NO344821B1

NO344821B1 - Chair and method for fixing elongate profiles to a supporting surface, for example a tunnel wall or roof surface.

Info

Publication number: NO344821B1
Application number: NO20180659A
Authority: NO
Inventors: John Oldroyd Cheetham
Original assignee: John Oldroyd Cheetham
Priority date: 2018-05-08
Filing date: 2018-05-08
Publication date: 2020-05-11
Also published as: NO20190590A1; NO20180659A1; IS050266A; SE1950551A1

Description

The Technical Field of the Invention

The invention relates to a chair and a method for fixing profiles to a supporting surface to support the supporting surface in such a way that it may be possible to maintain the supporting surface at a predetermined distance from a concrete reinforcement member, as further defined in the preamble of the independent claims.

Thus, the present invention relates to a chair for fixing an elongate profile on a lining or supporting surface to be concreted, for example arranged on a tunnel wall or roof surface, the chair comprises a base member configured to be rigidly fixed to the supporting surface; an intermediate part fixed to and extending out from one side of the base member and optionally a reinforcement bar fixing and locking device for receiving the reinforcement member, fixed to an opposite end of the intermediate part.

Furthermore, the invention also relates to a method for fixing an elongate profile on a lining or supporting surface, such as a supporting membrane or foil surface to be reinforced and subsequently covered with concrete, using chairs as claimed in claim 1 to 6, enabling the membrane surface to be at a predetermined, preferably uniform distance apart from the reinforcements, the reinforcement optionally being fixed to the membrane using chairs to be rigidly fixed to the membrane surface.

Background for the Invention

In many cases, there is a need for a waterproof and/or fire proof lining of a wall or a roof, such as for example the walls and/or roof of a tunnel, and at the same time there is a requirement that such linings or membranes are to be covered by concrete. The lining is affixed to the wall/roof by means of rock anchors fixed at one end to the rock, the other end extending a distance outwards from the rock, the lining being arranged as a continuous lining across the tunnel in lengthwise sections, forming a water tight barrier covering both the walls and the roof. In addition reinforcement is fixed to and supported by the same rock anchors whereupon a layer of concrete is shot on to the lining, the lining serving as formwork for such shotcrete.

In order to reinforce the concrete, reinforcement is required, either as reinforcement rebars, together with the lining, is extending both in a longitudinal direction of the tunnel and also in transverse direction, following the contour of the lining, or as reinforcement nets. Such reinforcement, together with the lining, is fixed to the rock by means of rock anchors while the lining is additionally supported by means of chairs, fixed to the lining and connected to a number of chairs prior to shotcreting in order to prevent parts of the flexible lining from being displaced during concreting and in order to secure the required minimum distance from the lining to the reinforcement and to secure the require coverage of the reinforcement, externally of the reinforcement.

The reinforcement can be affixed to the lining with chairs to keep the desired distance. For instance, chairs such as the one revealed in NO 341919 can be used. Using this type of chairs or other types of chairs for fixing the reinforcements with out any other support means that the distance between the flexible liner and the reinforcement only will be precisely maintain at the points where there is a chair present. To maintain the distance between liner and reinforcement in between chairs it is common to use supportive plastic profiles (from now on referred to as profiles) in between chairs, glued or welded on the surface of the lining. These profiles prevent the membrane from moving away from the reinforcements when exposed to the force from shotcreting, preventing it from yielding outwards during shotcreting and helps keeping the lining stretched out in the desired shape. Large quantities of profiles are needed, and fixing them to the lining is time consuming. Gluing is the common way for fixing the profiles to the lining as of today.

Use of glue incorporates a number of inherent drawbacks. Firstly, the glue it self must be of a two-component type, preferably mixed in the outlet of a glue pistol or melt glue pistol. Such glue is expensive, requiring a clean surface in order to secure sufficient and adequate gluing effect. Moreover, such method also requires a period of time for enable the glue to cure. Hence the method is both expensive due to time taken, man hours required and the cost of the glue. Moreover, experience has shown that the quality of the gluing effect may vary substantially, both due to lack of or varying proper distribution of a uniform layer of glue over the entire contact area of the profile and varying cleaness of the membrane surface and the presence of moist. As a consequence, it is experienced that some of the profiles drops off during concreting, such shotcrete being applied at a high pressure causing heavy impact on the supporting surface, reinforcement, chairs and profiles. In areas where one or more profiles have dropped off, the supporting surface will yield during the shotcreting operation, forcing the supporting surface outwards towards the rock behind. In such regions the layer of shotcrete will as a consequence be thicker, thus consuming more concrete than necessary due to the yielding outwards, thus increasing time taken for the concreting process and the cost of added volume of concrete necessary.

