CA1290512C - Lightweight bridge structure - Google Patents
Lightweight bridge structureInfo
- Publication number
- CA1290512C CA1290512C CA000544919A CA544919A CA1290512C CA 1290512 C CA1290512 C CA 1290512C CA 000544919 A CA000544919 A CA 000544919A CA 544919 A CA544919 A CA 544919A CA 1290512 C CA1290512 C CA 1290512C
- Authority
- CA
- Canada
- Prior art keywords
- plate
- bridge
- corrugated plate
- corrugated
- corrugations
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired - Lifetime
Links
Abstract
Abstract of the Disclosure A slab-type short span bridge constructed of at least one corrugated plate having para-llel, longitudinally extending corrugations of a generally trapezoidal cross-section. A
layer of concrete which defines the traffic carrying surface of the bridge and a gen-erally flat plate are secured to the corru-gated plate. The flat plate can be inter-posed between the concrete layer and the corrugated plate, or it may be spaced from the concrete layer by the corrugated plate.
The flat plate can simultaneously define por-tions of the corrugated plate. Means is provided for rigidly interconnecting all members of the bridge into a unitary, load carrying structure.
layer of concrete which defines the traffic carrying surface of the bridge and a gen-erally flat plate are secured to the corru-gated plate. The flat plate can be inter-posed between the concrete layer and the corrugated plate, or it may be spaced from the concrete layer by the corrugated plate.
The flat plate can simultaneously define por-tions of the corrugated plate. Means is provided for rigidly interconnecting all members of the bridge into a unitary, load carrying structure.
Description
~O~ilZ
~ L I GHTWE I GHT BR I DGE STRUCTURE
~ L I GHTWE I GHT BR I DGE STRUCTURE
2 Ba~kqround of the Invention 3 At the present, there are in the U.S. alone about 4 105,000 inadequate bridges. A majority of them are functionally obsolete while a lesser number of them are structurally de-6 ficient. The latter are defined as bridges which had to be 7 restricted to light vehicles only or closed,-while the former are 8 identified as bridges which can no longer safely service the 9 system of which they are an integral part. The replacement cost I0 for these bridges is in the tens of billions of dollars. A
II majority of these bridges are intermediate and short span bridges 12 having a length of less than 100 feet. A large part and perhaps 13 again a majority of these bridges have lengths of less than about 14 50 to 60 feet ~hereinafter referred to as "short span bridges").
Applicants Xave recently invented bridge systems which I~ are ideally suited for building bridges of intermediate and long 17 span lengths at relatively low production and erection costs.
18 These systems are expected to greatly facilitate the replacement I9 of such bridges. Although these systems can also be employed for the construction and erection of short span bridges, some of the 21 cost savings experienced with such bridges are reduced or lost 22 when the bridge span becomes too short, primarily because these 23 longer span bridge systems invented by applicants have a strength 24 and rigidity which exceeds that needed for shorter spans.
Generally speaking, prior art short span bridges forego 26 weight savings experienced by fabricating a variety of plates and 28 extrusions into a steel framework and they instead employ as the 1~905~2 1 main load carrying members a plurality of girders made of steel 2 profiles such as channels, I-beams, wide flange beams and the 3 like which are suspended between bridge support points, normally 4 bridge abutments. The girders are suitably tied together to give 5l the bridge lateral rigidity and a bridge deck is placed on top of 6~ the girders. The deck may take a variety of forms and may com-71 prise, for example, wood planking placed tranversely to the 8¦ length of the bridge and suitably secured, e.g. bolted to the 9¦ girders, steel deck plates and/or a concrete slab which defines 10¦ the traffic carrying surface of the bridge.
11 Although such structures are structurally adequate for 12¦ the intended purpose, they have a large relatively high dead-13 weight. To a large extent this is a result of a structurally 14 relatively inefficient use of the materials in the girders, especially when formeq of extruded profiles. Further this is a 16 result of the fact that such bridges typically use only a few, 17 e.g., 2 or 4 relatively widely spaced apart girders. The dis-18 tance between the girders must be spanned by the bridge deck and 19 the bridge deck must be sufficiently strong to support loads applied to it between adjacent girders. Yet, such relatively 21 heavy decks do not materially strengthen the bridge in a longi-22 tudinal direction and must therefore be considered as dead weight 23 which correspondingly increases the strength requirements placed 24 on the girders.
