GB2556432A

GB2556432A - Bridge with truss structures

Info

Publication number: GB2556432A
Application number: GB1715657.1A
Authority: GB
Inventors: Matiere Philippe
Original assignee: Matiere SAS
Current assignee: Matiere SAS
Priority date: 2016-09-30
Filing date: 2017-09-27
Publication date: 2018-05-30
Also published as: FR3056996B1; FR3056996A1; GB201715657D0

Abstract

A truss bridge, for example of the Warren type with a double intersection, comprises two truss structures each comprising an upper beam (100 Fig 1), a lower beam (102) and at least one X shaped reinforcement extending between the upper and lower beams and formed from a long member 1066 and two short members 1067 1068 which are connected to the long member. Preferably the truss comprises modules of a segment of the upper and lower beams and X shape reinforcements. Girders 8 are stretched between the truss structures to support a deck 6. Preferably the beam segments and members are formed from a welded reconstituted beam. The beam may be U shaped and have a bottom thicker than the flanks. The members may be I or H shaped girders. The beam segments and members may be joined using splice bars bolted onto their side flanks.

Description

(56) Documents Cited:

CN 204112245 U FR 002548234 A US 1901800 A US 0107576 A

CN 105735131 A JP 2015190122 A US 0682500 A (71) Applicant(s):

Matiere (Incorporated in France) place d'lena, Paris 75016,

France (including Overseas Departments and Territori es) (58) Field of Search:

INT CL E01D Other: EPODOC, WPI (72) Inventor(s):

Philippe Matiere (74) Agent and/or Address for Service:

Abel & Imray

Westpoint Building, James Street West, Bath, BA1 2DA, United Kingdom (54) Title of the Invention: Bridge with truss structures

Abstract Title: Bridge with truss structures and X shaped reinforcements (57) A truss bridge, for example of the Warren type with a double intersection, comprises two truss structures each comprising an upper beam (100 Fig 1), a lower beam (102) and at least one X shaped reinforcement extending between the upper and lower beams and formed from a long member 1066 and two short members 1067 1068 which are connected to the long member. Preferably the truss comprises modules of a segment of the upper and lower beams and X shape reinforcements. Girders 8 are stretched between the truss structures to support a deck 6. Preferably the beam segments and members are formed from a welded reconstituted beam. The beam may be U shaped and have a bottom thicker than the flanks. The members may be I or H shaped girders. The beam segments and members may be joined using splice bars bolted onto their side flanks.

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Bridge with truss structures

The invention relates to a bridge with truss structures, also called lattice structures, and in particular, but not exclusively, to a bridge of the Warren type with a double intersection.

In this type of bridge, truss or lattice structures are provided on either side of a deck to support this deck and owing to girders stretched between these truss structures. These truss structures are configured to withstand the weight of the bridge and the weight of the loads present on the deck of the bridge.

These truss structures generally comprise an upper beam and a lower beam that work by traction and compression or vice versa, as well as the stiffening members that extend between these beams. These members are sometimes made from metal profiles welded to form X-shaped reinforcements, intended to be assembled to the upper and lower beams on the installation site of the bridge. These X-shaped reinforcements must be conveyed to this site, most often inside containers, such as sea freight containers, within which they take up considerable space, since their shape does not allow them to be densely juxtaposed. This results in lost space and excess costs during transport, since the containers cannot be loaded with a quantity of material corresponding to their nominal maximum transport mass. Furthermore, these X-shaped reinforcements are heavy and difficult to manipulate both on the packaging site and on the installation site of the bridge.

Similar problems may arise with other types of bridges with truss structures.

The invention more particularly aims to resolve these drawbacks by proposing a new bridge structure with trusses, the assembly and conveyance of which on the site are facilitated.

To that end, the invention relates to a bridge with truss structures, this bridge comprising a deck, two truss structures that each comprise an upper beam, a lower beam and members that extend between the upper and lower beams while forming the Xshaped reinforcements. This bridge also comprises girders stretched between the truss structures and that support the deck. Each truss structure includes several modules that each comprise a segment of the upper beam, a segment of the lower beam and at least one X-shaped reinforcement. According to the invention, each X-shaped reinforcement is formed by a long member fixed, at a first end, on the upper beam segment, and, at a second end, on the lower beam segment, as well as by two short members each fixed, at a first end, on one of the beam segments, and at a second end, on the long member.

