Hydraulic and earth engineering – Foundation – Columnar structure
Patent
1996-01-04
1997-12-16
Taylor, Dennis L.
Hydraulic and earth engineering
Foundation
Columnar structure
405232, 405240, 405242, E02D 534
Patent
active
056977344
DESCRIPTION:
BRIEF SUMMARY
The invention relates to a method for forming a foundation pile in the ground utilizing a prefabricated pile shaft, in which, successively driven into the ground until the end of the tube extends into a bearing ground layer over a desired distance; the pile base and leaving clear an annular space between the walls of the tube and the pile shaft; direction over a limited distance with simultaneous exertion of pressure on the self-hardening mass around the base of the pile shaft; and
Such a method is known from DE-OS 21.20.691.
In this known method a smooth tube is used, driven into the ground by pile driving. After a prefabricated pile shaft has been placed into the tube and the annular space has been filled with a self-hardening mass, the tube is retracted from the ground with simultaneous exertion of pressure on the self-hardening mass by means of injection hoses, which self-hardening mass comes to lie around the pile shaft like a skin, at least in the bearing ground layer and also in the superjacent non-bearing ground layers. The thickness of this skin is substantially equal to the thickness of the annular space between pile shaft and tube. The adhesion of this skin of self-hardening mass to the bearing ground layer which surrounds this skin and which is compacted during pile driving, is not optimal and the presence of this skin in the non-bearing ground layer is undesired in view of the occurrence of negative adhesion at that location.
The object of the invention is to provide a method in which these drawbacks are overcome. To this end, the method according to the invention is characterized in that an interior injection tube connectable to the pile base; of an optionally self-hardening mixture via the injection tube to form a "mixed-in-place" mixture around the hollow tube; pile shaft is placed into the hollow tube, whereupon the hollow space in the tube, after closure thereof, is pressurized internally at the upper end and, subsequently, the tube is displaced in upward direction over a limited distance, thereby forcing the self-hardening mixture into the annular space, cleared through the upward movement of the tube; whereafter pressure being exerted thereby in downward direction on the self-hardening mixture in the annular space by the mixed-in-place mixture, surrounding the hollow tube.
The method according to the invention provides the following advantages over the known method: tube, but is determined by the width of the screw blade provided on the exterior of the tube, which width, at the location of the lowermost tube portion, may be chosen to be greater or smaller than the width of the screw blade at the location of the remainder of the hollow tube. During rotation of the tube in the unscrewing direction, the screw blade can exert a downward force on the skin of the mixed-in-place mixture present around the lower end of the pile shaft, so that this mixture is compacted and a good adhesion of this mixture to the surrounding ground layers and to the skin of self-hardening mass present around the pile base can be obtained. Also, a preload of the tip of the pile is realized, resulting in a very slight settlement behavior under load. Hence, the foundation pile thus formed has a greater bearing capacity than a foundation pile obtained with the use of the known method. non-self-hardening mixture such as bentonite may be supplied via the injection tube, so that in those ground layers the hollow tube is not surrounded by a self-hardening mixture. In this manner, negative adhesion, which has a adverse effect on the bearing capacity of the foundation pile, can be prevented.
It is observed that DE-PS 35.01.439 discloses a method for forming a foundation pile wherein a smooth tube, provided with a widened screw head at the lower end, is screwed into the ground, while, simultaneously, a self-hardening mixture is supplied via an injection tube and injected into the surrounding ground layer via the screw head. In this manner, a self-hardening--mixed-in-place--mixture is formed around the tube. However, the tube
REFERENCES:
patent: 2421666 (1947-06-01), Upson et al.
patent: 3198857 (1965-08-01), Childers et al.
patent: 3336760 (1967-08-01), Landau
patent: 3453832 (1969-07-01), Rehmar
patent: 4100750 (1978-07-01), Labrue
patent: 4623025 (1986-11-01), Verstraeten
Beheersmaatschappij Verstraeten B.V.
Taylor Dennis L.
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