Method and apparatus for stabilising a dike

Abstract

A ground plug for stabilizing a dike, includes a plug front end suitable for being driven into a dike, and an elongate plug body, wherein the plug body is provided with a pressure distributing member arranged to prevent earth flow in a direction perpendicular to a length direction of the plug, and the plug front end includes a recess for receiving a drive member.

Claims

1. A ground plug for stabilizing a dike, comprising a plug front end suitable for being driven into a dike, and an elongate plug body of at least two meters, wherein said plug body is provided with a pressure distributing member arranged to prevent earth flow in a direction perpendicular to a length direction of the plug, and the plug front end comprises a recess with a closed front end for receiving a drive member such that the plug is subjected to tensile force upon introducing the plug into a dike, wherein the plug is flexible such that the plug flexes upon shear within the dike, and wherein the recess extends to the closed front end of the plug.

2. The ground plug according to claim 1, wherein the pressure distributing member is elongated and extends along the plug over at least 50% of its length.

3. The ground plug of claim 2, wherein the pressure distributing member is elongated and extends along the plug over at least 80% of its length.

4. The ground plug according to claim 1, wherein the pressure distributing member comprises a bladed structure, having a star in cross-section.

5. The ground plug according to claim 1, wherein the pressure distributing member is integral with the plug body.

6. The ground plug according to claim 1, wherein the plug comprises a cavity which extends along the longitudinal axis of the plug and adjoins the recess and is configured for introducing a drive member there through.

7. The ground plug according to claim 6, wherein the cavity is centrally-arranged with respect to the plug.

8. The ground plug according to claim 1, wherein the plug body is integral with the plug front end.

9. Ground plug according to claim 1, wherein the pressure distributing member comprises a composite material.

10. The ground plug of claim 9, wherein the composite material comprises basalt epoxy composite.

11. The ground plug of claim 9, wherein the composite material comprises at least one of metals, corrosion resistant material, a treated metal, fibre composites, ceramic materials, plastics and vinyl.

12. An assembly of a ground plug according to claim 1 and a pivotable ground anchor that can be inserted into the dike by the drive member, wherein the pivotable ground anchor is coupled with the plug front end and the plug front is open for coupling the drive member with the pivotable ground anchor.

13. A dike comprising a plurality of adjacently arranged ground plugs according to claim 1, arranged to prevent earth flow in a direction (a) perpendicular to the length direction of the plug.

14. The dike according to claim 13, wherein a plug tail-end is provided near an outer surface of the dike.

15. A method for stabilizing a dike using a ground plug with a plug front end comprising a closed end, an elongate body of at least two meters and a pressure distributing member extending along the elongate body, the method comprising: connecting a drive member to a plug front end such that the drive member contacts the closed end at the plug front end; introducing the plug through the dike and at least partly into a stable layer beneath the dike; and arranging the pressure distributing member at a position within the dike where stabilization against lateral earth movement is required, wherein the plug is flexible such that the plug flexes upon shear within the dike.

16. The method according to claim 15, further comprising performing a geotechnical survey of the dike and positioning the pressure distributing member at a position corresponding to a slip zone within the dike.

Description

(1) The invention will be further elucidated referring to preferred embodiments shown in the drawing in which:

(2) FIG. 1 is a cross section through a dike according to the invention;

(3) FIG. 2 is perspective front view of a ground plug according to the invention;

(4) FIG. 3 is a perspective rear view of the ground plug of FIG. 2;

(5) FIG. 4a-d show respectively a side, front, rear and cross sectional side view of the ground plug of FIG. 2;

(6) FIG. 5a shows a perspective view of an assembly of a pivotable ground anchor and a ground plug according to the invention: and

(7) FIG. 5b shows a cross sectional side view of the assembly of FIG. 5a.

(8) A dike 8 is shown in FIG. 1. The dike 8 is arranged above the original soil layer 10 and comprises an earth core 9. One side of the dike 8 is subjected to pressure from water 11 whilst the other side thereof should remain dry.

(9) By placing a number of ground plugs 1 as shown in FIG. 2 adjacent to each other in length direction, the position of the earth core 9 is fixed in normal conditions.

