FR2628126A1 - Tubular self-supporting bridge construction - has trellis-type load bearing shell formed by orthogonal arrays of helical beams, supporting internal roadway etc. - Google Patents

Abstract

Tubular beam; The load-bearing level 1, such as a pavement table, is established inside a tubular structure whose cross section follows a closed curve and of which at least the upper part dominating the load-bearing level is formed by a network or a lattice of cross beams 3 leaving openings 4 between them; Application to bridges, walkways, aqueducts and other structures with a straight or curved axis.

Description

FRENCH REPUBLIC Publication no .: 2,628,126 (to be used only for

  NATIONAL INSTITUTE reproduction orders) OF INDUSTRIAL PROPERTY National registration number 88 02529 PARIS

 u Int CI4: E 01 D 7/02.

@ APPLICATION FOR A PATENT FOR INVENTION Ai

  Date of filing March 1, 1988. Q Applicant (s): Public limited company called: G.T.M. BETWEEN-

  POSE, Jean-Vincent BERLOTTIER and Responsible company

  ) Priority limited bility called: QUADRIC. - FR.

Inventor (s): Jean-Pierre Augoyard.

  Date of public availability of the

  application: BOPI "Patents" n 36 of September 8, 1989.

  References to other national documents appearing

rented (Holder (s)

(Agent (s): Cabinet de Boisse.

  - Device of tubular beam suitable in particular for the realization of bridges and similar works.

  L Tubular beam; load-bearing level 1, such as a shoe table-11l4 11 sée. is established inside a tubular structure, the cross section of which follows a closed curve and at least the upper part of which dominates the load-bearing level is formed by a network or lattice of crossed beams 3 leaving holes 4 between them;

  Application to bridges, walkways, aqueducts and other or-

  vr wages with straight or curved axis.

  N I {O N cc N oe oL O Sale of booklets at IlMPRIMERIE NATIONALE, 27. rue de la Convention - 75732 PARIS CEDEX 15

- i -

  The present invention relates to a device for

  self-supporting beam, straight or curved, for all.

  cations. It aims to obtain a large span between supports, which is particularly interesting for bridges,

  aqueducts or similar works, while avoiding an increase

  excessive weight mentation through optimal use

  male of the material and reducing the height of obstruction-

  ment of the beam under the load bearing level.

  It is characterized in that the supporting level, table of pavement for example, is established inside a tubular structure whose cross section

  follows a closed curve and at least the upper part of which

  superior dominating the load-bearing level is formed by a network or lattice of crossed beams, leaving between them orifices which allow the lightening of the structure,

its transparency and ventilation.

  At the top of the structure, the elements of the trellis are joined to a longitudinal element adapted to form

compression table.

  The lower part located under the load-bearing level can be constituted by a similar trellis but one will generally give the preference to the realization of this part in the form of a slab or full sole

  allowing the use of longitudinal reinforcements of pre-

  drag. Preferably, the curve of the cross section consists of two half-ellipses or ovals whose

  major axes are parallel or even coincide, half

  upper ellipse with a small axis of sufficient length

  health so that the usage template is registered,

  while the lower half-ellipse, on the other hand, is flattened

  tie to reduce the overall height of the beam

below it.

- 2 -

  The axis of the tubular structure can be recti-

  line, said structure then taking the form of a cy-

  lindre or this axis can be curved, the structure then taking the shape of a torus portion, even a complete torus. At its ends the tubular structure comprises a strong ring arranged transversely to the axis and the

role is multiple.

  First of all it constitutes a transverse stiffener of the structure and serves to transmit the forces to the supports; from this point of view, such a ring could also be arranged in intermediate zones, for example on the intermediate supports of a structure of

  long, or on the shroud fixing areas.

  On the other hand, this ring is used to receive the anchors of the prestressing reinforcements: reinforcements & helical layout of the lattice beams and reinforcements

  longitudinal of the full sole.

  This went up near its junction with

  the ring to improve the recovery of sharp effects.

  The structure according to the invention can be made of various materials. In addition to high-strength cement concrete, as used in modern technology,

  may include fiber concrete, metal, laminated wood -

glued, composite materials.

  To make the tubular structure, you can

  mold it in one piece but to facilitate confection

  tion of the molds and setting up, we will give the

  reference to the division into elements according to perpendicular planes

  circular or / and parallel to the axis and to the subsequent assembly

  laughing of the elements finished by means of the prestressing reinforcements.

