FR2523627A1 - METHOD FOR CONFORTING ARCHES OR SIMILAR CONSTRUCTIONS - Google Patents

Abstract

1. Process for strengthening an arch (1) comprising the operations consisting in prefabricating a relatively thin vault (2), for example of reinforced concrete, with a profile adapted to that of the arch (1) to be strengthened, in placing it under the intrados of the arch (1), in supporting it therein temporarily or permanently, and in then inserting between the extrados of the prefabricated vault (2) and the intrados of the arch, a suitable filling (5), temporary or permanent, suitable for transmitting the forces of the arch (1) to the prefabricated vault (2), characterized in that the filling (5) inserted between the vault (2) and the arch (1) contains means specially intended to facilitate the relative movements of the vault and of the arch in a direction tangential thereto.

Description

The present invention relates to a method for reinforcing at least one

arch, an archway, a voate or

a similar construction.

  There is the problem of reinforcing one or more constructions such as the arches of a bridge, whether they are made of masonry, concrete, or other materials, especially when these constructions are in poor condition; it can then be a definitive comfort, or a temporary comfort, limited to the duration of rehabilitation work The same problem arises

  when one wants to increase, for example,

  temporarily or temporarily, the carrying capacity of a

work such as a bridge.

  Various methods are already known for reinforcing works of the type indicated; these processes use

  usually metal structures, which are

  and the installation of which is also expensive and long, which leads to a long-term disturbance of the normal use of the structure. Such metal reinforcing structures, necessarily

  visible, usually have a deplorable aesthetic effect

  on the structure or construction to which they are applied, and they require at least some monitoring, and possibly some maintenance, if only periodic

  Finally, such structures have the incon-

  come to obstruct necessarily a part of each arch to comfort, whose free height, in particular,

is necessarily reduced.

  The method according to the present invention is of the type indicated initially, and it is characterized in that it consists essentially of prefabricating a relatively thin vo-fte, for example of reinforced concrete, of profile adapted to that of the arch to be reinforced, to place it under the intrados of the arch, to keep it there temporarily or permanently, then to insert, between the upper surface of the vo ce and the intrados of the arch, an appropriate filling, temporary or permanent, suitable for

  transmit efforts of the ark to the vote.

  The comforting method according to the present invention offers the following advantages: it only requires the prefabrication of a reinforced concrete vault,

  then its establishment, which are relative operations

  inexpensively; it does not require any intervention

  directly on the structure to be reinforced, such as the fixing of metal reinforcements; the vault of comfort may not be detrimental to the aesthetics of the work or the construction, provided that it - by exepiple,

  substantially the same color, which means that

  site no special provision when the structure itself is reinforced concrete The vault and its means of support are maintenance-free and can be

  set up in a few hours, which reduces

  the length of time necessary to interrupt the service of the work, for example the interruption of traffic on or below the bridge; because of its short duration, the setting up of the volte can

  take place for example in a period of low use

  the work, for example at night.

  In a preferred embodiment of the method

  in accordance with the present invention,

  Wise inserted between the vault and the arch is adapted to allow relative displacements of the vault and the arch. This lack of solidarity between the arch and the vault offers the following advantages: it allows a provisional comfort of the arch, the va Cte used for this purpose can be recovered without difficulty when the comfort has no more reason to be , and said vault can then be reused for other comforting operations; on the other hand, the absence of solidarity allows relative movements of the ark and the volte; it may be small tangential movements of various origins, for example due to differences in thermal expansion or overloads; but it can also be radial movements, the volte can be closer to more or less the fixed arch, for example with the help of jacks placed at the bottom of the vault, to allow the vault to cash a fraction more or less important of the

total charge of the ark.

  The filling inserted between the arch and the arch can be formed, according to the present invention, at least in part by solidifiable injection grout and / or at least partly by a material stratified in the radial direction; this laminated material preferably comprises an epoxy resin layer, adhering to the arch or arch, and one or more smooth films of a flexible synthetic material, for example one or

  several thin sheets of polyethylene, separated

  each other, and the resin layer, by layers of lubricant, or a substance more

or less viscous.

  The method of comforting according to the present invention

  This is applicable, for example, to the demolition and / or reconstruction of at least one arch, arch, vault or similar construction; in this application, the vault placed under the intrados of the arch serves as protective decking during the demolition of the arch and / or

  formwork or support during its reconstruction.

  The present invention also relates to a formwork for the prefabrication of vottes in reinforced concrete, in particular

  for implementing the comforting method previously

indicated.