Thus, high material costs, accentuated by the rela-26 tively large weight of such bridges together with the high cost 27 of erecting them render short span bridges constructed in accord-28 ance with the prior art relatively expensive. This cost, in lz~o~
1 turn, limits the rate with which the large number of obsolete 2 bridges can be replaced. Accordingly, there is presently a need 3 for short span bridges which are of a lightweight to minimize 4 material consumption and which can be manufactured and erected at a low cost so as to minimize the cost of short span bridges.
6 Summary of the Invention 7 The present invention is specifically directed to short 8 ¦ span bridges which are relatively lightweight, yet strong and 9 which can be manufactured and erected at relatively low cost.
10 ¦ The bridge of the present invention achieves this by combining 11 all elements of the bridge into a substantially homogenous, load 121 carrying structure, e.g. a structure which exhibits a substan-13¦ tially uniform strength over its entire cross-section at any 14 ¦ point along its length. The main load carrying member of that 15 ¦ structure is at least one corrugated plate, the corrugations of 16 ¦ which are longitudinally oriented and extend between abutments or 17 ¦ like supports for the bridge.
18 ¦ The use of corrugated plate as the maln load bearing 19 ¦ member is of great importance to the present invention. Corru-20 ¦ gated plate, as such, of course, has in the past been used for a 21 ¦ variety of applications. However, normally it is only used as a 22 ¦ secondary structural member for what may be termed light forms of 23 construction such as building floors or building roofs, for 24 example, or the above-discussed bridge decking. In such in-stances, the corrugated plate is supported by and/or secured to 26 an underlying, corrugated plate supporting framework of girder, 28 trusses, beams and the like.
17~9(~
1 Difficulties are encountered with corrugated plate when 2 it does not form part of a supporting framework of girders, posts 3 and the like and in particular when the corrugated plate is 4 subjected to large loads such as are encountered, for example, on 5l bridges. First of all, the large bridge loads require corrugated 61 plates which have dimensions much larger than those heretofore 7I encountered and utilized. For a typical short span bridge con-8 ¦ structed in accordance with the present invention, the corruga-9¦ tions may, for example, have a corrugation pitch of between 24 to 10¦ 36 inches, a corrugation depth of between 8 to 12 inches, and a 11¦ corrugated plate thickness of 3/16th inch.
121 Secondly, when such a plate is subjected to large point 13 ¦ loads, say from the wheels of a heavy truck, the relative lateral 14 I weakness of corrugated plate becomes a limiting factor for the 15 ¦ plate. In fact, such plate cannot provide for any significant 16 ¦ lateral distribution of point loads. Thus, only a fraction of 17 I the width of the corrugated plate, namely the corrugation under-18 ¦ lying the point load, actually supports the loads. When the 1g ¦ narrow width of the corrugated plate is overstressed the corruga-20 ¦ tion(s) underlying the load spread apart, in other words they 21 I effectively collapse. To overcome this by providing supporting 22 ¦ girders defeats the objective of reducing the overall weight and 23 ¦ complexity of such bridges.
24 ¦ In accordance with the present invention, the relative lateral weakness of corrugated plate subjected to large loads 26 and, in particular, of corrugated plate having relatively large 27 corrugations as above discussed, is overcome by applying to the 28 corrugated plate means which is rigidly secured to one or the 1~905~
1 other side of the corrugated plate, but preferably it is secured 2 to the upwardly facing side of the bridge and which extends over 3 substantially the full effective width thereof. The plate means 4 has an extent which substantially equals the length and width of 51 the corrugated plate and it (a~ distributes point loads in a 6 lateral direction over a plurality of side-by-side corrugations 7 ¦and (b) forms a member which spans open corrugation troughs and, 81 so to speak, ties adjacent corrugations together. In other 9¦ words, the plate means acts as a tie plate or member for adjacent 10¦ corrugations which prevents their spreading by being stressed in 11¦ tension.
