US2497377A

US2497377A - Pile

Info

Publication number: US2497377A
Application number: US52886A
Authority: US
Inventors: Swann Philip; Sung Reginald Henry Lothian
Original assignee: Individual
Current assignee: Individual
Priority date: 1947-10-17
Filing date: 1948-10-05
Publication date: 1950-02-14
Anticipated expiration: 1967-02-14

Description

2 Sheets-sheet 1 PILE P. SWANN ET AL Feb. 14, 195o Filed 001;. 5, 1948 Feb. 14, 1950 P. swANN ETAL PILE 2 Sheets-Sheet 2 Filed Oct. 5, 1948 Patented Feb. 14, 1950 PILE Philip Swann, Kildare, Hillbrow, Liss, England, and Reginald Henry Lothian Sung, Seria,

Brunei Application october 5, 1948, serial No. 52,886

In Great Britain October 17, i947 9 Claims. l

This invention relates to piles, and has for its object to provide an improved form of pile which will tend to have good load carrying properties and to overcome the difficulties normally experienced in obtaining adequate support for piles, particularly when sunk in sandy or other comparatively soft ground. A

The invention is particularly, but not exclusively, suitable for use where a foundation is to be formed by a comparatively large number of piles sunk in a small area.

The pile according to the invention comprises a stem containing a passage down which concrete or the like can be forced and a flexible expandible bag vso connected to the lower end portion of the stem that concrete or the like forced down the stem when the pile is in position enters and distends the bag laterally to provide a concrete or like footing for the pile, the dimensions of which are determined by the bag.

Preferably, the pile may comprise a point portion which is separable from the stem, the bag being initially folded within the pile with one edge connected to the stem and the other edge connected to the point portion, so that when concrete or the like is forced down the stem of the pile into the bag, the point portion-is moved away from the stem and the bag is then distended laterally through the gap thus formed between the point portion and the stem. Further, means may be provided for limiting the movement of the point portion away from the stem so as to determine the size of the gap through which the bag is distended laterally into the surrounding ground, and hence the depth of the foundation formed by the concrete in the bag.

For convenience the term ground is herein used to identify the material in which the lower portion of the pile is sunk, whether this be above or below water and irrespectively of whether it be of the character of soil, sand, mud, clay or otherwise.

According to a further feature of the invention, the pile is provided with one or more downwardly directed openings or nozzles communicating with a water passage within the stem of the pile through which water can be forced from the upper end of the pile so as to deliver jets of water through the nozzle or nozzles for the purpose of facilitating sinking of the pile and/or forming a cavity round the lower end ofthe pile when sunk.

The invention is illustrated by way of example by the accompanying drawings, in which Figure 1 is a longitudinal section of the lower end of the pile before distension of the bag,

and

Figure 2 is a similar View of the pile after distension of the bag.

The pile comprises essentially a reinforced concrete stem I with a longitudinal bore 2 therethrough, and a detachable steel point portion 3 initially secured to the lower end ofthe stern and formed with a series of openings or nozzles y.4 through which water jets can be forcedffor the purpose of displacing the material into which the pile is sunk round the point ofthe pile. The openings or nozzles 4 are shown inclined to the longitudinal axis of the pile and distributed over the conical lower end of the point portion 3, the inner ends of the passages communicating with a central water passage 5 in the point portion. Passing through the bore 2 of the stem is a water tube 6 the lower end of which is initially screwed into the upper end of the central waterpassage 5,4 so that the water tube serves to secure the point portion 3 to the stem I. The lower end portion o'f the stem comprises a metal housing 'I fixed to the main body of the stem, and defining an annular space in which is initially folded a exible canvas or like bag 8 formed for example from strong canvas reinforced with wire mesh, the bag being of annular form with one edge connected to the lower edge of the housing 'l and the other edge connected to the upper edge of the point portion 3. The stem I is provided with recesses Ill in which are slidable stop rods 9 each of which has an enlarged head I I at its upper end andis fixed at its lower end in bushes I2 in vthe point portion 3. V

In operation, the pile is sunk to the required depth and water is then forced'through thewater tube B and nozzles 4 to form a cavity round the point. During this operation, the upper end of the water tube 6 is held in position relatively to the top of the pile by a clamp so as to securejthe point portion 3 to the stem I, this upperend of the water tube'and pile not being shown in the drawing. When the ablove operation has 'been completed, the water tube 6 is unscrewed 'from the point portion and partially withdrawn there? frorn. To facilitate this the tube has right hand threads for its Various joints and a quick4 pitch left hand thread where it is connected to the point vportion 3. During the unscrewing operation the point portion 3 is prevented from turning by means of lugs I3 engaging recesses inthe housing 1.