  As examples, we have described below and illustrated

  schematically in the annexed drawing several modes of

embodiment of the invention.

  Figure 1 illustrates schematically the comfort

  bridge arch by the method according to the present invention. FIG. 2 is a view, at the end and in section

  part of a formwork for prefabrication

  reinforced concrete vault, intended for the

  of the reinforcement process according to the present invention.

  tion. Figure 3 represents on a larger scale the

detail III of figure 2.

  FIG. 4 is a perspective view, partially broken away, of the reinforced concrete volt of FIG. 2, its extrados being covered by a material

  laminate, surmounted by a layer of injection grout.

  FIG. 5 is a section along line V-V of

Figure 4.

  Figure 6 is a diagram illustrating different modes of installation of the reinforced concrete vault below

an arch to comfort.

  FIG. 7 is a partial view showing, in the end,

  the reinforced concrete void in the comforting position of the arch.

  FIG. 8 is a partial view along the arrow

VIII of Figure 7.

  Figure 9 shows on a larger scale the detail

IX of Figure 7.

  Figure 1 schematically illustrates the comfort

  an arch 1, for example one of the arches of a masonry or reinforced concrete bridge, by the method according to the present invention: this consolidation is provided by a vault 2, relatively thin, reinforced concrete in the embodiment considered; this arch 2 has a profile adapted to that of the arch to be reinforced, 1, on the underside of which it is placed and held by means of which two different embodiments have been illustrated respectively to the right and to the left of the arch 1; on the right, the foot of the vault 2 rests, for example by means of jacks or shims, which will be described later in detail on a die, 3, made of concrete or steel, fixed, by any means, to the pile corresponding to the arch 1, at an appropriate height above its foundation 4 In the embodiment illustrated in FIG.

  left, die 3a is not attached to the corresponding stack

  1, but rests on its foundation 4a, or a special foundation, by means of a support of appropriate height, 3b, to which, moreover, die 3a can be integrated, in particular if die 3 a and its support

  3 b consist of a single piece of reinforced concrete.

  The height of die 3 or support 3b above the base

  4 or 4 a is chosen so that there remains, between the intrados of the arch 1 and the extrados of the votte 2, an annular gap 5, whose radial width is very small compared to the diameter of the It is within this range that an appropriate filling, an embodiment of which will be described later, will be inserted so as to remove any gaps between the arch 1 and the arch 2, and thus to allow the transmission

  radial forces from the first to the second.

  The first phase of the implementation of the reinforcing process according to the present invention is therefore the prefabrication of a profile vault adapted to that of the arch to be reinforced; in the case of a reinforced concrete vault, this prefabrication can be carried out for example

  using the adjustable formwork which is illustrated

only in Figures 2 and 3.

  This formwork according to the present invention comprises

  a base frame 6, which rests on the floor via

  of adjustable height members 7, for example cylinders, sandbars, wedges, wedges or similar members The formwork further comprises parallel and transverse sets of sanders; the end view of FIG. 2 shows some of the trenches 8a to 8e of the first transversal assembly closest to the end of the formwork, which comprises other similar assemblies situated in transverse planes parallel to that of FIG. 2, The runners of each transverse assembly are hinged one at the end of the others, as can be seen in the detail view of FIG. 3, for the sand plates 8c and 8d, the ends of which are joined through Each transverse assembly of runners, such as that partially shown in FIG. 2, is supported at its joints such as 9, by radial struts, such as 10, and vertical struts, such as 11, at least some of which are of adjustable length, and which all rely on the base frame 6; horizontal struts 12, which may also be of adjustable length, may also be provided for joining the struts 10 and 11 together. All the struts of adjustable length are constituted for example by screw jacks. The detail view of FIG. 3 shows further that the neighboring sanders, for example 8c and 8d, are articulated by ball joints 13, which rest on the bottom, 10a, the fork of the screw jack, constituting the adjustable end of the radial strut Corresponding the ablières, which may be of wood or metal, support on the other hand pieces of wood, or vaux, such as 14 to 14 e (Figure 2), each having a flat face, applied to the corresponding sandpit , and an opposite face, curved appropriately On sets

  valleys such as 14 to 14 are supported by longitudinal joists

  such as 15, themselves supporting a formwork skin, of wood, metal, plastic, etc., designated by 16 At an appropriate distance from this interior formwork, and in particular from its skin 16, is supported, by means not shown, an external formwork, which may be limited to

  cover only the parts of said integral formwork

  The outer formwork element shown therein also comprises a formwork skin 17, longitudinal joists 18, and elements which are arranged on the right side of FIG.

transversal 19.

