Patent Publication Number: US-11035086-B2

Title: Structural assemblies for constructing bridges and other structures

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
     This application is a continuation of U.S. patent application Ser. No. 14/204,735 filed on Mar. 11, 2014, which is a continuation of U.S. patent application Ser. No. 13/122,955 filed on Apr. 6, 2011, now U.S. Pat. No. 8,667,633, which is a National Phase of International Patent Application No. PCT/CA2009/001404 filed on Oct. 6, 2009, which claims priority from U.S. Provisional Patent Application No. 61/103,181 filed on Oct. 6, 2008, all of which are incorporated by reference herein. 
    
    
     FIELD OF THE INVENTION 
     The invention relates to structural assemblies for constructing bridges and other structures. 
     BACKGROUND 
     Bridges, including pedestrian bridges and vehicular bridges, have a wide range of applications. For example, pedestrian bridges can be used in skywalks between buildings, gangways to embark or disembark ships and other vehicles, elevated walkways in architectural interiors, boardwalks, and any other setting where people move. 
     Currently, pedestrian bridges are often formed of welded components. Such bridges tend to be complicated and potentially expensive to assemble and often need to be transported to their site pre-assembled. Where welded bridges are assembled on-site, as may be the case in larger structures, assembly can be laborious, expensive and complicated, requiring intervention of highly-skilled welders and other professionals. Also, such bridges tend to be permanent, since their assembly is generally irreversible and they sometimes can only be removed by destructive deconstruction. 
     Pedestrian bridges that are not welded or that are generally disassemblable tend to suffer from a number of drawbacks, including being susceptible to vandalism, tampering, and accidental disassembly. Such acts can have devastating consequences, particularly in cases of bridges that can fail and cause human loss if intentionally or unintentionally weakened or disassembled. Additionally, such bridges tend to have highly visible weld lines which are detrimental to their aesthetic appeal. 
     Similar considerations can also arise in vehicular bridges. Furthermore, similar considerations can also arise in other types of structures, such as buildings, fences, towers (e.g., antennae tower), gantries (e.g., motorway gantries, crane gantries, etc.), to name a few. 
     For these and other reasons, there is a need for improvements in structural assemblies for constructing bridges and other structures. 
     SUMMARY OF THE INVENTION 
     According to a first broad aspect, the invention provides a structural assembly. The structural assembly comprises an elongated member defining an internal space. The structural assembly also comprises a plurality of framing members connected to the elongated member at a plurality of pin connection nodes, each pin connection node comprising a pin interconnecting the elongated member, a first one of the framing members, and a second one of the framing members, the pin having a first longitudinal end and a second longitudinal end, at least one of the first longitudinal end and the second longitudinal end of the pin being located in the internal space of the elongated member. 
     According to a second broad aspect, the invention provides a structural assembly comprising an elongated member defining an internal space. The structural assembly also comprises a plurality of framing members connected to the elongated member at a plurality of nodes. The structural assembly further comprises a support for supporting an illumination system, the illumination system comprising a lighting device for emitting light from the elongated member, at least part of the lighting device being located in the internal space when the support supports the illumination system. 
     According to a third broad aspect, the invention provides a bridge comprising a first chord defining an internal space. The bridge also comprises a second chord. The bridge further comprises a plurality of web members connected to the first chord at a plurality of pin connection nodes and to the second chord at a plurality of moment-transferring connection nodes. Each pin connection node comprises a pin interconnecting the first chord, a first one of the web members, and a second one of the web members, the pin having a first longitudinal end and a second longitudinal end, at least one of the first longitudinal end and the second longitudinal end of the pin being located in the internal space of the first chord. 
     According to a fourth broad aspect, the invention provides a bridge comprising a first chord and a second chord and a plurality of web members connected to the first chord at a first plurality of nodes and to the second chord at a second plurality of nodes. Each node of the first plurality of nodes is a pin connection node, the pin connection node comprising a pin interconnecting the first chord, a first one of the web members, and a second one of the web members, the pin being concealed from view for an observer on the bridge. 
     According to a fifth broad aspect, the invention provides a bridge comprising a first chord defining an internal space and a second chord. The bridge also comprises a plurality of web members connected to the first chord at a first plurality of nodes and to the second chord at a second plurality of nodes. The bridge further comprises a support for supporting an illumination system, the illumination system comprising a lighting device for emitting light from the first chord, at least part of the lighting device being located in the internal space when the support supports the illumination system. 
     According to a sixth broad aspect, the invention provides a bridge comprising a first chord and a second chord. The bridge also comprises a plurality of web members connected to the first chord at a first plurality of nodes and to the second chord at a second plurality of nodes. Each web member has a central longitudinal axis and comprises a plurality of interior channels, the interior channels receiving a plurality of fasteners each having a longitudinal axis generally parallel to the central longitudinal axis of the web member, the fasteners being adjacent to one another along a direction transverse to the central longitudinal axis of the web member. 
     According to a seventh broad aspect, the invention provides a structural assembly. The structural assembly comprises an elongated member and a plurality of framing members connected to the elongated member at a plurality of pin connection nodes. Each pin connection node comprises a pin interconnecting the elongated member, a first one of the framing members, and a second one of the framing members, the pin being concealed. 