When the point portion 3 has thus been released, concrete is pumped down the tube Band thus into the canvas or like bag 8; The point portion is thus forced down away from the stem until arrested by the stop rods 9, and the bag Ais then forced outwards through the gapV thus formed between the point portion 3 and :the housing 1, vthe-quantity of concrete introduced and the size of the footing for the pile thus provided being determined by the size of the bag when fully distended. An annular footing I4 of determined dimensions is thus provided and the concrete has the advantage of hardening in a coniined space under pressure, `thus ensuring a rm, strong and compact foundation, not adversely aiected by any extraneous matter nor `weakened by the presence of excess of water.

The central passage 5 and nozzles 4 in the point portion 3 of the pile are conveniently sealed off before the admission of concrete by a soft plug or ball l5 of wood which is dropped down the water tube 6 before its withdrawal and engages a shoulder I6 in the central passage in the point portion, so that the discharge of concrete through the jet nozzles 4 is prevented, and all the concrete is thus caused to iiow into the bag 8.

It will be seen that movement; of the stop rods V9 as the point portion 3 :moves away from the stem is limited by abutment of the enlarged heads rIl on .collars Il iixed in the recesses I0. The stop rods 9 act as reinforcing members in the final concrete footing i4, and the length and number of .these rods may be varied .to suit requirements.

It 'will be Iseen that by using piles according to the invention and giving to the canvas bag asuitn able shape, the dimensions of the concrete foundation `can be fully predetermined and controlled, thus enabling the accurate design of pile installations to be completed with condence for different types of ground, particularly where the use of water jets is possible, while moreover the :supporting Capacity of the piles does not rely only on surface friction.

Ordinary .types of piling frame can be used with the piles according to the invention, with the laddi-tion of an attachment in the form of a cradle which can -be yclamped around each pile to hold it in position whilethe concreting .operation is in progress and during hardening of the concrete.

It will `also be appreciated that the pressure exerted by the concrete-distended bag assists in producing Vrapid Nconsolidation of the surrounding soil around the pile point which is liable lto have been disturbed by the water jets, and this shortens the interval between vthe time when the pile is .erected and the time when it is rable to take its load.

Thus, particularly in large piling schemes in sandy land other soft ground formations, apprecable saving can be made by employing piles according to the inventions while, further, piling in exceptional sub-.surface conditions may be suc- .Cessfully effected by the use of piles according to the invention with suitable sizes and shapes of bag, when other forms of piling would be impossible or unsatisfactory.

'We claim:

1. A pile comprising an upper 4hollow section and a lower pointed section, releasable means ,for initially securing the lower section to the hollow section, a flexible expandible bag secured to the lower portion of the upper section and the upper portion of the lower pointed section initially folded within the sections, and means for introducing concrete to the bag, whereby when the means for initially securing the sections together is released and concrete is introduced into the bag, `the point section will be separated from the upper section and the bag containing the concrete will be distended laterally through the space formed between the separated sections.

2. A pile as dened in claim 1, wherein means are provided for limiting lthe movement of the lower point section from the upper hollow section.

3. A pile as defined in claim 1, wherein the lower point section is provided with downwardly directed nozzles for distribution of water introduced through the hollow upper section.

A4:. A pile as dened in claim l, wherein means are provided for holding the two sections together to prevent said sections independently rotating when driving the pile in the ground.

5. A pile comprising an upper hollow section and a lower pointed section, a tube initially securing the two sections together, the lower pointed section having a central passage with which the tube engages, whereby to initially hold `the two sections together, nozzles formed in the lower pointed section, said nozzles communicating with the passage, a flexible foldable bag secured to the lower .part of the upper section and to the .upper part Aof the pointed section, whereby when the tube is disconnected from the lower pointed section and concrete is forced through the tube the sections will be separated and the bag with the concrete forced laterally through the space formed between the separated sections.

6. A pile .comprising an upper hollow section and aY lower pointed section, a tube initially securing the two sections together the lower pointed section having 1a central passage with which the tube engages, downwardly inclined nozzles formed in the lower pointed section communicating with the passage, a rflexible foldable bag secured to .the lower portion of the upper section and to the upper por-tion lof the lower pointed section and initially confined in the hollow section, whereby water forced through the tube will be distributed through the nozzles to displace the earth, and whereby when the tube is disengaged from the lower pointed section and concrete is introduced into the upper hollow section the lower pointed section will be forced away from the upper section and the bag containing the concrete distended laterally through the space formed between .said sections.

7,. A pile as claimed in claim 5 wherein the passage in the lower pointed section is formed with a shoulder and a plug seated on the shoulder when the tube is disengaged from the lower pointed section.

8. A pile as claimed in claim 5, wherein means are provided between the two sections for limiting the separation of the lower pointed section from the upper hollow section.

9. A two-part pile having a cavity formed b tween the two parts, means for initially securing the two parts together, a exible bag initially folded in the cavity between the two parts of the pile, and means for separating the parts and introducing concrete tothe folded bag to distend the same through the space formed between the separated parts.

PHILIP SWANN. REGINALD HENRY LO'I'HIAN SUNG.

REFERENCES CITED The following references are of record in the file of this patent:

FOREIGN PATENTS Number l i l l