121 In its simplest form, the plate means comprises a flat 13¦ steel plate that has an effective width substantially equal to 14¦ that of the corrugated plate. It is placed on top of the cor- j 15 ¦rugated plate and secured thereto so that the two define a uni-16 ¦ tary structure akin to a slab. Provided the steel plate has the 17 ¦necessary thickness to effect a lateral distribution of point 18 ¦loads, it performs both of the above indicated functions and it 19 ¦may also form the traffic-carrying surface of the bridge. Since 20 ¦ the coefficient of friction of flat steel plate is normally too 21 ¦low for vehicular traffic, the upwardly facing surface of the 22 ¦steel plate may be roughened as by incorpsrating therein a raised 23 diamond pattern. Preferably, however, the flat steel plate is 24 maintained relatively thin so that by itself it would have in-sufficient rigidity to effect the lateral distribution of point 26 loads. In such a case, a layer of concrete is placed on top of 27 the flat steel plate and suitably anchored thereto so as to form 28 a unitary slab therewith.
30S~Z
1¦ The concrete layer may have a thickness of no more than 2 ¦ about 3 to 4 inches and it combines with the steel plate to effect the lateral distribution of point loads over a plurality 4' o~ corrugations. At the same time it defines the traffic-bearing surface of the bridge and gives it the relatively high coef-6¦ ficient of friction that is required for carrying vehicular 71 traffic.
81 By placing the flat steel plate on top of the corru-9¦ gated plate and pouring the concrete layer over the flat steel 10¦ plate, the upwardly opening troughs of the corrugated plate are 11¦ not filled with concrete when the concrete is poured, thereby 121 significantly reducing the amount of concrete that is placed on 131 top of the bridge and the deadweight of the bridge. This trans-14~ lates into corresponding cost-savings.
15¦ It is significant to note that by virtue of the combi-16¦ nation of a corrugated plate and of the plate means, the latter 17 ¦ normally comprising the above discussed flat tension plate and a 18 ¦ layer of concrete, it is possible to employ concrete layers in 19 ¦ the construction of bridges which have a thickness which is 2Q ¦ ordinarily considered totally insufficient for high load applica-21 ¦ tions, even in instances in which the concrete layer does not 22 ¦ form the primary load carrying member of the bridge but instead 23 ¦ is supported by spaced apart girders because in all such applica-24 ¦ tions, the concrete layer as such is subjected to a bending 25 ¦ moment. As a consequence, the lower portion of the concrete 26 layer is in tension where the concrete exhibits relatively little 28 strength. Thus, to attain the required strength prior art struc-~ l~ lZ
1 1 tures had to employ greater concrete layer thicknesses coupled 2 with steel reinforclng rods which is relatively expensive.
3 In contrast thereto, however, the present invention 4 structurally integrates the concrete layer with the flat tension plate and the corrugated plate and positions it so that the 6~ concrete layer forms the (relatively thin) top portion of the 71 resulting slab-like structure. Consequently, the concrete is 8 ! subjected to compression only, a mode in which it can be highly 9¦ stressed, while the corrugated plate is subjected to tension and 10¦ compression. The flat plate will be subjected to compression or 11¦ tension in a longitudinal direction while its function as the 12 above-discussed tie or tensioning member further subjects the 131 flat plate to tension in a lateral direction. In sum and sub-14¦ stance, therefore, the present invention combines all structural ~ ¦ members in such a manner that each can be stressed in its most 16 ¦ advantageous mode, thereby significantly reducing material re-17 ¦ quirements and making it possible to utilize the resulting struc-18 ¦ ture as the primary load bearing member which does not require 19 ¦ the heretofore necessary supporting beams, girders and the like.
A bridge constructed in accordance with the present invention is 21 ¦ therefore lighter than prior art bridges, it is simpler to 22 ¦ assemble and erect and it is relatively stronger than comparable 23 ¦ prior art structures. Consequently, the bridge of the present 24 ¦ invention offers significant cost savings in terms of its manu-25 ¦ facture and erection.
