GROUT INJECTION DEVICE AND METHOD FOR INJECTING GROUT INTO A LONGITUDINAL HOLE

Abstract

The present invention concerns a grout injection device (10) and a method for injecting grout into a longitudinal hole, e.g. a borehole. The grout injection device (10) comprises a hose (11) having at least three separate lines (12,13,14) defined in the interior of said hose (11); a packer system (16) arranged at one end (15) of said hose (11), said packer system comprising a chamber (17), said chamber (17) being provided with an inlet opening (18) into which said at least three lines (12,13,24) of said hose (11) lead and one or more discharge openings (22,23,24) for releasing fluid from said chamber (17) into the surrounding of the packer system; and a pump system (30) arranged at the opposite end (28) of said hose (11), configured to inject fluids into said at least three lines (12,13,14) of said hose (11).

Claims

1. A grout injection device comprising a hose having at least three separate lines defined in the interior of said hose; a packer system arranged at one end of said hose, said packer system comprising a chamber, said chamber being provided with an inlet opening into which said at least three lines of said hose lead and one or more discharge openings for releasing fluid from said chamber into the surrounding of the packer system; and a pump system arranged at the opposite end of said hose, configured to inject fluids into said at least three lines of said hose.

2. The grout injection device according to claim 1, wherein said hose is made from an extruded plastic material with said at least three separate lines being defined by smooth interior walls of said plastic material.

3. The grout injection device according to claim 1, wherein said chamber of said packer system comprises at least four circumferentially arranged discharge openings.

4. The grout injection device according to claim 1, wherein said chamber of said packer system is made from a plastic material or from a metallic material.

5. The grout injection device according to claim 1, wherein said packer system comprises an upper seal above said discharge openings of said chamber and a lower seal below said discharge openings of said chamber.

6. The grout injection device according to claim 5, wherein said upper and lower seals are selected from inflatable seals and mechanical seals.

7. The grout injection device according to claim 1, wherein said chamber comprises a static mixer.

8. The grout injection device according to claim 1, wherein said pump system comprises a multi-piston pump having each of said at least three lines of said hose associated with a dedicated piston of said multi-piston pump.

9. The grout injection device according to claim 1, wherein said pump system comprises a PLC-controller, configured to control pressure and flow rate of said fluids injected into said at least three lines of said hose.

10. The grout injection device according to claim 1, wherein said pump system is connectable to at least three different fluid sources.

11. The grout injection device according to claim 10, wherein said at least three different fluid sources comprise at least two components of a multi-component grouting material and at least one cleaning solution.

12. The grout injection device according to claim 1, further comprising a motorized hose-transporting system.

13. The grout injection device according to claim 12, wherein said motorized hose-transporting system comprises a rotatable hose reel for storing said hose and a motorized puller-roller for winding and unwinding said hose from said reel.

14. A method for injecting grout into a longitudinal hole comprising the steps of: (a) feeding a hose comprising at least three separate lines and a packer system arranged at a free end of said hose into said hole to a first injection site; (b) optionally, injecting a cleaning solution into a first of said at least three lines of said hose; (c) injecting at least two components of a grouting material into a second and third of said at least three lines of said hose; (d) mixing said at least two components of said grouting material in a chamber of said packer system at the injection site to form a grout; (e) injecting said grout from said chamber into the injection site; (f) injecting a cleaning solution into said first of said at least three lines of said hose to clean said chamber and the immediate surrounding of said packer system; (g) withdrawing said hose partially or completely from said hole.

15. The method of claim 14, wherein said hole is lined with a TAM (Tube a Manchette) pipe defining multiple injections sites and wherein, in step (a), said hose is fed into the TAM pipe until the injection site farthest from a pipe entrance is reached and, after optionally completing step (b) and steps (c) to (f), the hose is partially withdrawn until a nearer injection site is reached and optional step (b) and steps (c) to (g) are repeated one or more times.