Owing to the invention, the X-shaped reinforcement can be formed on the installation site of the bridge, by fixing both ends of the two short members on the long member, before securing this reinforcement to the lower and upper beams owing to the two ends of the long member and the first ends of the two short members. Each reinforcement can be transported to the site in the disassembled state, its long and short members being arranged parallel to one another, with a reduced bulk. This makes it possible to load a container with a significant number of reinforcements, with a mass close to its nominal maximum transport mass.

According to other advantageous, but optional aspects of the invention, such a bridge with truss structures may incorporate one or more of the following features, considered in any technically allowable combination:

- The bridge is of the Warren type with a double intersection.

- The beam segments and the members are each formed by a welded reconstituted beam.

- Each beam segment has a U-shaped section, with a bottom thicker than its flanks. In this case, the thickness of the bottom of the beam segment is advantageously comprised between 18 and 30 mm, preferably equal to about 20 mm, while the thickness of the flanks of the beam segment is comprised between 10 and 16 mm, preferably equal to about 12 mm.

- Each member has an I- or H-shaped section, with a core thinner than its flanks. In this case, the thickness of the core of the member is advantageously comprised between 4 and 8 mm, preferably about equal to 8 mm, while the thickness of the flanks of the member is comprised between 10 and 16 mm, preferably equal to about 12 mm.

- The flanks of the beam segment and the flanks of the member have identical thicknesses.

- The members are assembled to one another and to the beam segments and the modules are assembled to one another using splice bars bolted on the members and on the beam segments, in particular on side flanks of these members and segments.

- The upper beam works by traction, while the lower beam works by compression, the upper beam segments of two adjacent modules are assembled by arranging an axial space between them and the lower beam segments of two adjacent modules are assembled in contact with one another.

- The truss structures may include running modules that each include an upper beam segment, a lower beam segment and an X-shaped reinforcement, as well as at least one end module that comprises an upper beam segment, a lower beam segment and at least one X-shaped reinforcing part, while the length of the end module is smaller than the length of a running module and the total length of the bridge is a multiple of one third of the length of a running module.

The invention will be better understood, and other advantages thereof will appear more clearly, in light of the following description of one embodiment of a bridge with truss structures according to its principle, provided solely as an example and done in reference to the appended drawings, in which:

figure 1 is an interrupted side view of a bridge according to the invention, figure 2 is an interrupted side view of the bridge of figure 1, figure 3 is an enlarged sectional view along line Ill-Ill of figure 2, figure 4 is an enlarged sectional view along line IV-IV of figure 1, figure 5 is a section view using the same scale as figure 4 along line V-V in figure 1, figure 6 is a perspective view of one end of the bridge of figures 1 to 5, and figure 7 is a cutaway partial perspective view of the bridge of figures 1 to 6, at a running part of this bridge.

The bridge 2 shown in the figures extends, along a longitudinal axis X2, between two foundations M shown only in figure 1. Reference L2 denotes the total length of the bridge 2 measured parallel to the axis X2.

This bridge comprises a deck 4 formed by decking plates 6 supported by beams 8 arranged horizontally and perpendicular to the axis X2 and that are stretched between two metal truss structures 10 and 12, also called lattice structures, which in turn are arranged vertically and parallel to the axis X2. In figures 1 and 2, the bridge 2 is shown with a deck 4 that comprises, widthwise, four decking plates 6, whereas in figures 6 and 7, it is shown in the case where the deck comprises three decking plates arranged between the sidewalks. This corresponds to different possible configurations for the bridge 2.

The structures 10 and 12 are symmetrical relative to a vertical plane P2 passing through the axis X2, which is arranged between the structures 10 and 12 and equidistant therefrom.

The truss structure 10 comprises an upper beam 100 and a lower beam 102, as well as members that extend between the beams 100 and 102 while forming X-shaped reinforcements 104. These reinforcements 104 make it possible to stiffen the truss structure 100.

The bridge 2 is therefore a bridge with two truss structures, more particularly a bridge of the Warren type with a double intersection.

The truss structure 10 is made up of the juxtaposition, along the axis X2, of several modules, including at least two running modules 106 whereof the length, measured parallel to the axis X2, is denoted L106. In the example, the length L106 is about 9.15 m.

A running module 106 of the truss structure 10 is a module identical to several other modules juxtaposed to form the structure 10 over the majority of its length.

The structure 10 also comprises two end modules 108 and 109, the lengths of which, measured parallel to the axis X2, are respectively denoted L108 and L109. These £108 L109 lengths respectively have values of about 4.57 m and 1.52 m. The ratios -and-are ^{α r 1} L106 L106 respectively approximately equal to 1/2 and 1/6.

Each end module 108 or 109 comprises, on each side, a vertical end upright 108a, 109a, respectively.

