Classifications

• • E—FIXED CONSTRUCTIONS
  • E02—HYDRAULIC ENGINEERING; FOUNDATIONS; SOIL SHIFTING
  • E02D—FOUNDATIONS; EXCAVATIONS; EMBANKMENTS; UNDERGROUND OR UNDERWATER STRUCTURES
  • E02D29/00—Independent underground or underwater structures; Retaining walls
  • E02D29/045—Underground structures, e.g. tunnels or galleries, built in the open air or by methods involving disturbance of the ground surface all along the location line; Methods of making them

Definitions

• the subject of the invention is a work of passage under embankment likely to have a very large section, corresponding in particular to the road gauge, such a work being usable in particular for the passage under embankment of road or rail traffic.
• the tubular wall is centered on a longitudinal axis and comprises, in cross section, at least three prefabricated elements, respectively an upper element in an arc of a circle, resting on two side elements separated one from the other and each comprising a base resting on the ground and a side wall having an upper part curved towards the inside of the section so as to connect to the upper element.
• the previous invention makes it possible to produce very economically structures that can have a very large cross-section corresponding to the road gauge. It has even been possible to carry out, very economically, works covering several lanes of road traffic, for example, for motorways bypassing a city which can advantageously be buried so as to protect the environment.
• the longitudinal joints are usually made up of simple joints with a horizontal axis and it has been observed that such an arrangement allows to carry out works of very large section and capable of supporting a large load, for example the circulation of a motorway over the structure.
• a semicircular section leads to giving the structure a relatively large height relative to its width since it is equal to about half of the latter.
• the inventor therefore proposed using elements of different radii, the upper element, which still covers an angular sector of 90 °, having a radius larger than the curved parts of the side elements. In this way, the same arrangement of the joints articulated between the elements is kept, but the range between these joints can be increased.
• the deflection of the circular arc is proportional to the distance between supports and, due to the large radius required, the heightening with the key relative to the lateral supports may be too great to use this technique when the difference in height between the background on which the structure is placed and the taxiway passing over it is insufficient.
• passage structures of rectangular section can be made, consisting of a slab resting on two vertical walls, but the prefabrication technique can only be used for reduced passage sections, of the order of 10 to 15 m 2 . Indeed, for larger dimensions, prefabricated elements would no longer be manageable and it is then necessary to use the conventional techniques of bridge construction.
• the object of the invention is therefore to extend the possibilities of application of the technique of construction of engineering structures by prefabricated elements described in the patents cited above from the same inventor, by making it possible to reduce the total height of the work in relation to its scope, while retaining the essential advantages of the prior art.
• the invention therefore relates, in general, to an embankment passage structure comprising a tubular wall having a longitudinal axis and consisting of a plurality of concrete elements produced in advance and juxtaposed along longitudinal joints and transverse, said elements being assembled on the construction site so as to form a tubular wall comprising, in cross section with its axis, at least three prefabricated elements, respectively an upper element having two lateral sides parallel to the longitudinal axis and two elements sideways apart from each other and each comprising a base resting on the ground and a side wall having an upper part curved towards the inside of the section, with an upper edge parallel to the longitudinal axis, the element upper resting by its lateral sides along longitudinal joints, on the upper edges of the side elements.
• each upper element comprises a cylindrical wall with generation parallel to the longitudinal axis and having a transverse profile with double curvature comprising a central part with small curvature extended by two end parts each having the same radius of curvature as the curved upper part of the side element corresponding, so as to be connected tangentially thereto, said double curvature wall being associated with at least one stiffening rib capable of absorbing the stresses resulting from the self-weight of the upper element and from the load applied by the backfill covering the tubular wall.
• the curvature of the central part of the central part of the upper element is determined so that the total height, by the key, of the work, does not exceed a given limit and that the stiffening rib has a moment d sufficient inertia to give the upper member the necessary bending strength, taking into account the distance between the lateral sides and the loads applied.
• the lateral sides of the upper element and the upper edges of the side elements are provided with conjugate support parts, respectively hollow and projecting, so as to provide two articulated longitudinal joints, the tangential connection of the supporting parts of the upper element with the side elements determining the transmission of the support forces, in each longitudinal joint, in directions inclined with respect to the horizontal, with a horizontal component directed towards the outside.
• the longitudinal joint plane between the upper edge of a side element and the lateral side of the upper element resting thereon passes through a common center of curvature and is inclined substantially at 45 ° relative to horizontally.
• Figure 1 shows schematically, in cross section, a structure under embankment according to the invention.
• Figure 2 is a detail view of a longitudinal joint.
• Figure 3 shows a variant.
• FIG. 1 there is shown schematically, in cross section, a passage structure according to the invention, comprising a tubular wall 1 disposed on the bottom 11 leveled and packed with a trench 10 and covered with an embankment 12 up to at an upper level 13 located at a height h above the bottom 11 of the trench 10, to allow the passage of a traffic lane above the structure.
• the tubular wall 1 consists, in general, of prefabricated elements of reinforced or prestressed concrete, which are juxtaposed so as to form successive sections centered on a longitudinal axis O.
• Such an arrangement has been described in detail, in particular in previous patents EP-0.081.402. and EP-0,244,890 from the same inventor.
• each section comprises, in cross section, at least three elements, respectively two side elements 2, 2 'and an upper element 3, having two lateral sides 31, 31', parallel to the longitudinal axis O of the structure, which rest on the upper edges 21, 21 'of the side elements 2, 2'.
