A super-large-diameter hollow independent composite pile foundation and its construction method

Abstract

The invention discloses a super large diameter, hollow, independent and composite pile foundation and a construction method thereof. The composite pile foundation comprises a super large diameter thin wall reinforced concrete hollow pile, cement mixing piles, a pile end reinforced concrete thick plate and a pile surrounding grouted soil body, wherein the cement mixing piles surround the pile foundation to form a closed cement mixing pile wall; the super large diameter thin wall reinforced concrete hollow pile is made through section cast-in-place at the pile site or sectional splicing after prefabricating, and after the hollow pile body sinks to a designed position, the bottom end is sealed by concrete so as to form the hollow pile; after the formation of the hollow pile, high pressure jet grouting of cement grout is carried out at the part between the super large diameter thin wall reinforced concrete hollow pile and the cement mixing piles; and the pressure-injection of cement grout is further carried out at the bottom and the surrounding soil body of the hollow pile for reinforcement through pile bottom grouting pipes, horizontal grouting holes and vertical grouting holes, so as to form the composite pile foundation. According to the super large diameter, hollow, independent and composite pile foundation and the construction method thereof, a higher bearing capacity is achieved, the advantages of good pile quality and high safety are achieved, and meanwhile a better economic performance is achieved.

Description

technical field [0001] The invention relates to the field of building pile foundations, in particular to a super large-diameter hollow independent composite pile foundation and a construction method thereof. Background technique [0002] Pile foundations have been widely used in various projects, and the commonly used pile foundation forms are small and medium-diameter (including PC) single pile foundations and pile group foundations. Pile group foundations need to set caps (or connecting beams), and the interaction between piles and piles, piles and soil is relatively large, and the pile group effect is also obvious. The load transfer process of the pile body is complicated, and there are many factors affecting the bearing capacity. Both design and construction have brought higher cost and greater difficulty. With the development of society and economy, a large number of various engineering buildings (structures) have emerged, and large-diameter single piles (integrated pi...

AI Technical Summary

Problems solved by technology

Due to the limitations of existing theories, calculations, designs, construction methods, and reinstallation equipment, the bearing capacity of pile foundations mainly considers the support force at the pile end and the frictional resistance of the soil around the pile body, resulting in a large concrete in the super large diameter solid cast-in-situ pile. waste, and increase the pile body weight and the improvement of soil bearing capacity requirements; moreover, due to incomplete hole cleaning, necking, mud inclusions, fractures, etc., resulting in quality problems with the pile body, affecting the bearing capacity of the pile foundation, even the pile foundation safety; especially with the increase of pile diameter and pile length, the above unfavorable factors become more prominent, thus greatly restricting the application of ultra-large diameter pile foundations

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