EP1888847B1

EP1888847B1 - Sealing of a piling

Info

Publication number: EP1888847B1
Application number: EP05742489.7A
Authority: EP
Inventors: Jouko Lehtonen; Jari Laaksonen
Original assignee: Turun Ammattikorkeakoulu
Current assignee: Turun Ammattikorkeakoulu
Priority date: 2005-05-20
Filing date: 2005-05-20
Publication date: 2015-11-04
Anticipated expiration: 2025-05-20
Also published as: EP1888847A1; WO2006123009A1; WO2006123009B1

Description

The invention relates to a method for forming a sealed piling in soil of at least two tongue-and-groove elements, at least one of which comprises a broaching tool. In the method the broaching tool is fastened to the tongue-and-groove element at a distance from the first corner of the tongue-and-groove element, the distance being 0 - 20 % of the length of the first edge of the tongue-and-groove element. A sealing medium feeding device is fastened to the tongue-and-groove element and the tongue-and-groove element is arranged in the soil and sealing medium is fed by means of the sealing medium feeding device in the cavity created by arranging the broaching tool in the soil.

PRIOR ART

Pilings are used for many different purposes. The use of a piling in the form of a support wall is known for instance in waterfront structures such as piers, banks, dams, riverbanks and other corresponding target areas, in which the purpose of the wall is usually to support the soil. When using the piling as a support wall, the soil on the other side thereof normally forms a load, which the wall has to bear, whereas the other side of the wall can at least partly be open. In environmental technique pilings are used for example as underground impounding walls for separating the contaminated soil-area from clean soil and thus for preventing polluted water from flowing, whereby the tightness of the sealing is understandably an important feature. In some locations both supporting the load of the soil as well as watertightness are required of a piling. The features required of a piling depend on the application of use. The production material of the piling is selected according to the application of use and need. Known materials are e.g. steel, concrete, wood, aluminium, plastics and glass fibre. Naturally, the soil quality of the construction site affects the choice of piling solution. The soil can be for instance clay, sand or gravel. It can be soft or hard, wet or dry. The granular size of the soil is of importance as well as how tightly the soil is packed i.e. what the compactness of the soil is like. The location can also be a waste disposal site, where the soil is often comprised of degradable waste. The problem commonly related to pilings is that they are not tight and watertight enough but water can flow through the piling, usually at the joint of two tongue-and-groove elements.
Many solutions have been proposed to rectify the problem related to tightness in which the joint of two tongue-and-groove elements is sealed with concrete or with some other corresponding sealing medium. For example the interlocks of a hot-rolled steel piling is known to have been sealed with various sealing media, which are used inside the interlocks.
In the solution according to the patent applications FI 990594 or WO 00/55433 , the piling is formed in soil from a group of metal tongue-and-groove elements, which comprise a tubular tongue closed at the lower end by a tip element and a tubular groove showing a longitudinal slot in its housing as well as a web connecting the tongues-and-grooves. There is at the lower end of the tongues a pile shoe, which is comprised of an elongated tip element and a collar having a diameter larger than the outer diameter of the tongue. The tongue has above its collar flow apertures through which the mortar or corresponding hardening substance fed through the upper end of the pipe inside the tubular tongue the substance is transferred around the tongue in the cavity created by the pile shoe in the soil. The groove is embedded around the tongue along the tongue in the hardening substance, whereby the substance remains between the tongue and groove as sealing and surrounds the groove as well.
The above-described known technique, in which for the sealing of a piling nested tubular tongues and grooves, as well as a hardening substance is used, is very good in operation, however, the disadvantage of the technique is the fact that it requires a lot of pipe material, as tubular tongues and grooves are required in each joint between the tongue-and-groove elements. These tubular tongues and grooves remain in the soil after construction and thus a lot of pipes is required, it is costly also from the financial point of view.
GB-A-518727 discloses an interlocking sheet metal piling and a method of rendering the joint between the adjacent piles at the interlock completely watertight. This document discloses the preamble of claim 1.