• Each side element 2, 2 ′ comprises a sole 22 forming a base with a flat bottom 22 and a side wall 23 extending upwards, bending inwards at least at its upper part 24. The assembly is balanced so that the prefabricated side element 2 can be placed on the ground and stand by itself without scaffolding, even under the weight of the upper element 3.
• the bases of the side elements are connected by a concrete slab which allows the load applied to be distributed over a large area.
• the raft can be removed if the bearing capacity of the bottom 11 of the trench allows it and, in particular, when the span of the structure between the bases of the side elements 2, 2 'is important.
• each side element has the particular shape shown in Figure 1, the sole 22 comprising two wings 22a, 22b extending respectively outward and inwardly of the section, on either side. of the foot of the side wall 23 over a width determined according to the lift of the ground and the stability conditions.
• the wall 23 is curved inwards, experience has shown that such an element can be perfectly stable, even for very large spans.
• the passage section is cut, according to patent EP-0.081.402, from so that the longitudinal joints between the elements are placed in areas of constraint nodes whose positions are determined by studying the influence of the applied loads.
• articulated joints between each lateral side 31 of the upper element 3 and the upper edge 21 of the associated side element 2. These articulated joints are produced in the manner shown in FIG. 2, the upper edge 21 of the side element 2 being provided with a concave groove 41 while the lateral side 31 of the upper element 3 is provided with a convex edge 42.
• the tubular wall of the structure has a semicircular section symbolized by the dotted line SI in FIG. 1. It can be seen that the height of the structure, at the key is equal to half the span between supports.
• the rectangular gauge for passage in such a structure for example for a road traffic lane, therefore has a height of the order of half the width.
• the passage gauge G shown in phantom in the figure has a width L greater than twice the height H.
• the overall height hl of the key structure remains quite large and may be too high when the difference in height h between the upper level of the taxiway 13 passing over the structure and the bottom 11 thereof is reduced.
• the invention provides a solution to this problem while retaining, however, most of the advantages of the previously known arrangement.
• the structure according to the invention comprises, in cross section with its axis 0, an upper element 3 resting by its lateral sides 31, 31 'on the upper edges 21, 21' of two side elements 2, 2 'which can be perfectly identical to the side elements used in previously known structures.
• Each side element 2 therefore comprises, as in the previous arrangements, a side wall 23 of which at least the upper part 24 is curved so as to form a circular sector centered at a point Ol and which extends vertically from a sole-shaped base comprising two wings, respectively external 22a and internal 22b resistant to the overturning of the element 2 inwards or outwards.
• the upper element 3 has, however, a particular shape. It consists, in fact, of a curved wall 30 associated with a stiffening rib 32.
• the wall 30 has a cylindrical shape with generatrices parallel to the longitudinal axis 0 and having a double curvature. It comprises, in fact, a central part 33 with a very large radius of curvature which is connected to two end parts 34, 34 'having a radius of curvature equal to that of the curved upper part of the side wall 23, 23' of the 'associated side element 2, 2'.
• the two parts 34 and 24 are therefore centered at the same point 01, O'I and extend, respectively, on either side of the joint plane P.
• the central part 33 with a large radius of curvature can even be planar, as in the embodiment of FIG. 1, and is progressively connected to the end parts 34, 34 ′ centered at 01, O'I.
• the height e of the rib 32 is determined so as to give the assembly a sufficient moment of inertia to withstand the forces applied to the part 33 of the element 3.
• the elements are dimensioned so that the longitudinal supports are spaced apart by a width L and placed at a height H above the bottom 11, these dimensions corresponding to the desired clearance gauge G.
• the upper element 3 can be calculated as a beam with variable section resting on two articulated supports constituted by the longitudinal joints 4, 4 'formed on the upper edges 21, 21' of the side elements 2, 2 '.
• the height e is therefore not greater than that of a flat deck resting on two vertical abutments, in order to limit the same size.
• the articulated joint 4 can be produced in the same way, the joint plane P preferably being inclined relative to the horizontal, by an angle A equal to 45 °.
• this type of joint has given the best results, even for very large spans.
• the tangential connection of the elements by parts 24 and 34 of the same radius of curvature makes it possible to ensure the continuous transmission of forces by arching effect and to retain a certain flexibility of the structure which is particularly useful for resisting differential settlement and, even, to earthquakes, as we have been able to verify.
• the forces applied to the two articulated joints 4, 4 ′ have a component horizontal tending to push outwards the side elements 2, 2 'which bear on the side embankments, the latter being made so as to participate in the strength of the structure.
• the inwardly curved shape of the side elements 2, 2 'and the possibility of giving them a very small thickness with respect to their length gives the assembly a certain flexibility making it possible to mobilize the embankments. It appears that the total height H 'of the structure is not appreciably greater than that of a structure of rectangular section and therefore allows the passage of a traffic lane 13 at a fairly reduced height H above the bottom 11 of the trench 10, the upper element 3 can be covered with a thin layer of fill.
• the particular shape of the upper element makes it possible to reduce the effects of settlement which normally occur at the edge of a flat deck and which lead to degradation of the roadway. Indeed, since the central part 33 is extended by parts 34 of greater curvature, the thickness of the fill gradually increases until the lateral supports 4, 4 'which are further from the upper surface 13 and, due of the continuity of the circular external wall, this gradual increase or decrease in the height of the embankment above the concrete wall ensures better absorption of the threshold effect when the structure passes.
• the upper element 33 it is possible to use the usual techniques of reinforced concrete, in particular prestressing, so as to reduce the height of the stiffening rib. We can also increase the number of ribs associated with each element.
• the side elements 2, 2 ′ have a center of curvature 01 placed at the level of the bottom 11, so as to increase the height of the curved part 24 for a given ratio of the width L to the height H of the template.
• the height e of the rib must be just sufficient to give the upper element 3 the necessary resistance to bending while ensuring the desired clearance gauge.
• the internal edges of the bases 22, 22 'of the side elements can be connected by a concrete slab allowing the load to be distributed over a large area.