NO 341919 which describes an earlies invention made by the inventor discloses a chair for fixing reinforcements. This chair comprises a base and a reinforcement bar locking device. The base can be welded onto the liner and the reinforcements bars can be inserted into the locking device. The chair helps keeping the desired distance between the liner and the reinforcement.

From NO 333588 it is known a chair for fixing reinforcement nets or bar at a predetermined distance from an insulated tunnel wall. The chair comprises a threaded section intended to be screwed into the insulating material until a stop surface enters into engagement with the surface of the insulation. A part of the chair is configured to project outwards from the insulation with two parallel discs arranged at a predefined distance from the insulation, securing adequate position for the reinforcement with respect to the insulation. The chair is also provided with a spy, i.e. a devise to enable the concreting operator to identify whether an adequate concrete coverage is obtained in the shotcreting process or not.

US 3,673,753 describes a concrete reinforcing bar support devise which includes a base supporting an upright pedestal, configured to rest more or less firmly on a more or less horizontal surface. A lower clamping portion is supported by the pedestal which has a first rod-receiving open passageway there through.

Resilient detents extend from the lower clamping portion to retain detents extend from the lower clamping portion to retain a reinforcing rod disposed through the first passageway. An upper clamping portion is provided which includes a pair of hook members extending from the lower clamping portion. Each of the hook members has a mouth opening in the same direction to define a second rod-receiving passageway which is normally disposed to the first passageway. The chair disclosed is of a type intended to rest on a more or less horizontal surface without any fixing means to the supporting surface.

US 2008/0178554 disclose a chair for supporting one or more reinforcement bars in a concrete structure, designed for. The chair includes a base member having a centered opening, a pair of opposing first leg members extending upwards from the base member at a first angle, a pair of opposing second leg member extending upwards from the base element at a second angle, and a strapshaped locking cradle. The strap-shaped locking cradle includes an arc-shaped receiving portion attached to the first and second leg members, a flexible portion suitable for wrapping over the bars and a fastener to affix the flexible portion to the arc-shaped receiving portion or one of the first leg members such that transverse and vertical movement of the bars is limited and longitudinal movement of bars is allowed. The chair is also provided with a centrally arranged spike extending downwards from the cradle and downwards past the base, intended to be forced into the ground.

SE 526238 discloses a fastener for securing a reinforcement net, with a rod with support for cooperating with a mesh and an anchor for gripping against insulation material. The anchor being arranged at and projecting out from one end of the rod and the support cooperating with the mesh projecting radially out from the other end of the rod. The anchor being arranged as a barb/fluke with egg-shaped edges in order to ease the penetration into the insulation material. The fastener having the support for cooperating with the mesh with an outer and an inner fixing element axially displaced projecting radially out from the rod.

NO 334265 discloses a reinforcement chair comprising a stem with a fastening part and a holder part and a distance part there between. The holder part for supporting of a reinforcement, such as reinforcement net, constitutes a first supporting element and a second supporting element being axially displaced plane flanges at one end of the distance part and the fastening part for fastening to a supporting surface, such as a rocky wall or insulating plates, constitutes a helical thread to be screwed into the supporting surface.

GB 1169783 discloses a distance piece of a resilient plastic material for supporting a reinforcement, such as a reinforcement wire, mesh or rods, during the laying of concrete. The distance piece comprising a ball-shaped lower end part of a stem and an elastic locking device for supporting reinforcement elements a distance above the ball-shaped lower end part. The ball-shaped lower part adapted for attachment to a supporting surface through pressing the ball-shaped lower end part of the distance piece through a hole in the supporting surface.

