Patent Publication Number: US-10309068-B2

Title: Prefabricated bridge including steel abutments

Description:
TECHNICAL FIELD 
     This application relates generally to supported bridges that include abutments, as well as methods of constructing supported bridges including a prefabricated bridge and abutments. 
     BACKGROUND 
     Prefabricated bridges are generally associated with reduced installation times, reduced overall costs, and reduced construction times. In many cases, during the construction of prefabricated bridges, the foundation and substructure construction are the most costly and time consuming part. For example, concrete abutments are commonly used to support the ends of prefabricated bridges, and such concrete abutments require sufficient cure time if poured on-site or involve shipping difficulties if precast. 
     Accordingly, it would be desirable to provide a prefabricated bridge that utilizes a more suitable abutment arrangement. 
     SUMMARY 
     In one aspect, provided in this disclosure is a supported bridge. The supported bridge includes a prefabricated bridge including a deck and a plurality girders extending in a spanwise direction along the supported bridge. The deck is supported above the plurality of girders. The supported bridge further includes first and second steel abutments extending underneath the plurality of girders in a direction transverse to the spanwise direction. The first steel abutment is located toward a first end of the prefabricated bridge and the second steel abutment is located toward a second end of the prefabricated bridge. Each abutment includes an I-beam and a bottom plate. The I-beam includes an upper flange, a lower flange, and a web connecting the upper flange and lower flange. The bottom plate is mounted on a bottom surface of the lower flange and has a width that is at least 1.5 times as great as a width of the lower flange. 
     In some aspects, the girders are I-beam girders. Each I-beam girder has an upper flange, a lower flange, and an interconnecting web. The upper flange of each I-beam girder can support the bridge deck and the bottom flange of each I-beam girder can be supported by the first and second steel abutments. 
     In certain aspects, in each steel abutment, the bottom plate has a length that is substantially the same as, or greater than, a length of the I-beam. 
     The abutment can further include a plurality of stiffeners spaced apart along the length of the I-beam, with each stiffener interconnecting the upper flange of the I-beam to the bottom plate. In each steel abutment, the stiffeners can include at least first and second stiffeners at opposite ends of the steel abutments. Further, in each steel abutment, the plurality of stiffeners can include one or more intermediate stiffeners at intermediate points along the length of the I-beam. In certain aspects, each steel abutment includes at least one intermediate stiffener aligned with each girder. In certain aspects, each of the at least one intermediate stiffeners is vertically beneath a connection zone between the girder and the steel abutment. 
     In some aspects the girders are I-beam girders, and each of the at least one intermediate stiffeners is of substantially planar plate configuration that is aligned with a plane defined by a web of the girder. 
     In some aspects, each of the first and second steel abutments further includes a keel extending lengthwise along a bottom surface of the bottom plate. 
     In certain aspects, one or more mount plates are placed between the girders and the upper flanges of the I-beams. 
     As to each girder, a first end of the girder can be mounted to the first steel abutment by a first connection arrangement and a second end of the girder can be mounted to the second steel abutment by a second connection arrangement. The first connection arrangement can include a first upper mount plate connected to an underside of the girder, a first lower mount plate connected to the upper flange of the first steel abutment, and a plurality of bolts passing through aligned holes of the first upper mount plate and the second lower mount plate. The second connection arrangement can include a second upper mount plate connected to the underside of the girder, a second lower mount plate connected to the upper flange of the second steel abutment, and a plurality of bolts passing through aligned holes of the second upper mount plate and the second lower mount plate. In certain aspects, as to each girder, the first upper mount plate can be welded to the girder and the first lower mount plate can be welded to the upper flange of the first steel abutment. Further, the second upper mount plate can be welded to the girder and the second lower mount plate can be welded to the upper flange of the second steel abutment. 
     In another aspect, provided herein is a supported bridge that includes a prefabricated bridge including a deck supported by a plurality of steel girders extending in a spanwise direction along the supported bridge, wherein the deck is supported above the plurality of girders. First and second steel abutments extend underneath the plurality of girders in a direction transverse to the spanwise direction, wherein the first steel abutment is located toward a first end of the prefabricated bridge and the second steel abutment is located toward a second end of the prefabricated bridge. Each abutment includes a beam and a bottom plate, the beam including an upper flange, a lower flange, and a web connecting the upper flange and lower flange, wherein the bottom plate is mounted at a bottom surface of the lower flange and has a width that is at least 1.5 times as great as a width of the lower flange. The first steel abutment includes a stiffener toward each end and one or more intermediate stiffeners located at intermediate points along the length of the first steel abutment, wherein at least one intermediate stiffener is vertically beneath a connection zone between one girder and the first steel abutment. The second steel abutment includes a stiffener toward each end and one or more intermediate stiffeners located at intermediate points along the length of the second steel abutment, wherein at least one intermediate stiffener is vertically beneath a connection zone between one girder and the second steel abutment. In yet another aspect, provided herein is a steel abutment. The steel abutment includes a beam including an upper flange, a lower flange, and a web connecting the upper flange, and lower flange. A bottom plate is mounted on a bottom surface of the lower flange and has a width that is at least 1.5 times as great as a width of the lower flange. A plurality of stiffeners are located along a length of the beam, each stiffener arranged transverse to the length of the beam and interconnecting the upper flange and the bottom plate. A keel extends lengthwise along a bottom surface of the bottom plate. 
