AU716414B2

AU716414B2 - Screw pile system

Info

Publication number: AU716414B2
Application number: AU43610/97A
Authority: AU
Inventors: Paul Camilleri
Original assignee: STEEL FOUNDATIONS Ltd
Current assignee: STEEL FOUNDATIONS Ltd
Priority date: 1996-10-29
Filing date: 1997-10-29
Publication date: 2000-02-24
Anticipated expiration: 2017-10-29
Also published as: AU4361097A

Description

P/00/011 Regulation 3.2

AUSTRALIA

Patents Act 1990

ORIGINAL

COMPLETE SPECIFICATION STANDARD PATENT Invention Title: "SCREW PILE SYSTEM" The following statement is a full description of this invention, including the best method of performing it known to us: THIS INVENTION relates to a screw pile system.

In particular, the invention relates to, but is not limited to, a screw pile system where the screw pile is assembled from a plurality of segments.

The term "screw pile" shall be used to also include "screw piers" and the like.

Screw piles are driven into the ground to provide increased load bearing capacity for building foundations.

Conventionally, screw piles comprise a tubular shank or body provided with one or more helical flytes.

With conventional screw piles, it is preferred that the :respective ends of the tubular shanks are configured so that one end of a first screw pile can be connected to the other end of a second screw pile so that the piles can be interconnected into a string.

This configuration of the piles adversely affects the manufacturing costs of the piles and does not allow plain, tubular sections to be used to connect segments provided with one or more helical flytes.

It is an object of the present invention to provide a screw piling system where two or more screw piling segments, each having at least one helical flyte, can be interconnected by "plain" piling shanks.

It is a preferred object of the present invention to provide the pile segments with a sleeve assembly adapted to engage the pile shanks and to be releasably secured thereto.

It is a further preferred object of the present invention to provide such a system where the sleeves and shanks may be releasably connected by lock bolts.

Other preferred objects of the present invention will become apparent from the following description.

In a broad aspect, the present invention resides in a screw pile system including: at least one screw-piling segment, having at least one helical flyte; a respective sleeve member at each end of the segment to releasably engage ends of adjacent pile shanks in a piling string; and respective locking means to releasably secure the ends of the shanks in the sleeve members.

a the °Preferably, at least one nut is welded in or around a hole in the wall of each sleeve member and is adapted to screw-threadably a. •receive a locking bolt, providing the locking means, to releasably secure the pile shank in the sleeve member.

Preferably, a thrust plate is provided in each sleeve member to limit the insertion of the pile shank into the sleeve member.

In one embodiment, at an end of one of the sleeve members, the locking means includes a screw-threaded socket adapted 'to releasably engage a complementary screw-threaded portion of the 4 end of the adjacent pile shank. Preferably, at an end of the other of the sleeve members, the locking means includes a screw-threaded portion adapted to releasably engage a screw-threaded socket on the end of a second adjacent pile shank.

Preferably, the socket and the screw-threaded portions have complementary square thread configurations.

Preferably, the, or each, helical flyte includes: a pair of flyte plates, each of substantially helical configuration, arranged to have central portions mounted on the segment in spaced relationship, where respective leading and trailing portions of the plates are convergent to a respective leading edge and a trailing edge.

Preferably, the adjacent leading portions are welded, brazed, glued or otherwise fixed along the leading edge, and the trailing portions are similarly fixed along the trailing edge.

To enable the invention to be fully understood, preferred embodiments will now be described with reference to the accompanying drawings, in which: :0 -FIGS. 1 to 4 are respective side views of first to fourth embodiments; FIG. 5 is a top plan view showing the configuration of the helical flytes on the segments; FIGS 6 and 7 are respective side and end elevational views of the pile shank; FIGS 8 and 9 are respective side and end elevations of the joiner; FIGS 10, 11 and 12 are respective side, side and end elevations of the joiner sleeve; FIG 13 is a side view of a completed joiner assembly; FIG 14 is an exploded side view of a fifth embodiment; 10 and S. FIG 15 is a perspective view of an alternative form of helical flyte.

Referring to FIGS 1 to 3, the piling segments 10, 20, o have substantially rectangular square shank portions 11, 21, 31 provided with helical flytes 12, 22 and 23, 32, 33 and 34, respectively, the flytes having the plan view shown in FIG (Preferably, the flytes are formed by cutting the section out of a metal sheet and deforming the sheet to a substantially helical configuration.) Each segment 10, 20, 30 has a respective socket at each end to receive the end of a "plain" piling shank 40, as shown in FIG 4.

