FIELD OF THE INVENTION
The present invention relates to a prefabricated, modular, transportable bridge system.
BACKGROUND OF THE INVENTION
There is a need in the art for a prefabricated, modular bridge which can be transported, assembled and disassembled as needed.
SUMMARY OF THE INVENTION
In general terms, the invention comprises a prefabricated, modular bridge which can be transported, assembled and disassembled as needed. The bridge system may comprise any combination of elements or features as described below.
In one aspect, the present invention comprises a modular system for forming a roadway surface of a bridge comprising a plurality of transversely spaced apart longitudinal frame members supported on foundation elements. The modular system comprises: (a) a plurality of roadway deck panels: (b) a plurality of longitudinally spaced apart transverse hubs, wherein each of the transverse hubs defines a transverse ledge for supporting an end of one of the roadway deck panels: and (c) a plurality of transversely spaced apart hub attachment clamps attached to each one of the transverse hubs. Each of the hub attachment clamps is adapted for clamping a top flange of one of the longitudinal frame members against the transverse hub. Each of the hub attachment clamps is movable transversely relative to the transverse hub to selectively disengage or engage the top flange of one of the longitudinal frame members.
In another aspect, the present invention comprises a module for use with a roadway deck panel to form a portion of a roadway surface of a bridge comprising a plurality of transversely spaced apart longitudinal frame members supported on foundation elements. The module comprises: (a) a transverse hub defining a transverse ledge for supporting an end of one of the roadway deck panels: and (b) a plurality of transversely spaced apart hub attachment clamps attached to the transverse hub. Each of the hub attachment clamps is adapted for clamping a top flange of one of the longitudinal frame members against the transverse hub. Each of the hub attachment clamps is movable transversely relative to the transverse hub to selectively disengage or engage the top flange of one of the longitudinal frame members.
In another aspect, the present invention comprises a method for forming a roadway surface of a bridge comprising a plurality of transversely spaced apart longitudinal frame members supported on foundation elements. The method comprising the steps of: (a) positioning a plurality of transverse hubs longitudinally spaced apart from each other along the longitudinal frame members, wherein each of the transverse hubs has a plurality of transversely spaced apart hub attachment clamps attached to the transverse hub: (b) for each of the transverse hubs, moving the attached hub attachment clamps transversely relative to the transverse hub to engage a top flange of one of the longitudinal frame members: (c) fixing the longitudinal positions of the transverse hubs along the frame members by using the hub attachment clamps to clamp the top flanges of the longitudinal frame members against the transverse hubs: and (d) for each adjacent pair of the transverse hubs, placing a roadway deck panel between the transverse hubs, with the ends of the roadway deck panel supported by transverse ledges defined by the transverse hubs.
The modular system, the module, and the method may be used to assemble a bridge that crosses a valley at essentially a right angle. The ability to adjust the longitudinal position of the transverse hubs along the frame members allows the longitudinal distance between the longitudinal frame members and the ends of the longitudinal frame members to differ for different longitudinal frame members. This may make it convenient to assemble a bridge that crosses a valley at an oblique angle, such as shown in FIG. 1A.
Embodiments of the modular system, the module, or the method, may comprise one or a combination of the following features or steps. For each hub attachment clamp, a threaded fastener may be used to apply a force to the hub attachment clamp for clamping the top flange of the one of the longitudinal frame members against the transverse hub. The transverse hub may define a slot, wherein the threaded fastener extends through the slot and is movable transversely within the slot. The threaded fastener may comprise a bolt comprising a bolt head, wherein the bolt head is accessible from above the transverse hub. Each of the hub attachment clamps may have an L-shaped cross-sectional shape comprising a vertical leg and a horizontal leg, wherein the top flange of the one of the longitudinal frame members is disposed between a bottom surface of the transverse hub and horizontal leg. Each of the transverse hubs may comprise a hub bottom flange plate defining the transverse ledge. Each of the transverse hubs may comprise a hub top flange cover plate removably attachable by cover plate threaded fasteners to the remainder of the transverse hub to clamp the end of one of the roadway deck panels between the hub bottom flange plate and the hub top flange cover plate.
In another aspect, the present invention comprises an assembly for splicing together a pair of longitudinal frame members of a bridge. The assembly comprises, for each one of the longitudinal frame members, a bearing support attached to the one of the longitudinal frame members between a top flange and a bottom flange of the one of the longitudinal frame members, wherein the bearing support defines a bearing support aperture. The assembly further comprises an anchor bolt extending through the bearing support aperture of each of the bearing supports, and a nut at each end of the anchor bolt for tensioning the anchor bolt and bearing against one of the bearing supports. In one embodiment, the bearing support comprises a weldment comprising a transverse bearing plate defining the bearing support aperture, and at least one longitudinal stiffener plate extending from the bearing plate.
In another aspect, the present invention comprises a modular bridge system comprising: (a) a longitudinal frame member to be supported by foundation elements, and comprising a top flange, a bottom flange, and a vertical web extending between the top flange and the bottom flange, and defining a framed opening: and (b) an external reinforcing assembly comprising: (i) a pair of longitudinal tendons: and (ii) an anchor block for anchoring the longitudinal tendons on opposite sides of the vertical web, wherein the anchor block is received in the framed opening, and bears against the vertical web.