     These and other aspects of the invention will now become apparent to those of ordinary skill in the art upon review of the following description of embodiments of the invention in conjunction with the accompanying drawings. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       A detailed description of embodiments of the invention is provided below, by way of example only, with reference to the accompanying drawings, in which: 
         FIG. 1  shows a perspective view of a bridge comprising a structural assembly in accordance with an embodiment of the invention; 
         FIG. 2  shows an exploded view of the structural assembly; 
         FIG. 3  shows an upper chord and a pair of web members interconnected at a pin connection node of the structural assembly; 
         FIG. 4  shows a side elevation view of the upper chord and the web members; 
         FIG. 5  shows a transversal elevation view of the upper chord and the web members; 
         FIG. 6  shows a cross-sectional elevation view of the upper chord and the web members; 
         FIG. 7  shows a connector for the pin connection node; 
         FIG. 8  shows a transversal cross-sectional view of the upper chord; 
         FIG. 9  shows a bottom view of the upper chord and the web members; 
         FIG. 10  shows interconnection of two sections of the bridge in accordance with another embodiment of the invention; 
         FIG. 11  shows a perspective view of a lower chord and three web members interconnected via a lower node connector; 
         FIG. 12  shows a side elevation view of the lower chord, the web members, and the lower node connector; 
         FIGS. 13 to 15  show different cross-sectional views of the lower chord, the web members, and the lower node connector; 
         FIG. 16  shows a cross-sectional view of one of the web members; 
         FIGS. 17 to 20  show variants for interconnecting the lower chord, the web members, and the lower node connector in accordance with other embodiments of the invention; 
         FIG. 21  shows a cross-sectional view of a web member in accordance with another embodiment of the invention; and 
         FIG. 22  shows a cross-sectional view of an upper chord in accordance with another embodiment of the invention. 
     
    
    
     It is to be expressly understood that the description and drawings are only for the purpose of illustrating certain embodiments of the invention and are an aid for understanding. They are not intended to be a definition of the limits of the invention. 
     DETAILED DESCRIPTION OF EMBODIMENTS 
       FIGS. 1 and 2  show a bridge  10  comprising a structural assembly  12  in accordance with an embodiment of the invention. In this example, the bridge  10  is a pedestrian bridge (i.e., a footbridge) providing a pathway that can be used for various purposes. For instance, the bridge  10  may be part of: a crossing to go over a depression or obstacle on the ground, a stream or body of water, or another outdoor area; a crossing to move over a room or other space in a building; an overpass above a highway or other road; a skywalk connecting two buildings; a gangway for boarding a ship, an airplane, a train or another vehicle; or any other structure bridging two or more areas. 
     The structural assembly  12  comprises an assembly of structural members forming a framework of the bridge  10 . More particularly, in this embodiment, the structural assembly  12  comprises: a pair of upper elongated members  20   1 ,  20   2 , a pair of lower elongated members  22   1 ,  22   2 , and a plurality of framing members  24   1 - 24   N ,  30   1 - 30   N ,  32   1 - 32   M  each extending between two of these upper and lower elongated members. The elongated members  20   1 ,  20   2 ,  22   1 ,  22   2  and the framing members  24   1 - 24   N ,  30   1 - 30   N ,  32   1 - 32   M  are connected to one another at a plurality of nodes, including a plurality of upper nodes  36   1 - 36   P ,  37   1 - 37   P  and a plurality of lower nodes  38   1 - 38   R ,  39   1 - 39   R . 
     More particularly, in this embodiment, the bridge  10  is a truss bridge, in this case, a pony-truss bridge (also known as a “half-through” truss bridge), and the structural assembly  12  is a truss assembly in which the upper elongated members  20   1 ,  20   2  are upper chords, the lower elongated members  22   1 ,  22   2  are lower chords, and the framing members  24   1 - 24   N ,  30   1 - 30   N ,  32   1 - 32   M  are web members. The structural assembly  12  can thus be viewed as comprising a first vertical truss  40   1 , which comprises the upper chord  20   1 , the lower chord  22   1 , and the web members  24   1 - 24   N , and a second vertical truss  40   2 , which comprises the upper chord  20   2 , the lower chord  22   2 , and the web members  30   1 - 30   N . The framing members  32   1 - 32   M  interconnect the vertical trusses  40   1 ,  40   2  and support a floor (not shown) of the bridge  10  (e.g., stringers, decking, etc.). The bridge  10  may also comprise fencing (not shown) mounted to the vertical trusses  40   1 ,  40   2 . 
     With additional reference to  FIGS. 3 to 9 , the vertical truss  40   1  will be described in further detail with an understanding that, in this embodiment, the vertical truss  40   2  is configured in a similar manner. 
     The upper chord  20   1  can be made in various ways. In this embodiment, the upper chord  20   1  is an extruded metallic member. Specifically, in this example, the upper chord  20   1  is an extruded aluminum member. This may facilitate manufacturing of the upper chord  20   1  and help to minimize its weight and consequently that of the bridge  10 . The upper chord  20   1  may be made using various other processes and/or other materials in other embodiments. For example, in some embodiments, the upper chord  20   1  may comprise a plurality of parts affixed to one another (e.g., by welding, fastening, interlocking, etc.) and/or may be made of other metallic materials (e.g., steel) or other materials (e.g., polymer, composite). 
     The upper chord  20   1  has a periphery  42 . In this embodiment, the periphery  42  comprises a top surface  43  and a pair of lateral surfaces  44   1 ,  44   2  opposite one another. In this case, the top surface  43  is generally flat and the lateral surfaces  44   1 ,  44   2  are curved. The periphery  42  may be shaped in various other ways in other embodiments. For example, in other embodiments, the top surface  43  and/or the lateral surfaces  44   1 ,  44   2  may be shaped differently and/or oriented differently, and/or the periphery  42  may comprise one or more other surfaces (e.g., a bottom surface). 
     The upper chord  20   1  defines an internal space  48 . The internal space  48  is within and delimited by the periphery  42  of the upper chord  20   1 . More particularly, in this embodiment, the upper chord  20   1  comprises an outer wall  50  defining the periphery  42  and delimiting the internal space  48 . Also, in this embodiment, the upper chord  20   1  comprises a plurality of inner walls  52   1 ,  52   2  which partition the internal space  48  into a plurality of portions, including a first portion  49   1 , a second portion  49   2  and a third portion  49   3 . In this case, each of the inner walls  52   1 ,  52   2  merges with the outer wall  50  at two points such that each of the first portion  49   1  and the third portion  49   3  of the internal space  48  is a closed portion of the internal space  48 . In contrast, the second portion  49   2  of the internal space  48  is open at a bottom of the upper chord  20   1 . In other cases, each of the inner walls  52   1 ,  52   2  may merge with the outer wall  50  at a single point (e.g., near the top surface  43 ) or at more than two points. The internal space  48  may be configured in various other ways in other embodiments. For example, in some embodiments, the outer wall  50  may be thicker and/or have a varying thickness, and/or the inner walls  52   1 ,  52   2  may have various other shapes and/or thicknesses or may be omitted. 
