GB2363150A

GB2363150A - Spigot and socket pile section connection

Info

Publication number: GB2363150A
Application number: GB0012147A
Authority: GB
Inventors: Roger Alfred Bullivant
Original assignee: Roxbury Ltd
Current assignee: Roxbury Ltd
Priority date: 2000-05-20
Filing date: 2000-05-20
Publication date: 2001-12-12
Also published as: GB0012147D0

Abstract

A sectional pile is made of pile sections (10A, 10B) joined by introducing a spigot (14) into a socket (32). The socket (32) has internal dimensions sufficient to receive the spigot (14) without interference and joints are thus formed without the introduction of additional material into the socket (32). Alternatively, hot melt adhesive may be used within the socket (32).

Description

2363150 Immovements in or Relatim to Piles The present invention relates

to piles. Especially, but not exclusively, the present invention relates to concrete piles formed from pile sections adapted to be driven in end-to-end relationship into the ground to form a continuous loadbearing pile.

The present invention provides a pile comprising a plurality of pile sections each comprising an elongate body, there being spigot and socket means for connecting pile sections together, the socket means having internal dimensions sufficient to receive the spigot without interference, and there being joints formed between adjacent pile sections by the introduction of spigot means into socket means substantially without the introduction of additional material therebetween.

Preferably each pile section comprises spigot means projecting from one end of the body, and socket means provided at the other end of the body for receiving a spigot of a like pile section during use. A reinforcing member preferably extends through the pile section, between the spigot means and the socket means. The socket means are preferably provided by a socket insert connected to the reinforcing member and open at the said other end of the body. The socket insert preferably fits around the reinforcing member and may be an interference fit around the reinforcing member. The socket insert preferably provides two oppositely directed and substantially coaxial sockets for receiving the reinforcing member and a spigot, respectively. The socket insert may be a plastics member.

Preferably the spigot means is formed by an extension of the reinforcing member.

The elongate body is preferably concrete.

The invention also provides a pile joint formed between two pile sections, each comprising an elongate body, the joint comprising spigot means received in socket means, the socket means having internal dimensions sufficient to receive the spigot without interference, and the joint being formed substantially without the introduction of additional material between the spigot and socket. The pile may be as set out above.

The invention also provides a method of forming a pile from pile sections which each comprise an elongate body with which spigot means and socket means are associated for connecting pile sections to form a pile, the pile being formed by mating the spigot means with the socket means without interference and substantially without the introduction of additional material therebetween. The pile and pile joints so formed may be as set out in any of the preceding definitions.

In another aspect, the invention provides a pile comprising a plurality of pile sections each comprising an elongate body, there being spigot and socket means for connecting pile sections together, and there being joints formed between adjacent pile sections by the introduction of spigot means into socket means, there being hot melt adhesive introduced between the spigot and socket as or before the joint is formed.

Preferably, the adhesive is introduced into the socket before the joint is formed. The adhesive is preferably settable substantially immediately.

The elongate body is preferably concrete.

The invention also provides a pile joint formed between two pile sections, each comprising an elongate body, the joint comprising spigot means received in socket means, there being hot melt adhesive introduced between the spigot and socket as or before the joint is formed. The pile may be as set out above.

The invention also provides a method of forming a pile from pile sections which each comprise an elongate body with which spigot means and socket means are associated for connecting pile sections to form a pile, the pile being formed by mating the spigot means with the socket means and there being hot melt adhesive introduced between the spigot and socket as or before the joint is formed. Preferably the adhesive is introduced before the joint is formed. The pile and pile joints so formed may be as set out in any of the preceding definitions.

Embodiments of the present invention will now be described in more detail, by way of example only, and with reference to the accompanying drawings, in which:

Fig. I is a schematic side view of pile sections according to the invention, in use; Fig. 2 is a schematic side view, partly cut-away, of a pile section according to the present invention; and Fig. 3 is an enlarged, schematic and part cut-away view of a joint formed according to the present invention.

Fig. I shows a first pile section 10A, which has been driven into the ground 12 by conventional means. The pile section IOA consists of an elongate body of cast concrete, through which a reinforcing bar extends, as will be described. Fig. 1 shows a second pile section IOB being introduced to the pile section IOA, again comprising an elongate body of concrete, with a spigot 14 projecting from the lower end of the body. The spigot 14 is preferably an extension of the reinforcing bar, as will be described. A similar spigot extends from the lower end of the pile section 10A, but is capped at 16, as the pile section 10A is the first section to be driven. The upper end of the pile section 10A incorporates a socket, to be described further below, to receive the spigot 14 without interference. The spigot and socket arrangement ensures correct alignment between the pile sections IOAJOB, allowing pile driving to continue until, with additional pile sections being added as required, a pile of the required length is formed from several pile sections.