In another aspect, the present invention comprises a spacer for deviating a longitudinal tendon of an external tension reinforcing assembly from a bottom of a longitudinal frame member of a bridge. The spacer comprises a plurality of members that are adapted to be bolted together to form a stack, wherein a number of the members selected to form the stack may be varied to vary a height of the stack.
In another aspect, the present invention comprises a hanger for deviating a longitudinal tendon of an external tension reinforcing assembly from a bottom of a longitudinal frame member of a bridge. The hanger comprises an elongate member extending from an upper end to a lower end. The upper end defines a bolt hole for receiving a bolt to secure the hanger to the longitudinal frame member. The lower end defines a tendon aperture for receiving the longitudinal tendon.
BRIEF DESCRIPTION OF THE DRAWINGS
In the attached drawings or views, like elements may be assigned like reference numerals. The drawings are not necessarily to scale, with the emphasis instead placed upon the principles of the present invention. Additionally, each of the embodiments depicted are but one of a number of possible arrangements utilizing the fundamental concepts of the present invention.
FIG. 1A is a plan view of an embodiment of a bridge of the present invention, extending over a waterway between two abutments.
FIG. 1B is a top perspective view of the bridge of FIG. 1A.
FIG. 2 is a top perspective view of a beam pack of the bridge of FIG. 1B.
FIG. 3 is a top perspective view of a longitudinal frame end member of the beam pack of FIG. 2.
FIG. 4 is a top perspective view of a longitudinal frame center member of the beam pack of FIG. 2.
FIG. 5 is a bottom perspective view of an end portion of the longitudinal frame end member of FIG. 3.
FIG. 6 is a top perspective view of an end portion of the bridge of FIG. 1B, when supported on an abutment.
FIG. 7 is a top perspective view of an end portion of the bridge of FIG. 1B, when supported on an intermediate pier.
FIG. 8 is a top perspective view of an end portion of the bridge of FIG. 1B, when supported on an abutment.
FIG. 9A is a top perspective view of a transverse hub of the bridge of FIG. 1B.
FIG. 9B is an enlarged view of region “A” of FIG. 9A.
FIG. 10 is a top perspective view of an end portion of the bridge of FIG. 1B, with some of the roadway deck panels removed.
FIG. 11 is a bottom perspective view of an intermediate portion of the bridge of FIG. 1B.
FIG. 12 is a bottom perspective view of a transverse hub and hub attachment assemblies of the bridge of FIG. 1B.
FIG. 13 is a top plan view of an end portion of the bridge of FIG. 1B, when supported on two abutments, with some of the roadway deck panels removed.
FIG. 14 is a top perspective view of a roadway deck panel of the bridge of FIG. 1B.
FIG. 15 is an end elevation view of the longitudinal frame center member of FIG. 4.
FIG. 16 is a side elevation view of a portion of the longitudinal frame end member of FIG. 3.
FIG. 17 is a top perspective view of the longitudinal frame center member of FIG. 4.
FIG. 18 is a top perspective view of an end portion of the beam pack of FIG. 2.
FIG. 19 is a top perspective view of a transverse diaphragm of the beam pack of FIG. 2.
FIG. 20 is a bottom perspective view of a splice connection between two longitudinal frame members.
FIG. 21 is a bottom perspective view of half of the splice connection and one of the longitudinal frame members shown in FIG. 20.
FIG. 22 is a top perspective view of one of the top flange splice weldments shown in FIGS. 20 and 21.
FIG. 23 is an exploded, top perspective view of two transverse hubs joined by a transverse hub splice.
FIG. 24 is a side elevation view of part of the bridge of FIG. 1B.
FIG. 25 is a top perspective view of an external tension reinforcing anchor block and tendons of the bridge of FIG. 1B.
FIG. 26 is a side elevation view of an end portion of the longitudinal frame end member of FIG. 3.
FIG. 27 is a perspective view of a portion of the external tension reinforcing anchor block and tendons of FIG. 25.
FIG. 28 is an enlarged view of region “A” of FIG. 24.
FIG. 29 is a perspective view of a portion of a longitudinal frame end member and tension reinforcing hanger of the bridge of FIG. 1B.
FIG. 30 is an elevation view of tension reinforcing hanger of FIG. 29.
FIG. 31 is an elevation view of an access ramp beam attached to a portion of the bridge of FIG. 1B.
FIG. 32 is a perspective view of the access ramp beam of FIG. 31.
FIG. 33 is an elevation view of a transverse hub, traffic railing post, and pedestrian railing post of the bridge of FIG. 1B.
FIG. 34 is a perspective view of a transverse hub, traffic railing post, and pedestrian railing post of the bridge of FIG. 1B.
DETAILED DESCRIPTION OF THE INVENTION
Any term or expression not expressly defined herein shall have its commonly accepted definition understood by a person skilled in the art. As used herein, the terms “longitudinal” and “transverse” are used to refer to directions that are perpendicular to each other, in a horizontal or substantially horizontal plane.