     In yet another aspect, provided in herein is a method of constructing a supported bridge. The method includes providing a prefabricated bridge including a deck and a plurality of girders extending in a spanwise direction along the prefabricated bridge, wherein the deck is supported above the plurality of girders; providing first and second steel abutments, each abutment including a beam and a bottom plate, the beam including an upper flange, a lower flange, and a web connecting the upper flange and lower flange, wherein the bottom plate is at a bottom surface of the lower flange and has a width that is at least 1.5 times as great as a width of the lower flange; placing the first steel abutment on a first side of an obstruction and the second steel abutment on a second side of the obstruction; placing the prefabricated bridge on the first and second steel abutments such that the first and second steel abutments extend underneath the plurality of girders in a direction transverse to the spanwise direction; and securing the prefabricated bridge to the first and second steel abutments. 
     In some aspects, each of the first and second steel of abutments further includes a plurality of stiffeners, with each stiffener interconnecting the upper flange of the beam to the bottom plate. The stiffeners are spaced apart along a length of the beam, wherein the plurality of stiffeners includes one or more stiffeners at intermediate points along the length of the beam. Accordingly, the method can further include placing the prefabricated bridge on the first and second steel abutments by aligning the girders of the prefabricated bridge with the intermediate stiffeners of the first and second steel abutments and then mounting the prefabricated bridge on the first and second steel abutments. 
     The details of one or more embodiments are set forth in the accompanying drawings and the description below. Other features, objects, and advantages will be apparent from the description and drawings, and from the claims. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a perspective view of one embodiment of a supported bridge; 
         FIG. 2  is an side view of one embodiment of a supported bridge; 
         FIG. 3  is a end view of one embodiment of a supported bridge; and 
         FIG. 4  is a perspective view of one embodiment of a steel abutment. 
     
    
    
     DETAILED DESCRIPTION 
     Referring to  FIGS. 1-3 , an exemplary supported bridge  1  is shown. The supported bridge  1  includes a bridge  10  and first and second steel abutments  20 . The first and second steel abutments  20  can serve as a supporting foundation for the bridge  10 . The steel abutments  20  extend in a direction transverse to the spanwise direction of bridge  10 . Further, as shown in  FIG. 1 , the first and second steel abutments  20  are located at the two opposite ends of bridge  10 ; however, other configurations are possible. For example, the steel abutments can be located near the two opposite ends of bridge  10  but not at the ends of the bridge. 
     Referring to  FIGS. 1-3 , the bridge includes a deck  11 . The bridge also includes a plurality of girders  12 , which can be I-beams, as illustrated in  FIGS. 1-3 . The girders can extend in a spanwise direction along the supported bridge, as shown in  FIG. 1 . Further, the girders can be steel (e.g., galvanized steel). The deck  11  can be placed directly on, and secured to, the girders  12 , as illustrated in  FIGS. 1-3 . 
     The girders  12  are designed to be mounted on top of, and be secured to, the first and second steel abutments  20 . The steel abutments  20  include I-beam  21 . I-beam  21  includes upper flange  22 , bottom flange  28 , and web  29  connecting the upper flange and lower flange, as illustrated in  FIGS. 2-4 . Further, the I-beam can be steel (e.g., galvanized steel). 
     The girders  12  can be mounted on top of the upper flange  22  of the steel I-beams  21 , as illustrated in  FIGS. 2-3 . One or more mounting plates (e.g., shims or bearing pads) can be placed between the upper flange  22  of the I-beam and the girders  12 , as shown in  FIGS. 2-3 , which depicts two mounting plates,  23  and  24 , between the upper flange  22  and girder  12 . The girders can be mounted on the one or more mounting plates and are secured thereon, for example, by welding. The one or more mounting plates can have matching fastener holes with the upper flange, allowing the girders to be securely held in place by bolting the one or more mounting plates with bolts to the upper flange of the I-beam. For example, as illustrated in  FIG. 2 , two mounting plates, lower mounting plate  23  and upper mounting plate  24 , and upper flange  22 , have matching fastener holes  25 , allowing girder  12  to be securely held in place by bolting the two mounting plates with bolts  26  to the upper flange  22  of I-beam  21  and girder  12 . The fastener holes  25  of I-beam  21  are also depicted in  FIG. 4 . Lower mounting plate  23  can also be welded to the upper flange  22  of I-beam  21 . The upper mounting plate  24  can be welded to girder  12 . Furthermore, the one or more mounting plates can have a width that is equal to the width of the top surface of the upper flange of the I-beam of the abutment and a length that is equal to or greater than the width of the girder. 