26 ¦ A bridge constructed in accordance with the present 27 invention therefore generally comprises as the sole load carrying 28 ¦ members of the bridge, at least one corrugated plate extending l~90Sl;~
1 over the full length and width of the plate and having longitu-2 dinally extending corrugations defined by alternating corrugation 3¦ peaks and corrugation troughs. Ends of the corrugated plate are 4 placed on suitable supports such as bridge abutments. Further, 5 ¦ the bridge includes the above discussed plate means and means for 6 ¦ rigidly interconnecting the corrugated plate and the plate means, 7 e.g. the layer of concrete and the flat plate, so as to define a 8 unitary bridge structure.
II majority of these bridges are intermediate and short span bridges 12 having a length of less than 100 feet. A large part and perhaps 13 again a majority of these bridges have lengths of less than about 14 50 to 60 feet ~hereinafter referred to as "short span bridges").
Applicants Xave recently invented bridge systems which I~ are ideally suited for building bridges of intermediate and long 17 span lengths at relatively low production and erection costs.
18 These systems are expected to greatly facilitate the replacement I9 of such bridges. Although these systems can also be employed for the construction and erection of short span bridges, some of the 21 cost savings experienced with such bridges are reduced or lost 22 when the bridge span becomes too short, primarily because these 23 longer span bridge systems invented by applicants have a strength 24 and rigidity which exceeds that needed for shorter spans.
Generally speaking, prior art short span bridges forego 26 weight savings experienced by fabricating a variety of plates and 28 extrusions into a steel framework and they instead employ as the 1~905~2 1 main load carrying members a plurality of girders made of steel 2 profiles such as channels, I-beams, wide flange beams and the 3 like which are suspended between bridge support points, normally 4 bridge abutments. The girders are suitably tied together to give 5l the bridge lateral rigidity and a bridge deck is placed on top of 6~ the girders. The deck may take a variety of forms and may com-71 prise, for example, wood planking placed tranversely to the 8¦ length of the bridge and suitably secured, e.g. bolted to the 9¦ girders, steel deck plates and/or a concrete slab which defines 10¦ the traffic carrying surface of the bridge.
11 Although such structures are structurally adequate for 12¦ the intended purpose, they have a large relatively high dead-13 weight. To a large extent this is a result of a structurally 14 relatively inefficient use of the materials in the girders, especially when formeq of extruded profiles. Further this is a 16 result of the fact that such bridges typically use only a few, 17 e.g., 2 or 4 relatively widely spaced apart girders. The dis-18 tance between the girders must be spanned by the bridge deck and 19 the bridge deck must be sufficiently strong to support loads applied to it between adjacent girders. Yet, such relatively 21 heavy decks do not materially strengthen the bridge in a longi-22 tudinal direction and must therefore be considered as dead weight 23 which correspondingly increases the strength requirements placed 24 on the girders.
Thus, high material costs, accentuated by the rela-26 tively large weight of such bridges together with the high cost 27 of erecting them render short span bridges constructed in accord-28 ance with the prior art relatively expensive. This cost, in lz~o~
1 turn, limits the rate with which the large number of obsolete 2 bridges can be replaced. Accordingly, there is presently a need 3 for short span bridges which are of a lightweight to minimize 4 material consumption and which can be manufactured and erected at a low cost so as to minimize the cost of short span bridges.
6 Summary of the Invention 7 The present invention is specifically directed to short 8 ¦ span bridges which are relatively lightweight, yet strong and 9 which can be manufactured and erected at relatively low cost.
10 ¦ The bridge of the present invention achieves this by combining 11 all elements of the bridge into a substantially homogenous, load 121 carrying structure, e.g. a structure which exhibits a substan-13¦ tially uniform strength over its entire cross-section at any 14 ¦ point along its length. The main load carrying member of that 15 ¦ structure is at least one corrugated plate, the corrugations of 16 ¦ which are longitudinally oriented and extend between abutments or 17 ¦ like supports for the bridge.
