GB2181174A - A pile and method of installation thereof - Google Patents

Abstract

A pile has a longitudinal bore (3) and at least one opening (4) in its outer surface communicating with said longitudinal bore (3). Concrete, ceramic or metallic bodies (5) are placed within the openings (4), and after the pile has been placed (by driving or by positioning in a bore hole), these bodies (5) are urged outwardly into the surrounding ground by mechanical, pneumatic, or hydraulic means (not shown). Concrete is then cast into the central bore (3) and into any space (8) between the pile and the surrounding ground. The pile may have any cross sectional shape and the bodies (5) may be arranged in axially spaced circumferential groups (as shown, Figure 4), or helically along the pile. <IMAGE>

Description

SPECIFICATION Improvements in or relating to piling Fieldofinvention The present invention concerns bearing piles intended to support a vertical load. More particularly, the invention relates to concrete or metal piles which to their greater part are prefabricated.

Background of invention There are known two kinds of load bearing piles, namely, piles which are cast in situ directly into the drilled hole, the second type are prefabricated piles which are hammered into the ground.

It is generally known to employ prefabricated piles for various purposes, such piles are elongated, slen derbodieswhicharedriven i nto the g rou nd at chosen sites.

To some ofthe cast in situ piles, the holes into which the piles being cast are provided with cavities to add to the bearing capacity of the pile.

There are known various devices and techniques for making such cavities in the holes. These techniques or devices cannot be employed for prefabricated piles even though it has advantages as it adds to the bearing capacity of the pile by a great degree. It is therefore considered desirableto provide a method and prefabricated pile which is hammered into the ground andwhichwill have the advantages of a conventional hammered pile and the advantages of cast in situ pilewhich has been cast into a hole with the above mentioned cavities.

It is also considered desirable to provide a prefabricated pilewhich can be inserted into a made bore thus using a prefabricated pile in place where hammering is not possible or difficult.

Advantages By employing the method and pile according to one embodiment ofthe invention the following advantages are achieved: 1. A multiuse prefabricated pile.

2. Accuracy of production and product.

3. Better control and supervision of the product.

4. The possibility of performing additional operations after the insertion into the ground.

Short summary disclosure According to the present invention a new method isusedforobtaining abearingpilewhichalmost wholly can be prefabricated, this new method comprising the steps of: a) preparing or obtaining by casting or otherwise a pile body whose dimensions are in accordance with the purpose to which it is put, and having a sub stantiallycentral,throughgoing axial bore, b) providing recesses in the outerwall of the said pile body, either during preparation thereof or su bse- quently, the said recesses being in communication with the said central, throughgoing bore, c) placing concrete, ceramic or metal pressure resistant bodies within the said recesses, extending into the said central bore, d) placing the pile into its position by either hammering or inserting it into a prepared bore hole, e) urging the said bodies out of said recesses by means placed in the said central bore ofthe pile body that the said concrete, ceramic or metal bodies late rally enter into the interiorwail ofthe bore hole, f) grouting concrete mix into the said central bore ofthe pile, in case of the inserted pile grouting also the circumferential space between the pile body and the interiorwall of the bore hole made in the ground, such that the pile body, the said concrete, ceramic or metal bodies placed in the said recesses and the cast or grouted skin become united.

The invention further relates to pile bodies comprising a central, prefabricated part from which laterally extend concrete or other ceramic bodies and an outer skin which encloses the said central part and the laterally extending bodies.

Short description of drawings The above and furtherfeatures will become clear from the following detailed description which has re ference to the annexed drawings.

In the drawings: Figures 1 - 4 illustrate the steps ofthe new process.

Figure 5is a cross sectional view of a pile body according to the invention.

Figures 6-9 illustrate different pile bodies of differentcross sectional shapes before and afteractivation of the concrete, ceramic or metal bodies.

Detailed description ofone embodiment Pile bodies of differing length and cross sectional dimensions are being prepared and are kept in storage as might be required from timetotime.

In case the piles according to the invention are to be inserted into the bore holes, bore hole 1 is prepared in the ground at the site where piling is required to serve as foundation forthe vertical load expected.