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• Engineering & Computer Science (AREA)
• Civil Engineering (AREA)
• Life Sciences & Earth Sciences (AREA)
• General Life Sciences & Earth Sciences (AREA)
• Mining & Mineral Resources (AREA)
• Paleontology (AREA)
• Environmental & Geological Engineering (AREA)
• General Engineering & Computer Science (AREA)
• Structural Engineering (AREA)
• Road Paving Structures (AREA)
• Pit Excavations, Shoring, Fill Or Stabilisation Of Slopes (AREA)
• Revetment (AREA)
• Underground Structures, Protecting, Testing And Restoring Foundations (AREA)

Priority Applications (3)

Applications Claiming Priority (2)

Publications (1)

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Family Applications (1)

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Citations (4)

Family Cites Families (9)

• 1998
  • 1998-03-09 FR FR9802846A patent/FR2775704B1/fr not_active Expired - Fee Related
• 1999
  • 1999-03-08 DK DK99907667T patent/DK1062392T3/da active
  • 1999-03-08 WO PCT/FR1999/000518 patent/WO1999046450A1/fr active IP Right Grant
  • 1999-03-08 ES ES99907667T patent/ES2257033T3/es not_active Expired - Lifetime
  • 1999-03-08 PT PT99907667T patent/PT1062392E/pt unknown
  • 1999-03-08 JP JP2000535802A patent/JP4644367B2/ja not_active Expired - Fee Related
  • 1999-03-08 EP EP99907667A patent/EP1062392B1/fr not_active Expired - Lifetime
  • 1999-03-08 CA CA002322980A patent/CA2322980A1/fr not_active Abandoned
  • 1999-03-08 MY MYPI9900837 patent/MY129555A/en unknown
  • 1999-03-08 OA OA00000247A patent/OA11902A/fr unknown
  • 1999-03-08 EP EP04076571A patent/EP1452646A3/fr not_active Withdrawn

Patent Citations (4)

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