  The description which follows with regard to the

  attached sins given as an example will allow good

  understand how the invention can be realized.

  Figure 1 is an elevational view of a bridge

  rectilinear according to an embodiment of the invention.

-3-

  Figure 2 shows on a larger scale a sec--

  cross section of this bridge along line II-II of the

figure 1.

Figure 3 is an end view.

  Figure 4 is a view similar to the figure

  2, illustrating a phase of the manufacturing process.

  Figure 5 is a view similar to Figure 1 schematically illustrating the assembly of the elements

  by prestressing helical reinforcement.

  Figure 6 shows a section on a larger scale

of a truss truss.

  Figure 7 is a horizontal projection view of a bridge similar to that of the previous figures but

whose axis is curved.

  We see in Figures 1 to 3 an embodiment

tion of a bridge according to the invention.

  This bridge has a cylindrical shape with a rec-

  tilinear and comprises, in this embodiment, a cross section constituted by two half-ellipses a b c and a bl c, which are superimposed, the main axes a c being in coincidence. The upper half-ellipse abca a small axis large enough to be able to register, above the load-bearing level 1, road pavement for example, the useful rectangle of the template represented by the dotted lines 2. The wall of the tubular structure is not continuous, but consists above the supporting level 1 of a kind of trellis

  consisting of a network of 3-way orthogonal beams

  posed according to pseudo-helices, which leave between them openings 4 giving transparency and also allowing ventilation. Along the generators at the top of the structure, the orifices 4 are narrowed so as to give additional material to form the compression table 5. A continuous table could moreover be provided. The lower part of the structure could

  be performed in the same way, but we will give the pre-

  reference to a solid wall 6 which has various advantages, in particular that of allowing prestressing by means of - 4 -

  reinforcements arranged longitudinally according to generati-

these of the structure.

  This wall or sole 6 may be provided with supports

  7 to support the slab 8 forming the level of use

  tion. Voids such as 9 can be used to

place various pipes.

  By a judicious arrangement of the supports 7, it will be possible to give the slab 8 a certain slope if the structure is curved as in the case illustrated by the plan view

in Figure 7.

  We could also make slab 8 in one

  part with the wall 6 of the structure.

  In Figure 2 there is shown sidewalks 10 which are raised to take advantage of the width

maximum of the structure.

  As seen in Figure '1, the beams 3 of the trellis are connected to the sole 6 on spikes

  3a of this sole, the edge of which is in a broken line.

  At its ends 6a, 6b, the sole 6 occupies an increasing portion of the periphery of the structure with

  a corresponding layout of the prestressing reinforcements.

  At each of its ends, the structure has

  a strong ring 11 in excess thickness which maintains the structure

  ture in form, constituting a stiffener and which is also used for anchoring the prestressing reinforcements, both of the helical beams 3 of the trellis and of the part

low or sole 6.

  Each ring 11, the shape of which can be seen in FIG. 3, comprises, at its base, a plate 12 by which it rests on the surface 13 of the abutment or of the pile, by means of support members 14 The reinforcements of the sole 6, placed parallel in the current part of this sole, diverge in the widening of this

  sole at the ends thereof. This led to a de-

  viation in altitude of the prestressing and therefore a varia-

  tion of its eccentricity, favorable & a good recovery of

sharp efforts.

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  The material of each ring 11, concrete for example, is made in continuity with that of the beams

  helical 3 and sole 6 to form a single piece.

  The beams 3 of the trellis are prestressed by reinforcements etched in grooves which follow

  the helical layout of these beams.

  In Figure 5, we have drawn at 15 and 16. the reinforcements of two beams. As shown in the cut

  of figure 6, there is in this example for each pou-

  trelle, two frames placed in two parallel grooves

  17. We see that one of the frames 15, near the end of the structure, is anchored & its end a in the ring 11, while its lower end 15b is anchored in the sole 6 of the structure. The other drawn reinforcement 16 is anchored at 16a in the sole 6. It passes over the top of the structure and is anchored on the opposite side in the sole 6. To allow prestressing, the reinforcements placed in the grooves 17 of the beams 3 are sheathed and greased according to

usual procedures.

