Composite foundation and construction method thereof

Abstract

The invention aims to provide a composite foundation which is high in pile strength, is large in stress area, is capable of improving a pile-soil replacing ratio and sufficiently transferring a pile-end soil body to participate in stress, and a construction method thereof. The composite foundation comprises a pile foundation and an upper cushion layer of the pile foundation, wherein the pile foundation consists of a peripheral cemented soil pile body, an inner concrete pile body, a pile top expanding part and a pile end carrier part; and the diameter of the pile top expanding part is greater than or equal to that of the cemented soil pile body. The invention further discloses a construction method for the composite foundation, wherein the construction method comprises the following steps: (1) stirring a soil body at pile location by adopting a mode of not excavating soil, and spraying cement paste into the soil body to form a cemented soil pile body; (2) before strength of the cemented soil pile body reaches initial setting strength, forming holes in the middle part of the cemented soil pile body by adopting a mode of extruding soil, wherein the hole-forming depth is greater than or equal to depth of the cemented soil pile body; (3) carrying out pile end carrier part construction; (4) carrying out concrete pile body and pile top expanding part construction; and (5) laying the cushion layer on the pile top.

Description

technical field [0001] The application relates to the field of civil engineering, in particular to a composite foundation form and a construction method thereof. Background technique [0002] At present, composite foundations are widely used in foundation treatment engineering in the field of construction engineering. Among the commonly used composite foundation treatment methods, deep-layer mixing piles and high-pressure rotary grouting piles are traditional treatment methods. The advantages of these two methods are that they are not excavated and can be used Original soil, but it also has its limitations, such as deep mixing piles have high requirements on soil quality and organic matter content, high-pressure rotary grouting piles are strictly controlled, and it is easy to cause slurry waste and environmental pollution, and the strength of the piles constructed by these two methods is not high. High, so the overall bearing capacity of its composite foundation is limited. ...

AI Technical Summary

Problems solved by technology

[0002] At present, composite foundations are widely used in foundation treatment engineering in the field of construction engineering. Among the commonly used composite foundation treatment methods, deep-layer mixing piles and high-pressure rotary grouting piles are traditional treatment methods. The advantages of these two methods are that they are not excavated and can be used Original soil, but it also has its limitations. For example, deep mixing piles have high requirements on soil quality and organic matter content. High, so the overall bearing capacity of its composite foundation is limited

In the high-strength composite foundation, due to the difficulty of passing through the soil layer and sometimes reaching the design depth during the construction of the prefabricated pile body, cast-in-situ concrete piles are often used as the reinforcement of the composite foundation. Concrete pouring technology is used for construction, such as CFG piles, but this kind of construction method uses the soil discharge method when forming holes, which requires on-site soil removal and is likely to cause problems such as empty soil at the bottom of the hole and environmental pollution.

Moreover, most of the bearing capacity of the above three methods comes from the side resistance of the pile, so in order to increase the bearing capacity, the length of the pile body has to be increased, resulting in increased construction costs

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