WO 2005/115682 discloses holding device being a profile with openings for installing holding means, where reinforcement rods can be placed in the holding means and DK 110065 discloses a supporting body for securing of tubes placed in a wall construction for casting and particularly discloses a supporting body with to legs and an intermediate stem with barbs for placement into a hole in the casting mould. It should be appreciated that the lining on the one hand, although fixed to the tunnel wall by means of the rock anchors, is flexible and pliable, so that the distance between the lining and the established or mounted reinforcement may vary due to said flexibility. On the other hand the reinforcement fixed to the rock anchors forms a quite rigid frame structure. Because of the varying distance between the fixed reinforcement and the flexible lining, and in order to secure an even distance between these two elements, chairs and profiles are used. Said chairs and profiles are fixed subsequent to mounting of the lining and reinforcement on the rock anchors, the chairs and profiles being used to obtain the correct distance between the ling and the fixed reinforcement. As a consequence some times the lining must be pushed away from the reinforcement using the chairs and profiles and in other instances the chairs are used to pull the lining towards the fixed reinforcement. It is therefor a need for a method that allows quick fixing of both chairs profiles and that secure adequate fixing, enabling pulling or pushing the lining into required position rapidly after fixing of the chair.

In some instances there is for different reasons a need for adding additional rigidity to and to support the lining. This is proposed solved by using elongate profiles, for example made of re-circulated plastic materials. It has proved difficult and/or time consuming, however, to provide a proper fixture of the elongate profiles to the supporting lining or surface.

There is a need for hardware and a method that allows quick and efficient mounting of profiles and where the profiles is maintained in the intended position during the shotcreting process.

Summary of the Invention

An object of the present invention is to provide a simplified and more efficient way for interconnecting at least profiles, and preferably also reinforcements to a lining covering the roof and/or walls for example in tunnels, before concrete is applied in a shotcreting process.

Another object of the present invention is to provide a method and a chair that makes the process of affixing the profiles effective and less time consuming compared to using the prior art methods and hardware.

Yet another objective of the present invention is to make the fixture of chairs and profiles sufficiently rigid and resistant to withstand the impact from the shotcreating process.

Yet another object of the invention is to provide a system that distributes the impact from the shotcreting more evenly over a larger surface area.

A further objective of the present invention is to make a chair that fulfills the already mentioned objectives and at the same time being easy to manufacture, leaving the casting mold easily; and thereby being cost effective to produce.

The objects are achieved by a chair and a method for affixing profiles to a supporting surface by the use of such a chair as further defined by the independent claims, while embodiments, alternatives, modifications and variants are defined by the dependent claims.

In a first aspect the present invention relates to a chair for fixing an elongate profile and supporting a reinforcement member for concrete on a lining or supporting surface, for example arranged on a tunnel wall or roof surface, comprising a base member configured to be attached to the supporting surface; an intermediate part fixed to and extending out from one side of the base member and a reinforcement bar supporting and locking device for receiving the reinforcement member, fixed to an opposite end of the intermediate part. Moreover, the chair is provided with at least one fin extending sideways or laterally out from the intermediate part and is configured to fix an elongate profile to the lining or supporting surface by threading the chair through an opening of the elongate profile.

According to one embodiment the at least one fin is provided with a flexible tip, allowing a profile with an opening or a hold to be snapped over the fin(s).

According to another embodiment of the invention the flexible tip of the at least one fin is pointed towards the base member of the chair.

According to yet another embodiment of the invention the at least one fin is provided with the at least one side surface, inclined outwards and downwards towards the base member.

Further according to one possible embodiment of the invention the at least one fin is provided with a locking surface, facing the base member and arranged at a distance apart from a surface of the base member.

According to another embodiment of the invention the at least one fin extends more or less continuous in circumferential direction around the intermediate part and preferably, but not necessarily extending 360 degrees around the intermediate part. As a variant the external surface of such fin may be provided with one or more recess, allowing the tip to be yielding when pressed through an opening in the profile.