  For the prestressing of the sole 6, the reinforcements

  longitudinal sheaths also sheathed and greased will be placed in channels used in manufacturing, or placed in surface grooves as has been exposed

next to Figure 6.

  As can be understood, such a structure, the section of which has a large moment of inertia makes it possible to reach high spans of the order of several tens of meters, while the upper part in openwork lattice gives transparency and allows the users circulating inside the structure to see the outside. At the same time, ventilation is perfectly guaranteed without the need to provide devices

special.

  For the manufacture of the structure, one can pro-

  yield on site by placing the desired supports and forms. However, preference will be given to manufacturing by parts which will then be assembled on site in

-6- 262 81 26

6 -

  using prestressing reinforcements.

  One can for example make parts of the tubular structure having a length of 3 to 6 meters and stopped at both ends in transverse planes passing through the nodes of the trellis so that the

  The abutment surfaces are as large as possible.

  We can further divide these parts by planes

parallel to the axis.

  Considering for example Figure 4, we can ima-

  giner to divide the structure into four parts

  between them in joint planes d-d passing through

  the trellis nodes and parallel to the axis of the structure-

  ture. One of these parts el comprises the entire sole 6, and the other parts e2, e3 and e4 share the lattice part. We will make these parts separately

  in molds and then transport them to the place of use

to assemble them.

  Figure 4 illustrates the assembly operation.

  After placing the sole portion el on support pads 20, arranged on a platform 21, a

  portal 22 which will facilitate the installation of the parts.

  The elements will then be assembled by means of armatures.

  helical prestressing res.

- 7 -

Claims (14)

  1. Tubular beam particularly suitable for   the construction of bridges and similar works, characteristic   sée in that the load bearing level (1), such as a road table, is established inside a tubular structure whose cross section follows a closed curve and at least the upper part dominating the level carrier is formed by a network or lattice of crossed beams (3) leaving between them orifices (4).   2. Beam according to claim 1, characterized   in that the beams (3) of the trellis follow pseu-   do-propellers. 3. Beam according to claim 2, characterized   in that two families of pseudo-helices are orthogona- the.   4. Beam according to one of claims 2 and   3, characterized in that the beams (3) of the trellis are prestressed by reinforcements which follow the propellers.   5. Beam according to one of the preceding claims.   tes, characterized in that at the top of the structure the   lattice girders are connected to a longitu-   dinal (5) forming compression table.   6. Beam according to claim 5, characterized in that the compression table is obtained by reducing the dimensions of the orifices at the top of the structure (4) between beams.   7. Beam according to one of the preceding claims -   tes, characterized in that the lower part of the tubular structure is made under. wall shape full or sole (6).   8. Beam according to claim 7, characterized   in that at the ends of the tubular structure the   tion of its periphery occupied by the sole increases so much.   8- 9, beam according to claim 8, characterized in that the sole is prestressed by longitudinal reinforcements which are diverging at the ends so   to resume sharp efforts.   10. Beam according to one of the preceding claims.   tes, characterized in that the ends have a ring-shaped extra thickness (11) which forms a stiffener   and is also used for anchoring pre-   drag. 11. Beam according to claim 10, characterized in that the ring (11) has at its base a dish (12)   to support the beam on a abutment or a pile.   12. Beam according to one of the preceding claims -   tes, characterized in that its cross section follows a curve whose part (a bl c), located below the bearing level (1) is flattened relative to the part   (a b c) located above this level.   13. Beam according to claim 12, characterized   in that said curve is constituted by two half overlapping ellipses.   14. Beam according to claim 7, characterized in that the solid wall or sole (6) supports by   supports (7) a slab (8) constituting the level of use tion.   15. Method for producing a beam according to one   de.s previous claims, characterized in that   manufactures parts of the beam separately and   that these parts are assembled on site by means of arma- prestressing structures.   16. Method according to claim 15, characterized   in that the parts are delimited by per-   pendulars to the middle line of the beam and passing   by nodes of the trellis structure.   17. The method of claim 15 or 16, charac-   characterized in that the parts are delimited by planes parallel to the midline of the 'beam and passing by the nodes of the trellis. C'M <'JI cm OL ('J 1 4- D LL p p P P \ III I_ {--e'p 4-- -   - - De /, / "{_ D_ /, \ I I / IL, re.// o 15 '16 16a 6 b ru