     As further discussed below, in this embodiment, the upper nodes  36   1 - 36   P  are located in the internal space  48 . The upper chord  20   1  is configured to facilitate connection of the web members  24   1 - 24   N  to itself at the upper nodes  36   1 - 36   P , while preventing tampering with these nodes. To that end, in this embodiment, the upper chord  20   1  comprises a plurality of openings  56   1 - 56   P ,  54   1 ,  54   2 , an inner pin-retaining portion  58 , and a barrier-supporting portion  71 , whose purposes are discussed later on. 
     The web members  24   1 - 24   N  can be made in various ways. In this embodiment, the web members  24   1 - 24   N  are extruded metallic members. Specifically, in this example, the web members  24   1 - 24   N  are extruded aluminum members. This may facilitate manufacturing of the web members  24   1 - 24   N  and help to minimize their weight and consequently that of the bridge  10 . The web members  24   1 - 24   N  may be made using various other processes and/or other materials in other embodiments. For example, in some embodiments, each of the web members  24   1 - 24   N  may comprise a plurality of parts affixed to one another (e.g., by welding, fastening, interlocking, etc.) and/or may be made of other metallic materials (e.g., steel) or other materials (e.g., polymers, composite). 
     With additional reference to  FIG. 16 , in this embodiment, each web member  24   i  of the web members  24   1 - 24   N  is a tubular member having an outer wall  70  delimiting an internal space  77 . The web member  24   i  also comprises a plurality of inner walls, including an inner tubular wall  72  running generally parallel to the outer wall  70  and connected to the outer wall  70  by three inner walls  74   1 - 74   3  extending generally radially. In this case, the outer wall  70 , inner tubular wall  72  and inner walls  74   1 - 74   3 , all have the same length. In other cases, any one of these walls may extend pass or stop short of any extremity of any other one of these walls. The inner tubular wall  72  and the inner walls  74   1 - 74  partition of the internal space  77  into a first portion  78   1 , a second portion  78   2  and a third portion  78   3 . An interior elongated channel  76  is defined by the inner tubular wall  72 . As further discussed below, the interior elongated channel  76  may be adapted to receive a fastener. Each web member  24 ; is thus mainly hollow and relatively lightweight, while providing sufficient strength. 
     Each web member  24   i  may be configured in various other ways in other embodiments. For example, in other embodiments, the outer wall  70  may have a shape other than circular (e.g., polygonal). As another example, in other embodiments, any one of the inner tubular wall  72  and the inner walls  74   1 - 74   3  may be shaped differently or omitted, or the web member  24   i  may comprise more or less inner walls such as the inner walls  74   1 - 74   3 . As yet another example, in other embodiments, the web member  24   i  may be full instead of hollow. 
     Each of the upper nodes  36   1 - 36   P  is a pin connection node, i.e., a node constituting a pin connection. A pin connection is designed to transfer axial and shear forces but not moments. In other words, in two dimensions, a pin connection restrains two translational degrees of freedom but does not restrain a rotational degree of freedom. 
     Each upper node  36   i  interconnects a first web member  24   j  of the web members  24   1 - 24   N , a second web member  24   k  of the web members  24   1 - 24   N , and the upper chord  20   1 . Thus, the web member  24   j , the web member  24   k , and the upper chord  20   1  are interconnected via a pin connection. 
     The upper node  36   i  comprises a first connecting portion  37   1  for connecting the web member  24   j  and a second connecting portion  37   2  for connecting the web member  24   k . In this embodiment, the first connecting portion  37   1  is part of a first connector  47   1  which is separate from and mounted to the web member  24   j . Similarly, the second connecting portion  37   2  is part of a second connector  47   2  separate from and mounted to the web member  24   k . In other embodiments, the first connecting portion  37   1  may be integral with the web member  24   j  and/or the second connecting portion  37   2  may be integral with the web member  24   k . 
     The upper node  36   i  also comprises a pin  60  interconnecting the web member  24   j , the web member  24   k , and the upper chord  20   1 . The pin  60  comprises an elongated object having a first longitudinal end  62   1  and a second longitudinal end  62   2  and suitable for interconnecting the web member  24   j , the web member  24   k , and the upper chord  20   1  in a pin connection. For example, in various embodiments, the pin  60  may comprise a rod, a shaft, a key, a fastener (e.g., a bolt or stud with a nut, a screw, etc.), or any other hardware capable of being used to interconnect the web member  24   j , the web member  24   k , and the upper chord  20   1  in a manner which permits a degree of rotational movement of one of these structural members relative to another one of these structural members. In this embodiment, the pin  60  comprises a generally cylindrical part. The pin  60  may be configured in various other ways in other embodiments (e.g., the pin  60  may comprise a part having a noncircular periphery). 
     In this embodiment, the pin  60  also serves to fasten the web member  24   j , the web member  24   k , and the upper chord  20   1 . To that end, the pin  60  comprises a fastener. For instance, the fastener may be a threaded fastener (e.g., a bolt or stud with a nut, a screw, etc.), a rivet, a clamp, or any device or group of devices capable of fastening the web member  24   j , the web member  24   k , and the upper chord  20   1 . More specifically, in this embodiment, the pin  60  comprises a bolt. 
     The connectors  47   1 ,  47   2  may be configured in various ways. In this embodiment, the connectors  47   1 ,  47   2  are made of metal, in this case, aluminum, cast into shape. The connectors  47   1 ,  47   2  may be made of other metallic material (e.g., steel) or other materials (e.g., polymer, composite) and/or using other manufacturing processes (e.g., milled or otherwise machined) in other embodiments. Also, in this embodiment, the connectors  47   1 ,  47   2  are substantially identical, such that only one type of connector needs to be produced for both the web members  24   i ,  24   k . In other embodiments, the connectors  47   1 ,  47   2  may be different from one another. 