In a second aspect, the present invention relates to a method for fixing a elongate profile to a lining or supporting surface such as a supporting membrane of foil surface to be reinforced and subsequently covered with concrete, using a chair as claimed in the claims 1 to 6, enabling the membrane surface to be at a predetermined, preferably uniform distance apart from the reinforcement, the reinforcement being fixed to the membrane using chairs to be fixed to the membrane surface through the steps of threading an elongate profile onto the chair by insertion and/or snapping of the intermediate part and the fin through an opening of the elongated profile and fixing the chair with its base on the lining or supporting surface. According to the invention the locking effect is obtained by using one or more of the chairs to fix the elongate profile to the membrane surface.

According to one embodiment the chair is being threaded into a hole in the profile and then the profile or the chair is being turned approximately 90 degrees around the intermediate part of the chair so that a part of the profile becomes fixed between the fins and the base member. For such purpose both the hole and the cross sectional foot print of the chair, seen from the opposite end of the base may be rectangular, allowing the intermediate part and the reinforcement bar fixing and locking device to pass through the hole in the profile when aligned, but is prevented to be removed when rotated the said 90 degrees.

According to another embodiment the profile is being secured to the chair before the chair is being affixed to the supportive surface.

According to yet another embodiment a profile is being fixed by using one or more chairs that are fixed to the supporting surface whereupon the profile is being threaded and snapped onto the at least one chair.

Further according to another embodiment of the invention a profile is being threaded onto a chair and forced past at least one flexible fin or a flexible collet on the chair.

Brief Description of the Drawings

Below, embodiments of the invention will be described, referring to the accompanying drawings, wherein:

Figure 1 shows schematically, in perspective and simplified a part of a tunnel wall and roof provided with a lining attached to the rock and reinforcement the lining also being strengthened by means of conventional profiles, fixed to the lining by means of one possible embodiment of the chair, also used for fixing reinforcement to a supporting surface;

Figure 2 shows schematically and in perspective of the profiles and reinforcement fixed to a supporting surface by means of a number of chairs;

Figure 3 shows schematically in perspective and in an enlarged scale details for one way of fixing the profile to the lining or supporting surface; and

Figure 4 shows schematically, one possible embodiment of the chair seen from the side.

Detailed Description of Embodiments disclosed in the Drawings

The following description of the exemplary embodiments refers to the accompanying drawings. The same reference numbers in different drawings identify the same or similar elements. The following detailed description does not limit the invention. Instead, the scope of the invention is defined by the appended claims. The following embodiments are discussed, for simplicity, with regard to a method for fixing profiles to a lining or to insulation, using the chairs as fixing points.

Reference throughout the specification to “one embodiment” or “an embodiment” means that a particular feature, structure, or characteristic described in connection with an embodiment is included in at least one embodiment of the subject matter disclosed. Thus, the appearance of the phrases “in one embodiment” or “in an embodiment” in various places throughout the specification is not necessarily referring to the same embodiment. Further, the particular features, structures, or characteristics may be combined in any suitable manner in one or more embodiments.

Although a chair comprising a base element 12, an intermediate stem or part 14 projecting upwards from the base 12 and a reinforcement bar holding and locking device 16 and possibly a spy 18 and two locking fins 24 is described below, it should be appreciated that the chair also may be modified in such way that chair only consist of the base or foot and the stem or intermediate part 14 extending out from the foot.

Figure 1 shows schematically, in perspective and simplified a lining or supporting surface 28 as a part of a tunnel wall and roof. the lining or supporting surface 28 being attached to the rock (not shown) and reinforcement 26, the lining or supporting surface 28 also being strengthened by means of conventional profiles 30, fixed to the lining 28 by means of one possible embodiment of the chair 10, also used for fixing reinforcement to a supporting surface. In Figure 1 one can see the supporting surface 28, the chairs 10, the profiles 30 and the reinforcement 26 assembled on a sidewall and partly in the roof of a tunnel. Although only a section of a lining 28 is shown, the lining or supporting surface 28 may extend around the full profile of the tunnel and along the entire length of the tunnel. The number of profiles 30 used depends on the need for strengthening of the rigidity of the supporting surface 28 both lengthwise and crosswise in the tunnel. Both the reinforcement and the profiles are arranged on the side of the supporting surface facing the tunnel cavity.

Figure 2 shows one profile and reinforcement fixed to a number of chairs. The purpose of this figure is to show the details in a enlarged view compare to figure 1.

