A reinforcement element for retaining walls, equipped with a sealing holder

Description

Domaine Technique

[0001] The invention relates to the field of manufacturing diaphragm walls in the ground. It relates in particular to the techniques for joining two adjacent panels of the diaphragm wall. Technique Antérieure

[0002] As is known, a diaphragm wall consists of a plurality of adjacent panels, connected one after the other. To ensure continuity and watertightness between two adjacent panels, it is important that the junction between the panels is correctly made.

[0003] To do this, several techniques are traditionally used.

[0004] According to a first technique, after having made a first concrete panel, the first panel is towed so that the concrete of the second panel will come into contact with the concrete of the first panel in order to ensure the continuity of concrete between the two panels.

[0005] A second technique involves using formwork, usually metal, which is temporarily inserted into the trench and removed after the concrete has hardened. This formwork allows the installation of a waterproof joint that extends vertically along the end edge of the panel. Such a technique is notably described in EP 0 101 350. The use of formwork makes the second technique more expensive and time-consuming than the first technique.

[0006] A technique similar to the second is disclosed by document CN101608447 A, which particularly describes the preamble of independent claim 1. Exposé de l'invention

[0007] An aim of the present invention is to make it possible to create a junction between two adjacent panels without using formwork.

[0008] To this end, the invention relates to a reinforcement element for a diaphragm wall according to claim 1 comprising a reinforcement cage which has a length defining a longitudinal direction, a width and a thickness, the reinforcement cage having a first end portion and a second end portion opposite the first end portion, the first and second end portions extending in the longitudinal direction of the reinforcement cage, the reinforcement element further comprising at least one seal holder provided with a mounting portion for receiving at least one sealing gasket which is elongate, the seal holder being fixed to the first end portion of the reinforcement cage and extending in the longitudinal direction of said reinforcement cage,the reinforcement element is characterized in that said seal holder comprises two wings extending in the longitudinal direction and a bottom so as to define a housing for receiving the sealing gasket, at least a first part of which is surrounded by a sacrificial material.,

[0009] The reinforcing element according to the invention therefore makes it possible both to reinforce the concrete constituting the panel, and to place and fix the sealing joint along the first vertical edge of the panel, without using a formwork element.

[0010] It is understood that the reinforcement element according to the invention is placed in a first trench before pouring the concrete.

[0011] Once the concrete of the first panel has hardened, the second trench is drilled and then the sacrificial material is removed so as to expose the first part of the seal, the second part of the seal being engaged in the concrete of the first panel.

[0012] This first part of the seal will then be embedded in the concrete when pouring concrete into the second trench. In other words, the first part will be embedded in the concrete of the second panel adjacent to the first panel, so as to create a seal between the first and second panels.

[0013] It is understood that the seal is intended to be arranged in the housing. Without departing from the scope of the present invention, the seal holder can receive several seals arranged side by side.

[0014] In a known manner, the reinforcement cage comprises a plurality of reinforcement rods, so as to produce reinforced concrete.

[0015] The wings of the housing flank the sacrificial material, in order to protect it, in particular when introducing the reinforcement element into the trench.

[0016] Preferably, the distance between the wings is less than the width of the reinforcement cage, more preferably, this distance is less than half the width of the reinforcement cage.

[0017] Preferably, the wings are parallel.

[0018] According to the invention, the sealing gasket is fixed to the bottom of the housing.

[0019] The joint holder is preferably a longitudinal profile. It extends along the height of the reinforcement cage.

[0020] Preferably, the longitudinal profile has a “U” section.

[0021] According to a preferred embodiment, the longitudinal profile consists of two longitudinal “L”-shaped elements. Preferably, the two longitudinal “L”-shaped elements are spaced apart from each other in order to form a slot into which the sealing gasket is inserted.

[0022] Advantageously, the longitudinal profile is fixed, for example by welding, to the reinforcement cage, preferably at its first end part.

[0023] Without departing from the scope of the present invention, the joint holder may be mounted at least partly in the volume of the reinforcement cage. In other words, the joint holder may be located in a recess in the reinforcement cage.

[0024] According to the invention, the mounting part comprises a longitudinal slot provided in the bottom to receive the sealing gasket.

[0025] According to one embodiment, the sealing joint has a length which is greater than the length of the longitudinal slot of a reinforcement element. In other words, the length of the sealing joint is greater than the length of the seal holder. In this case, the sealing joint is successively engaged in the slots of the seal holders of several reinforcement elements arranged vertically above each other in the trench. Such an assembly makes it possible to ensure the vertical continuity of the sealing.