In one aspect, as shown in FIGS. 1A and 1B, a prefabricated, modular bridge (10) comprises a plurality of beam packs (12). In the embodiment shown in FIG. 1B, the bridge (10) has two beam packs (12). As shown in FIG. 2, in this embodiment, each beam pack (12) comprises two pairs of parallel, longitudinal frame end members (14) which can be extended with one or more pairs of longitudinal frame center members (16) extending longitudinally between the end members (14). The beam packs (12) are supported on foundation elements comprising abutments (18, 20) as shown in Figures IA, 6, and 8, and/or intermediate piers (22) as shown in FIG. 7.
FIG. 3 shows one of the longitudinal frame end members (14) in isolation, and FIG. 5 shows an end portion of the longitudinal frame end member (14). FIG. 4 shows one of the longitudinal frame center member (16) in isolation. In preferred embodiments, the longitudinal frame members (14, 16) are fabricated from steel, however these elements could also be fabricated from other materials with suitable strength and rigidity.
Referring to FIGS. 10 to 12, the beam packs (12) support a roadway surface (23) comprising a plurality of transverse hubs (24) that are securely fastened to the top flanges (26) of the longitudinal frame members (14, 16) using hub attachment clamps (28).
FIG. 12 shows one embodiment of the hub clamps (28). Each hub clamp (28) comprises a member having an L-shaped transverse cross-section, having a vertical leg and a horizontal leg. Threaded nuts (31) are securely attached (e.g., by welds) to the bottom surface of the horizontal leg. The apertures defined by the nuts (31) align with apertures defined by the horizontal leg of the hub clamp (28), and with transverse slots (25) defined by the hub bottom flange plate (32) of the transverse hub (24). Threaded clamp bolts (27) pass through these aligned apertures. The clamp bolts (27) have bolt heads (not visible in FIG. 12) that are disposed in the cavity of the transverse hub (24) defined by the hub bottom flange plate (32), the hub top flange cover plate (34), and the pair of hub webs (36). The bolt heads are accessible when the hub top flange cover plate (34) is detached from the hub webs (36): the hub top flange cover plate (34) is removably attached to the hub webs (36) by fasteners, as described below. Accordingly, the bolt heads are conveniently accessible to a worker working from above the transverse hub (24). The bottom surfaces of the bolt heads interface with the upper surface of the bottom flange plate (32). Before the clamp bolts (27) are tensioned, the clamp bolts (27) can slide transversely within the slots (25) away from the centerline of the longitudinal frame members, so that the hub clamps (28) disengage from the top flanges (26) of the longitudinal frame members. When the hub clamps (28) are in this “disengaged state”, the hub clamps (28) are also in a “released state” that permits adjustment of a longitudinal position of the transverse hub (24) along the longitudinal frame members (14, 16). The hub clamps (28) may be slid transversely toward the centerline of the longitudinal frame members (14, 16) so that they engage the top flanges (26) as shown in FIG. 11. When the hub clamps (28) are in this “engaged state”, the hub clamps (28) are still in the “released state”. Torque is applied to the bolt heads of the clamp bolts (27) to tension the clamp bolts (27). As a result, the horizontal leg of the hub clamps (28) compress the top flanges (26) of the longitudinal frame members (14 or 16) against the bottom surface of the transverse hub (24). Friction between these parts prevents relative movement between the transverse hub (24) and the longitudinal frame members (14, 16). As a result, the hub clamps (28) are put into a “clamped state” in which they fix the longitudinal position of the transverse hub (24) along the longitudinal frame members (14, 16). It will be appreciated that in other embodiments, the nut (31) may bear against the transverse hub (24) and the bolt head may bear against the hub clamp (28). It will also be appreciated that in other embodiments, the clamp bolt (27) and nut (31) combination may be modified by use of another combination of threaded fastener (e.g., a screw) and complementary threaded surfaces associated with either the transverse hub (24) or the hub clamp (28) to effect the same result.
In one embodiment as shown in FIG. 10, the hubs (24) are placed at regular intervals along the length of the beam packs (12), with the first hub (24) being positioned perpendicular to and equidistant to the ends (13) of each of the beam packs (12). However, the distances from the ends of the beam packs (12) to the location of the first hub attachment clamps (28) (i.e., most proximal to the end (13) of the beam pack (12)) may vary across the width of the bridge (10) effectively making it possible to construct the roadway surface (23) of the modular bridge (10) at an oblique skew angle (a) (29) that deviates from a perpendicular orientation to the abutments (18, 20) and/or intermediate piers (22), as is shown in FIG. 1A. For example, in one embodiment in FIG. 13, the longitudinal distance between the end (13a) of a first beam pack (12a) supported on a first abutment (18a) to the hub attachment clamps (28) of first hub (24) is greater than the longitudinal distance between the end (13b) of a second beam pack (12b) supported on a second abutment (18b) to the hub attachment clamps (28) of first hub (24).