THE PURPOSE OF THE INVENTION AND BRIEF DESCRIPTION

The aim of the invention is to achieve a solution which reduces or at least partly eliminates the disadvantages of the prior art mentioned above. The aim of the invention is to provide a method, in which the amount of valuable pipe material could be reduced in the joints between tongue-and-groove elements sealed with a sealing medium and thereby achieving an improved tightness in the joints with less costs than by using known techniques.
The invention as described in the characterising parts of the enclosed independent claims, solves at least some of the above-mentioned problems of the prior art.
It is characteristic for a method for sealing a piling according to the invention, by means of which an improvement to the above-mentioned problems is to be achieved, what is presented in the characterising part of the independent claim 1.
In a typical method according to the invention a sealed piling is formed in soil of at least two tongue-and-groove elements, at least one of which comprises a broaching tool. In the method the broaching tool is fastened to the tongue-and-groove element at a distance from the first corner of the tongue-and-groove element, the distance being 0 - 20 % of the length of the first edge of the tongue-and-groove element. A sealing medium feeding device is fastened to the tongue-and-groove element and the tongue-and-groove element is arranged in the soil and sealing medium is fed by means of the sealing medium feeding device in the cavity created by arranging the broaching tool in the soil. It is characteristic for a typical method for forming a sealed piling according to the invention that the sealing medium feeding device is fastened to the tongue-and-groove element by means of an openable fastening device. It is further characteristic for a method according to the invention that the fastening device is released and the sealing medium feeding device is disconnected from the tongue-and-groove element after the tongue-and-groove element has been arranged at a desired depth inside the soil. The further characteristics for a method according to the invention are described in claim 1.
The tongue-and-groove element comprises a broaching tool, which can be arranged to form a cavity in the soil. It is typically characteristic for a tongue-and-groove element that the tongue-and-groove element has a fastening tool, to which the sealing medium feeding device can detachably be fastened.
A sealed piling can be formed by using a method according to the present invention for forming a sealed piling. It is characteristic for a sealed piling which can be formed by the method that it is comprised of tongue-and-groove elements.

BRIEF DESCRIPTION OF THE DRAWING

In the following, the invention will be described in more detail with reference to the appended drawing, in which

Fig. 1: shows a tongue-and-groove element which can be used in the method according to the invention,
Fig. 2: shows a sealed piling which can be formed by the method according to the invention,
Fig. 3: shows the sealed piling which can be formed by the method according to the invention as a cross section in the direction of the ground level,
Fig. 4: shows a broaching tool which can be used in the method according to the invention,
Fig. 5: shows the broaching tool which can be used in the method according to the invention,
Fig. 6: shows the broaching tool which can be used in the method according to the invention,
Fig. 7: shows the broaching tool which can be used in the method according to the invention,
Fig. 8: shows the broaching tool which can be used in the method according to the invention,
Fig. 9: shows an additional flange which can be used in the method according to the invention,
Fig. 10: shows a solution which can be used in the method according to the invention, and
Fig. 11: shows a solution which can be used in the method according to the invention.