18 ¦ The use of corrugated plate as the maln load bearing 19 ¦ member is of great importance to the present invention. Corru-20 ¦ gated plate, as such, of course, has in the past been used for a 21 ¦ variety of applications. However, normally it is only used as a 22 ¦ secondary structural member for what may be termed light forms of 23 construction such as building floors or building roofs, for 24 example, or the above-discussed bridge decking. In such in-stances, the corrugated plate is supported by and/or secured to 26 an underlying, corrugated plate supporting framework of girder, 28 trusses, beams and the like.
17~9(~
1 Difficulties are encountered with corrugated plate when 2 it does not form part of a supporting framework of girders, posts 3 and the like and in particular when the corrugated plate is 4 subjected to large loads such as are encountered, for example, on 5l bridges. First of all, the large bridge loads require corrugated 61 plates which have dimensions much larger than those heretofore 7I encountered and utilized. For a typical short span bridge con-8 ¦ structed in accordance with the present invention, the corruga-9¦ tions may, for example, have a corrugation pitch of between 24 to 10¦ 36 inches, a corrugation depth of between 8 to 12 inches, and a 11¦ corrugated plate thickness of 3/16th inch.
121 Secondly, when such a plate is subjected to large point 13 ¦ loads, say from the wheels of a heavy truck, the relative lateral 14 I weakness of corrugated plate becomes a limiting factor for the 15 ¦ plate. In fact, such plate cannot provide for any significant 16 ¦ lateral distribution of point loads. Thus, only a fraction of 17 I the width of the corrugated plate, namely the corrugation under-18 ¦ lying the point load, actually supports the loads. When the 1g ¦ narrow width of the corrugated plate is overstressed the corruga-20 ¦ tion(s) underlying the load spread apart, in other words they 21 I effectively collapse. To overcome this by providing supporting 22 ¦ girders defeats the objective of reducing the overall weight and 23 ¦ complexity of such bridges.
24 ¦ In accordance with the present invention, the relative lateral weakness of corrugated plate subjected to large loads 26 and, in particular, of corrugated plate having relatively large 27 corrugations as above discussed, is overcome by applying to the 28 corrugated plate means which is rigidly secured to one or the 1~905~
1 other side of the corrugated plate, but preferably it is secured 2 to the upwardly facing side of the bridge and which extends over 3 substantially the full effective width thereof. The plate means 4 has an extent which substantially equals the length and width of 51 the corrugated plate and it (a~ distributes point loads in a 6 lateral direction over a plurality of side-by-side corrugations 7 ¦and (b) forms a member which spans open corrugation troughs and, 81 so to speak, ties adjacent corrugations together. In other 9¦ words, the plate means acts as a tie plate or member for adjacent 10¦ corrugations which prevents their spreading by being stressed in 11¦ tension.
121 In its simplest form, the plate means comprises a flat 13¦ steel plate that has an effective width substantially equal to 14¦ that of the corrugated plate. It is placed on top of the cor- j 15 ¦rugated plate and secured thereto so that the two define a uni-16 ¦ tary structure akin to a slab. Provided the steel plate has the 17 ¦necessary thickness to effect a lateral distribution of point 18 ¦loads, it performs both of the above indicated functions and it 19 ¦may also form the traffic-carrying surface of the bridge. Since 20 ¦ the coefficient of friction of flat steel plate is normally too 21 ¦low for vehicular traffic, the upwardly facing surface of the 22 ¦steel plate may be roughened as by incorpsrating therein a raised 23 diamond pattern. Preferably, however, the flat steel plate is 24 maintained relatively thin so that by itself it would have in-sufficient rigidity to effect the lateral distribution of point 26 loads. In such a case, a layer of concrete is placed on top of 27 the flat steel plate and suitably anchored thereto so as to form 28 a unitary slab therewith.
30S~Z
1¦ The concrete layer may have a thickness of no more than 2 ¦ about 3 to 4 inches and it combines with the steel plate to effect the lateral distribution of point loads over a plurality 4' o~ corrugations. At the same time it defines the traffic-bearing surface of the bridge and gives it the relatively high coef-6¦ ficient of friction that is required for carrying vehicular 71 traffic.