     The connector  47   1  will be discussed further with an understanding that a similar discussion applies to the connector  47   2 . 
     In this case, the connector  47   1  is mounted to an upper extremity of the web member  24   j . The connector  47   1  is dimensioned so as to cover an upper extremity surface  80  of the web member  24   j . Here, the connector  47   1  comprises a circular base portion  82  for abutting the upper extremity surface  80 . The connector  47   1  may be located elsewhere along the length of the web member  24   i  in other cases. 
     The connector  47   1  comprises an upper portion  84  projecting from the base portion  82 . In this example, the upper portion  84  is tapered and off-center relative to a central longitudinal axis  21  of the web member  24   i . As such, the web members  24   i  and  24   k  can be crossed at the location of their connectors  47   1  and  47   2  such that their central longitudinal axes  21  intersect. In other embodiments, the central longitudinal axes  21  of the web members  24   i  and  24   k  may not intersect. 
     The upper portion  84  of the connector  47   1  comprises a contact surface  88  for contacting a corresponding contact surface  88  of the connector  47   2 . In this example, the contact surface  88  is generally flat to facilitate sliding over the corresponding contact surface  88  of the connector  47   2 . In other examples, the contact surface  88  may have a different profile (e.g., curved, jagged, etc.). In yet other examples, there may be no contact surface  88  on the upper portion  84 , such as in cases where the connectors  47   1 ,  47   2  do not contact one another at the pin connection node  46   i . Indeed, in some embodiments, the connectors  47   1 ,  47   2  may be spaced apart and possibly separated by an intermediate component. 
     The connector  47   1  comprises a through-hole  110  to receive the pin  60 . When the connector  47   1  is mounted to the web member  24   i , the through-hole  110  extends in a direction transverse to the central longitudinal axis  21  of the web member  24   i . In this case, the through-hole  110  extends inwardly from the contact surface  88  such that the contact surface  88  adjacent the through-hole  110  acts as a bearing surface. 
     The connector  47   1  may be mounted to the web member  24   i  in various ways. In this embodiment, the connector  47   1  is mounted to the web member  24   i  via a fastener  86 . In this example, the fastener  86  is a threaded fastener, and more specifically a bolt. An aperture  90  provides a passage through the circular base  82  for receiving the fastener  86 . The fastener  86  holds the connector  47   1  to the web member  24   i  by engaging the inner tubular wall  72  defining the inner elongated channel  76  to screw tightly therein. For instance, the inner elongated channel  76  may comprise internal threading to engage threads of the fastener  86 . A recess  92  is provided in the upper portion  84  to accommodate, and provide access to, a head of the bolt. 
     In this embodiment, the fastener  86  extends along a neutral axis of the web member  24   i , which in this case corresponds to the central longitudinal axis  21 . In embodiments, the fastener  86  may extend along a different longitudinal axis of the web member  24   i . For example, in some embodiments, the fastener  86  may extend along an axis parallel to the neutral axis of the web member  24   i . The fastener  86  may be oriented or otherwise arranged in various other ways to fasten the connector  47   1  to the web member  24   i  in other embodiments. 
     When assembled, the upper node  36   i  interconnects the web member  24   j , the web member  24   k , and the upper chord  20   1 . Specifically, the opening  56   i  in the outer wall  50  of the upper chord  20   1  and the openings  54   1 ,  54   2  in the inner walls  52   1 ,  52   2  of the upper chord are coaxial such that the pin  60  can be inserted through the opening  56   i  and extend through the openings  54   1 ,  54   2  and the through-holes  110  of the connectors  47   1 ,  47   2  mounted to the web members  24   i ,  24   k . This allows a degree of rotation of the upper chord  20   1 , the web member  24   i  and the web member  24   k  relative to one another about the longitudinal axis of the pin  60 . 
     Also, in this embodiment, the pin  60  is held in place and fastens together the web member  24   j , the web member  24   k , and the upper chord  20   1 . Specifically, in this embodiment, the pin  60  comprises a bolt which comprises a tool-engaging head  64  and a shank  65  with threads. The bolt is held in place and fastens together the web member  24   j , the web member  24   k , and the upper chord  20   1  by having the tool-engaging head  64  abut against the inner wall  51   1  of the upper chord  20   1  and the threads of the shank  65  engaged in the inner pin-retaining portion  58  of the upper chord  20   1 . 
     More particularly, in this example, the inner pin-retaining portion  58  is a thread-engaging portion which comprises a pair of ridged surfaces  59   1 ,  59   2  having facing each other for engaging the threads on the bolt  60 . Thus, the bolt  60  can be screwed into place in the upper chord  20   1 . In this case, the ridged walls  59   1  and  59   2  are straight and run the entire length of the upper chord  20   1  so that they can be formed during the upper chord&#39;s extrusion process. The inner pin-retaining portion  58  may be configured in various other ways in other embodiments. For instance, in some embodiments, the inner pin-retaining portion  58  may comprise a built-in nut-like structure. 
     In this embodiment, the upper node  36   i  is concealed from view and inaccessible to an observer on the bridge  10 . This may improve overall esthetics of the bridge  10  and discourage potential vandals from attempting to tamper with the upper node  36   i . 
     More particularly, in this embodiment, the first longitudinal end  62   1  and the second longitudinal end  62   2  of the pin  60  are located in the internal space  48  of the upper chord  20   1 . This positioning of the first and second longitudinal ends  62   1  and  62   2  of the pin  60  in the internal space  48  creates a natural concealment of the pin  60 . In other embodiments, only one of the longitudinal ends  62   1 ,  62   2  of the pin  60  may be located in the internal space  48 , while the other one may be located outside of the internal space  48 . 