DETAILED DESCRIPTION OF THE INVENTION

In a typical method according to the invention a sealed piling is formed in soil of at least two tongue-and-groove elements, at least one of which comprises a broaching tool. In the method the broaching tool is fastened to the tongue-and-groove element at a distance from the first corner of the tongue-and-groove element, the distance being 0 - 20 % of the length of the first edge of the tongue-and-groove element. A sealing medium feeding device is fastened to the tongue-and-groove element and the tongue-and-groove element is arranged in the soil and sealing medium is fed by means of the sealing medium feeding device in the cavity created by arranging the broaching tool in the soil. It is characteristic for a typical method for forming a sealed piling in soil according to the invention that the sealing medium feeding device is fastened to the tongue-and-groove element by means of an openable fastening device. It is further characteristic for the method according to the invention that the fastening device is released and the sealing medium feeding device is disconnected from the tongue-and-groove element after the tongue-and-groove element is arranged at a desired depth inside the soil. The furhter characteristics for the method according to the invention are described in claim 1.
The tongue-and-groove elements can typically be plate-like or pile-formed pieces made of steel, concrete, wood, aluminium, plastic or glass fibre. At least two tongue-and-groove elements are needed to form a sealed piling with a method according to the invention. It is obvious to someone skilled in the art that a required amount of tongue-and-groove elements will be used, such as 3, 4, 5, 7, 10, 15 or 37.
The soil can for example be gravel, sand, clay, topsoil, waste from a waste disposal site or mixture of some of these constituents.
The task of the broaching tool is to form a cavity in the soil when the broaching tool is arranged in the soil with the tongue-and-groove element, the broaching tool being fastened to the tongue-and-groove element. The purpose of the cavity is to be filled by the sealing medium and thus to seal the seam between two tongue-and-groove elements to be substantially liquidtight. The broaching tool is described in more detail below.
The first edge of the tongue-and-groove element refers to that edge of the tongue-and-groove element, to a lock element of which the next tongue-and-groove element is fastened. The first edge is one of those edges in the direction of which the tongue-and-groove element is arranged in the soil. In a typical tongue-and-groove element this first edge is a vertical edge. The second edge of the tongue-and-groove element is an opposing edge in relation to the first edge and advantageously substantially parallel thereto. The third edge of the tongue-and-groove element is that which normally remains on the surface of the soil or closest to the soil. The force required to arrange the element in the soil is mainly directed at the third edge. Respectively, the fourth edge of the tongue-and-groove element refers to that edge which leads when the tongue-and-groove element is arranged in the soil and which advantageously is substantially parallel to the third edge. The first corner of the tongue-and-groove element refers to the corner between the first and fourth edge. Typically, the broaching tool is fastened to the tongue-and-groove element at a distance from the first corner of the tongue-and-groove element, the distance being 0 - 20 % of the length of the tongue-and-groove element's first edge, more advantageously 0 - 15 %, very advantageously 0 - 10 %, still very advantageously 0 - 5 % of said distance.
The tongue-and-groove element can be arranged in the soil for example by beating, ramming, vibrating, pushing or by otherwise directing a suitable force at the third edge of the element. Arranging the tongue-and-groove element in the soil can also be referred to as installing, driving or sinking. The tongue-and-groove elements are generally arranged in the soil vertically or substantially in a vertical position, however, the elements can also be arranged in the soil obliquely, whereby the angle between the tongue-and-groove element and the "surface" of the soil can be in the range of 0 - 180°. The elements can thus be arranged in the soil for example horizontally.
The cavity created by the broaching tool is filled with sealing medium. Advantageously sealing medium is fed according to the sinking speed of the tongue-and-groove element so that the cavity created by the broaching tool is constantly substantially filled with sealing medium. A hardening sealing medium can be used as sealing medium, which hardens in the cavity created by the broaching tool or an non-hardening sealing medium which substantially does not harden. The sealing medium can be selected for example from the group comprising hydraulically hardening binding media, concrete, cement, blast furnace slag, bentonite and two-component plastics, for example two-component plastics of the resin type, as well as mixtures thereof. The sealing medium is fed to the cavity by means of a sealing medium feeding device at least partly in an unhardened form, meaning that the sealing medium is sufficiently elastic and fluid in order to be fed by means of a feeding device. The sealing medium fills the cavity and surrounds the first edge of the tongue-and-groove element arranged in the soil.
The sealing medium feeding device can be a pipe or a hose, for example, and its feeding head refers to that head of the feeding device through which the sealing medium exits the feeding device into the cavity created by the broaching tool.