Description

[0066] The present invention will now be described in more detail with reference to a preferred embodiment, which is schematically depicted in the appended drawings. In the drawings,

[0067] FIG. 1 shows a TAM pipe in a borehole where a grout injection device according to the invention is inserted;

[0068] FIG. 2 shows a cross-sectional view of the hose of the grout injection device of FIG. 1 according to line II-II of FIG. 1; and

[0069] FIG. 3 shows a more detailed drawing of an injection site of FIG. 1.

[0070] FIG. 1 is a schematic drawing showing the grout injection device 10 of the present invention installed to a TAM (Tube a Manchette) pipe system injecting grout into an area to be grouted. FIG. 1 shows a cross-sectional view of a terrain 100, having a surface 101 on which the grout injection device 10 is installed. In the terrain 100, a borehole 102 has been drilled. The borehole 102 is lined with a TAM pipe 103 which is provided with several spaced-apart injection sites 104, 105, 106. The injection sites are defined by valve plates 104a, 104b, 105a, 105b, 106a, 106b arranged in the wall of TAM pipe 103. In the embodiment of FIG. 1, the lowest injection site, i.e. the injection site farthest away from surface is the first injection site 104 to be grouted. The second injection site 105 and the third injection site 106 are sequentially closer to the surface 101.

[0071] The grout injection device 10 comprises a hose 11 made from an extruded plastic material which, in the depicted embodiment, has three separate lines 12, 13, 14 defined in the solid interior of the hose. A cross-sectional view of the hose 11 showing a typical arrangement of three separate lines 12, 13 and 14 is shown in FIG. 2 corresponding, for instance, to a cross-section indicated by reference signs II-II in FIG. 1. As can be taken from FIG. 2, the lines 12, 13, 14 of hose 11 are provided with smooth interior walls 12a, 13a, 14a.

[0072] As can be taken from FIG. 1, hose 11 is inserted into the TAM pipe 103 down to the first injection site 104. At the free end 15 of hose 11, a packer system 16 is arranged. As can be seen particularly from the enlarged view of the first injection site 104 in FIG. 3, the packer system comprises a chamber 17, into which lines 12, 13, 14 of hose 11 lead. As can be taken from FIG. 3, the chamber 17 is provided with an inlet opening 18 to which hose 11 with its three internal lines 12, 13, 14 are connected, respectively, in order to release fluid from lines 12, 13, 14 into the chamber 17. Hose 11 and packer system 16 can be connected in a variety of manners. In the embodiment depicted in FIG. 3, the inlet opening 18 of the packer system is provided with an internal thread 19 into which an external thread provided at the free end 15 of hose 11 engages. For the sake of clarity, in FIG. 3 the free end 15 of hose 11 is shown separately from the packer system 16. In operation, the packer system is screwed onto the free end of the hose before being lowered into the borehole. At the free end 15 of hose 11, each line 12, 13, 14 can be provided with a non-return valve (not shown in the drawings) ensuring that no grout mixture from chamber 17 can enter and potentially clog the lines of the hose. The chamber 17 is provided with a static mixer 21 allowing to mix the components of a multi-component grout. In the depicted example, the two components of a binary grout system are fed via first line 12 and second line 13 into the chamber 17, while the third line 14 is used for a cleaning fluid. The chamber 17 of packer system 16 and the static mixer 21 arranged in chamber 21 can be made from a plastic material or from a metallic material or from a combination of those materials.

[0073] At its outer circumference, the chamber 17 is provided with discharge openings 22, 23, 24 for releasing fluid, especially the grout mixture obtained in the chamber 17 or cleaning fluid pumped fed via line 14, into the surrounding of the packer system, i.e. into a space 107 defined between the exterior of the packer system 16 and the interior of the TAM pipe 103. In the depicted example, four discharge openings are equally spaced around the circumference of the chamber 17 but in the view of FIG. 1, only discharge opening 22 is visible while in the view of FIG. 2, two discharge openings 23, 24 are shown. The other discharge openings are provided on the backside of chamber 17. Other configurations of the discharge openings could be used for optimizing the grouting injection process of different grouting materials.

