Novel construction method adapted to frost weather and used for spinning, extruding and expanding thread pile

Abstract

Provided is a novel construction method adapted to the frost weather and used for spinning, extruding and expanding a thread pile. A concrete conveying pipe arranged in a drilling rod is omitted. An output pipe of a concrete pump car is directly placed in a protective pipe arranged in a pile well for concreting, so that the external distance of concrete conveying is shortened effectively, and the technical problem that normal construction fails because of freezing and blocking of concrete in the conveying pipe due to the frost weather is avoided.

Description

technical field [0001] The invention belongs to the technical field of civil engineering, and in particular relates to a new construction method of a rotary-punching-squeezing-expanding screw thread pile suitable for severe cold weather. Background technique [0002] The rotary punching, extruding and expanding thread (screw) construction method is a mature pile method at present. It is widely used because of its following advantages: First, because the pile body has shallow screw teeth, it can change the frictional force into shearing force. Second, the combined roughness of the pile and soil is greater than that of ordinary piles, and its ultimate bearing capacity can reach 1.5-2 times that of ordinary piles; third, it can achieve no void soil at the pile end, and its rotary extrusion The overall settlement of the pressure grouting pile is smaller than that of the soil borrowing type pile, and the end resistance can be effectively exerted; the fourth is that the existence ...

AI Technical Summary

Problems solved by technology

During this construction process, there are two technical problems that cannot be overcome at present: one is that the outlet end of the concrete delivery pipe inside the drill pipe is very close to the drill bit. It is easy to generate heat, which is inevitably transferred to the outlet end of the concrete delivery pipe inside the drill pipe. The concrete will solidify when heated, causing blockage at the outlet end of the concrete delivery pipe, causing construction and safety hazards; Usually the length of the drill pipe will be greater than the depth of the pile well. When the drill pipe is lifted to the limit, the output pipe of the concrete pump truck is in order to achieve the purpose of communicating with the inlet end of the concrete delivery pipe inside the drill pipe. The length of the output pipe of the concrete pump truck It is very long. When the concrete is poured at the previous station and there is residue inside and it is severely cold, the residual concrete is easy to freeze in the output pipe of the pump truck and is extremely difficult to remove, which will affect the normal work of the concrete pump truck at the next station.

The above-mentioned defects restrict the use area and season time of the rotary punching extrusion thread expansion (screw) method, so it is necessary to propose an improvement