Into the bore hole 1 is inserted a pile 2 which has a central,throughgoing bore3(see Figure 5). Inthe outer wall of pile 2 are provided, axially distanced from one another, openings 4which communicate withthethoughgoing bore 3. Intothese openings are placed concrete bodies or bodies of other materialsay burnt clay blocks or metal-which extend into bore 3. These bodies are indicated in Figure 5 by the numeral 5.

Bodies 5 may be placed in circumferential groups which groups are axially distanced from one another, they may also extend on the line of a helix along the pile body 2.

In a subsequent step, see Figure 2, the so prepared pile bodyis placed intothe bore hole 1. Following this, by mechanical, pneumatic or hydraulic means (which do not form part of this invention), the bodies 5 are moved radially, outwardly of the pile body (indicated by the arrows in Figure 3) and enter into the soil around the bore hole 1.

The means for bringing about the outward movement of the bodies 5 are symbolized by the broken lines 6 in Figures 3 and 4.

As has been stated, the diameter of the pile body 2 is less than that of the bore hole 1,thus a ring shaped empty space 7 remains between the pile body and the interior wall of bore hole 1. Into this space 7 is nowcastorgrouted a concrete mix which aftersetting forms a skin 8 on the pile body 2 enclosing also partly the bodies 5 and thus uniting the pile body 2, the bodies 5 with one another.

Whilethe bore hole in practicewill mostly be of circular cross section, the pile bodies may be cylindr icai, of square, hexagonal or other cross sectional shape.

Figures 6 - 9 exemplify such shapes.

Figure 6 shows a pile body 2 of hexagonal cross section (as does FigureS). Figure 7 shows a pile body of a cross section which may be likened to the shape ofthree letters Tjoined at the free ends of the legs of the T. The openings 4thus are created between the webs of the T's.

Figure 8 shows the pile body of Figure 6, placed in a circular bore hole with bodies 5 pressed into the soil around the bore hole 1.

Similarly Figure 9 exemplifies the position ofthe pile body 2 of Figure 7 in the circular hole 1 with bodies 5 pressed into the soil. In both Figures 8 and 9 the skin 8 is shown.

In casethatthe piles are being hammered into the ground, the above described method is similar, with the exception that the prepared bore hole 1 does not exist and cavities 8 are not existing as well.

It can be easily seen that the present method and pile enables one to choose the most suitable installation method according to the specific requirements and according to the soil condition at the site. For example, in unstable soil condition itis preferableto hammerthe pilewhile in stable conditions might be prefabricated to insert the pile into a prepared bore hole.

Also, and most important, all prefabricated piles driven into the ground obtain their bearing capacity by friction along their side walls of the hole. It is the purpose ofthis invention to provide a pile which obtain its bearing capacity by both friction and bearing elements along its side walls.

Claims (6)

1. Method of providing in the ground bearing piles intended to supportfoundations of building structures or serving like purposes, which method comprises the steps of: a) preparing or obtaining by casting or otherwise a pile body whose dimensions are in accordance with the purpose to which it is put, and having a sub- stantially central, throughgoing axial bore, b) providing recesses in the outerwall ofthe said pile body, either during preparation thereof orsubsequently, the said recesses being in communication with the said central, throughgoing bore, c) placing concrete, ceramic or metal pressure resistant bodies within the said recesses, extending into the said central bore, d) placing the pile into its position by either hammering or inserting it into a prepared bore hole, e) urging the said bodies out of said recesses by means placed in the said central bore of the pile body thatthe said concrete, ceramic or metal bodies laterally enter into the interior wall of the bore hole, f) grouting concrete mix into the said central bore ofthe pile, in case ofthe inserted pile grouting also the circumferential space between the pile body and the interior wall ofthe bore hole made in the ground, such that the pile body, the said concrete, ceramic or metal bodies placed in the said recesses and the cast or grouted skin become united.

2. Pile bodies comprising a prefabricated part having a central axis bore and opening in its outer surface which communicate with the said central bore.

3. Pile bodies, as claimed in claim 1, characterised by concrete, ceramic or metal-pressure resisting bodies placed in the said apertures.

4. Method of providing in the ground bearing piles substantially as hereinbefore described.

5. Bearing piles, substantially as hereinbefore described and shown in the annexed drawings.

6. A pile having a longitudinal bore and at least one opening in the outer surface ofthe pile communicating with said longitudinal bore.