Figure 3 shows schematically and in perspective a section through a single profile 30 fixed to the supporting surface 28 (not shown in Figure 2). The profile 30 according to the embodiment shown has a general U-shaped form with two wings 36 and an intermediate bottom structure or plate 34, interconnecting the two wings 36, preferably, but not necessarily made of recycled plastic material. According to the embodiment shown a portion of the profile 30 is locked to the supporting surface 28 (not shown in Figure 3) by means of fins 24 on the chair , pressing the intermediate bottom structure 34 against the foot 12 of the chair, fixed to the supporting surface 28. According to the embodiment shown, the chair 10 is threaded through an opening 32 in the intermediate bottom structure 34 and then rotated to a position as disclosed where the lower surface of the fins 24 forces the intermediate bottom structure 34 of the profile 30 against the referenced foot or base 12. For this purpose, the hole 32 may be elongate, i.e. smaller width than length, the longitudinal opening being lengthways oriented in the longitudinal direction of the profile. Correspondingly, the shape and dimension of the chair in one plane correspond in size to the shape of the slot, while when rotated, 90 degrees the chair is prevented from being retracted from the profile. In order to fix the chair to the profile, the profile is inserted into the opening from the bottom of the profile and pressed until it is physical contact between the base plate 12 of the chair and the bottom surface of the intermediate bottom structure 34 of the profile. At this stage the chair is rotated 90 degrees whereby the chair is locked in position by means of the lower surface/edge of the flexible (or rigid) fins. When the required number of chair on a profile is adequately installed, the base plate of each chair is fixed to the supporting surface, for example by welding or gluing.

Alternatively the required number of chairs may be welded or glued to the supporting surface, aligned and distanced apart corresponding to the corresponding openings in a profile, whereupon the profile is threaded onto the aligned row of chairs, pressed down and snapped over the outwards extending fins, which preferably, but not necessarily may be somewhat flexible or yielding. Again, in this position the profile is in a locked position between the respective base plates and the adjacent surface(s) of the fins.

The reinforcement may be snapped into the opening in the head at the free end of the chair, while the spy is dimensioned in such way that it visually may be determined when sufficient thickness of the concrete covering layer over the reinforcement is obtained.

Figure 4 shows schematically a side view of one embodiment of a chair 10 according to the present invention. As indicated the disclosed embodiment of the chair 10 comprises a base or a foot 12, preferably having a circular foot print, although also an oval or a rectangular foot print may be beneficial; a intermediate part 14 projecting upwards from the base 12; a reinforcement bar holding and locking device 16; a spy 18 and two locking fins 24. The diameter of the foot or the length along the major axis of the oval or the longest side in case of a rectangle should be arranged such that when the chair is fixed to the profile the foot extend laterally out past the base of the profile, allowing access to the bottom surface of the base for welding or gluing of the chair to the supporting surface.

The purpose of the spy 18 is to serve as an indicator for required concrete thickness during the shotcreting process. Concrete is shot on to the supporting element and the concrete so as to achieve an even thickness of concrete over the entire surface of the supporting surface. The length of the spy 18 is chosen so as to secure sufficient concrete coverage for the reinforcement.

Moreover, it should be appreciated that the distance from the top surface of the base 12, i.e. the surface facing the intermediate part 14, to the adjacent surface of the fin(s) should be equal to or larger than the thickness of the intermediate bottom structure 34 of the profile, thereby locking the profile when threaded past the fin(s), Moreover, the distance from the base of the chair to the reinforcement bar locking device 16 is configured such that sufficient concrete also may be placed between the supporting surface and the reinforcement.

The reinforcement bar locking device comprises a ventrally arranged aperture 19 with an area somewhat larger than the cross sectional area of the reinforcement bar to be inserted into the aperture 19. In order to enable reinforcement bars to be inserted into the aperture 19, the reinforcement bar locking device 16 is provided with an opening 17.

In the embodiment shown in Figure 4 the two locking fins 24 are extending radially sideways out from the intermediate part 14 on opposite sides of the intermediate part 14. The shape of the fins 24 according to the view shown in Figure 4 equals to the axial cross sectional shape of a cone. The purpose of the two fins 24 is to act as a locking mechanism for locking profiles 30 to the chair.