The structure 10 is primarily made up of running modules 106.

Inasmuch as the desired length L2 for the bridge 2 can be a multiple of the length L106, the end modules 108 and 109 are optional and the structure 10 can be made up exclusively of running modules 106, optionally modified to include a vertical end upright.

Owing to the use of running modules 106, the number of which is adapted to the desired span of the bridge 2 as well as the end modules 108 and/or 109, the total length L2 of the bridge 2 can be a multiple of one third of the length L106 of a running module 106.

Each running module 106 comprises a segment 1060 of the upper beam, a segment 1062 of the lower beam and three X-shaped reinforcements 104. Only two reinforcements 104 are shown in position in figure 7, having specified that the third reinforcement 104 is intended to be mounted, along the axis X2, overlapping an adjacent module, situated on the left or right of the running module 106 in figures 1 and 7. This third X-shaped reinforcement 104 is shown in the exploded configuration in the lower left part of figure 7.

Each X-shaped reinforcement 104 is formed by a long member 1066 and two short members 1067 and 1068.

Each long member 1066 comprises a first end 1066A by which it is fixed to the upper beam segment 1060 and a second end 1066B by which it is fixed to the lower beam segment 1062. The short member 1067 comprises a first end 1067A by which it is fixed to the lower beam segment 1062 and a second end 1067B by which it is fixed to the long member 1066. The short member 1068 in turn comprises a first end 1068A by which it is fixed to the upper beam segment 1060 and a second end 1068B by which it is fixed to the long member 1066. In practice, the ends 1067B and 1068B are fixed on either side of an intermediate zone of the long beam 1066, midway between its ends 1066A and 1066B.

The fixing of the ends 1066A, 1066B, 1067A and 1068A on the beam segments 1060 and 1062 is done using splice bars 1069 that overlap these ends and lugs 1060A and 1062A respectively arranged on the beam segments 1060 and 1062 to serve as a starting point for the members 1066, 1067 and 1068. In practice, orifices 1060C and 1062C are arranged in the lugs 1060A and 1062A and orifices 1066C, 1067C and 1068C are arranged in the ends 1066A, 1066B, 1067A and 1068A, these orifices being intended to be aligned with corresponding orifices of one of the splice bars 1069. Bolts with nonrustible heads, of the HRC type, are inserted into these orifices and tightened in position until their heads break, which causes reliable and lasting immobilization of the ends of the members 1066, 1067 and 1068 with respect to the beam segments 1060 and 1062.

Likewise, splice bars 1069 are used to secure the ends 1067B and 1068B of the short members 1067 and 1068 on the intermediate part of the long member 1066, which is provided with other orifices 1066C at this level.

In figure 7, for clarity of the drawing, only some of the splice bars are shown, which makes it possible to view the passage orifices of the bolts 1060C, 1062C, 1066C, 1067C and 1068C respectively provided in the beam segments 1060 and 1062 and in the members 1066 to 1068. Splice bars 1069 are also shown separately, in the bottom part of figure 7, which makes it possible to identify their bolt passage orifices 1069C.

The upper beam segment 1060 is formed by a welded reconstituted beam or “WRB”, also called “poutre reconstituee soudee” or “PRS in French, that is made by welding steel plates with a U-shaped cross-section more particularly shown in figure 4. Reference 1060D denotes the bottom of the U-shaped section of the segment 1060. References 1060E and 1060F also denote the branches of this U-shaped section that constitute the flanks of the beam segment 1060. Weld beads 1061 provide the connection between the parts 1060D, 1060E and 1060F, respectively. Reference e1 denotes the thickness of the bottom 1060D and e2 denotes the thickness of a flank 1060E or 1060F, which is the same. The thickness e1 is greater than the thickness e2, which corresponds to the fact that it is the horizontal part of the upper beam 100 that works by traction, more than its flanks. In practice, the thickness e1 is comprised between 18 and 30 mm, preferably about 20 mm, while the thickness e2 is comprised between 10 and 16 mm, preferably about 12 mm.

The lower beam segment 1062 is also formed by a WRB or PRS made from steel plates, with a U-shaped cross-section similar to that of the segment 1060.