[0074] Before grout injection, the packer system 16 is arranged at such a height within TAM pipe 103 that the discharge openings 22, 23, 24 of chamber 17 are located at the same height as the valve plates of the selected injection site, i.e. in the example of FIG. 1 at the height of valve plates 104a, 104b of the first injection site 104.

[0075] As can be taken from FIGS. 1 and 2, the packer system 16 is provided with an upper seal 26 arranged above the discharge openings 22, 23, 24, 35 and a lower seal 27 arranged below said discharge openings of chamber 17. The terms upper and lower refer to the distance from terrain surface 101 when the packer system 16 is inserted into a borehole or a TAM pipe installed within a borehole. The upper and lower seals 26, 27 are configured to seal-off the space 107 at the injection site (in this case injection site 104) from the rest of the TAM pipe 103 to ensure that cleaning solution or grout material injected from the discharge openings of chamber 17 will not disperse throughout the rest of the TAM pipe 103 but remain within space 107 defined by the exterior of the packer system 106, the interior of TAM pipe 103 and the upper and lower seals 26, 27, respectively. The seals 26, 27 are also configured to still allow movement of the packer system 16 within TAM pipe 103.

[0076] The upper and lower seals 26, 27 can be chosen from a variety of packer seals known in the art, for instance from inflatable seals. In the depicted embodiment, however, the upper and lower seals are chosen from mechanical seals. Specifically, each seal 26, 27 is provided with three elastic V-rings 26a, 26b, 26b and 27a, 27b, 27b, respectively, which are arranged adjacent to each other (c.f. FIG. 3). Within each three-ring package 26 and 27, the inner seal rings 26b and 27b are made from more elastic material and are arranged between more rigid outer seal rings 26a, 26c and 27a, 27c, respectively. The more rigid outer seal rings provide for structural integrity of the seals as well as exhibiting some guidance functionality when the hose 11 with the packer system 16 is moved within TAM pipe 103. In the embodiment of FIG. 3, the upper and lower seals 26, 27 further comprise guidance jackets 29a, 29b, 29c, 29d, which can be made, for instance, from polytetrafluoroethylene (PTFE) or (polyethylene) and which provide for a more stable movement of the packer system with the TAM pipe.

[0077] Outside of the borehole 102, the opposite end 28 of hose 11 of grout injection device 10 is attached to a pump system 30, which comprises a piston pump 31, which is connects three fluid reservoirs 32, 33, 34 to the three separate lines 12, 13, 14 of hose 11, respectively. Reservoirs 32, 33 contain two components of the binary grouting mixture of the present example. Piston pump 31 will pump the two components at a pre-selected ratio through the first and second lines 12, 13, respectively, to the chamber 17 of packer system 16, where the two components are mixed and the mixture is injected from the internal chamber through the valve plates of TAM pipe 103 into the injection site. Reservoir 34 contains a cleaning fluid, for instance an oil or grease or a mixture thereof which can be pumped via third line 14 to chamber 27 of packer system 16. The piston pump 31 can be operated such that the fluid flow through each of the lines 12, 13 and 14 can be adjusted separately, i.e. independent from each other. To this effect, pump system 30 also includes a PLC controller 35, which allows to control pressure and flow rate of the fluid injected into lines 12, 13 and 14 of hose 11. The pump system also comprises a suitable connector, where three lines coming from piston pump 31 are attached and which has a connecting piece with three openings, to which the three line hose 11 is attached in a manner that each fluid can be fed into one of the three lines of the hose.