[0026] Advantageously, the reinforcement element further comprises at least one reinforcing member connecting at least one of the wings to the reinforcement cage. The reinforcing members have the effect of increasing the robustness of the attachment of the joint holder to the reinforcement cage.

[0027] According to a preferred embodiment, the reinforcement cage, considered in a plane perpendicular to the longitudinal direction, comprises two adjacent reinforcement portions each provided with at least two parallel reinforcements, the joint holder being fixed to each of the two adjacent reinforcement portions. According to a variant, the joint holder is arranged between the two adjacent reinforcement portions. The two adjacent reinforcement portions are also fixed to each other by means of fixing means separate from the joint holder.

[0028] The invention further relates to a reinforcement device comprising a reinforcement element according to the invention, as well as at least one seal and a sacrificial material in the housing, the seal being mounted on the seal holder while being at least partly bordered by the sacrificial material.

[0029] Preferably, the sacrificial material is disposed in the housing, on either side of the seal. More specifically, the sacrificial material is disposed on either side of the first portion of the seal that is in the housing. More preferably, the sacrificial material substantially fills the volume of the housing. One advantage is to prevent concrete from adhering to the first portion of the seal that is in the housing.

[0030] Considered in a plane perpendicular to the longitudinal direction, and parallel to the thickness of the reinforcement cage, the span, i.e. the maximum thickness of the sacrificial material, is less than the thickness of the reinforcement cage.

[0031] According to an advantageous embodiment, the seal further has a second part, the first and second parts being arranged on either side of the bottom when the seal is mounted on the seal holder, so that the seal extends transversely on either side of the bottom, the first part being located in the housing and flanked by the sacrificial material.

[0032] Preferably, the first part of the seal is located entirely within the volume of the housing.

[0033] According to one embodiment, the sacrificial material is a friable material. It preferably comprises polystyrene.

[0034] The invention finally relates to a method of producing, according to claim 10, a diaphragm wall in a ground in which a first vertical trench is drilled in the ground, a first reinforcement device according to the invention is placed in the first trench, concrete is poured into the first trench and then, after the concrete has hardened, a second vertical trench is drilled in the ground, juxtaposed with the first trench on the side of the joint holder, the sacrificial material is removed from the housing using the scraper tool according to the invention, so that the first part of the sealing joint extends into the second trench, and then concrete is placed in the second trench.

[0035] The scraper tool comprises two parallel teeth spaced apart from each other so as to define a passage for the seal. Preferably, the width of the scraper tool is substantially equal to the distance between the wings of the seal holder. The teeth are engaged in the housing, on either side of the first part of the seal.

[0036] To remove the sacrificial material, the scraper tool is placed in the housing while engaging the first part of the seal in the passage between the two teeth of the scraper tool. When the scraper tool is moved vertically in the longitudinal direction, the vertical movement of the teeth has the effect of removing the sacrificial material from the housing. Preferably, the teeth have a face inclined relative to the bottom so as to facilitate the removal of the sacrificial material.

[0037] It is understood that, after the concrete placed in the first trench has hardened, the first panel is obtained, which includes the reinforcement element. The second part of the joint seal is engaged with the concrete of the first panel. After removing the sacrificial material from the housing, the first part of the seal is uncovered. The housing then opens onto the second trench. When concrete is placed in the second trench, the concrete flows into the housing so that the first part of the seal engages with the concrete of the second trench.

[0038] Preferably, the first panel can be towed if necessary when drilling the second adjacent trench, in order to clear the ground between the second trench and the accommodation. Description des dessins

[0039] The invention will be better understood on reading the following description of embodiments of the invention given as non-limiting examples, with reference to the appended drawings, in which: [ Fig. 1 ] There figure 1 is a schematic perspective view of an exemplary embodiment of a reinforcement device according to the present invention, comprising a reinforcement element according to the invention, as well as a sealing joint and a sacrificial material; [ Fig. 2 ] There figure 2 is a top view of the reinforcement device of the figure 1 ; [ Fig. 3 ] There figure 3 illustrates a first variant of the reinforcement device of the figure 2 ; [ Fig. 4 ] There figure 4 illustrates a second variant of the reinforcement device of the figure 2 ; [ Fig. 5 ] There figure 5 is a side view of the armature device of the figure 1 ; [ Fig. 6 ] There figure 6 illustrates an example of the embodiment of a scraper tool used in the implementation of the method for producing a diaphragm wall in accordance with the invention; [ Fig. 7 ] There figure 7 illustrates a first step of the method for producing a diaphragm wall according to the invention; [ Fig. 8 ] There figure 8 illustrates a second step of the method for producing a diaphragm wall according to the invention; [ Fig. 9 ] There figure 9 illustrates a third step of the method of producing a diaphragm wall according to the invention; [ Fig. 10 ] There figure 10 illustrates a fourth step of the method of producing a diaphragm wall according to the invention; [ Fig. 11 ] There figure 11 illustrates the first panel and the second trench, at the end of the fourth stage; [ Fig. 11 ] There figure 11 illustrates a fifth step of the method of producing a diaphragm wall according to the invention; [ Fig. 12 ] There figure 12 illustrates a sixth step of the method of producing a diaphragm wall according to the invention; [ Fig. 13 ] There figure 13 illustrates a seventh step of the method of producing a diaphragm wall according to the invention; and [ Fig. 14 ] There figure 14 illustrates an eighth step of the method for producing a diaphragm wall according to the invention. Description détaillée