81 By placing the flat steel plate on top of the corru-9¦ gated plate and pouring the concrete layer over the flat steel 10¦ plate, the upwardly opening troughs of the corrugated plate are 11¦ not filled with concrete when the concrete is poured, thereby 121 significantly reducing the amount of concrete that is placed on 131 top of the bridge and the deadweight of the bridge. This trans-14~ lates into corresponding cost-savings.
15¦ It is significant to note that by virtue of the combi-16¦ nation of a corrugated plate and of the plate means, the latter 17 ¦ normally comprising the above discussed flat tension plate and a 18 ¦ layer of concrete, it is possible to employ concrete layers in 19 ¦ the construction of bridges which have a thickness which is 2Q ¦ ordinarily considered totally insufficient for high load applica-21 ¦ tions, even in instances in which the concrete layer does not 22 ¦ form the primary load carrying member of the bridge but instead 23 ¦ is supported by spaced apart girders because in all such applica-24 ¦ tions, the concrete layer as such is subjected to a bending 25 ¦ moment. As a consequence, the lower portion of the concrete 26 layer is in tension where the concrete exhibits relatively little 28 strength. Thus, to attain the required strength prior art struc-~ l~ lZ
1 1 tures had to employ greater concrete layer thicknesses coupled 2 with steel reinforclng rods which is relatively expensive.
3 In contrast thereto, however, the present invention 4 structurally integrates the concrete layer with the flat tension plate and the corrugated plate and positions it so that the 6~ concrete layer forms the (relatively thin) top portion of the 71 resulting slab-like structure. Consequently, the concrete is 8 ! subjected to compression only, a mode in which it can be highly 9¦ stressed, while the corrugated plate is subjected to tension and 10¦ compression. The flat plate will be subjected to compression or 11¦ tension in a longitudinal direction while its function as the 12 above-discussed tie or tensioning member further subjects the 131 flat plate to tension in a lateral direction. In sum and sub-14¦ stance, therefore, the present invention combines all structural ~ ¦ members in such a manner that each can be stressed in its most 16 ¦ advantageous mode, thereby significantly reducing material re-17 ¦ quirements and making it possible to utilize the resulting struc-18 ¦ ture as the primary load bearing member which does not require 19 ¦ the heretofore necessary supporting beams, girders and the like.
A bridge constructed in accordance with the present invention is 21 ¦ therefore lighter than prior art bridges, it is simpler to 22 ¦ assemble and erect and it is relatively stronger than comparable 23 ¦ prior art structures. Consequently, the bridge of the present 24 ¦ invention offers significant cost savings in terms of its manu-25 ¦ facture and erection.
26 ¦ A bridge constructed in accordance with the present 27 invention therefore generally comprises as the sole load carrying 28 ¦ members of the bridge, at least one corrugated plate extending l~90Sl;~
1 over the full length and width of the plate and having longitu-2 dinally extending corrugations defined by alternating corrugation 3¦ peaks and corrugation troughs. Ends of the corrugated plate are 4 placed on suitable supports such as bridge abutments. Further, 5 ¦ the bridge includes the above discussed plate means and means for 6 ¦ rigidly interconnecting the corrugated plate and the plate means, 7 e.g. the layer of concrete and the flat plate, so as to define a 8 unitary bridge structure.
9 The means for rigidly interconnecting the corrugated plate and the plate means preferably comprises welds, bolts, 11 rivets or the like for securing the flat plate to the corrugated 12 plate and in instances in which the plate means includes a layer 131 of concrete, means is further provided to form a mechanical ¦ interlock between the concrete layer and the flat plate to struc-15¦ turally intergrate all three. This makes it possible to stress 16 ¦ the concrete in its most advantageous mode, namely in compression 17 ¦ since it then forms the upper part of the homogenous beam or a 18 ¦ slab. Further, it enables one to employ the relatively large 19 ¦ moment of inertia of the concrete layer in the overall design of 20 ¦ the bridge instead of having it represent dead weight only. Of 21 ¦ course such an advantageous use of the concrete layer in compres-22 ¦ sion only is only possible if the underlying member is coexten-23 ¦ sive with the former and rigidly secured thereto; the use of 24 ¦ girders or spaced apart, longitudinally extending bridge members 25 ¦ as encountered in prior art structures would preclude such a 26 ¦ stressing of the concrete layer alone. The corrugated plate of 228 the present invention, which homogenously ~ 30~
¦ extends over the full width of the bridge, however, is ideally 21 suited for this construction.