Fig. 2 illustrates a pile section 10 in more detail. The main elongate body 18 of the section 10 is of concrete material cast around the other components. The body 18 is of circular section, but could be square or of other section. A reinforcing bar 20 runs axially along the body 18, projecting from one end of the body 18 to form the spigot 14, and carrying a socket 22 at the other end, as will be described. The reinforcing bar 20 is preferably of steel and may have a serrated or roughened surface to ensure a good key with the concrete of the body 18, or there may be spiral or other flanges formed around the bar 20, again to ensure an adequate key.

Approximately mid-way along the bar 20, spacer legs 24 are provided to support the bar 20 in a mould, while the body 18 is cast around the bar 20.

The cylindrical wall of the body 18 is reinforced at each end of the section 10 by steel collars 26 which are connected with the bar 20 by spacer arms 28 for strength during use, and also to further assist in correct positioning of the various components while the body 18 is being cast.

The socket 22, and a joint formed between two pile sections 10, is shown in more detail in Fig. 3. The socket 22 is a body of appropriate material, such as a synthetic plastics material, and provides a first, relatively narrow socket 30, and a second, relatively wide socket 32. The sockets 30, 32 will be referred to, respectively, as the interference socket and the loose socket, for reasons which will become apparent.

The internal dimensions of the interference socket 30 are sufficiently small to ensure that when the socket 30 is fitted over the bar 20, an interference fit will be formed between the bar 20 and the walls of the socket 30, as can be seen in Fig. 3. This ensures a tight, effectively permanent connection between the socket 22 and the bar 20. The socket 22 is connected in this way to the bar 20 prior to the bar and its associated components being placed into a mould for casting the body 18. The socket 22 is pushed over the bar 20 until the bar 20 fully penetrates the interference socket 30, abutting a wall 34 which divides the interference socket 30 from the loose socket 32. An aperture 36 in the wall 34 allows air to vent as the bar 20 enters the socket 30.

The loose socket 32 has wider internal dimensions so that a reinforcing bar 20 (in this case the spigot 14 of another pile section 10) will be received in the socket 32 without interference. However, the walls of the socket 32 will guide the spigot 14 to ensure correct alignment of the pile sections 10A,10B. The joint formed in this manner is a "dry" joint. That is, no other material, such as adhesive or lubricant, is used to form a functional component of the joint. This limits the pile to being used only under compression, not tension, because there is no means for preventing the spigot withdrawing from the socket. However, we have realised that in very many piling applications, the pile is not required to perform under tension. Forming the joint dry, as described, ensures that consistent joints are formed, by removing the requirement for a workman to introduce adhesive or other material at the time f of forming the joint. This improves the consistency and predictability of performance of the joints.

While no additional material is used as a functional component of the joint, material may be used for temporary effect at the time of forming the joint, such as a lubricant.

During use, as has been briefly described above in relation to Fig. 1, each pile section 10 is driven until nearly wholly into the ground, leaving the socket exposed at the upper end. It is then a relatively simple matter to mate a further pile section for further driving, inserting the spigot 14 into the exposed loose socket 32. The loose fit of the spigot 14 in the loose socket 32 greatly simplifies the operation of mating pile sections 10. Pile driving can then continue.

In the description set out above, the joint has been described as "dry", i.e. substantially without the introduction of additional material between the spigot and socket. The arrangements described above can be modified to allow the use of the joint in tension, by introducing hot melt adhesive between the spigot and socket as the joint is formed, or before the joint is formed. For instance, hot melt adhesive can be injected into the socket. Any excess will be displaced by the spigot, as the spigot enters the socket. Hot melt adhesive will cool instantly, as it is introduced to the joint. This gives some instant bonding performance and also seals the joint against ingress of water during pile driving. The instant nature of the tension joint arises because the hot melt adhesive will quickly go off (perhaps within about 30 seconds). In particular, the speed of setting of the adhesive will be sufficient to give 20% or 30% of the final strength sufficiently quickly to prevent any other operations being delayed and is thus "instant" in this sense.

Many variations and modifications can be made to the apparatus described above, without departing from the scope of the present invention. In particular, dimensions, relative dimensions, materials and shapes can all be changed according to the particular application envisaged. The pile section described above is formed as male at one end and female at the other. However, pile sections could be male at both ends or female at both ends and used alternately, or female piles could be used with a separate double-ended spigot.

Whilst endeavouring in the foregoing specification to draw attention to those features of the invention believed to be of particular importance it should be understood that the Applicant claims protection in respect of any patentable feature or combination of features hereinbefore referred to and/or shown in the drawings whether or not particular emphasis has been placed thereon.