An alternative method may be utilized to fix the chair 10 to the lining prior to fixing the profiles 30 to the chairs 10. For this method the chairs 10 that are to support one profile 30 have to be aligned so that the fins 24 point in almost the same direction seen perpendicular onto the base 12 of the chair 10. The direction of the fins 24 should not be parallel, but slightly different from parallel seen from the said angle. By doing this one can use the flex in the profile 30, bend it with force and then thread it onto the second (and the third, fourth etc.…) chair 10. When the force is taken of the profile 30 it will be secured to the chairs 10.

In other embodiments of the invention one can have only one of the fins 24, or one can have several placed out in a star pattern around the intermediate part 14.

As mentioned earlier a snap on solution can be utilized to secure the profiles 30 to the chairs 10. In such a case the fins 24 should preferably but not necessary have a flexible tip and it would be preferred if the tip would be angled towards the base 12 of the chair 10 to act as a snap on barb. In this case a profile with a hole 32 slightly narrower than the fins 24 from tip to tip could be treaded down on the chair 10 and forced passed the fins 24. Instead of separate fins one could extend the fins 24 to form a continuing collet stretching 360 degrees around the intermediate part 14.

The chair can be made of plastic material using a molding technique, but other materials and manufacturing methods can also be utilized.

Claims

Patent Claims

1. Chair (10) for fixing an elongate profile (30) on a lining or supporting surface (28), for example arranged on a tunnel wall or roof surface, said chair (10) comprising a base (12) member configured to be attached to the lining or the supporting surface (28) and at least an intermediate part (14) fixed to and extending out from one side of the base (12) member

c h a r a c t e r i z e d i n that the chair (10) is provided with at least one fin (24) extending sideways out from the intermediate part (14) and is configured to fix the elongate profile (30) to the lining or supporting surface (28), by threading the chair (10) through an opening (32) of the elongate profile (30).

2. Chair (10) according to claim 1, wherein the at least one fin (24) is provided with a flexible tip.

3. Chair (10) according to claim 2, wherein the flexible tip of the at least one fin (24) is pointed towards the base (12) member of the chair (10).

4. Chair (10) according to one of the claims 1 to 3, wherein the at least one fin (24) is provided with at least one side surface, inclined outwards and downwards toward the base (12) member.

5. Chair (10) according to one of the claims 1 to 4, wherein the at least one fin (24) is provided with a locking surface, facing the base (12) member and arranged at a distance apart from a surface of the base (12) member.

6. Chair (10) according to one of the preceding claims, wherein the at least one fin (24) is continuous and extends 360 degrees around the intermediate part (14).

7. Method for fixing an elongate profile (30) to a lining or supporting surface (28), such as a supporting membrane or foil surface to be reinforced and subsequently covered with concrete, using a chair (10) as claimed in one of the claims 1 to 6, enabling the membrane surface to be at a predetermined as uniform distance apart as possible,

c h a r a c t e r i z e d b y using one or more of the chairs (10) to fix the elongate profile (30) to the lining or supporting surface (28) through the steps of threading an elongate profile (30) onto the chair (10) by insertion and/or snapping of the intermediate part (14) and the fin (24) through an opening (32) of the elongate profile (30) and fixing the chair (10) with its base (12) on the lining or supporting surface (28).

8. Method according to claim 7, wherein the chair (10) is being threaded into a hole (32) in the profile (30) and then the profile (30) or the chair (10) is being turned approximately 90 degrees around the intermediate part (14) of the chair (10) so that the profile (30) becomes fixed between the fins (24) and the base (12) member.

9. Method according to claim 8, wherein the profile (30) is being secured to the chair (10) before the chair (10) is being affixed to the lining or supporting surface (28).

10. Method according to claim 7, wherein the profile (30) is being fixed by using one or more chairs (10) that are fixed to the lining or supporting surface (28) whereupon the profile (30) is being threaded and snapped onto the at least one chair (10).

11. Method according to claim 7, wherein the profile (30) is being threaded onto the chair (10) and forced past at least one flexible fin (24) or a flexible collet on the chair (10).