[0078] The grout injection device can further include a hose-transporting system 40, which includes a motorized puller-roller 41 for transporting the hose to and from a hose reel 42 into the borehole 102. A motor 43 of the puller-roller 41 is provided with a motor-controller 44, which allows to control the puller-roller in such a manner that a pre-determined length of the holes can be lowered into or pulled from a borehole 102, so that the packer system 16 can be arranged at a desired height at a free-selected injection site. If the main hose 11 is stored on a reel, it is usually preferred to have an intermediate three-line hose 36 connecting the hose 11 with the pump system, rather than connecting hose 11 directly with the pump system.

[0079] In the following, the operation of the grout injection device of the present invention will be described with reference to a binary chemical grouting composition:

[0080] Typically, operation begins with drilling a borehole at the desired site into the ground and installing a TAM pipe inside the borehole.

[0081] Then, a three-line hose having a double-seal-packer at its free end is connected with its' opposite end to a pumping system fed by grouting components (for instance of a binary chemical grout system) and a cleaning fluid.

[0082] The three-line hose is lowered via a motorized puller-roller into the borehole and placed at the lowest valve plate system of the TAM pipe, which constitutes the first grout injection site.

[0083] The two components of the binary grout system are pumped separately through two lines of the three-line hose and the components are mixed in a chamber of the packer. Accordingly, the reaction can start immediately at the injection site before permeation of the grout mixture into the ground, thus allowing to use very fast reacting resins. The grout components are continuously pumped through the two lines of the three-line hose, mixed in the packer and injected into the surrounding of the injection site of the TAM pipe through appropriate valve plates of the TAM pipe until the pre-defined injection design parameters are achieved.

[0084] Once the injection is finished, the third line of the three-line hose is used to flush the packer system and the sealed space surrounding the packer system with a cleaning fluid such as grease and/or oil. As the third line is already pre-filled with cleaning fluid, cleaning can start immediately after termination of grout injection, so that even fast working resins will not damage the injection equipment. Further, only a low amount of cleaning fluid is required, thus presenting an environmental friendly solution. Finally, as only non-reacting components are transported to the lines of the hose, it is not necessary to clean the two lines for the grout components themselves.

[0085] After cleaning, the hose and packer system are lifted upwards towards the next injection site/TAM-type valve and the injection procedure is repeated.

REFERENCE SIGNS

[0086] 10 grout injection device [0087] 11 three-line hose [0088] 12 first line of hose 11 [0089] 13 second line of hose 11 [0090] 14 third line of hose 11 [0091] 12a interior wall of first line 12 [0092] 13a interior wall of first line 13 [0093] 14a interior wall of first line 14 [0094] 15 free end of hose 11 [0095] 16 packer system [0096] 17 chamber of packer system [0097] 18 inlet opening of chamber 17 [0098] 19 internal thread of packer system [0099] 20 external thread of hose [0100] 21 static mixer [0101] 22 first discharge opening of chamber 17 [0102] 23 second discharge opening of chamber 17 [0103] 24 third discharge opening of chamber 17 [0104] 26 upper seal of packer system 16 [0105] 26a, 26b, 26b V-rings of upper seal 26 [0106] 27 lower seal of packer system 16 [0107] 27a, 27b, 27b V-rings of lower seal 27 [0108] 28 opposite end of hose 11 [0109] 29a,29b,29c,29d PTFE jacket [0110] 30 pump system [0111] 31 piston pump [0112] 32 reservoir for first grout component [0113] 33 reservoir for second grout component [0114] 34 reservoir for cleaning fluid [0115] 35 PLC controller [0116] 36 three line intermediate hose [0117] 40 hose transporting system [0118] 41 puller-roller [0119] 42 hose reel [0120] 43 motor of puller-roller [0121] 44 motor controller of motor 43 [0122] 100 terrain [0123] 101 surface of terrain [0124] 102 borehole [0125] 103 TAM pipe [0126] 104 first injection [0127] 105 second injection site [0128] 106 third injection site [0129] 104a, 104b valve plates of first injection site [0130] 105a, 105b valve plates of second injection site [0131] 106a, 106b valve plates of third injection site [0132] 107 space between packer system 16 and TAM pipe 103