     The first longitudinal end  62   1  and the second longitudinal end  62   2  of the pin  60  are thus located within the periphery  42  of the upper chord  20   1 . That is, each of the longitudinal ends  62   1 ,  62   2  of the pin  60  does not extend beyond the periphery  42  of the upper chord  20   1 . Specifically, in this embodiment, each of the longitudinal ends  62   1 ,  62   3  of the pin  60  is located between the lateral surfaces  44   1 ,  44   2  of the upper chord  20   1 . 
     The opening  56   i  in the outer wall  50  of the upper chord  20   1  and the openings  54   1 ,  54   2  in the inner walls  52   1 ,  52   2  of the upper chord  20   1  allow the pin  60  to be inserted from a single side of the upper chord  20   1 , such that no opening is required in the outer wall  50  on the opposite side of the opening  56   i . Thus, in this embodiment, the outer wall  50  is free of (i.e., lacks) openings extending inwardly from the lateral surface  44   2  and aligned with the openings  56   1 - 56   P . As such, when the pin  60  is inserted, the second longitudinal end  62   2  of the pin  60  is within the internal space  48  (in this case, within the third portion  49   3  of the internal space  48 ) and concealed from view to an observer on the bridge  10 . Because there is no need to have openings extending inwardly from the lateral surface  44   2  of the upper chord  20   1 , in this embodiment, the lateral surface  44   2 , which faces the pathway of the bridge  10  and is thus viewed by observers on the bridge  10 , is a flush continuous surface. 
     The pin  60  is inserted deep enough into the upper chord  20   1  that its first longitudinal end  62   1  is in the internal space  48  of the upper chord  20   1 . In this case, the first longitudinal end  62   1  of the pin is in the first portion  49   1  of the internal space  48  of the upper chord  20   1 . Although the first longitudinal end  62   1  of the pin  60  is located in the internal space  48  of the upper chord  20   1 , a plug (not shown) may be inserted into the opening  56   i  so as to block the opening  56   i  and conceal the first longitudinal end  62   1  of the pin  60  from an observer. Such plugs in the openings  56   1 - 56   p  may also improve the overall esthetics of the bridge  10  when viewed from the side of the openings  56   1 - 56   p . 
     While plugs can be useful, they can sometimes be removed with a tool such as a screw driver. Therefore, while plugging the opening  56   i  with a plug may block the view of the pin  60 , it may not necessarily greatly reduce the possibility of tampering with the pin  60 . In particular, in some cases, it may be desirable to render the pin  60  inaccessible, for example, to preclude vandals from tampering with the pin  60 . 
     To that end, in this embodiment, a tamperproof arrangement  100  is provided to prevent access to the pin  60 . More particularly, in this embodiment, the tamperproof arrangement  100  comprise a barrier  104  supported by the aforementioned barrier-supporting portion  71  of the upper chord  20   1 . The barrier  104  is placed in front of the first longitudinal end  62   1  of the pin  60  and blocks access to the pin  60  through the opening  56   i . 
     In this example, the barrier-supporting portion  71  comprises upper and lower projections  106   1 ,  106   2  that run the entire length of the upper chord  20   1  such that the barrier-supporting portion  71  can be formed during the chord&#39;s extrusion process. The barrier  104  comprises a blocking panel which can be slidably received in the barrier-supporting portion  71  from a longitudinal extremity of the upper chord  20   1 . In this case, this blocking panel extends the entire length of the upper chord  20   1 . In other cases, the barrier  104  may be discontinuous and present only in the vicinity of the openings  56   1 - 56   p . 
     Although the brace  102  is shown here as extending inwards from the outer wall  50 , it should be understood that the brace  102  may be formed in one or more other walls. For example the brace  102  may consist of projections extending from the inner wall  52   1 . 
     The tamperproof arrangement  100  may be configured in various other ways in other embodiments. For example, in other embodiments, the barrier-engaging portion  71  may be shaped differently and/or may be formed in one or more other walls of the upper chord  20   1  (e.g., the inner wall  52   1 ). Also, in other embodiments, the barrier  104  may comprise any other suitable component for preventing access to the pin  60 . For example, the barrier  104  may comprise one or more tamper-proof plugs that may be used instead of regular plugs to block opening  56   1 - 56   p . Such tamper-proof plugs may snap-in permanently, be glued, or be affixed by non-removable fasteners. 
     Also, while in this embodiment the tamperproof arrangement  100  is provided only on the side of the upper chord  20   1  which has the opening  56   i  since only the opening  56   i  allows access to the pin  60  (as the second longitudinal end  62   2  of the pin  60  is inaccessible by virtue of being located in the interior space  48  and overlaid by the lateral surface  44   2  of the outer wall  50 ), in other embodiments, the tamperproof arrangement  100  may comprise one or more other components anywhere where access is to be blocked. For example, in embodiments where an opening is provided in the upper chord  20   1  on the opposite side of the opening  56   1  (giving access to the second longitudinal end  62   2  of the pin  60 ), the tamperproof arrangement  100  may comprise a barrier and barrier-supporting portion, similar to the barrier  104  and the barrier-supporting portion  71 , on that opposite side of the upper chord  20   1  as well. 
     The web members  24   i ,  24   k  protrude from a bottom region of the upper chord  20   1 . As such, in this embodiment, the internal space  48  is open at the bottom region of the upper chord  20   1  to allow passage of the web members  24   i ,  24   k . However, in this embodiment, in areas of the upper chord  20   1  between the upper nodes  36   1 - 36   p , the bottom region of the upper chord  20   1  is closed. 
