, and the durability of the rebar structure is poor. Therefore, a new structure and construction method is needed to achieve Underpin the existing cap, so that the connection surface between the old cap and the new cap is in the compression area after the cap is loaded. In this way, there is no need to plant bars to resist tension, and only need to use the compressive capacity of the concrete structure, which can be compared Good Construction Quality and Durability of Reinforced Underpinning Structures

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