Referring to FIGS. 1B and 14, the roadway surface (23) of the modular bridge (10) comprises roadway deck panels (30) that could be fabricated of fiber reinforced polymer (FRP) sandwich panels but could comprise other materials such as steel or concrete panels. In the preferred embodiment, the panels (30) all comprise the same dimensions to minimize the number of components in the bridge (10). In some embodiments, a number of different sizes of panels (30) may be available to accommodate different spacing and bridge lengths. However, in the case of a bridge (10) of non-standard length or where the roadway surface (23) is oriented on a skewed angle relative to the foundation elements such as abutments (18, 20) and/or intermediate piers (22), custom length panels (30) may be provided to accommodate the variations in the positioning of the hubs (24) relative to the ends (13) of the beam packs (12).
Referring to FIGS. 8 to 12 the roadway deck panels (30) are supported on a transverse ledge (33) comprising the hub bottom flange plates (32). The roadway deck panels (30) are then secured in place by a clamping force resulting from threaded fasteners (e.g., bolts or screws) extending through the hub top flange cover plates (34) into apertures defined by the outstanding legs of the hub webs (36). In the preferred embodiment, all the hub components (32, 34, 36) comprise structural steel, but could be fabricated from other suitable materials.
Referring to FIGS. 3 to 5, and 15 to 17, each of the longitudinal frame members (14, 16) comprise a top flange (26), a bottom flange (38) and one or more vertical webs (40), said webs (40) being rigidly secured to the adjacent flanges (26, 38) through welding or other means. In the preferred embodiment, the longitudinal frame end members (14) also have a sloped bottom flange (42) extending from the end of the longitudinal frame end member (14) for a length approximately equal to the length of a typical roadway deck panel (30). These sloped bottom flanges (42) and corresponding tapered vertical webs (42A) facilitate a reduction in the depth of the beam packs (12) at the abutments (18, 20) and/or piers (22) in order to reduce the amount of fill required to match the elevations of the roadway surface (23) with the elevations of the adjacent roadways. Longitudinal frame end members (14) without the sloped beam flanges (42) could also be used without compromising other benefits or features of this invention.
Referring to FIGS. 3 to 5, and 15 to 19, each of the longitudinal frame members (14, 16) also comprise a plurality of intermediate transverse stiffeners (44) on each side of the framing member, extending between flanges (26, 38), and spaced equidistant from each other. The transverse stiffeners (44) have a series of holes that are pre-drilled to receive transverse diaphragms (46) comprising steel channels that are positioned between a pair of longitudinal framing members (14, 16) and attached by fastening devices that could be high-strength steel bolts. The transverse diaphragms (46) serve to provide lateral stability to the beam pack assemblies (12).
One feature of a prefabricated modular bridge system is the ability to construct bridges (10) of various lengths, widths and skew angles using a finite set of standard components that are reusable and interchangeable. Standard lengths for the modular bridge system are established that correspond to multiples of the standard lengths of the roadway deck panels (30). In the simplest embodiment, the bridge (10) comprises beam packs (12) comprising two pairs of longitudinal frame end members (14). For bridges (10) spanning longer distances, longitudinal frame center member(s) (16) can be added.
Referring to FIG. 20, in all cases the longitudinal frame members (14 or 16) are joined together utilizing conventional bolted splices on the bottom “tension” flanges (38) using a pair of tension flange top splice plates (50) positioned opposite of a tension flange bottom splice plate (52) and connected with high-strength bolts in a matter that results in a clamping force on the tension flanges (38) of the adjacent longitudinal framing members (14 or 16). Likewise, the webs (40) of the longitudinal framing members (14 or 16) are joined with a pair of web splice plates (54) positioned opposite of each other with high-strength bolts extending through the combination of plates (54) to provide a clamping force between the webs (40) of adjacent longitudinal framing members (14 or 16).
Referring to FIGS. 20 to 22, to provide a smooth continuous surface on the top flanges (26) of the longitudinal frame members (14 or 16), the top “compression” flanges (26) of the longitudinal frame members (14 or 16) are spliced using a pair top flange tension splice rods (56) positioned on either side of the vertical webs (40) and underneath the top flange (26). The tension splice rods (56) are in the form of anchor bolts, which are anchored using top flange splice weldment (58) located on the bottom sides of the top flanges (26), said weldment (58) comprising a transverse bearing plate (60) oriented perpendicular to the top flange (26) and supported by longitudinal stiffener plates (62) welded to the top flanges (26) and serving as a bearing support for the anchor bolts. The bearing plate (60) defines a bearing support aperture (61) for through passage of an end of the anchor bolt. The top flange tension splice rods (56) are tensioned using nuts (63) in a manner to ensure a tight seal between the adjacent ends of the top flanges (26) of the longitudinal framing member (14 or 16), which are milled to bear against each other.
To accommodate variations in bridge span lengths, the bridge (10) may also include at least one transverse hub (24) and at least one non-standard length roadway panel (30) to offer a custom span length that deviates from the standard.
The preferred embodiment of the modular bridge (10) might comprise two beam packs (12) and a plurality of transverse hubs (24) and roadway panels (30) whereby the width of the bridge (10) would be established by the width of the standard roadway panels (30). However, a bridge (30) with a wider roadway surface (23) could be constructed by adding additional beam packs (12), providing adjacent transverse hubs (24) of either longer dimensions, or by joining adjacent transverse hubs with transverse hub splices (64) as shown in FIG. 23, and additional roadway panels (30) placed side by side to match the dimensions of the longer transverse hub (24) or joined transvers hubs (24).