In a method according to the invention the sealing medium feeding device is fastened to the tongue-and-groove element by means of an openable fastening device, which can be for example a wire, rope, string or other device suitable for fastening. The fastening device is released and the sealing medium feeding device is disconnected from the tongue-and-groove element and pulled away from connection with the cavity filled with sealing medium after the tongue-and-groove element has been arranged at the desired depth inside the soil. By this procedure the advantage over the prior art is attained, that sealing medium can be fed in to all joints between the tongue-and-groove elements by means of one and the same sealing medium feeding device and no separate feeding device is required for every joint, whereby the amount of required pipe material is considerably reduced. When the need for pipe material is considerably reduced, the sealed piling can be formed in to the soil with the method according to the invention clearly cheaper than by using prior art.
When beginning to form a piling with a method according to the invention, a first tongue-and-groove element has to be installed in the soil so that there are no previously installed elements in the soil, to the immediate connection of which the first tongue-and-groove element could be installed. In an embodiment the first tongue-and-groove element is thus installed in the soil without being able to fasten its second edge to a lock tool of another tongue-and-groove element and to the soft sealing medium surrounding it, as this other tongue-and-groove element has not been arranged in the soil in the situation in question. A starting situation of this type occurs if a hardening sealing me-dium is used and if such a long time has passed after the previous tongue-and-groove element was installed that the sealing medium surrounding the first edge thereof has had time to substantially harden and the next tongue-and-groove element can not be arranged in the lock tool of the tongue-and-groove element previously installed in the soil.
According to the invention the second tongue-and-groove element to be arranged in the soil is fitted in the lock tool of the first tongue-and-groove element previously arranged in the soil, which lock tool and the first edge of the first tongue-and-groove element previously arranged in the soil are surrounded by at least partly unhardened sealing medium. The second edge of the second tongue-and-groove element thus substantially meets the first edge of the first tongue-and-groove element.
The lock tool may be typically a folding, rail or tubular tool equipped with a longitudinal slot in the edge of the tongue-and-groove element, in which the counterpart of the lock tool arranged in the next tongue-and-groove element can be arranged. In the lock tool the tongue or the groove part can be discontinuous, for example so that the tongue part of the lock tool is a continuous pipe and the pipe of the groove part is discontinuous or so that the groove part is continuous and the tongue part is discontinuous.
After having arranged the second tongue-and-groove element in the lock tool of the first tongue-and-groove element previously arranged in the soil and having arranged it at a desired depth inside the soil, the openable fastening device of the sealing medium feeding device is released and the sealing medium feeding device is disconnected from the tongue-and-groove element, whereafter the feeding device can be pulled away from the connection with the tongue-and-groove element arranged in the soil. If hardening sealing medium is used, the sealing medium is allowed to harden in the cavity so that is surrounds and seals the joint between two adjacent tongue-and-groove elements arranged in the soil. Also non-hardening sealing medium can be used for sealing, which surrounds and seals the joint between two adjacent tongue-and-groove elements arranged in the soil. By a sealed piling a piling is meant, in which the joints between the tongue-and-groove elements are according to this example surrounded by and sealed with hardening or unhardened sealing medium.
According to an embodiment of the invention in the method for sealing two adjacent tongue-and-groove elements sealing medium is used which does not harden, for example bentonite. When non-hardening sealing medium is used for sealing, the tongue-and-groove elements can be removed from the soil when they no longer are needed. The method according to this embodiment can be used for example for forming a temporary piling or temporary impounding wall. After a usage according to this method the tongue-and-groove elements can be recycled and re-used for forming another piling.
The tongue-and-groove element comprises a broaching tool, which can be arranged to form a cavity in the soil. It is typically characteristic for a tongue-and-groove element that the tongue-and-groove element comprises a fastening tool, to which the sealing medium feeding device can detachably be fastened.
The fastening tool can be for example a hook or a loop. According to the method according to the invention, the sealing medium feeding device is detachably fastened to the fastening tool, which entails that the fastening can easily be opened. According to the method according to the invention the fastening of the sealing medium feeding device to the fastening tool can advantageously be opened at ground level after the tongue-and-groove element together with its broaching tool as well as the feeding device together with its fastening tool are arranged at a desired depth in the soil. A wire can be used as an advantageous fastening device of the sealing medium feeding device, which wire can be pulled away from the connection with the fastening tool, whereby fastening of the sealing medium feeding device is released and the feeding device can be pulled away from the cavity and be re-used for filling the next cavity. For fastening the sealing medium feeding device to the fastening tool also a lock tool can be used, which is openable at ground level by means of a bar or wire.