[0040] With the help of the figures 1 And 2 , we will describe a first example of the production of a reinforcement device 10 in accordance with the present invention.

[0041] This reinforcement device comprises a reinforcement element 12 for a molded wall according to the invention, as well as a sealing joint 14 and a sacrificial material 16 which will be described in more detail below.

[0042] The reinforcement element 12 includes a reinforcement cage 18which is made up of a plurality of horizontal bars 20 and vertical 22 which are fixed to each other, for example by welding, in a manner known elsewhere.

[0043] The reinforcement cage 18 has a length L defining a longitudinal direction, which is generally vertical. This length can also be considered as the height of the reinforcement cage. The reinforcement cage 18 also has a width l and a thickness e visible in figure 2 .

[0044] The reinforcement cage 18 presents, considered according to its width, a first end part 18 a and a second end part 18 b opposite the first end part 18 has.

[0045] The first and second end portions 18a, 18b extend vertically in the longitudinal direction Aof the reinforcement cage.

[0046] In this example, the gasket 14 is longer than the length of the reinforcement cage.

[0047] The reinforcement element 18 also includes a seal holder 30 located at the first end part 18 has the reinforcement element 18. The seal holder 30 is designed to receive the sealing gasket 14. Without departing from the scope of the invention, the seal holder 30 could accommodate several sealing gaskets arranged side by side. As can be seen on the figures 1 And 2 , the seal holder 30 is fixed to the first end part 18 has the reinforcement cage 18. The seal holder 30 extends further in the longitudinal direction A of the reinforcement cage. The joint holder 30 includes two wings 30a, 30b separated by a distance d.Preferably, the two wings are parallel and extend in the longitudinal direction. A. When they are parallel, this makes it easier to guide the scraper tool which will be described below.

[0048] Considered according to the width of the reinforcement cage, the distance d between the flanges of the joint holder is less than the thickness of the reinforcement cage, and more precisely less than half the thickness e of the reinforcement cage 18.

[0049] The seal holder 30 also includes a background 34 which, in this example, is perpendicular to the wings 30 has, 30 b. The bottom also extends in the longitudinal direction. The two wings and the bottom thus define a housing 36 to receive the long, thin seal 14.

[0050] In this example, the seal holder 30is a longitudinal profile, which has a “U” section, considered in a horizontal plane.

[0051] More precisely, in this example, the longitudinal profile is made up of two longitudinal elements 31a, 31b in “L”. These two longitudinal elements are spaced apart from each other so as to delimit a longitudinal slot 40, this longitudinal slot being made in the bottom 14 and constituting a mounting part 32 to receive the seal 14.

[0052] In this example, the seal holder 30 is fixed, for example by welding, to reinforcing bars 20 which constitute the first end part 18 has the reinforcement cage 18. In this non-limiting example, the seal 14 is flat and has two side bulges 15a, 15b and a central bead 15c, the side beads and the central bead being parallel and extending along the length of the seal 14.

[0053] As seen in the example of the figure 2 , the first part of the seal is surrounded by the sacrificial material 16, while its second part 14 b extends inside the volume of the reinforcement cage. In other words, the sealing gasket extends on either side of the first end part 18 has the reinforcement cage 18. The seal 14 also extends on either side of the bottom 34, perpendicular to said bottom 34. Considered according to the thickness of the reinforcement cage, the span of the sacrificial material is strictly less than the thickness e of the reinforcement cage, and moreover less than half the width of the reinforcement cage.

[0054] To reinforce the retention of the joint holder to the reinforcement cage, the reinforcement element 12 also includes reinforcing members 42, 44 which connect the wings 30a, 30b from the joint holder to the reinforcement cage 18. In this example, these are metal rods that are welded to the wings on one hand and to the reinforcement cage on the other.