One limitation of prefabricated, modular bridge systems is that the framing systems can only be constructed in a manner such that the longitudinal support members and corresponding roadway surfaces must be oriented perpendicular to the abutments and intermediate piers. In embodiments of the modular bridge (10) of the present invention, the bridge (10) can be constructed at any skewed angle to the abutments (18, 20) and intermediate piers (22) by simply setting the beam packs (12) parallel to each other but with adjacent beam packs (12) shifted longitudinally to align with the centerlines of the supports at the abutments (18, 20) and/or intermediate piers (22). The transverse hubs (24) and roadway deck panels (30) can still be set transversely and perpendicular to the longitudinal frame members (14, 16) of the beam packs (12). This feature allows for much greater flexibility in the applications of the modular bridge (10), particularly in applications for disaster relief where it may be necessary to rapidly install a bridge that must conform to existing foundation elements, i.e. abutments (18, 20) and intermediate piers (22).
For shorter lengths, a modular bridge (10) can be constructed using only two beam packs (12), each beam pack (12) comprising two pairs of longitudinal frame end members (14) connected by transverse diaphragms (46). It is generally necessary, when increasing the length of a bridge structure, to also increase the depth of the longitudinal frame members to satisfy deflection requirements. When the same depth of longitudinal frame members is used for large variations in span lengths, then the longitudinal frame members, when used on shorter spans, are not efficiently designed. The prefabricated modular bridge (10) disclosed herein avoids these inefficiencies and results in the ability to extend the span length by attaching external tension reinforcing (66) to increase the strength and stiffness of the bridge (10) while still utilizing the same longitudinal frame members (14, 16).
Referring to FIGS. 1B, 3, 5, and 24 to 28, the external tension reinforcing assembly comprises, in respect to each, longitudinal frame member (14, 16), a pair of high-strength tendons (66) anchored at the ends of the longitudinal frame end members (14) using external tension reinforcing anchor blocks (68) that are positioned in framed openings (70) for the anchor blocks (68). The framed openings (70) for the anchor blocks (68) comprise a framed opening web plate (72) that serves as an extension of the vertical web (42A) of the frame end member (14). The opening (70) in this framed opening web plate (72) is bounded on one side by an anchor block bearing plate (74) that bears on the termination of the vertical webs (40) and is also cut to tightly fit between the top flanges (26) and bottom flanges (38) of the longitudinal end frame members (14). Conventional bearing stiffeners (76) are positioned on the opposite side of the framed opening (70) for the anchor blocks (68) and serve as the bearing stiffeners that transfer the reactions of the beam packs (12) to the piers (22) and/or abutments (18, 20). The external tension reinforcing anchor also includes pairs of tension anchor longitudinal stiffeners (78) that bear against the anchor block bearing plate (74) to transmit the external tension reinforcing force into the webs (42A) of the longitudinal end frame members (40).
In the preferred embodiment of the modular bridge (10), the external tension reinforcing comprises high-strength steel strand tendons (80) anchored in a conventional multi-strand anchor plates as is well known in the art of post-tensioning systems. The high-strength steel strand tendons (80) are inserted into steel ducts (82) that are sequentially coupled together over the lengths of the assembled beam packs (12) and also serve as a tension member contributing to the overall external tension reinforcing.
The high strength steel strand tendon anchor plates (74) bear directly against the anchor blocks (68) positioned in the framed openings (70) with one tendon (66, 80) on either side of the vertical webs (14) of the longitudinal frame members (14, 16). The ends of the tendons (66, 80) generally follow an alignment that is parallel to and along the same angle as the sloped bottom flange (42) for the length of approximately two panels (30). The tendon profile is altered to be parallel to the horizontal portion of the bottom flanges (38) of the longitudinal frame members (16) using a deviation saddle (84) that is attached to the bottom flanges (38) of the longitudinal frame members (14, 16). The deviation saddle (84) comprises a bent section of the steel ducts (82) that is also threaded to accommodate coupling of the steel ducts (82) for continuity over the lengths of the tendons (80).
Referring to FIGS. 29, and 30, the external tension reinforcing is further supported at panel points using intermediate tension reinforcing hangers (86). The hanger (86) is an elongate member extending from an upper end to a lower end. The upper end defines bolt holes (89) for receiving bolts to secure the hanger to one of the stiffeners (44) of the longitudinal frame members (14, 16). The lower end defines a tendon aperture (91) for receiving the tendon (66 or 80).
For longer spans, it may be necessary to place the profile of the horizontal portions of the external tension reinforcing further from the bottom flanges (38) of the longitudinal frame members (14, 16). Referring to FIG. 28, this is accomplished using spacers (87) that can be positioned between the deviation saddle (84) and the bottom flanges (38) of the longitudinal frame members (14, 16). The spacer (87) is a series of stacked members, in the form of boxes in this embodiment, which are bolted together and allow for variable positions of the horizontal ducts (82). Adding or removing these boxes varies the height of the spacer (87), and thereby changes the position of the ducts (82). All the external tension reinforcing appurtenances, including: deviation saddles (84), tension reinforcing hangers (86) and spacers (87) are fabricated using the same bolt hole pattern as the tension flange bottom splice plates (52) such that the said splice plate (52) can be omitted if it conflicts with the location of a spacer (87) and the spacer (87) will serve as the tension flange bottom splice plate (52) in its stead.