  The adaptation of the interior formwork which has just been described, and in particular of its formwork skin 16, to the profile of the arch to be reinforced, results in particular from the adjustment of the

  lengths of the different struts, such as 10, 11 and possibly

  12, as well as the choice of dimensions and shape, in particular the curvature of the outer surface of the vales, such as 14 to 14 after solidification of the concrete poured on the inner formwork and in the annular gap between the latter and its parts re-opened by the outer partial formwork, the reinforced concrete vault, 2, rests by its feet, such as 2a, on a support

  21 To proceed with the dechiltration, it suffices then to reduce

  the base frame 6 by reducing the height of the members 7, for example cylinders, so that the vault

  2 is based only on its supports such as 21; those-

  may be provided for example with rolling members for transferring the arch 2 from its molding position to the foot of the structure to be reinforced, or all at

  less to its place of loading on a means of trans-

  appropriate port to carry it to the foot of the work.

  Before, and preferably after the transport of the prefabricated vault at the foot of the work to be reinforced, one

  applies on the upper surface of said vault a strati-

  embedded image, an embodiment of which will be described with reference to FIGS. 4 and 5 before the deposit of this laminated material,

  the extrados of the prefabricated vault are prepared by

  by brushing and / or sanding, then apply directly

  on the upper surface, for example by spraying

  let, or by brush coating, a layer of resin

  epoxide, 22, having a superficial coefficient of friction

  very weak, and an average thickness of the order of 0.30 mm; to constitute this layer, it is possible, for example, to use the UTAREP 105 material from the Laboratories

UITTWIILER.

  On top of the epoxy resin layer, 22, a very thin layer 23 is deposited, for example a mineral, vegetable or synthetic grease, or a

  equivalent substance, more or less viscous.

  On top of the grease layer 23, finally a polyethylene sheet 24 is deposited, having for example a thickness of 0.45 mm; this sheet may be, for example, POLYANE BTP from OLUYAN ISOOCBNTIER. It is essential that this polyethylene sheet is impermeable in the radial direction for the injection grout that will be mentioned later, and that over the entire surface of the upper surface of the roof 2; therefore, in the case of a large vault, this sheet may be constituted by several juxtaposed, whose edges are welded or glued together to ensure impermeability for the injection grout In the embodiment example considered, a second layer of grease, 25, for example identical to the layer 23 described above, is deposited on top of the polyethylene sheet 24 Of course, the laminate material which has just been described could comprise several polyethylene sheets such as 24 , separated by an appropriate number of layers of fat

  such as 23 and 25 These are also optional.

  The prefabricated vault, whose extrados has been covered with the previously described laminate material,

  can then be put in place by one of the two

  following assignments, which will be described with the aid of FIG. 6: 1) The dice 3 are first put in place by one of the two techniques illustrated in FIG. 1 and previously indicated (in FIG. we have

  assumed they are attached directly to the battery

  as in the right part of Figure 1) With appropriate lifting gear,

  which can be supported on the ground and / or

  If the resistance is sufficient, vertically, following the arrow Fl, the prefabricated vault whose extrados is covered by the laminate material described above, until its two feet, such as 2a, are substantially at the upper faces of the two corresponding dice, 3 With the aid of previously mentioned lifting devices then communicates to the vault 2 a horizontal translational movement, along the arrow F 2, which brings it below the arch 1 to be comforted, in the position illustrated with a view to

face in Figure 1.

  As a variant, the prefabricated volte 2, covered by the laminated material, is deposited at the foot of the structure on a track 26, extending to below the arch to be reinforced 1; before the positioning of the dice such as 3, the vo te 2 is moved horizontally by rolling 7 on the track 26, along the arrow F 3, so as to be brought below the arch 1; it is then raised to the level of the arch 1 by appropriate lifting devices, following the arrow F 4, and maintained at the correct height

  by said apparatus during the laying of the dice, 3,

born to bear it.

  Before the introduction of the prefabricated

  it may be possible to prepare the in-

  trados of the arch 1, in particular by cleaning it by brushing and / or sanding, and possibly by

  piquetant, to promote the attachment of the grout

  jection, whose pose will now be described.