[0055] On the figure 3 , a first variant of the reinforcement cage of the figure 2 , in which the reinforcing bars have another conformation.

[0056] In the second variant illustrated in figure 4 , the reinforcement cage 18, considered in a plane perpendicular to the longitudinal direction A, that is to say in a horizontal plane, comprises two portions of reinforcement 19, 21 which are adjacent and which are each provided with at least two parallel rods 23, 25.As can be seen on the figure 4 , the joint holder is fixed to each of the two adjacent frame parts 19, 21. More precisely, the wings 30a, 30b of the seal holder are fixed to the parallel rods 23, 25. Also, in this embodiment, it is not necessary to provide reinforcing members. It can be seen that in this embodiment, the joint holder is engaged in a recess made in the reinforcement cage. 18, this recess being delimited laterally by the parallel rods 23, 25.

[0057] We note that the first and second parts 14a, 14b of the joint are arranged on either side of the bottom 34 when the seal is mounted on the seal holder 30, so that the seal 14 extends transversely to the bottom 34, the first part being located in the housing and flanked by the sacrificial material.

[0058] In the example of the figure 4 , the seal 14 is arranged in the volume of the reinforcement cage 18.

[0059] Preferably, the sacrificial material 16 includes polystyrene. More generally, the sacrificial material is brittle. In this example, the sacrificial material 16 consists of two blocks 16 has, 16 b which flank the first part 14 has a seal 14.

[0060] To remove the sacrificial material 16 outside the accommodation 36, we use a scraper tool 100, illustrated in figure 6 . The scraper tool 100 is attached to a frame 102 which is vertically movable by suitable means known elsewhere and not illustrated here. For example, the scraper tool can be fixed to one side of the chassis of a bucket-type drilling tool.

[0061] The scraper tool 100 has two teeth 104, 106 which are parallel to each other while being distant from each other so as to define a passage between them 109 for the seal 14. The width of the passage 109 is slightly larger than the thickness of the gasket.

[0062] The width q of the scraper tool, considered between the outer edge 104 has the first tooth 104, and the outer edge 106 has a second tooth 106, is approximately equal to the distance between the wings 30a, 30b of the seal holder 30. The two teeth 104, 106 are, in this example, fixed to a plate 108 which is itself fixed to the chassis 102.

[0063] In this non-limiting example, the end of the teeth 104, 106 is beveled to facilitate the evacuation of polystyrene from the housing 36.

[0064] With the help of the figures 7 à 14 , We will now describe a process for creating a diaphragm wall in a floor S in accordance with the present invention.

[0065] During the first stage, illustrated in figure 7 , we drill a first vertical trench T1 in the ground S.

[0066] Conventionally, drilling is carried out while filling the trench with mud to prevent the trench walls from collapsing.

[0067] The trench has a length a and a width b. It has first and second vertical walls 200, 202 opposite each other, and third and fourth vertical walls 204, 206 opposite each other. In this example, the first and second vertical walls 200, 202 are smaller than the third and fourth vertical walls 204, 206.

[0068] According to a second step, illustrated in figure 8 , we place in the first trench T1 a first reinforcement device 10 according to the invention, for example that of the example of the figure 2 .

[0069] As can be seen on the figure 8 , the reinforcement device 10 is placed in the trench T1 so that the seal holder 30 is opposite the first wall 200. As seen in this example, the first end part of the device 18 has the reinforcement cage 18, constituted by the opening 37 housing 36 is distant, considered in a horizontal plane, from the first wall 200 from the trench T1. This distance is referenced X. In practice, it is appropriate that this distance Xis as small as possible, if possible equal to or close to zero. In this example, this distance is of the order of 10 cm. Without departing from the scope of the present invention, the reinforcement device 10 could be placed in the trench so that the joint holder 30 rests against the first wall 200 from the trench T1.

[0070] According to a third step, illustrated in figure 9 , concrete is poured into the trench T1.

[0071] According to a fourth step illustrated in figure 10 , after the concrete has hardened, a second vertical trench is drilled T2 in the ground S, this second trench T2 being juxtaposed to the first vertical trench T1 on the side of the seal holder 30. As illustrated in figure 10 , drilling is carried out using a drilling tool shown diagrammatically by the reference 300,the drilling tool 300 being placed as close as possible to the seal holder 30.

[0072] On the figure 11 , we illustrated the first panel 250, obtained after hardening of the concrete in the first trench T1, and towed along part of its length in order to reach the seal holder 30 or at least to minimize the thickness of residual concrete between the joint holder and the second trench T2. The result is illustrated in figure 11 . In this example, the sacrificial material 16 comes into contact with the mud of the second trench T2.

