Bottom expanding and pile-forming method for pipe sinking prefabricated steel concrete pedestal pile

Abstract

The invention discloses a construction foundation-pile project and a construction method, in particular to a bottom-expanding and pile-forming method of a sinking tube precast steel concrete bottom pile, which comprises: compressing the sinking tube to a hardpan of design evaluation through a soft soil layer; taking out a metal pile head for the construction of soil excavating and bottom-expanding; conducting a second soil uploading by using air; putting radiation steel bars into a base cavity and nailing the steel bars into the hard stratum; packing a certain amount of concrete which is made at the ground into a long barrel and putting the concrete on the bottom of the sinking tube through a sinking tube mouth; when an iron bar which is arranged at the bottom of the barrel contacts the hardpan, pressing off a barrel bottom door to cause the inside concrete to fall into the base cavity to form a cast-in-place base; putting a pre-stressed precast hollow pile to connect and fix with the cast-in-place concrete base into a body through the steel bar arranged at the bottom; and pulling out the sinking tube to form the pile. The bottom-expanding cavity of the invention has a regular geometry shape, the clean soil uploading without granular sediment and high efficiency; the invention effectively increases the bearing capacity of a single pile, reduces the construction cost, improves the utilization ratio of material strength, ensures the pile to work under a most economical condition and enhances the working safety.

Description

[0001] This application is a divisional application of application number 200610047085.4, application date 2006.06.30, invention name of bottom expansion and pile forming method of immersed tube prefabricated steel concrete expansion bottom pile. technical field [0002] The invention relates to a construction pile foundation project and a construction method, in particular to a bottom expansion and pile formation method of prefabricated steel concrete expanded bottom piles with immersed tubes. Background technique [0003] 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 ...

AI Technical Summary

Problems solved by technology

[0004]1. Part of the soil in the pile body was excavated manually, the construction surface was too large, the workload of soil extraction increased significantly, and the efficiency was low;

[0005]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 pile The quality of the pile is not easy to control, and it is difficult to meet the design requirements, resulting in a greatly reduced bearing capacity of the single pile;

[0006]3. There are potential safety hazards for construction personnel, and accidents are likely to occur if construction personnel do not pay attention;

[0007] 4. The scope of use is narrow, not only not suitable for small-diameter pile bottom expansion, but also not suitable for bottom expansion and bottom expansion of prefabricated piles and highly complex geological conditions. Pile;

[0008]5. The granular loose soil sediment in the cavity of the expanded bottom is not clean, which has a serious adverse effect on the bearing capacity of the pile. Based on the above situation, in order to improve the unit Pile bearing capacity, to reduce foundation engineering costs, must be improved

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