     Referring again to  FIGS. 1-4 , steel abutments  20  also include a bottom plate  27  that is mounted on the bottom surface of bottom flange  28 . The bottom plate can be steel (e.g., galvanized steel). The longitudinal axis of bottom plate  27  is directly below the web  29  of I-beam  21  and the bottom plate is secured to the bottom surface of the bottom flange  28 . For example, bottom plate  27  can be centered on bottom flange  28  and welded to the bottom surface of the bottom flange. The length of the bottom plate can equal the length of the I-beam, as illustrated in  FIG. 3-4 , or the bottom plate can be longer or shorter in length than the I-beam. Bottom plate  27  can have a width that is greater than the width of the bottom flange  28 , as illustrated in  FIGS. 2 and 4 . In some aspects, the ratio of the width of the bottom plate to the width of the bottom flange can be between about 1.5:1 to about 5:1 or between about 2:1 to about 4:1. In some aspects, the ratio of the width of the bottom plate to the width of the bottom flange is about 3:1. In certain aspects, the ratio of the width of the bottom plate to the width of the bottom flange is about 1.5:1. 
       FIGS. 1 and 3-4  show internal transverse stiffeners  30  and end transverse stiffeners  31   a  and  31   b . The stiffeners can function to prevent the I-beam from bending relative to the bottom plate and also can prevent the web of the I-beam from yielding, crippling and/or buckling. The stiffeners can be steel (e.g., galvanized steel). As can be seen in  FIG. 3 , the internal transvers stiffeners  30  can be spaced-apart and can be positioned below the girders  12  of the bridge such that the intermediate stiffeners are vertically aligned with girders. Further, the intermediate stiffeners can be vertically beneath a connection zone between the girder and the steel abutment, where the connection zone includes the area defined by lower mounting plate  23 , upper mounting plate  24 , and the corresponding girder  12  that upper mounting plate  24  is secured to. The end stiffeners  31   a  and  31   b  are positioned at, or near, opposite ends of I-beam  21  and the end stiffeners are aligned vertically with the intermediate stiffeners  30  and are perpendicular to the top surface of the bottom plate  27 . 
     As can be seen in  FIGS. 1, 2, and 4 , corresponding stiffeners  31   a  and  31   b  are placed on opposite sides of I-beam  21 . Each stiffener  31   a  and  31   b  has an inner side edge having a surface that is in continuous contact with the surface of web  29 , an upper side edge having a surface that is in continuous contact with the bottom surface of upper flange  22 , and can have a bottom side edge having a surface that is in continuous contact with the top surface of bottom flange  28 . Although not shown in  FIGS. 2-4 , intermediate stiffeners are placed on corresponding sides of the abutment I-beam, in a similar fashion as the end stiffeners. Further, the stiffeners (e.g. stiffeners  30 ,  31   a , and  31   b ) can be welded (e.g. corner welded) to I-beam  21 . 
     Referring again to  FIGS. 2-3 , each abutment  20  further includes a keel  34 . The keel can serve to provide longitudinal stability. For example, the keel can prevent sliding. Keel  34  is secured to the bottom surface of bottom plate  27  and the keel extends longitudinally along the bottom plate. The keel can be steel (e.g., galvanized steel). As shown in  FIG. 3 , keel  34  is located directly below the web  29  of I-beam  21  and has a length that is equal to the length of the bottom plate; however, the keel can also have a length that is greater than or shorter than the length of the bottom plate. Further, keel  34  is secured to bottom plate  27 , for example, by welding. Furthermore, the keel can be rectangular, as shown in  FIG. 2 . The width of the keel can vary, but in embodiments the keel has a width that is less than 1/10 the width of the bottom plate (e.g., less than 1/15 the width of the bottom plate). 
     As can be seen in  FIG. 2 , the supported bridge can also include closure angles  32 . The closure angles can provide stability for the decking edge closure  33 . The closure angles can also prevent the flange of I-beam  21  from damaging decking edge closure  33 . As shown in  FIG. 2 , the decking edge closure can have a height that is greater than the height of girder  12 . The decking end closure can also have a width equal to that of the deck and can be secured to the deck. The decking closure  33  in  FIG. 1  covers half of a spanwise end of bridge  1 ; however, it is to be understood that the decking end closure can cover the entire spanwise end of bridge  1 . Additionally, decking end closures can be placed on both spanwise ends of bridge  1 . The decking closures can prevent debris, such as dirt and rocks, from entering into the space below bridge  1 . 
     It is to be clearly understood that the above description is intended by way of illustration and example only, is not intended to be taken by way of limitation, and that other changes and modifications are possible. For example, in some implementations multiple stiffeners can be placed at the same intermediate point on the abutment. In such implementations, the stiffeners can be placed flush against each other. For example, in some implementations, three stiffeners can be place at the same intermediate point directly under a girder. In some implementations, the supported bridge includes more than two abutments, such as three, four, or six transverse abutments. In some implementations, all components of the transverse steel abutments are steel (e.g., galvanized steel). In some implementations, the I-beam, bottom plate, stiffeners, and keel of the transverse abutments are steel (e.g. galvanized steel). In other implementations the beam of the steel abutments could be of a different shape than I-beam, such as a C-channel beam with upper and lower flanges extending to only one side the web that interconnects the upper and lower flanges.