[0073] Using the scraper tool 100 previously described, the sacrificial material is removed from the housing 30. To do this, the scraper tool 100 is engaged in the housing at the top of the seal holder 30 so that the seal 14be placed in the passage 109 located between the teeth 104, 106. As can be seen on the figure 12 , illustrating the step of evacuation of the sacrificial material, each of the teeth 104, 106 is located between the first part 14 has a seal and one or the other of the wings 30a, 30b of the seal holder 30, so as to be engaged in the volume which is occupied by the sacrificial material. We understand that the descent along the vertical axis Z of the scraper tool 100 has the effect of evacuating the sacrificial material towards the second trench T2.

[0074] After the removal of the sacrificial material, we understand that the housing is open in the second trench T2 so that the mud fills the housing. The first part 14a of the seal 14 is then surrounded by mud.

[0075] Then, in a next step, illustrated in figure 14, a second reinforcement device is placed 10', then we put concrete in the second trench T2 so as to obtain, after hardening, the second panel 252.

[0076] We understand that when putting the concrete in the second trench, the concrete fills the housing 30 of the first reinforcement device 10, so that after hardening, the first part 14a of the joint 14 engages with the concrete of the second panel. The sealing joint 14, in contact with the concrete of the first and second panels 250, 252, thus creates a seal between the two panels.

Claims

1. A reinforcement element (12) for a diaphragm wall including a reinforcement cage (18) which has a height defining a longitudinal direction (A), a width (I) and a thickness (e), the reinforcement cage (18) having a first end part (18a) and a second end part (18b) considered along its width as opposite to the first end part, the first and second end parts (18a, 18b) extending along the longitudinal direction (A) of the reinforcement cage, the reinforcement element further including at least one seal-carrier (30) provided with a mounting part (32) for receiving at least one seal (14) which is elongated, the seal-carrier (30) being fixed to the first end part (18a) of the reinforcement cage (18) and extending along the longitudinal direction (A) of said reinforcement cage, the reinforcement element (12) being characterized in that the seal-carrier has two flanges (30a, 30b) extending along the longitudinal direction (A) and a bottom (34) so as to define a housing (36) for receiving the seal (14), at least a first part of which (14a) is surrounded by a sacrificial material (16), the mounting part (32) including a longitudinal slot (40) formed in the bottom (34) to receive the seal (14).

2. The reinforcement element according to claim 1, wherein the seal-carrier (30) is a longitudinal profile (31).

3. The reinforcement element according to claim 2, wherein the longitudinal profile (31) has a "U" section.

4. The reinforcement element according to claim 2 or 3, wherein the longitudinal profile consists of two "L"-shaped longitudinal elements (30a, 30b).

5. The reinforcement element according to any one of the preceding claims, further including reinforcing members (42, 44) connecting at least one of the flanges to the reinforcement cage (18).

6. The reinforcement element according to any one of the preceding claims, wherein the reinforcement cage (18), considered in a plane perpendicular to the longitudinal direction (A), includes two adjacent reinforcement portions (19, 21) each provided with at least two parallel reinforcements (23, 25), the seal-carrier being fixed to each of the two adjacent reinforcement portions.

7. A reinforcement device (10) including a reinforcement element (12) according to any one of the preceding claims, as well as at least one seal (14) and a sacrificial material (16) in the housing (36), the seal being mounted on the seal-carrier while being at least partly bordered by the sacrificial material.

8. The reinforcement device according to claim 7, wherein the seal further has a second part (14b), the first and second parts (14a, 14b) being disposed on either side of the bottom (34) when the seal (14) is mounted on the seal-carrier (30), so that the seal extends transversely relative to the bottom, the first part being located in the housing and flanked by the sacrificial material.

9. The reinforcement device according to claim 7 or 8, wherein the sacrificial material (16) comprises polystyrene.

10. A method for making (30a, 30b) a diaphragm wall in the ground (S) wherein a first vertical trench (T1) is drilled in the ground (S), a first reinforcement device (10) according to any one of claims 7 to 9 is placed in the first trench (T1), concrete is poured into the first trench then, after hardening of the concrete, a second vertical trench (T2) is drilled in the ground (S), juxtaposed with the first vertical trench (T1) on the side of the seal-carrier (30), the sacrificial material is discharged out of the housing using a scraping tool (100) including two parallel teeth (104, 106) spaced apart from each other so as to define a passage (109) for the seal (14), the width (g) of the scraping tool being substantially equal to the distance between the flanges (30a, 30b) of the seal-carrier (30), so that the first part (14a) of the seal (14) extends into the second trench, then concrete is put in the second trench (T2).