     More particularly, in this embodiment, a barrier  114  is mounted to the upper chord  20   1  to close the bottom region of the upper chord  20   1  in the areas between the upper nodes  36   1 - 36   p . The barrier  114  may comprise any suitable structure openable (e.g., hinged), removable or permanently affixed to the upper chord  20   1  to close its bottom region in the areas between the upper nodes  36   1 - 36   p . In this example, the barrier  114  comprises a door hingedly connected to the upper chord  20   1  (in this case, to the inner wall  52   1  of the upper chord  20   1 ) so that it can be “swung” open. In this case, the door is hingedly connected via a live hinge  121 . In other cases, the door may be hinged by any other hinging means (e.g., a pivot hinge). In this example, the door also comprises a retaining portion  118  to keep it in its closed position. In this case, the retaining portion  118  is a snap-fit portion which fits in a corresponding recess formed by the outer wall  50  of the upper chord  20   1 . In other embodiments, the barrier  114  may be removable (e.g. by having snap-fit arrangements on both transverse sides or by any other means) or may be permanently affixed to the bottom region of the upper chord  20   1  (e.g. by being permanently snap-fit into place, by being glued, or by being welded in place). The barrier  114  may also be slid into place from a longitudinal end of the upper chord  20   1  during assembly. 
     In this embodiment, the structural assembly  12  comprises a support  89  for supporting an illumination system  112  for emitting light from the upper chord  20   1 . The illumination system  112  comprises one or more lighting devices to emit light, which can be used on the bridge  10  for functional and/or aesthetic reasons. In this embodiment, the support  89  is implemented by the barrier  14  in the bottom region of the upper chord  20   1 . The support  89  may be implemented in various other ways in other embodiments (e.g., by the outer wall  50 , one or more of the inner walls  52   1 ,  52   2 , and/or another portion of the upper chord  20   1 ). 
     More particularly, in this embodiment, the illumination system  112  comprises a plurality of lighting devices  120   1 - 120   L  distributed along the upper chord  20   1 . At least part of each of the lighting devices  120   1 - 120   L  is located in the internal space  48  of the upper chord  20   1 . This helps to protect the lighting devices  120   1 - 120   L . In this example, the lighting devices  120   1 - 120   L  are mounted to the barrier  114  in the bottom region of the upper chord  20   1  for illuminating an area beneath the upper chord  20   1 . In other examples, the lighting devices  120   1 - 120   L  may be mounted elsewhere on the upper chord  20   1  for illuminating one or more other areas adjacent to (e.g., adjacent, on lateral sides, etc.) the upper chord  20   1 . 
     Each of the lighting devices  120   1 - 120   L  may take on various forms. In this embodiment, the lighting devices  120   1 - 120   L  are light-emitting diode (LED) lighting devices. More specifically, in this case, each of the LED lighting devices  120   1 - 120   L  comprise three different LED light sources, each generating light of a different color. In other cases, each of the LED lighting devices  120   1 - 120   L  may emit monochromatic light only. The lighting devices  120   1 - 120   L  may take on other forms (e.g., light bulbs) in other embodiments. 
     Illumination may be controlled by any suitable means (e.g., for turning the lights on and off, and/or for providing light of different colors). In this example, wires (not shown) connected to the lighting devices  120   1 - 120   L  for powering and/or controlling the lighting devices  120   1 - 120   L  run inside the internal space  48  of the upper chord  20   1 . This protects the wires and connections to the lighting devices  120   1 - 120   L  from weather elements and avoids the esthetical unpleasantness of exposed wires. 
     As described above, in this embodiment, the upper chord  20   1  has the barrier  104  inserted therein from a longitudinal end of the upper chord  20   1  as well as the barrier  114  slid into place from a longitudinal end of the upper chord  20   1 . In order to increase the tamper-proofness of the bridge  10 , in this embodiment, each of the longitudinal ends of the upper chord  20   1  is fitted with an end-piece  195 , as shown in  FIGS. 1 and 2 . The end-piece  195  may be secured to the chord  20   1  by any suitable manner. For instance, in this case, the end-piece  195  is bolted thereto using a tamper-proof bolt that can be tightened but not loosened. In addition, in this example, a handrail  197  is mounted to the end-piece  195  and linked to the lower chord  22   1 . 
     Turning now to the lower chord  22   1 , in this embodiment, the web members  24   1 - 24   N  and the lower chord  22   1  connect together at the lower nodes  38   1 - 38   R  by way of respective lower node connectors  130   1 - 130   R . The framing members  32   1 - 32   M  are connected to the lower chord  22   1  via the lower node connectors  130   1 - 130   R . In this case, the framing members  32   1 - 32   M  include transverse members  134   1 - 134   S  and floor diagonals  132   1 - 132   Q . 
     Connections to the lower chord  22   1  will now be described with reference to  FIGS. 11 to 15 and 17 to 20 . In this example, at a lower node  38   i  of the lower nodes  38   1 - 38   R , a lower node connector  130   i  of the lower node connectors  130   1 - 130   R  interconnects a first web member  24   k  of the web members  24   1 - 24   N , a second web member  24   M  of the web members  24   1 - 24   N , a transverse member  134   i  of the transverse members  134   1 - 134   S , and the lower chord  22   1 . In this case, the lower node connector  130 ; also connects to first and second floor diagonals  132   i ,  132   j  of the floor diagonals  132   1 - 132   g . 
     In this embodiment, the lower node  38   i  is a moment-transferring connection node, i.e., a node constituting a moment-transferring connection, which is a connection designed to transfer axial and shear forces as wells moments. In other words, in two dimensions, a moment-transferring connection restrains two translational degrees of freedom and a rotational degree of freedom. 
     More particularly, the lower node connector  130   i  is able to transfer bending moments. In this example, the transverse member  134   j  comprises a first longitudinal end  138  that is inserted into a cavity  142   1  of the lower node connector  130   i . The web members  24   k ,  24   m  comprise respective lower longitudinal ends  140   k ,  140   m  that are inserted into respective cavities  142   2 ,  142   3  of the lower node connector  130   i . The web members  24   k ,  24   m  and the transverse member  134   j  may have tapered end portions for inserting into the respective cavities  142   2 ,  142   3 ,  142   1 . The tapered end portions of the web members  24   k ,  24   m  and the transverse member  134   j  may be machined (e.g., milled, turned, swaged) or brought to this tapered shape by any other process. 