  Figures 7 and 8 show larger

  scale the method of fixing a die 3, of the type

  On the right of FIG. 1, it can be seen that the dè, 3, is fixed to the corresponding stack of the arch 1 by prestressing bars 27, each having an Otae 7 S Udan the corresponding stack of the arch 1 while its other end passes through a hole in the die 5 and has a thread on the unblocked face thereof, on which a nut such as 28 can be screwed, possibly with the interposition of a clamping plate (no shown) The prestressing bars 27 could also be replaced by prestressing cables The facing faces of the die, 3, and the corresponding foot, 2 a, of the vault 2 are armed by steel plates 29 and 30, intended to ensure a good distribution of the forces Each plate such as 29 can notably facilitate the rolling or sliding of the prefabricated vault 2 on the track 26 (Figure 6) In the embodiment illustrated on a large scale in Figures 7 and 8, dice such as 3 are fixed to the arch 1 in positions such that there remains between the steel plates 29 and 30, an interval in which are arranged cylinders

  vertical action, 31, the r 8 of which will be explained later.

  surely; the number and arrangement of said jacks along each of the dice such as 3 are chosen to ensure the stability of the vessel 2 As already indicated, a

  narrow annulus, 5, then remains between the intra-

  back of the arch 1 and the extrados of the vault 2, covered by the laminated material; during manufacture, pipes, generally metallic, such as 32, have been embedded for example in the feet 2a of the roof 2, so as to open into the annular gap 5 The radial width of the latter is then adjusted to a predetermined value by

  the action of the cylinders 31 and then proceed to the caulking-

  of the ends of the annular gap 5, on the

  front faces of Arch 1 and Arch 2, which are

  wind respectively in the same planes; this caulking can be carried out by any appropriate means, for example by means of planks and / or cement mortar. Then a solidifiable grout is injected through the tubes such as 32; this grout, which may be of the STU P. or LSPI type, fills the annular gap 5, sealed by the caulking. The injection pressure has a value chosen so that, after solidification of the grout, the vault 2 eventually casts a at least part of the load of the arch 1 It is understood that the solidified grout layer (which has been designated 33 in Figures 4 and 5) fills all the inequalities of the intrados of the arch to be reinforced and ensures its continuity with the extrados of the roof 2, or at least with the outermost layer, 25, of the laminate material, which covers it Finally, the roof 2 is clamped against the arch 1 by the action of the cylinders 31, taking support on dice 3, of

  in order to ensure proper transmission of

  the arch 1 to the vault 2, through the filling constituted by the superposition of the laminated material 22

  at 25 and the layer 33 of solidified slurry.

  The charges, generally variable over time, which are applied to the arch 1, reinforced by the vault 2, can however produce some reduction in the pressure of clamping the arch against the arch This clamping pressure can be restored at its initial value by acting on the jacks 31 and / or by re-injecting, under a

  determined pressure, solidifiable slurry, through

pipes 32.

  For some applications, it is possible to

  between shims 31 (FIG. 8), wedges such as 34, made of concrete, wood or steel. In this case, after having reduced the height of the jacks 31 so that the roof 2 is only supported by the shims. such as 34 he

  It is possible to recover the cylinders 31 for other uses.

  In this case, the eventual reestablishment of the clamping pressure requires either the repositioning of the cylinders 31,

  the reinjection of solidifiable slurry.

  The method of reinforcing a bridge arch, which has just been described, offers the important advantage of allowing the possible suppression of the comfort, in particular in the case where the feet, such as 2 a, of the vault 2 rest on jacks, such as 31; after removing the wedges such as 34, it is sufficient to reduce the height of the cylinders 31 so that the vault descends slightly below the arch 1; the separation is generally carried out at the level of the grease layer 25 (FIGS. 4 and 5), the solidifiable grout layer remaining adhering to the intrados of the arch 1, while

  that the laminated material, or at least its

  22 to 24 follow the downward movement of the vault 2; the latter can obviously be reused to reinforce another arch of my dimensions, thanks to the repetition of the implementation operations.

previously described.

  The present invention is not limited to the embodiments previously described. It encompasses all their variants. The reinforcing method according to the present invention is particularly advantageous when it is necessary to proceed with the demolition and / or reconstruction of the invention. less an arch of a work such as a bridge; in this case, the veil placed under the intrados of the arch can be used as protective decking during the demolition of the arch, which avoids any interruption of the service, in particular the circulation below the arch. during the demolition operation In the case of reconstruction of the arch, especially by concreting, the prefabricated vault can serve as

  formwork, or support, especially for a formwork.