The support of the external tension reinforcing at these discreet points effectively increases the depths of the beam packs (12) without increasing the depths of the longitudinal frame members (14, 16). This feature allows for spanning longer distances without having to raise the approach roadways or significantly reducing the hydraulic opening underneath the bridge (10) as it relates to accommodating increased stream flows from flooding events.
For deployment of the prefabricated modular bridge (10) in remote locations, it may be desirable to provide access ramps to get from the adjacent roadway surface on to the bridge roadway surface. Referring to FIGS. 31 and 32, the modular bridge system is designed to accommodate this feature using access ramp beams (88). These access ramp beams (88) are attached to the longitudinal end frame members (14, 16) with articulated access ramp beam hinges (90), which are attached to longitudinal end frame diaphragms (92) (see FIG. 1B) secured to the ends of the beam packs (12). The roadway surface (23) placed on the tops of the access ramp beams (88) comprise the same transverse hubs (24) and roadway deck panels (30) used for the preferred embodiment of the bridge (10), subsequently making these components interchangeable with the main components of bridge (10).
The roadway surface (23) can accommodate vehicular as well as passenger traffic. Referring to FIGS. 1B, 33, and 34, in the preferred embodiment of the modular bridge (10) the roadway surface is flanked by horizontal traffic railings (94) located on either side of the delineated lane(s). These railings (94) are supported by traffic railing posts (96) which are attached to the transverse hubs (24) with traffic railing anchor bolts (98) extending through the transverse hubs (24) and being secured to transverse railing anchor post plates (100) welded to the bottoms of the posts (96).
Further, in some embodiments, it will be necessary to provide a pedestrian walkway and fall protection separate from the vehicular lanes on the roadway surface. This pedestrian walkway comprises a portion of the transverse hub (24) and roadway deck panel (30) cantilevering out past one of the beam packs (12). On one side of the walkway, the pedestrian traffic is protected by the shared horizontal traffic railing (94). Referring to FIGS. 1B, 33, and 34, along the outside edge of the pedestrian walkway, fall protection is provided by a pedestrian railing (102). This pedestrian railing is supported by pedestrian railing posts (104) which are attached to the transverse hubs (24) with pedestrian railing anchor bolts (108) extending through the transverse hubs (24) and being secured to pedestrian railing anchor post plates (106) welded to the bottoms of the posts (104).
Assembly
An exemplary method of assembly may comprise the following methods. Various steps described may be optional or preferred in the circumstances.
1. Site Preparation
Assembly site should be on firm ground with a clear, flat area. It is recommended to use 8″×8″ or larger wood dunnage for the support of the beam components as they are assembled. Position the dunnage with consideration to the room required to install splice plates and hardware. Use a laser level to ensure dunnage is level within ¼″/30′. Shims may be required as assembly progresses to adjust for any settling.
2. Beam Sections
Inspect beam packs (12) (FIGS. 3, 4) in the area of their splice locations. The splice surfaces (FIGS. 20, 21) must be clean and only a light primer coat should be present on the surfaces. Position beam packs (12) end to end on dunnage with adequate room for assembly of splice plates at ends. Ensure the top flanges (26) (FIG. 20) are butted together and the beam pack (12) edges are flush and straight. Use a laser level to align beam packs (12) within 1″ of straight for each beam assembly. Loosely attach all splice plates with all bolts inserted. Draw each of the top flanges (12) together using the 2 horizontal alignment bolts of top flange splice rods (56) (FIGS. 20, 21). Bolts should be snug only and no gaps should be visible between top flanges (26). Check straightness of the beam pack (12) connection and snug all splice plate (50, 52, 54) bolts. There should be ¼″ of gap between beam packs (12) at adjoining webs (40) and bottom flanges (38). This gap must be maintained through all steps of assembly and will be present in the final product.
At this point in assembly all sections of the beam packs (12) will be aligned and all splice components in place with bolts having snug tension. All splice plate (50, 52, 54) nuts can now be manually tensioned to ⅓ turn past snug. Use reference gauge and ensure to back up opposite nut or bolt head to ensure accurate adjustment. Mark all bolt/nut connections with a paint pen as they are tensioned.
3. Diaphragms
Position two beam pack (12) assemblies in parallel on blocking with the correct spacing between flanges (26). Inspect all areas where the diaphragms (46) will be bolted. The mating surfaces must be clean and only a light primer coat should be present. Assemble all diaphragms (46) to the beams loosely with all bolts inserted (FIG. 18). Tension bolts to snug while checking that the beam pack (12) positions are maintained. Continue with assembly of adjacent beam packs (12) and diaphragms (46). The beam packs (12) now need to be checked for parallel, level, and squareness to each other. All diaphragm (46) bolts can now be tensioned to ⅓ turn past snug. Use reference gauge and ensure to back up opposite nut or bolt head to ensure accurate adjustment. Mark all bolt/nut connections with a paint pen as they are tensioned.