     The lower node connector  130   i  is connected to the lower chord  22   1 . In this embodiment, the lower node connector  130   i  comprises a channel  144  for receiving the lower chord  22   1 . In this case, the channel  144  is open to allow the lower node connector  130   i  to simply be placed over the lower chord  22   1  to embrace the lower chord  22   1  in the channel  144 . In other cases, the channel  144  may be closed (that is, surrounded as in a tunnel or partially surrounded such that the lower chord  22   1  cannot escape the channel  144  except by sliding out of it), requiring the lower node connector  130   i  to be slid into place along the lower chord  22   1 . 
     Any suitable fastener may be used for securing the lower node connector  130   i  and the lower chord  22   1  to one another. In this embodiment, a pair of threaded fasteners is used to this end. More specifically, the lower node connector  130   i  is fastened to the lower chord  22   i  by a pair of bolts  148  and nuts  149  through two like pairs of holes adapted to align the lower node connector  130   i  and the lower chord  22   1 . Both of the floor diagonals  132   i ,  132   j  attach to the lower node connector  130   i  with bolts  158  and nuts  159 . 
     The web members  140   k ,  140   m  and the transverse member  134   j  may be secured to the lower node connector  130   i  in various manners. In this embodiment, the lower node connector  130   i  is adapted to receive a fastener  152  for holding each of the web members  24   k ,  24   m  and the transverse member  134   j  in place in their respective cavities  142   2 ,  142   3 ,  142   1 . The lower node connector  130   i  comprises an aperture  150  through the bottom of each cavity  142   2 ,  142   3 ,  142   1  such that, for each cavity, the fastener  152  can extend between the channel  144  and the cavity. In this example, the fasteners  152  are bolts that screw into the interior elongated channel  76  of the web members  24   k ,  24   m  in a manner similar to that described above in relation to the fastener  86 . 
     In this case, the fasteners  152  each have a tool-engaging head  153  and recesses  151  are provided to accommodate the tool engaging heads  153  of fasteners  152 . The recesses  151  may be dimensioned so as to allow a tool to engage a tool-engaging head  153  while within the recess  151 . In such a way, before the lower chord  22   1  is inserted into the channel  144 , the fasteners  152  can be inserted into apertures  150  through the channel  144  into the respective web members  24   k ,  24   m  or transverse member  134   j  until the tool-engaging heads  153  are contained within respective recesses  151 . In this way, the channel  144  is not blocked by the fasteners and the lower chord  22   1  is not impeded from being received therein. In addition to allowing unimpeded close contact between the lower chord  22   1  and the lower node connector  130   1 , this arrangement has the added benefit that once the lower chord  22   1  is installed, the fasteners  152 , and particularly their tool engaging heads  153 , are not only concealed from sight of observers on or around the bridge  10 , but they are rendered inaccessible such that an observer cannot remove the fasteners  152  so long as the lower chord  22   1  is in place in the channel  144 . Indeed, so long as the lower chord  22   1  is in the channel  144 , the fasteners  152 , and particularly their tool engaging heads  153  cannot be reached with a tool or otherwise, and the fasteners are prevented from backing out of their respective apertures  150  by the lower chord  22   1 . 
     The lower node connector  130   i  thus forms a very stable connection between the lower chord  22   1 , the transverse member  130   1  and the web members  24   k ,  24   m  for maintaining structural integrity throughout the lower chord  22   1 . As shown in reference to  FIG. 11 , bolts that are used to secure diagonals and transversals are hidden so they cannot be unscrewed while the node is attached to the chord providing additional safety against thief or sabotage. Additionally, antitheft nuts can be used instead of regular nuts to secure the lower node connector  130   i  to the lower chord  22   1 . 
     The floor diagonals  132   i ,  132   j  act to resist horizontal loading act on the projected area of the bridge  10 . The web members  24   k ,  24   m  act to resist tension and compression forces but they also transfer some bending moment to the transverse member  134   j  as well as they transfer torsion to the lower chord  22   1    FIG. 13  shows a cross-sectional view taken along line A-A in  FIG. 12 . A fastener  152  is shown in this view, which in the example shown is a bolt which secures the transverse member  134   j  to the lower node connector  130   1  in the cavity  142   1 .  FIG. 14  shows a cross-sectional view taken along lines B-B in  FIG. 12 , while  FIG. 15  shows a cross-sectional view taken along line C-C in  FIG. 14 . 
     The web members  140   k ,  140   m  and the transverse member  134   j  may be secured to the lower node connector  130   i  in various other ways in other embodiments. For example,  FIG. 17  shows a possible variant to the use of a multi-hollow section shown in  FIG. 16  for the web members  24   1 - 24   N  or for the transverse members  134   1 - 134   S . As shown, it may be possible to use a regular hollow shape that could be secured into a cavity by way of a rod partially or completely threaded.  FIG. 18  shows a cross-sectional view taken along line E-E in  FIG. 17 . A rod  170  may run on or near the neutral axis of a tube. A nut  172  may give a pre-tension to maintain the tube inside the cavity with adequate pressure. As another example,  FIG. 19  shows another possible variant. Here, a hollow section  174  is secured into place with using a threaded insert  176 .  FIG. 20  is a cross-sectional view taken along line F-F in  FIG. 19 . As shown, the threaded insert  176  may fit the inside of the hollow section  174 . The threaded insert  176  may be maintained inside the hollow section  174  by being welded therein or by any other suitable means. The threaded insert  176  may be used to secure in place the hollow section  174  using a fastener  178 , such as a bolt. 
     In view of the foregoing, in this embodiment, the structural assembly  12  of the bridge  10  may be a “weldless” structural assembly, i.e., it can be assembled with no welding being required to hold together its structural members. This may greatly simplify the distribution and assembly process of the bridge  10 , making it suitable for uses and in locations otherwise not suited for welded bridges. Furthermore, individual components may be shipped individually for assembly, and this assembly may be performed without expensive welding services. Furthermore, the structural assembly  12  may be disassemblable, making it possible to easily relocate it or to simply take it down, opening up the prospect of installing it in non-permanent locations or even renting it. 