In this embodiment, a piling segment 10, with a single helical flyte 12, has been used to interconnect the two piling shanks As shown in FIGS 6 and 7, the piling shanks 40 are 6 formed of RHS steel and are dimensioned to fit within the shanks 11, 21, 31 of the piling segments 10, 20, Referring to FIGS 10 to 13, the segment 10 has a shank 11 with a slot 15 provided in a side wall 16 to enable the insertion of a thrust plate 17 (which is welded within the shank 11) to divide the interior of the shank 11 into respective sockets 18, 19 to receive the ends of adjacent piling shanks Holes 110, 111 are provided in opposite side walls 16, 16a of the shank 11 and nuts 112, 113 are welded in the holes 110, 111 to receive locking bolts 114, 115 adapted to bear against the adjacent side face of a pile shank 40 received in socket 18, 19, respectively.

In use, the string will be assembled with two or more of the "plain" piling shanks 40 interconnected by one or more of the segments 10, 20, 30 until the pile is assembled to the desired length.

It may be preferred that only the piling segments 10 are used to interconnect the piling shanks 40 along the length of the string *000 and that the first portion of the string (or "pilot") is provided by one of 00 the segments 10, 20, 30 fitted with a point attack bit 50 (see FIG 1).

It will be readily apparent to the skilled addressee that the use of the segments enables piles of different lengths to be easily produced, where most of the length is provided by the "plain" piling shanks 40 which are much less expensive to manufacture than the conventional screw pile sections hereinbefore described.

In the embodiment of FIG 14, the sleeve 210 has an enlarged diameter socket 260, with a screw-threaded formation 261, to releasably engage complementary square threads 241 at one end of a cylindrical pile shank 240. Similar threads 262 on the sleeve 210 are releasably engageable in a complementary socket 242 on the shank 240 of a second file, or in a socket 251 on a point attack bit 250.

The screw threads provide easy installation (and removal 10 if required) of the sleeve 210 from the drilling string. The helical flyte r 212 may be substituted by the "folded" helical flyte 312 of FIG. i A pair of flyte plates 370, 371 are each formed from metal sheet and each has a central portion 372 373 intermediate a leading portion ~374, 375 and trailing portion 376, 377 respectively. The plates 370, 371 are spaced apart, eg., 10-50mm at the central portions 372, 373.

The leading portions 374, 375 are convergent to, and welded at, a leading edge 378. Similarly, the trailing portions 376, 377 are O convergent to, and welded at, a trailing edge 379.

In experimental tests, a flyte 312, formed from two sheets of 12mm thick steel, has approximately four times the strength of a helical flyte formed from a single sheet of 25mm thick steel with the same MPa rating.

The weld material 380, 381 can be selected for its hardwearing characteristics, to ensure long-life for the leading and trailing edges 378, 379.

Various changes and modifications may be made to the embodiments described and illustrated without departing from the present invention.

ai a. a

Claims

1. A screw pile system including: at least one screw-piling segment, having at least one helical flyte; a respective member at each end of the segment to releasably engage ends of adjacent pile shanks in a piling string; and respective locking means to releasably secure the ends of the shanks in the sleeve members.

2. A system as claimed in Claim 1 wherein: at least one nut is welded in or around a hole in the wall of each sleeve member and is adapted to screw-threadably receive a locking bolt, providing the locking means, to releasably secure the pile shank in the sleeve member. 9

3. A system as claimed in Claim 2 wherein: a thrust plate is provided in each sleeve member to limit the 9* insertion of the pile shank into the sleeve member.

4. A system as claimed in Claim 1 or Claim 2 wherein: at an end of one of the sleeve members, the respective locking means includes a screw-threaded socket adapted to releasably engage a complementary screw-threaded portion of the end of the adjacent pile shank.

A system as claimed in Claim 4 wherein: at an end of the other of the sleeve members, the locking 3/fb t means includes a screw-threaded portion adapted to releasably engage a screw-threaded socket on the end of a second adjacent pile shank.

6. A system as claimed in Claim 4 or Claim 5 wherein: the socket and the screw-threaded portion have complementary square thread configurations.

7. A screw pile system as claimed in any one of Claims 1 to 6 wherein: the, or each, helical flyte includes: a pair of flyte plates, each of substantially helical configuration, arranged to have central portions mounted on the segment or sleeve of a screw pile in spaced relationship where respective leading and trailing portions of the plates are convergent to a o respective leading edge and a trailing edge. 4 9e~

8. A screw pile system as claimed in Claim 7 wherein: 9* S o the adjacent leading portions are welded, brazed, glued or otherwise fixed along the leading edge, and the trailing portions are similarly fixed along the trailing edge. °o

9. A screw pile system having a segment substantially as hereinbefore described with reference to FIG. 1; or FIG. 2; or FIG. 3; or 4; or FIG. 13; or FIG. 14 of the accompanying drawings. DATED this twenty-second day of October 1999. STEEL FOUNDATIONS LIMITED By its Patent Attorneys AFISHER ADAMS KELLY