4. Duct and Strand Installation
Install duct hanger brackets (86) (FIGS. 29, 30) with fasteners loosely to web plates on each beam pack (12). Install deviation saddles (84) to bottom of beam flanges (38) and tension bolts. Thread one section of duct (82) tube into each side of the deviation saddles (84) (FIG. 28) resting the opposite end on the adjacent duct hanger bracket (86). Be certain that full thread engagement is archived by measuring thread standoff. Install remaining tube sections between deviation saddles (84) using the couplings and one split coupling that facilitates the final connection. Tension the split coupling bolts to snug only at this time. Continue assembly of the duct (82) tubes from the deviation saddles (84) to each end of the span.
Insert the duct anchor blocks (68) (FIG. 25) into their square receiving opening (70) at the end of each beam (FIG. 26) prior to threading on the last outboard duct section. Install anchor block (68) nuts (FIG. 27) loosely onto each duct tube protruding from the anchor blocks (68). At this point the center split coupling should be tightened and all threaded couplings inspected for engagement. Tension the anchor block (68) nuts to snug ensuring that the anchor block (68) remains square and flat to the receiver openings (70). Anchor blocks (68) and nuts should now be inspected at both ends of the span, making certain that they are aligned and equally snug.
Lay out all strands (80) for each duct (82) at one end of beam packs (12). Both ends of the strands (80) should be bound to prevent fraying. Install strands (80) into each duct (82) by pulling through with a fishtape or rod. Install wedge anchors onto each strand (80) (FIG. 27) at one end of span. Pull the strands (80) taught at opposite end of span using an accepted post tensioning system and correct tension value from specification sheet. Install dust caps and seals on all ducts (82).
5. Hubs and Deck Panels
Loosely position the first hub (24) (FIGS. 9A and 9B) closest to the center of the span. Square the hub base to the beam packs (12) and measure its position to the longitudinal end face of both beam pack (12) assemblies. Slide the hub attachment clamps (28) transversely into position, fully engaging the top flange (26) (FIG. 11) of all beam packs (12). Tension the first outboard clamp bolts (27) (FIG. 12) to snug and recheck squareness of the beam pack (12) and hub (24). Engage the opposite outboard clamp and snug the clamp bolts (27). All subsequent hub attachment clamps (28) can now be engaged with the top flanges (26) by sliding the hub attachment clamps (28) transversely toward the centerline of longitudinal frame members (14, 16). The clamp bolts (27) are snugged. Starting at one end of the transverse hub (24), tension all clamp bolts (27) to ⅓ turn past snug. At both ends of the span of the longitudinal frame members (14, 16), position a transverse hub (24) and secure it to the beam packs (12) ensuring the beam packs (12) remain straight and square. This will help maintain squareness as the hub (24) and deck panel (30) assembly progresses. Remove the hub cover plate (34) (FIG. 9) and bolts. Place the next hub (24) in position loosely with approx. 1″ of extra space between the faces of the hubs (24) where the deck panel (30) will rest. Install the belt cushion strips on top of the 4 beam pack flanges (26) (FIG. 10) where the first panel (30) will be positioned. Apply a single ¼″ bead of silicone adhesive under each cushion strip. Set a deck panel (30) in place between the two hubs (24). Push the panel (30) firmly against the stationary, clamped hub (24) and draw the loose hub (24) up to the panel's (30) opposite edge. Check the loose hub's (24) position, straightness, and square with the beam packs (12) and clamp securely to all beam pack top flanges (26) by tensioning the clamp bolts (27) ⅓ turn past snug. Install the next adjacent hubs (24) and panels (30) in the same fashion, progressing from center to outboard ends.
At this point in the assembly, all hubs (24) should be secured to the beams with clamp bolts (27) tensioned. All panels (30) must be in place and flush with outboard edges of hubs (24).
Install all hub cover plates (34) and bolts loosely. Starting from the center of span hub (24), tension the cover plate (34) bolts to snug and work progressively from the center of span to ends, snug the remaining cover plates (34). Inspect position of all panels to hubs (24) and confirm panels (30) are resting on the belt cushion strips. Tension all hub cover plate (34) bolts to ⅛ turn past snug working from the middle of the hub (24) to outboard edges.
6. Barrier Posts and Rails
Install all barrier traffic railing posts (96) on top hub cover plates (34) loosely with studs and double nuts on top and bottom (FIG. 9B). Rail (94) tube sections and rail tube couplings can be bolted to posts (96) (FIGS. 1B, 6). The couplings must be staggered over the length of the span so no two adjacent couplings are in the same section between posts. Tighten all barrier couplings and then post (60) bases to hubs. All handrail posts (104) can be attached to the hubs using studs and double nuts on top and bottom of connection. Tighten all posts (96, 104) to hubs (24). Bind both ends of the two walkway steel cable rails (102) and pass cables through corresponding openings in each handrail post (104). Assemble cable anchors to each end and clamp in position making certain that there is no slack.