  The method according to the present invention is applicable to reinforcing vaults of any shape, such as for example cupolas or similar constructions The filling inserted between the extrados of the prefabricated volte and the intrados of the arch to be reinforced can 9 be made in such a way that the laminated material (22 to 25 in FIGS. 4 and 5) is applied to the intrados of the arch to be reinforced, whereas the grout is injected between this material

  laminate and the extrados of the prefabricated voce.

  Of course, the prefabricated vault can be lightened by interior voids; to comfort an arch of great depth, one can use several vodtes

  prefabricated, juxtaposed one after the other.

  The detail view of FIG. 9 shows that the sealing of the injection space, 5, of the solidifiable slurry can be significantly improved by providing layers of a suitable adhesive, on the one hand (layer 35), between the flange 32a of each grout injection pipe 32, and the polyethylene sheet 24, and secondly (layer 36), between each lower edge 24a of said sheet 24 and the corresponding foot from the square 2 or the slice of the

steel plate 29.

Claims (11)

  1 Method for reinforcing at least one arch, an arch, a vault or a similar construction, characterized in that it consists essentially of prefabricating a relatively thin vault (2), for example reinforced concrete, of a profile adapted to that of the arche (1) to comfort, to place it under the intrados of the arch (1), to keep it there temporarily or permanently, then to insert between the extrados of the vault (2) and the intrados, a filling   appropriate (5), temporary or permanent, suitable for trans-   put efforts from the arch (1) to the vault (2).   Process according to Claim 1, characterized in that the filling (5) inserted between the volt (2) and   the arch (1) is adapted to allow movements relative to   of the vault (2) and the arch (1).   Process according to any one of the claims   1 and 2, characterized in that the filling (5) inserted between the roof (2) and the arch (1) is formed at least by   partly by solidifiable injection grout (33).   Process according to any one of the claims   2 and 3, characterized in that the filling (5) inserted between the roof (2) and the arch (1) is formed at least in part by a laminate material in the radial direction, and comprising at least one layer of resin epoxy (22), adhering to the arch (2) or the arch (1), and one or more smooth films (24) of a flexible synthetic material, for example one or more thin sheets of polyethylene, separated optionally from each other and from the resin layer (22) by lubricant layers (23, 25), or   of a more or less viscous substance.   A method according to claim 4, characterized in that the laminate material (22-25) is in all respects impervious to the injection slurry, by means of a sheet (24) of synthetic material in one piece, or formed by welding or bonding of several juxtaposed is injected solidifiable slurry (33) between, on the one hand, the laminated material (2225), applied on the extrados of the vault   (2), and, on the other hand, the intrados of the arch (1).   Process according to any one of the claims   1 to 5, characterized in that, after placing the filling (5), in particular the injection grout (33), the arch (2) is clamped against the arch (1), by the action of jacks (31) bearing for example on the supports (3, 3 a) of said arch (2)) so that the arch cashes at least part of the load of the arch, said jacks (31) allowing subsequently adjust the support pressure of the arch (1) on the arch (2), or   then being replaced by fitted shims (34).   Process according to any one of the claims   1 to 5, characterized in that, the vault (2) being held under the intrados of the arch (1) by appropriate supports (3, 3 a), the solidifiable grout (33) is injected under an appropriate pressure so that, after solidification of the grout (33), it ensures a perfect distribution of   efforts of the arch (1) on the vault (2).   Process according to Claim 7, characterized   in that the injection means (32) of the grout are now   in place to allow for the re-establishment or further increase   the pressure of support of the arch (1) on the vault (2), re-injecting grout.   9 Application of the method according to claim 2 to the demolition and / or reconstruction of at least one arch, an arch, a vault or a similar construction, the arch (2) placed under the intrados of the arch (1 ) used as protective decking during the demolition of the arch   and / or formwork or support during its reconstruction.   Formwork for the prefabrication of reinforced concrete vaults, especially for the implementation of the method according to   any of claims 1 to 8, characterized in that   it comprises a base frame (6), resting on the ground by means of organs (7) of adjustable height for the stripping, parallel and transverse sets of sand plates (8 to 8 e), hinged the one at the end of the others, and supported, at their joints (9), by struts (10, 11, 12) of adjustable length, resting on the base frame (6), an inner form, essentially formed by longitudinal joists (15) supported by the transverse assemblies of sand plates (8 a be), by means of parts (14 to 14 e) shaped such that said inner form is adapted, for a suitable adjustment of the lengths props (10, 11, 12) on the underside of the prefabricated vault (2) and an outer formwork (19), supported at an appropriate distance above the inner form parts, the most inclined on the horizontal.