(10) Due to rain or other particular circumstances it might normally be possible that the moisture content in the dike 8 becomes so high that flow of earth material is possible resulting in removal of earth material. However, according to the invention by using pressure distributing member 2, movement of earth is substantially prevented. By placing a number of ground plugs 1 adjacent to each other occurrence of a flow of earth material is blocked.

(11) In FIG. 1, arrow a shows a flow direction perpendicular to the plug 1. It should be understood that other flows, for example horizontal flows, are also prevented.

(12) The dike 8 has a top surface 13 and earth core 9. In this embodiment, 14 shows possible slip lines. Portions of the dike can slide with respect to each other under unfavourable circumstances in the direction of arrows d along these slip lines 14. The location of these slip lines 14 or planes can be determined through geotechnical surveying of the dike 8. Through the presence of the ground plug 1 according to the invention and more particular the pressure distributing members 2 such migration can be effectively prevented. In the FIG. 1 the ground plug 1 is located such as to span a respective slip line 14, even two slip lines 14. Here, the plug extends through the surface layer 13, the ground core 9, the original soil layer 10 which may be stable, and stable layers 15, 16 beneath the soil layer 10.

(13) In FIG. 2-4d a ground plug 1 according to the invention is generally shown at 1. The substantial entire plug body 5 is provided with a pressure distributing member 2. The pressure distributing member 2 is elongated and extends along the plug 1, over the entire length of the plug body 5. The pressure distributing member 2 has a bladed structure, having a star in cross-section as shown in FIGS. 4b and 4c. The plug has a plug diameter 22 of, here, 25 cm. The plug pressure distributing member 2 then has a width, or better height transverse with respect to the longitudinal axis 12, of 5 cm.

(14) The plug front end 4 has a reduced frontal area compared with the plug body 5 such that the plug 1 may be introduced into the dike 8 more easily. The driving member 3 may be a rod or a similar means. The plug front end 4 comprise a recess 6 for receiving the driving member 3. The plug body 5 is provided with a centrally arranged cavity 7 which extends along the longitudinal axis 12 of the plug 1. The cavity 7 adjoins the recess 6 of the plug front end 4 and is configured for introducing the drive member 3 there through. As best shown in FIG. 4d, the driving member 3 extends through the cavity 7 and ends in the recess 6 upon driving the pug 1 into a dike 8. It is also possible to introduce a hardening or non-hardening stabilizing material into the cavity 7 after introduction of the plug 1 into the dike 8.

(15) In FIGS. 3b and 3c the pressure distributing member 2 is shown as having a star shape in cross-section. Other shapes are conceivable like in the form of a strip. or in the form of a three bladed shape. It will be understood that these shapes are merely exemplary and that any other suitable cross-section may be provided that increases the surface area for the prevention of lateral flow. The pressure distributing member 2 may also be spiralled along the length of the plug 2. It is also possible that the shape of the pressure distributing member 2 is not the same over the length of the plug 21 but might vary according to the requirements set which depend from the constitution of the several ground layers and the probability of lateral movement.

(16) FIG. 5a en 5b show an assembly 17 of a ground plug 1 and a pivotable ground anchor 18 that can be inserted into the dike by the drive member 3. The pivotable ground anchor 18 is coupled with the plug front end and the plug front is open as shown for coupling the drive member 3 with the pivotable ground anchor 18. Therefore the anchor 18 is provided with a driving recess 21 as is known for these anchors 18 per se. The ground anchor 18 is coupled with the plug 1 in such a way that the pivotable ground anchor maintains its ground introducing position upon driving the plug into the dike 8. Therefore the plug front end is provided with a plug cam 19 which mates with a positioning recess 20 of the anchor 18.

(17) It should be realized that the above are only examples of the invention. Furthermore it should be clear that combinations can be made with other techniques resulting in further effectiveness of stabilization.

(18) Starting from this disclosure, many more embodiments will be evident to a skilled person, which are within the scope of protection and the essence of this invention and which are obvious combinations of prior art techniques and disclosure of this invention.