3¦ One aspect of the present invention, provides that the 4l corrugated plate be constructed of a plurality of longitudinally 51 extending, parallel and upwardly opening channel members which 6l are arranged side-by-side. Each channel member includes a gen-7 erally horizontally disposed flange which protrudes laterally 8¦ from an upper end of the channel and which extends over the full 9¦ length thereof. The flange has a width which is greater than the 10¦ lateral spacing between adjoining channel members so that it 11¦ covers the upwardly opening portion of an adjoining channel member and overlaps the flange of such adjoining member. Means 13l such as welds, bolts, rivets, or the like rigidly secures the 14¦ overlapping portions of the flanges of the adjoining channel 15~ members to each other so that the channel members simultaneously 161 define a corrugated plate that extends over the full length and 17 ¦width of the bridge and the flat plate. The latter is defined by 18 ¦the lateral succession of the horizontally disposed, overlapping 19 ¦ and interconnected flanges.
20 ¦ The concrete layer poured on top of the resulting flat 21 ¦plate and means such as anchoring studs are secured, e.g. welded 221 to the flat plate, or a multiplicity of upwardly oriented protru-231 berances and depressions in the plate form a mechanical interlock 241 between the concrete layer and the remainder of the bridge, e g.
25 ¦ the flat plate and the corrugated plate.
26 ¦ According to another aspect of the present invention, 271 the strength of the bridge is increased, particularly for ~short 29 span bridges of greater length, e.g. having lengths of between 45 l 1~
1 to 60 feet by securing additional, lower corrugated plates to the 2 first mentioned, upper corrugated plate. The lower corrugated 3 ¦ plates may have the same length as the upper plate or they may be 4 shortened and centered relati~e to the length of the bridge so as 5¦ to give the bridge maximum strength at its center between its end 61 supports. Preferably, the lower corrugated plate is secured to 7 ¦ the upper corrugated plate so that the two define a plurality of 8 ¦ laterally spaced apart, longitudinally extending tubular members 9 ¦ to increase the strength and rigidity of the bridge while main-10 ¦ taining a relatively low overall weight. Further, the tubular 11 ¦ members may be utilized as protective conduits for cables, pipes ~ and the like while keeping them out of sight and thus increasing 13l the aesthetic overall appearance of the bridge. Ends of the 14¦ tubular member may be closed to prevent the accumulation of 15 ¦ moisture, debris, etc. therein.
16 ¦ For particular applications the flat plate may be 17 ¦ secured to the underside of the corrugated plate while the con-18 ¦ crete layer is poured directly onto the top of the corrugated 1~ ¦ plate and mechanically interlocked therewith. In such an in-20 ¦ stance the concrete layer alone effects the lateral distribution 21 ¦ of point loads over a plurality of corrugations while the (lower) 22 ¦ flat plate acts as the tie member for the corrugation. Addi-23 ¦ tional, lower corrugated plates are then secured to the upper 24 ¦ corrugated plate. This embodiment has the advantage that the 25 ¦ bridge has a relatively greater moment of inertia due to the 26 ¦ greater amount of concrete that is utilized since in such an 27 instance the concrete will fill the upwardly opening corrugations 228 I f the corrugated plate. In all other respects, however, this 31 ~
32 ~ A !
~ ~ 3()~
1~ aspect of the present invention is constructed and functions in li 21 the same manner.