According to an embodiment of the method according to claim 1, the fastening tool in the tongue-and-groove element is arranged in the broaching tool. When the fastening tool, in which the sealing medium feeding device is detachably arranged, is arranged in the broaching tool, advantageously inside the walls of the broaching tool, the feeding head of the sealing medium feeding device is easily arranged to be protected by the walls of the broaching tool, so that the soil can not get mixed with the sealing medium at the same time as the sealing medium exits the feeding head of the feeding device. The fastening tool can advantageously be arranged in the immediate vicinity of the broaching tool, so that the feeding head of the sealing medium feeding device to be fastened to the fastening tool is at least partly protected by the walls of the broaching tool or substantially close to the broaching tool. In some embodiments the feeding head of the sealing medium feeding device can be further away from the broaching tool so that the feeding head is not protected by the walls of the broaching tool, for example in the case of ar-gillaceous soil which does not crumble in the cavity but the cavity substantially retains its original structure created by the broaching tool.
According to the nvention, the sealing medium feeding device is detachably fastened to the fastening tool by a fastening device.
According to an advantageous embodiment of the method according to claim 1, the broaching tool is shaped like a box having one side open so that the walls of the broaching tool protect the feeding head of the sealing medium feeding device. When the walls of the broaching tool protect the feeding head of the sealing medium feeding device, soil can not get mixed with sealing medium while it exits the feeding head of the feeding device. The open side of the boxlike broaching tool is most advantageously that side which is opposite to the bottom of the broaching tool and is limited to the walls of the broaching tool. In a typical operating situation, this open side is the upper side of the broaching tool. The bottom of the broaching tool refers to that side of the broaching tool which leads when arranging the broaching tool in the soil. The broaching tool can advantageously be boxlike or cylindrical and with regard to its walls the perpendicular cross section can be for example shaped like a quadrangle, triangle, pentagon or some other polygon or a circle, oval or ellips. The bottom of the broaching tool can be regarding the walls of the broaching tool and the tongue-and-groove element substantially perpendicular or oblique. The bottom can be advantageously even, more advantageously cone-shaped. Very advantageously the bottom can be tapered towards its end or sharp, whereby when installing the tongue-and-groove element in the soil the friction forming between the broaching tool and the soil is remarkably reduced.
According to another embodiment of the method according to claim 1, the broaching tool is arranged in the first corner of the tongue-and-groove element and in the second corner of the tongue-and-groove element a notch corresponding to the size of the broaching tool is arranged. The notch has advantageously substantially the shape and size of the broaching tool so that the tongue-and-groove element can easily be arranged in connection with the previously installed tongue-and-groove element and at the same depth therewith inside the soil. The second corner of the tongue-and-groove element refers to the corner between the second and fourth edge of the element.
According to yet another embodiment of the method according to claim 1, the broaching tool has a fastening pin for fastening the broaching tool to the tongue-and-groove element. The fastening pin can be rail-formed or can resemble the lock of the tongue-and-groove element. The fastening pin can also be a split pipe to be arranged around the lock of the tongue-and-groove element. With the aid of the fastening pin the broaching tool can be firmly fastened to the tongue-and-groove element.
In an embodiment of the invention, an additional flange is arranged in the tongue-and-groove element for balancing the arranging of the tongue-and-groove element in the soil. The additional flange can be made for example of steel plate by breaking and cutting-off and it can advantageously be fastened to the fourth edge of the tongue-and-groove element which typically is the lower edge of the tongue-and-groove element. When arranging the tongue-and-groove element in the soil a resistance is formed between the fourth edge and the soil as well as the bottom of the broaching tool and the soil. The purpose of the additional flange is to create a substantially equal resistance as the broaching tool creates in the first corner of the tongue-and-groove element. The additional flange is advantageously fastened to the fourth edge of the tongue-and-groove element at a point which typically is closer to the second corner than the first corner. It is obvious to someone skilled in the art that the size and shape of the flange can be altered if necessary and the fastening point of the flange on the fourth edge of the tongue-and-groove element can be chosen on a case-specific basis depending on the characteristics of the soil, for example. By using an additional flange of a suitable size and shape and by fastening it to a suitable point on the fourth edge of the tongue-and-groove element, it possible to balance arranging the tongue-and-groove element in the soil and the risk of driving the tongue-and-groove element in a skewed manner in the soil is reduced.
A tongue-and-groove element used in a method according to the invention can be made of a material selected from the group comprising steel, wood, concrete, aluminium, plastic, glass fibre and mixtures thereof.
The aim of the invention is to form a sealed piling, which has been formed by using a method according to the present invention.
A method for isolating contaminated soil can be performed with such a sealed piling.
By isolating a contaminated area the flowing of liquid in the contaminated soil, for example, can remarkably well be prevented to flow outside the contaminated area as the sealed piling is liquidtight and does not allow liquids flowing in the soil to penetrate. Contaminated soil can be found for example in waste disposal sites, service station areas or factory areas.
The above-described embodiments regarding the method for forming a sealed piling relate where applicable also to a subsequent use of the method as a method for isolating contaminated soil.

