Bottom-expanding and piling method for immersed tube bottom-expanding pile

Abstract

The invention discloses a construction pile foundation project and a method for constructing the same, in particular a method expanding bottom and forming pile by immersed tube. The method comprises the following steps that: an immersed tube with a metal pile head is pressed into a firm ground layer to a designed elevation; the metal pile head is taken out, soil body is burst by detonators, and then is absorbed; a bottom is expanded by a bottom expansion device, after a base cavity is formed at the bottom, the soil is taken out by an air absorption soil device; radial reinforcing steel bars are put into the base cavity and are hammered into the firm ground, the concretes which are prepared well on the ground are poured into the base cavity to form a concrete base; a prefabrication steel concrete pile body which is put into the concrete base and a cast-in-place concrete base are butt jointed and anchor fixed to form a whole through inserted reinforcing steel bars at the bottom of the concrete base; the immersed tube is pulled out, and a pile is formed. Compared with the prior art, the invention which uses the technical proposal has the advantages that: the process method is simple and advanced, the shape of the bottom expansion cavity is regular, soil is cleanly taken out without granular loose soil and the efficiency is high, thereby the bearing capacity of the single pile is effectively improved and reaches the designed specification, the quality of pile foundation project is ensured, the construction cost is lowered, the utilization ratio of the material strength is improved, the pile can be operated in the most economic condition and the constructing security is improved.

Description

technical field [0001] The invention relates to a building pile foundation engineering and a construction method, in particular to a method for expanding the bottom and forming piles of bottom-expanding piles with sinking tubes. Background technique [0002] It is well known that the quality of building foundation works plays a vital role in the influence of building quality, so each construction unit not only pays attention to the construction quality of above-ground buildings, but also pays more attention to the quality of foundation works. And invest in scientific research to tap the potential of the pile foundation project, so that it can improve the utilization rate of material strength on the premise of ensuring the quality of the project. As can be seen from the calculation, the bearing capacity of the pile tip designed by the solid pile only uses about 20% of the strength of the pile body. For the sake of safety, all countries have stipulated a safety factor, some co...

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Problems solved by technology

[0003] 1. Part of the soil body of the pile is dug out manually, the construction surface is too large, the workload of soil extraction is obviously increased, and the efficiency is low;

[0004] 2. Since there is no immersed tube as support for the bottom expansion equipment, the positioning is not accurate, the expansion angle of the base is too small, and the parameters in the bottom expansion process cannot be guaranteed, so that the quality of the pile is not easy to control, and it is difficult to meet the design requirements, resulting in the single pile The bearing capacity is greatly reduced;

[0005] 3. There are potential safety hazards fo...

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