Expanding precast pile and construction method for expanding precast pile

Abstract

The invention discloses a diameter-expanded precast pile and a construction method for the diameter-expanded precast pile. The expanding precast pile comprises a precast pile body and an elastic air bag, the precast pile body is provided with a pile cavity and a drainage channel used for communicating the pile cavity with the outside, the side wall of a precast pile body is sleeved with the elastic air bag, and the elastic air bag is configured to be capable of expanding under the pressure effect of a filling medium introduced along the drainage channel and define a filling cavity with the side wall of the pile body. The construction method for expanding the precast pile comprises the following steps: driving the precast pile into a soil layer; the pile cavity is inflated, so that the elastic air bag is expanded by air pressure to form a filling cavity; and air inflation is stopped, concrete grout is poured into the pile cavity, and the filling cavity is filled with the concrete grout. And the concrete grout in the filling cavity is combined with the precast pile into a whole after being condensed, so that the concrete precast pile with the expanded section is formed in the soft soil, the upper load of the precast pile is effectively transmitted to a deep soil layer, the relative displacement of the precast pile and the soil layer and the settlement amount of the precast pile are reduced, and the bearing capacity of a soft soil foundation is remarkably improved.

Description

Technical field [0001] The present invention relates to the field of soft land base treatment, and in particular, to an expanded preform pile and a construction method for expanding the prefabricated pile. Background technique [0002] Soft soil usually has poor water content, high compression, low load capacity, etc., and improve the mechanics and engineering characteristics of such soils before engineering construction. At present, most soft soil foundation projects use a composite foundation method or a method of playing prefabricated piles. Composite foundation methods include having cement soil piles, gray piles or perfusion pile composite foundations, but due to high water content, large pores ratio, complicated material components, and a hole in the forming hole, the phenomenon, The quality of the pile cannot be guaranteed. Although the method of making a prefabricated pile can improve the soft land base carrier capacity, since the stiffness of the prefabricated pile is to...

AI Technical Summary

Problems solved by technology

Composite foundation methods include setting cement-soil piles, lime-soil piles or cast-in-place pile composite foundations, etc. However, due to the high water content, large void ratio, and complex material composition of soft soil, shrinkage or collapse is very easy to occur during the process of hole formation. As a result, the quality of the pile cannot be guaranteed

Although the method of setting prefabricated piles can improve the bearing capacity of soft soil foundation to a certain extent, due to the large difference between the stiffness of prefabricated piles and that of soft soil, the side friction of prefabricated piles is small, and it is easy to cause prefabricated piles to collide with soft soil. In the case of relative movement, the upper load cannot be effectively transmitted to the deep soil layer, so it is often necessary to increase the diameter of the prefabricated pile, but this will significantly increase the economic cost and increase the difficulty of pile driving

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