Each member is also formed by a WRB or PRS made from steel plates, with an Ior H-shaped cross-section, as shown in figure 5 for a long member 1066. More specifically more specifically, this member has a core 1066D and two flanks 1066E and 1066F that are connected to the core 1066D by weld beads 1063. Reference e3 denotes the thickness of the core 1066D and e4 denotes the thickness of the flanks 1066E or 1066F, which is the same. The thickness e3 is smaller than the thickness e4, which is preferably equal to the thickness e2, which makes it possible to align the flanks 1060E and 1066E vertically, as well as the flanks 1060F and 1066F. In practice, the thickness e3 is comprised between 4 and 8 mm, preferably about 8 mm, while the thickness e4 is comprised between 10 and 16 mm, preferably about 12 mm. Here again, the distribution of the thicknesses of the sheets making up the WRB or PRS forming the member 1066 is optimized based on the mechanical stresses of these sheets and their interaction with the component parts of the segments 1060 and 1062. In particular, the core 1066D can be relatively thin, since it is not stressed very much by the weight of the bridge and loads present on the deck 4.

The members 1067 and 1068 each have an I-shaped cross-section similar to that of the member 1066 shown in figure 5.

In practice, the orifices 1060C, 1062C, 1066C, 1067C and 1068C are formed in the flanks 1060E, 1060F, 1066E, 1066F and equivalent of the parts 1060, 1062, 1066, 1067 and 1068, such that the splice bars 1069 can be affixed bearing on the outside of these flanks.

In this respect, it will be noted that the intermediate part of a long member 1066 is provided, on its flanks, with lugs 1066G comparable to the lugs 1060A and 1062A and in which certain orifices 1066C are arranged that are intended to receive bolts for immobilizing splice bars 1069, which also cooperate with the second ends 1067B and 1068B of the short members 1067 and 1068.

According to one aspect of the invention that is not shown, splice bars can also be provided to connect the cores of the members to one another and with intermediate ribs provided at the lug 1060A and 1062A inside beam segments 1060 and 1062.

Making the beam segments 1060 and 1062 and the members 1066 to 1068 in WEB or PRS form provides great freedom in the design of the modules 106 of the truss structure 10. This freedom makes it possible to optimize the quantity of steel consumed to form each module 106, and therefore the weight and cost of the truss structure 10.

Thus formed, each running module 106 of the truss structure 10 forms a rigid structure that can be assembled with adjacent modules, of the running or end type, using splice bars, some of which are visible in figures 6 and 7 with references 1071 and 1073.

Likewise, the truss structure 12 comprises an upper beam 120, a lower beam 122, reinforcements 124, running modules 126 and end modules 128 and 129. A running segment 126 comprises an upper beam segment 1260, a lower beam segment 1262 and reinforcements 124 formed by long members 1266 and short members 1267 and 1268.

In practice, a running module 126 is identical to a running module 106. Likewise, an end module 128 or 129 is identical to an end module 108 or 109, down to the fact that straight and bent elements exist.

The end modules 108, 109, 128 and 129 each comprise an upper beam segment, a lower beam segment and at least one reinforcement 104 or 124 or a reinforcing part. The main difference between an end module 108, 109, 128 or 129 and a running module 106 or 126 is the length of its beam segments, which is smaller than that of the beam segments 1060 and 1062, as explained above.

In order to impart a camber to the bridge 2, it may be provided that the upper beam segment 1060 of a running module 106 is assembled to the upper beam segments of the adjacent modules by arranging a nonzero axial space between them, along the axis X2, greater than 20 mm, this space being defined by the geometry of the splice bars 1071 and 1073 used at these upper beam segments. On the contrary, the lower beam segments of two adjacent modules are assembled in contact with one another or with an axial distance between them smaller than that used at the upper beam segments, for example about 2 to 4 mm.

When the bridge 2 is conveyed to its installation site, the component elements of a running module 106 to 109 or 126 to 129 can be transported in containers, in particular sea freight containers, since the maximum length of a piece of such an element is the maximum length of a beam segment 1060, 1062, 1260 or 1262 of a running element 106 or 126, which is 9.15 meters. Furthermore, the members 1066, 1067, 1068, 1266, 1267, 1268 and equivalents can be arranged parallel to one another inside the container, which allows them to be stored with a high density and avoids filling containers with a load significantly lower than the nominal weight that they can transport, which would be the case if the X-shaped reinforcements were formed by rigid and preassembled cross structures.

Thus, owing to the truss structures 10 and 12, the beam can be conveyed relatively easily to its installation site, while having a relatively low mass per unit length.

This makes it possible to create a bridge 2 that may have a span greater than 90 meters with a mass per unit length of about 2 tons for a bridge with a deck having one traffic lane. In the case of a bridge with a deck having two traffic lanes, the span of the bridge may be greater than 60 m.

According to possible developments of the deck 4 of the bridge 2, the latter may be equipped with safety gates 42, as shown in figures 1 to 3, or sidewalks 44 and hand rails

46, as shown in figures 6 and 7. Other developments, not shown, of the deck may be considered, such as lighting columns. Alternatively, the sidewalks 44 can be arranged outside the truss structures 10, 12, cantilevered relative to the latter.