     While in this embodiment the structural assembly  12  is configured in a particular way, the structural assembly  12  may be configured in various other ways in other embodiments. 
     For example, in some embodiments, the structural assembly  12  may comprise other structural members and components to make the bridge  10  longer. For instance, as shown in  FIG. 10 , in some embodiments, splices  200   1 ,  200   2  may be provided for linking upper chords of a first bridge section to respective upper chords of a second bridge sections and splices  202   1 ,  202   2  may likewise be provided for linking lower chords of the first bridge section to respective lower chords of the second bridge section. The splices  200   1 ,  200   2 ,  202   1 ,  202   2  may be inserts to be inserted into a first chord of a first bridge section and secured thereto such that a portion of the splice protrudes from the first chord and is inserted into a second chord of a second bridge section and secured thereto so as to effectively connect the two chords together. The splices  200   1 ,  200   2 ,  202   1 ,  202   2  may be secured by bolts or other fasteners, thus maintaining the weld-less nature of the bridge  10 . 
     As another example, although in this embodiment the upper chord  20   1  is a one-piece member, in other embodiments, the upper chord  20   1  may be a multi-piece member comprising a plurality of parts affixed to one another (e.g., by welding, fastening, interlocking, etc.). For instance, as shown in  FIG. 22 , in some embodiments, the upper chord  20   1  may comprise a central part  69  and a pair of lateral parts  73   1 ,  73   2  connected to the central part  69 . Thus, in such embodiments, the periphery  42  of the upper chord  20   1  is defined by external surfaces of the central part  69  and the lateral parts  73   1 ,  73   2 , and the internal space  48  of the upper chord  20   1  is delimited by the central part  69  and the lateral parts  73   1 ,  73   2 . Also, in such embodiments, the outer wall  50  of the upper chord  20   1  comprises a first wall portion  53   1  formed by the central part  69 , a second wall portion  53   2  formed by the lateral part  73   1 , and a third wall portion  53   3  formed by the lateral part  73   2 . In this example, each of the lateral parts  73   1 ,  73   2  is interlocked with the central part  69 . More particularly, in this example, the central part  69  comprises four flanges  79   1 - 79   4  and each of the lateral parts  73   1 ,  73   2  comprises a pair of flanges  75   1 ,  75   2 . The lateral part  73   1  is interlocked with the central part  69  by engagement of its flanges  75   1 ,  75   2  with the flanges  79   1 ,  79   2  of the central part  69 . The flanges  75   1 ,  75   2  of the lateral part  73   1  may be slid into engagement with the flanges  79   1 ,  79   2  of the central part  69  by sliding the lateral part  73   1  relative to the central part  69 , or may be snap-fitted into engagement with the flanges  79   1 ,  79   2  of the central part  69 . Similarly, the lateral part  73   2  is interlocked with the central part  69  by engagement of its flanges  75   1 ,  75   2  with the flanges  79   3 ,  79   4  of the central part  69 . 
     As another example, in other embodiments, a web member  24   x  of the web members  24   1 - 24   N  may be connected to a connector  47   x  of the connectors  47   1 ,  47   2  of an upper node  36   x  of the upper nodes  36   1 - 36   P  by two or more fasteners such as the fastener  86 . For instance, as shown in  FIG. 21 , in some embodiments, the inner walls of the web member  24   x  may define two interior elongated channels  76   1 ,  76   2  such as the interior elongated channel  76  which can receive two fasteners (e.g., bolts) such as the fastener  86  each generally parallel to the neutral axis  21  of the web member  24   x  and adjacent to one another along a direction transverse to the neutral axis  21  of the web member  24   x . The connector  47   x  would in such embodiments comprise two apertures for receiving the two fasteners. Similarly, the web member  24   x  may be connected to a lower node connector  130   x  of the connectors  47   1 ,  47   2  of a lower node  38   x  of the lower nodes  38   1 - 38   R , by two or more fasteners such as the fastener  152 . Other ones of the web members  24   1 - 24   N ,  30   1 - 30   N ,  32   1 - 32   M  may be connected in a similar manner. Such use of two or more fasteners may provide enhanced structural rigidity and redundancy in case of failure of one of the fasteners. 
     As another example, although in this embodiment the lighting devices  120   1 - 120   L  are present on the underside of the upper chord  20   1 , in other embodiments, the lighting devices  120   1 - 120   L  of the illumination system  112  may be placed elsewhere on the bridge  10  to illuminate in any desired direction. For instance, some or all of the lighting devices  120   1 - 120   L  may be arranged along the lower chord  22   1  in a manner similar to that described above in respect of the upper chord  20   1 . 
     As another example, in some embodiments, the structural assembly  12  may support a sound system comprising one or more speakers, which may be arranged in a manner similar to the lighting devices  120   1 - 120   L  of the illumination system  112  discussed above, with wires running inside the internal space  48  of the upper chord  20   1  or mounted to other components (e.g., the lower chord  22   1 ). 
     Although in this embodiment the bridge  10  is a pedestrian bridge, in other embodiments, the bridge  10  may be another type of bridge. For example, in some embodiments, the bridge  10  may be a bridge providing a pathway for vehicles (e.g., automobiles, trucks, military vehicles, etc.). 
     While in this embodiment the structural assembly  12  is included in a bridge, the structural assembly  12  may be part of structures other than bridges in other embodiments. For example, in other embodiments, structural assemblies such as the structural assembly  12  may part of, inter alia, buildings, fences, towers (e.g., antennae tower), gantries (e.g., motorway gantries, crane gantries, etc.), flag post bases, furniture, and various other lattice structures and other types of structures. 
     Although various embodiments and examples have been presented, this was for the purpose of describing, but not limiting, the invention. Various modifications and enhancements will become apparent to those of ordinary skill in the art and are within the scope of the invention, which is defined by the appended claims.