DETAILED DESCRIPTION OF THE DRAWING

Figure 1 shows a tongue-and-groove element 1 which can be used in a method according to the invention, in a first corner 9 of which element a broaching tool 2a is fastened, which broaching tool is shown in Figure 4 in more detail. To a fourth edge 3 of the tongue-and-groove element 1 an additional flange 4 is fastened, which edge in the example according to the Figure is the lower edge of the element, and which flange is shown in more detail in Figure 9 serving the purpose of balancing the installing of the tongue-and-groove element 1 in the soil. In a second corner of the tongue-and-groove element 1 shown in the Figure, which in the example of this Figure is the lower right-hand side corner of the element, a notch 5 is arranged substantially having the shape and size of the broaching tool 2a, whereby the tongue-and-groove element 1 in question can easily be installed at the same depth as the corresponding tongue-and-groove element previously installed inside the soil so that the second corner of the tongue-and-groove element does not hit the broaching tool fastened to the previously installed element. The Figure also shows a first edge 8 of the tongue- and-groove element.
Figure 2 shows a sealed piling which can be used in a method according to the invention. Several tongue-and-groove elements 6a, 6b, 6c and 6d are installed in the soil and the joints between the elements are surrounded by a sealing medium 7. In the situation shown in the Figure, the installation of one element 6e is not finished. The second edge 12 of the element 6e to be installed is arranged in a lock tool of the adjacent element 6d previously installed in the soil, whereby the element 6e to be installed can be installed in the close vicinity of the adjacent element 6d previously installed in the soil. The sealing medium 7 surrounding the first edge 11 of the adjacent element 6d previously installed in the soil has not had time to harden in the situation shown in the Figure and the second edge 12 of the element 6e to be installed is also covered by the sealing medium 7. The sealing medium feeding device 13 is detachably fastened to the broaching tool 2a by the fastening device. The feeding head of the sealing medium feeding device 13 is protected by the walls of the broaching tool 2a, wherefore the soil does not get mixed with fresh sealing medium 7. The Figure also shows the third edge 16 of the tongue-and-groove element 6e to be installed, which edge in the situation of the Figure is the upper edge of the element, and by directing a suitable force at which edge the tongue-and-groove element can be installed in the soil. According to the example in the Figure, when installing the tongue-and-groove element 6e in the soil sealing medium 7 is fed in the cavity created by the broaching tool 2a so that the cavity is the entire time substantially filled with sealing medium 7 up to the ground level 17.
Figure 3 shows a sealed piling which can be formed by a method according to the invention as a cross section in the direction of the ground level. The adjacent tongue-and-groove elements 18 are fastened to each other by means of the lock tools 22. The seams between the adjacent elements 18 are surrounded by sealing medium 23.
Figure 4 shows a broaching tool 2a which can be used in a method according to the invention, the cross section and bottom 24 of which are substantially quadrangle in shape and the bottom is substantially flat and perpendicular to the walls 25 of the broaching tool. The Figure also shows the fastening tool 26 in the broaching tool, to which fastening tool the sealing medium feeding device is detachably fastened by means of the fastening device. In this embodiment the broaching tool 2a has a fastening pin 27, by means of which the broaching tool 2a can be fastened to the tongue-and-groove element. There is a slot 10 in the wall 25 of the broaching tool 2a making it possible for the broaching tool 2a to be fitted on the level of the fourth edge of the tongue-and-groove element. The broaching tool 2a is fastened advantageously to the first corner of the tongue-and-groove element or substantially close to the corner so that the first corner of the tongue-and-groove element comes through the slot 10 inside the broaching tool 2a and the corner of the tongue-and-groove element can be fastened to the fastening pin 27 in the broaching tool 2a. The fastening can take place by means of a friction joint, click joint, by welding or connecting to a fitting piece in the broaching tool. It is obvious, that also other known fastening means, such as nails, screws, pins, pop rivets or lock pins can be used for fastening. The broaching tool 2a according to this embodiment is shown in Figure 1 installed in a tongue-and-groove element.
In Figure 5 a broaching tool 2b which can be used in a method according to the invention is shown, the cross section and bottom 29 of which are circular in shape and the bottom 29 is substantially flat and perpendicular to the wall 30 of the broaching tool. The Figure also shows the fastening tool 26, the fastening pin 27 and the slot 31 in the wall of the broaching tool.
Figure 6 shows a broaching tool 2c which can be used in a method according to the invention, the cross section of which is quadrangle in shape and the bottom 32 is oblique compared to the level, which is perpendicular to the walls 33 of the broaching tool. There is a fastening tool 26 and fastening pin 27 in the broaching tool 2c and a slot 34 in the wall thereof, in order to able to fasten the broaching tool suitably to the tongue-and-groove element.
Figure 7 shows a broaching tool 2d which can be used in a method according to the invention, the cross section of which is circular in shape and the bottom 35 is oblique compared to the level, which is perpendicular to the wall 36 of the broaching tool.
Figure 8 shows a broaching tool 2e which can be used in a method according to the invention, wherein the sealing medium feeding device 13 is fastened to the fastening tool 26 of the broaching tool by means of a fastening device 37. In the example of the Figure the bottom 38 of the broaching tool is cone shaped which serves the purpose of reducing the friction between the soil and the broaching tool when installing the tongue-and-groove element and the broaching tool in the soil.
Figure 9 shows an additional flange 4 which can be used in a method according to the invention, which comprises wings 39, a tip element 40 and a slot 41, in which the fourth edge of the tongue-and-groove element is fitted. This additional flange is shown in Figure 1 installed in a tongue-and-groove element.
Figure 10 shows a solution which can be used in a method according to the invention. The Figure shows a wall 42 of the broaching tool being circular in shape in cross section and a fastening tool 26 for fastening the sealing medium feeding device. The broaching tool is fastened to the tongue-and-groove element 43 by means of a fastening pin 44 resembling the lock of the tongue-and-groove element.
Figure 11 shows a solution which can be used in a method according to the invention. The Figure shows a wall 42 of a broaching tool being circular in shape in cross section and a fastening tool 26. The broaching tool is fastened to the tongue-and-groove element 43 by a fastening pin 45, which is a split pipe to be arranged around the lock of the tongue-and-groove element.