Claims

1. A pile comprising a plurality of pile sections each comprising an elongate body, there being spigot and socket means for connecting pile sections together, the socket means having internal dimensions sufficient to receive the spigot without interference, and there being joints formed between adjacent pile sections by the introduction of spigot means into socket means substantially without the introduction of additional material therebetween.

2. A pile according to claim 1 in which each pile section comprises spigot means projecting from one end of the body, and socket means provided at the other end of the body for receiving a spigot of a like pile section during use.

3. A pile according to claim 2 in which a reinforcing member extends through the pile section, between the spigot means and the socket means.

4. A pile according to claim 3 in which the socket means are provided by a socket insert connected to the reinforcing member and open at the said other end of the body.

5. A pile according to claim 4 in which the socket insert fits around the reinforcing member.

6. A pile according to claim 4 or 5 in which the socket insert is an interference fit around the reinforcing member.

7. A pile according to claim 5 or claim 6 in which the socket insert provides two oppositely directed and substantially coaxial sockets for receiving the reinforcing member and a spigot, respectively.

8. A pile according to any of claims 4 to 7 in which the socket insert is a plastics member.

9. A pile according to any of claims 3 to 8 in which the spigot means is formed by an extension of the reinforcing member.

10. A pile according to any of the preceding claims in which the elongate body is concrete.

11. A pile section for use in forming a pile according to any of claims 1 to 10.

12. A pile joint formed between two pile sections, each comprising an elongate body, the joint comprising spigot means received in socket means, the socket means having internal dimensions sufficient to receive the spigot without interference, and the joint being formed substantially without the introduction of additional material between the spigot and socket.

13. A pile joint according to claim 12 in which the pile sections form, in use, a pile according to any of claims 1 to 10.

14. A method of forming a pile from pile sections which each comprise an elongate body with which spigot means and socket means are associated for connecting pile sections to form a pile, the pile being formed by mating the spigot means with the socket means without interference afid substantially without the introduction of additional material therebetween.

15. A method according to claim 14 in which the pile sections form, in use, a pile according to any of claims 1 to 10.

16. A pile comprising a plurality of pile sections each comprising an elongate body, there being spigot and socket means for connecting pile sections together, and there being joints formed between adjacent pile sections by the introduction of spigot means into socket means, there being hot melt adhesive introduced between the spigot and socket as or before the joint is formed.

17. A pile according to claim 16 in which the adhesive is introduced into the socket before the joint is formed.

18. A pile according to claim 17 in which the adhesive is settable substantially immediately.

19. A pile according to any of claims 16 to 18 in which each pile section comprises spigot means projecting from one end of the body, and socket means provided at the other end of the body for receiving a spigot of a like pile section during use.

20. A pile according to claim 19 in which a reinforcing member extends through the pile section, between the spigot means and the socket means.

21. A pile according to claim 20 in which the socket means are provided by a socket insert connected to the reinforcing member and open at the said other end of the body.

22. A pile according to claim 21 in which the socket insert fits around the reinforcing member.

23. A pile according to claim 21 or 22 in which the socket insert is an interference fit around the reinforcing member.

24. A pile according to any of claims 21 to 23 in which the socket insert provides two oppositely directed and substantially coaxial sockets for receiving the reinforcing member and a spigot, respectively.

2S. A pile according to any of claims 21 to 24 in which the socket insert is a plastics member.

26. A pile according to any of claims 19 to 2S in which the spigot means is formed by an extension of the reinforcing member.

27. A pile according to any of claims 16 to 26 in which the elongate body is concrete.

28. A pile section for use in forming a pile according to any of claims 16 to 27.

29. A pile joint formed between two pile sections, each comprising an elongate body, the joint comprising spigot means received in socket means, there being hot melt adhesive introduced between the spigot and socket as or before the joint is formed.

30. -A pile joint according to claim 29 in which the pile sections form, in use, a pile according to any of claims 16 to 2 7.

31. A method of forming a pile from pile sections which each comprise an elongate body with which spigot means and socket means are associated for connecting pile sections to form a pile, the pile being formed by mating the spigot means With the socket means and there being hot melt adhesive introduced between the spigot and socket as or before the joint is formed.

32. A method according to claim 31 in which the adhesive is introduced before the joint is formed.

33. A method according to claim 31 or claim 32 in which the pile sections form, in use, a pile according to any of claims 16 to 27.

34. A method of forming a pile as hereinbefore described, with reference to the accompanying drawings.

35. A pile as hereinbefore described, with reference to the accompanying drawings.

36. A pile joint as hereinbefore described, with reference to the 12 accompanying drawings.

37. Any novel subject matter or combination including novel subject matter disclosed herein, whether or not within the scope of or relating to the same invention as any of the preceding claims.