PARTS LIST
- Prefabricated modular bridge system 10
- Beam packs 12
- Beam pack end 13
- Longitudinal frame end member 14
- Longitudinal frame center member 16
- Abutments 18, 20
- Intermediate piers 22
- Roadway surface 23
- Transverse hub 24
- Transverse hub slot 25
- Top flanges 26
- Hub attachment clamp bolts 27
- Hub attachment clamps 28
- Skewed angle 29
- Roadway deck panel 30 Hub attachment clamp nut 31
- Hub bottom flange plate 32
- Hub ledge 33
- Hub top flange cover plate 34
- Hub webs 36
- Bottom flange 38
- Vertical web 40
- Sloped bottom flange 42
- Tapered vertical web 42A
- Transverse stiffeners 44
- Transverse diaphragms 46
- Tension flange top splice plates 50
- Tension flange bottom splice plate 52
- Web splice plates 54
- Top flange tension splice rods 56
- Top flange splice weldment 58
- Top flange splice weldment bearing plate 60
- Bearing support aperture 61
- Top flange splice weldment stiffener plate 62
- Nut 63
- Transverse hub splice plate 64 (wider roadway)
- External tension reinforcing 66
- External tension reinforcing anchor block 68
- Framed opening for anchor blocks 70
- Framed opening web plate 72
- Anchor beam bearing plate 74
- Bearing stiffener 76
- Tension anchor longitudinal stiffeners 78
- High strength steel strand tendons 80 (lock nut) not for preloading
- Steel ducts 82
- Deviation saddle 84
- Intermediate tension reinforcing hanger 86
- Spacers 87 (stacked between saddle and beam) offset elevation of saddle 84
- Access ramp beam 88
- Intermediate tension reinforcing hanger bolt holes 89
- Access ramp beam hinge 90
- Intermediate tension reinforcing tendon aperture 91
- Longitudinal frame end diaphragms 92
- Horizontal traffic railing 94
- Traffic railing post 96
- Traffic railing anchor bolts 98
- Traffic railing post anchor plate 100
- Pedestrian railing 102
- Pedestrian railing post 104
- Pedestrian railing post anchor plate 106
- Pedestrian railing anchor bolts 108
Exemplary Aspects
In view of the described devices, systems, and methods and variations thereof, certain more particularly described aspects of the invention are presented below. These particularly recited aspects should not however be interpreted to have any limiting effect on any different claims containing different or more general teachings described herein, or that the “particular” aspects are somehow limited in some way other than the inherent meanings of the language literally used therein.
Aspect 1. A modular bridge system having: a longitudinal support frame supported by foundation elements such as abutments or piers, a roadway surface comprising a plurality of transverse hubs and roadway deck panels on said longitudinal support frame members, said longitudinal frame members, transverse hubs and roadway deck panels being such that these standard components can be arranged to construct bridges of various lengths, widths and skew angles relative to the orientation of foundation elements.
Aspect 2. A modular bridge system having: a longitudinal support frame supported by foundation elements such as abutment or piers, a roadway surface comprising a plurality of transverse hubs, roadway deck panels and external tension reinforcing comprising framed openings in the longitudinal frame end members that receive anchor beams for securing longitudinal tendons that are further supported by deviation saddles and intermediate tension reinforcing hangers that effectively allow for an increase in the longitudinal span of the bridge using the standard longitudinal framing members.
Interpretation.
The corresponding structures, materials, acts, and equivalents of all means or steps plus function elements in the claims appended to this specification are intended to include any structure, material, or act for performing the function in combination with other claimed elements as specifically claimed.
References in the specification to “one embodiment”, “an embodiment”, etc., indicate that the embodiment described may include a particular aspect, feature, structure, or characteristic, but not every embodiment necessarily includes that aspect, feature, structure, or characteristic. Moreover, such phrases may, but do not necessarily, refer to the same embodiment referred to in other portions of the specification. Further, when a particular aspect, feature, structure, or characteristic is described in connection with an embodiment, it is within the knowledge of one skilled in the art to affect or connect such module, aspect, feature, structure, or characteristic with other embodiments, whether or not explicitly described. In other words, any module, element or feature may be combined with any other element or feature in different embodiments, unless there is an obvious or inherent incompatibility, or it is specifically excluded.
It is further noted that the claims may be drafted to exclude any optional element. As such, this statement is intended to serve as antecedent basis for the use of exclusive terminology, such as “solely,” “only,” and the like, in connection with the recitation of claim elements or use of a “negative” limitation. The terms “preferably,” “preferred,” “prefer,” “optionally,” “may,” and similar terms are used to indicate that an item, condition or step being referred to is an optional (not required) feature of the invention.
The singular forms “a,” “an,” and “the” include the plural reference unless the context clearly dictates otherwise. The term “and/or” means any one of the items, any combination of the items, or all of the items with which this term is associated. The phrase “one or more” is readily understood by one of skill in the art, particularly when read in context of its usage.
As will also be understood by one skilled in the art, all language such as “up to”, “at least”, “greater than”, “less than”, “more than”, “or more”, and the like, include the number recited and such terms refer to ranges that can be subsequently broken down into sub-ranges as discussed above. In the same manner, all ratios recited herein also include all sub-ratios falling within the broader ratio.
Patent Application
20240218616