The invention is described above in the case of a Warren-type bridge with a double 5 intersection. It is, however, applicable to other types of bridges having truss structures including X-shaped reinforcements, in particular Pratt bridges with a double intersection, or Parker, Bowstring, Camelback, Pennsylvania or Baltimore bridges.

The embodiment and alternatives considered above may be combined with one another to create new embodiments.

Claims

1. - A bridge (2) with truss structures comprising:

- a deck (4);

- two truss structures (10, 12) that each comprise an upper beam (100, 120), a lower beam (102, 122) and members (1066-1068, 1266-1268) that extend between the upper and lower beams while forming X-shaped reinforcements (104, 124), and

- girders (8) stretched between the truss structures (10, 12) and that support the deck (4), each truss structure including several modules (106, 108, 126, 128) that each comprise a segment (1060, 1260) of the upper beam, a segment (1062, 1262) of the lower beam and at least one X-shaped reinforcement (104, 124), wherein each X-shaped reinforcement (104, 124) is formed by a long member (1066, 1266) fixed, at a first end (1066A), on the upper beam segment (1060, 1260), and, at a second end (1066B), on the lower beam segment (1062, 1262), as well as by two short members (1067, 1068, 1267, 1268) each fixed, at a first end (1067A, 1068, 1267, 1268), on one of the beam segments (1060, 1062, 1260, 1262), and at a second end (1067B, 1068B), on the long member (1066, 1266).

2. The bridge according to claim 1 wherein the bridge is of the Warren type with a double intersection.

3. - The bridge according to either of claims 1 or 2, wherein the beam segments (1060, 1062, 1260, 1262) and the members (1066-1068, 1266-1268) are each formed by a welded reconstituted beam (WRB).

4. - The bridge according to claim 3, wherein each beam segment (1060, 1062, 1260, 1262) has a U-shaped section, with a bottom (1060D) thicker than its flanks (1060E, 1060F).

5. - The bridge according to claim 4, wherein the thickness (e1) of the bottom (1060D) of the beam segment (1060, 1062, 1260, 1262) is comprised between 18 and 30 mm, preferably equal to about 20 mm, while the thickness (e2) of the flanks (1060E, 1060F) of the beam segment is comprised between 10 and 16 mm, preferably equal to about 12 mm.

6. - The bridge according to one of claims 3 to 5, wherein each member (10661068, 1266-1068) has an I- or H-shaped section, with a core (1066D) thinner than its flanks (1066E, 1066F).

7. - The bridge according to claim 6, wherein the thickness (e3) of the core (1066D) of the member (1066-1068, 1266-1268) is advantageously comprised between 4 and 8 mm, preferably equal to about 8 mm, while the thickness (e4) of the flanks (1066E, 1066F) of the member is comprised between 10 and 16 mm, preferably equal to about 12 mm.

8. - The bridge according to claims 4 and 6, wherein the flanks (1060E, 1060F) of the beam segment (1060, 1062, 1260, 1262) and the flanks (1066E, 1066F) of the member (1066-1068, 1266-1268) have identical thicknesses (e2, e4).

9. - The bridge according to any of the preceding claims, wherein the members (1066-1068, 1266-1268) are assembled to one another and to the beam segments (1060, 1062, 1260, 1262) and the modules (106-109, 126-129) are assembled to one another using splice bars (1069, 1071, 1073) bolted on the members and on the beam segments, in particular on side flanks (1060E, 1060F, 1066E, 1066F) of these members and segments.

10. - The bridge according to any of the preceding claims, wherein

- the upper beam (100) works by traction,

- the lower beam (102) works by compression,

- the upper beam segments (1060, 1260) of two adjacent modules (106, 108, 109, 126, 128, 129) are assembled with a space arranged between them, and

- the lower beam segments (1062, 1262) of two adjacent modules are assembled in contact with one another.

11. - The bridge according to any of the preceding claims, wherein

- the truss structures (10, 12) include running modules (106, 126) that each comprise a segment (1060, 1260) of the upper beam, a segment (1062, 1262) of the lower beam and at least one X-shaped reinforcement (104, 124), and at least one end module (108, 109, 128, 129) that comprises an upper beam segment, a lower beam segment and at least one X-shaped reinforcing part,

- the length (L108, L109) of the end module is smaller than the length (L106) of a running module (106),

- the total length (L2) of the bridge is a multiple of one third of the length of a running module.

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