EP0097525B1

EP0097525B1 - Piles

Info

Publication number: EP0097525B1
Application number: EP83303569A
Authority: EP
Inventors: Chi-Lung Hsiao
Original assignee: Wang Su-Jen
Current assignee: Wang Su-Jen
Priority date: 1982-06-21
Filing date: 1983-06-21
Publication date: 1986-09-17
Also published as: GB8316822D0; GB2123067A; GB2123067B; ATE22332T1; EP0097525A2; DE3366260D1; EP0097525A3

Abstract

Piles for acting as supports or strengthening members comprise hollow, rigid tubular members including a pointed end and a plurality of holes in which are mounted pivotable sharp members 4. The pile is inserted into a pre-formed hole in the ground with the sharp members 4 retracted and a heavy tool is passed through the pile to force the sharp members 4 outwardly into the ground. The piles have much improved bearing load capacity.

Description

This invention relates to piles, that is pointed stakes, posts or like longitudinal members drivable into the ground for use as supports or strengthening members.
An object of this invention is to increase the bearing load capacity of piles.
In the United States Patent 1,982,687 a pile of improved load bearing capacity is proposed in which members, in the form of prongs can be extended into the surrounding ground after the pile has been driven into the ground. The present invention which is defined in the claims appended hereto, represents an improvement in respect of the form of the extensible members.
Tests have shown that these piles have improved bearing load capacity.
Embodiment of this invention are described by way of example, with reference to the drawings, in which:

Figure 1 is a sectional view through a pile according to this invention;
Figure 2 is a front view of the device shown in Figure 1;
Figure 3 is a side view of the device shown in Figure 2;
Figure 4 is an exploded view of a sharp member used in the device shown in Figure 1;
Figure 5 shows a hole into which a pile according to this invention may be inserted;
Figures 6 to 8 show a cast-in-situ pile according to this invention; and
... Figure 9 is a perspective view of a modified form of the pile shown in Figure 1 according to this invention.

A non-core pile 1, as shown in Figure 1, includes in its walls a plurality of evenly spaced holes. To the upper edge of each hole a sharp member is pivotally attached.
The sharp members are moved through the holes by a hammer E or other heavy tool, which is passed through the pile and they are urged into the ground surrounding the pile, fixing the pile. The hammer E has a smaller outer diameter than the internal diameter of the pile.
The sharp members are fin-shaped and comprise an attachment portion including a hole for receiving a bolt 7 via an elongate member having an end embedded in the edge of the corresponding aperture in the pile. Alternatively, the sharp members may be fixed on the inside wall of the pile. The sharp member further includes an arcuate sharp edge for cutting into the ground with a strengthened pointed portion 6.
In use, a hole A is made in the ground of slightly greater size than the pile and the pile is inserted into it, using a crib B, with the sharp members retracted. The hammer E is then employed to force the sharp members outwardly and into the surrounding ground. Next, the interior of the pile is filled with liquid concrete C or similar filler material.
Piles according to the invention have been tested and found to be very effective. Piles were inserted into the ground and left for three days. A load was applied to each pile and increased eight times at six hourly intervals following settlement of the pile.

1. Conventional pre-reinforced non-core pile:
- Pile diameter 1m
- Pile length 12m
- Maximum load 220 ton. (1 ton = 1.016 tonne)
2. Pile according to this invention:
- Pile diameter 1m
- Pile length 6m
- Maximum load 223 ton
3. Conventional pre-reinforced non-core pile:
- Pile diameter 1m
- Pile length 3m
- Maximum load 43 ton.
4. Pile accordiing to this invention:
- Pile diameter 1m
- Pile length 3m
- Maximum load 89 ton.
The maximum load is the load which corresponds to 1.5 cm of movement of the pile. Thus, result 2 shows that a pile according to this invention can bear about the same load as a conventional pile of twice its length. 0.5-0.56 of the bearing energy of a conventional pile is required for the same maximum load capacity.

Thus, approximately half the filling material is needed, half the pile material and 50-65% of the number of sharp members. Less work is also needed in preparing the hole for the pile and in transporting the pile. The slender-ratio
of the pile is lower and so control is easier.

Claims

1. A pile comprising a hollow rigid tubular body (1) having a plurality of apertures (3) along its length, in each of which a member (4) is pivotable for outward movement through the aperture, characterised in that each member (4) is pivotally mounted on said tubular body and is in the form of a fin having an arcuate cutting edge and a pointed tip (6), each member (4) being pivotable outwardly through the respective aperture upon impact by a tool (E) passed through the tubular body.

2. A pile according to claim 1 in which the members (4) are sharp.

3. A pile according to claim 1 or claim 2 in which the pointed tips (6) of the members are strengthened.

4. A method of piling in which a pile (1) according to any preceding claim is inserted into the ground, a tool (E) is then passed through the pile to force the fin-shaped members (4) outwards into the surrounding ground, and the interior of the pile is filled with liquid concrete (C).