Claims

Method for forming a sealed piling in soil of at least two tongue-and-groove elements (1, 6, 18), at least one of which tongue-and-groove elements comprises a broaching tool (2), which method comprises the following steps:
- the broaching tool is fastened to the tongue-and-groove element at a distance from the first corner (9) of the tongue-and-groove element, and

- the tongue-and-groove element is arranged in the soil and by means of sealing medium feeding device sealing medium (7) is fed in a cavity created by arranging the broaching tool in the soil, characterised in that

- the aforesaid distance is 0 - 20 % of the length of the first edge (8, 11) of the tongue-and-groove element,

- a sealing medium feeding device (13) is fastened to the tongue-and-groove element by an openable fastening device (37),

- the fastening device is released and the sealing medium feeding device is disconnected from the tongue-and-groove element and pulled away from connection with the cavity after having arranged the tongue-and-groove element at a desired depth inside the soil,

- a second tongue-and-groove element to be arranged in the soil is fitted in a lock tool (22) of the first tongue-and-groove element previously arranged in the soil, which lock tool and the first edge (11) of the first tongue-and-groove element previously arranged in the soil are surrounded by at least partly unhardened sealing medium (7).
Method according to claim 1, characterised in that in the method non-hardening sealing medium is used, and that the tongue-and-groove elements are removed from the soil when they no longer are needed.