Bidirectional helix extruding-enlarging pile construction method and bidirectional helix closed extruding-enlarging aiguille

Abstract

The invention relates to a construction method for bidirectional spiral expand pile and the bidirectional spiral closed expand bit. The construction method comprises drilling and expanding bore by the bidirectional spiral closed expand bit; pushing soil, which is obtained in drilling and expanding bore downwards, into the side wall of pile bore; the bidirectional spiral closed expand bit rotating upwards to drill and expand the bore again; pushing soil, which is obtained in drilling, expanding and lifting upwards, into the side wall of pile bore; starting the concrete pump to press the pile material into the pile bore while the bit is lifted. The bidirectional spiral closed expand bit comprises a connecting bar. At the lower of the connecting bar spiral expand body, closed expand body and dynamic sealing expand body are assembled on the connecting bar in the same axial line in turn from the bottom to the top or they are machined on the connecting bar together. The invention is provided with high loading capacity, small sedimentation quantity, better quality, low cost and smaller energy consumption so on.

Description

technical field [0001] The invention relates to a construction method for a bidirectional spiral extruded and expanded pile and a bidirectional helical closed extruded and expanded drill bit, which are applied in the field of civil engineering. Background technique [0002] In the field of civil engineering, modern pile foundations can be divided into three categories: non-compacted soil piles, partially compacted soil piles and fully compacted soil piles according to the influence of the pile-forming method on the soil layer. Due to the many technical, cost and environmental problems of non-squeeze piles, geotechnical engineering circles have been devoting themselves to the development of new types of piles, especially spiral piles, because the construction method of this pile is the same as Compared with non-squeeze piles, in addition to obvious technical and cost advantages, it also has environmental protection advantages such as no mud, no dregs, no vibration, and low no...

AI Technical Summary

Problems solved by technology

[0017] ——The prefabricated semi-screw pile adopts the high-frequency vibrator pile sinking method, which can only be applied to soft soil strata and small-diameter short piles

[0018] 2. Defects and problems of cast-in-place fully threaded piles and semi-screwed piles

[0021] ——Because of the uncertainty and non-uniformity of soil, soft and hard changes in the stratum, it is difficult to ensure the instantaneous synchronization during the generation of pile threads, which may cause some pile threads to be difficult to form according to the design requirements;

[0022] ——Because the two pile-forming methods both use the same-diameter center pipe and the long auger with a longer helical section, more drilling rig power will be consumed during the pile-forming process, which will affect the piling in the same formation and the same pile diameter. Drilling depth and cannot be applied to hard formations;

[0023] ——How to define the effective diameter of fully threaded piles or semi-screwed piles in the design calculation is still inconclusive. If the outer diameter of the spiral is used as the effective diameter of the pile, it may cause safety problems; if the outer diameter of the central tube is used as the pile The effective diameter of the pile will cause underestimation of the bearing capacity of the pile

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