Collapsible loess section raft bearing pile casing cast-in-situ bored pile construction method

Abstract

The invention discloses a collapsible loess section raft bearing pile casing cast-in-situ bored pile construction method, and relates to the technical field of building construction. Concrete pouring is conducted in a raft foundation pit to form raft concrete, soil is backfilled and compacted and then excavated to the top face of raft mixed soil, a pile casing is buried, and the center of the pile casing is kept consistent with the center of a pile position as much as possible. A concrete raft plate with a large area is cast in situ in advance, a pile casing is installed on the raft plate, the stress area of the raft plate is increased by fully utilizing the concrete raft plate, and point loads generated by traditional cast-in-situ bored pile construction are replaced with surface loads, so that the pressure borne by undisturbed soil of a collapsible loess section in the construction process is reduced, and the bearing capacity and stability of the bottom of the pile casing are improved; it is guaranteed that the raft bearing pile casing does not sink, and the hole forming rate of the cast-in-situ bored pile at the collapsible loess section is increased.

Description

technical field [0001] The invention relates to the technical field of building construction, in particular to a construction method for bored piles with raft support and casing in collapsible loess sections. Background technique [0002] Collapsible loess is a kind of unsaturated under-pressure dense soil. When it is soaked in water, the strength of the soil will be significantly reduced, and it will be unstable due to the additional pressure and the self-weight pressure of the soil. The permanent deformation has a significant impact on the stability of the bridge bored pile casing. [0003] The bored pile casing has the functions of positioning the pile, controlling the pile hole, guiding the drilling direction, preventing hole collapse, and controlling the pile top elevation. The quality of the casing embedding directly affects the pouring quality of the bored pile. At present, the burial of pile foundation casings in collapsible loess sections is an urgent problem to be...

AI Technical Summary

Problems solved by technology

[0005] The purpose of the present invention is to provide a construction method for bored piles with raft support and casing in collapsible loess sections, aiming to solve the problem of burying pile foundation casings in collapsible loess sections

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