3 ¦ Preferably, the metallic components of the bridge, 4 ¦ namely the corrugated plate and the flat plate are constructed of corrosion resistant materials such as stainless steel or copper 6 bearing steel as is marketed under the trade designation COR-TEN
7 by the U.S. Steel Corporation of Pittsburgh, Pennsylvania, for 8 example. sriefly, upon exposure to the atmosphere, copper bear-9 ing steel surface oxidizes and forms a self-protective coating, thereby providing far superior resistance to atmospheric cor-11 rosion. Accordingly, by constructing the plates of such l~l corrosion-resistant materials, thinner cross-section materials 13l can be employed which, in turn, are more readily worked and 14¦ enable one, for example, to corrugate the material at a lesser 15¦ cost by cold working it while requiring little or no maintenance 16¦ over the li^fe of the bridge.
17 ¦ Additionally, it is preferred to construct the corru-18 gated and flat plates used in the bridge of the present invention l9¦ of relatively high strength steel, for example, steel having a 201 yield strength of at least about 50,000 psi. This enables a 21¦ further reduction of the wall thicknesses for the plates at a 22¦ very modest increase in the per pound cost of the material which 2~1 is substantially out-weighed by reductions in the overall weight.
24 ¦ The perhaps greatest cost savings afforded by the 25 ¦present invention are encountered during the actual assembly and 26 ¦ erection of the bridge. To the extent the bridges employ flat 27 ¦plates, they are readily available at very reasonable prices.
28 T e corrugated plate, or the above-discussed flanged chanr.el .
~9(~512 1 members from which the corruga$ed plate is formed are readily 2 cold formed by corrugating flat sheet metal stock in suitable 3 corrugating machines. The corrugated plate and the flat plate 4 are then cut to the desired length and secured, e.g., spot-welded ~¦ to each other, or if channel members are used they are welded 61 together with high speed, automatic welding equipment or the 7 ¦ like.
8 ¦ Thereafter the bridge is ready for shipment to the 9 ¦ construction site and erection. To facilitate shipment the 10 ¦ bridge may be constructed in separate bridge modules of a prac-11 ¦ tical width, say 8 feet. To erect a bridge, all that is neces-12 ¦ sary is to hoist it into place. If modules are employed they are 13 hoisted into place and assembled, i.e., tied together with welds, 14 ¦ bolts or separate transverse tie-strips, for example. Lastly, 15 ¦ the thin layer of concrete is poured on top of the corrugated or 16 ¦ flat plate and the bridge is ready for use. Suitable guard rails 17 ¦ or similar lateral barriers can also be installed. If the bridge 18 is erected at a location where concrete is not available, each 19 module can be factory assembled and anti-skid material such as 20 ¦ l/4" or l/2" thick floor plate, diamond plate, etc., can be 21 ¦ secured to the flat plate (or form the flat plate as such) before 22 ¦ or after the modules are in place.
¦ extends over the full width of the bridge, however, is ideally 21 suited for this construction.
3¦ One aspect of the present invention, provides that the 4l corrugated plate be constructed of a plurality of longitudinally 51 extending, parallel and upwardly opening channel members which 6l are arranged side-by-side. Each channel member includes a gen-7 erally horizontally disposed flange which protrudes laterally 8¦ from an upper end of the channel and which extends over the full 9¦ length thereof. The flange has a width which is greater than the 10¦ lateral spacing between adjoining channel members so that it 11¦ covers the upwardly opening portion of an adjoining channel member and overlaps the flange of such adjoining member. Means 13l such as welds, bolts, rivets, or the like rigidly secures the 14¦ overlapping portions of the flanges of the adjoining channel 15~ members to each other so that the channel members simultaneously 161 define a corrugated plate that extends over the full length and 17 ¦width of the bridge and the flat plate. The latter is defined by 18 ¦the lateral succession of the horizontally disposed, overlapping 19 ¦ and interconnected flanges.
20 ¦ The concrete layer poured on top of the resulting flat 21 ¦plate and means such as anchoring studs are secured, e.g. welded 221 to the flat plate, or a multiplicity of upwardly oriented protru-231 berances and depressions in the plate form a mechanical interlock 241 between the concrete layer and the remainder of the bridge, e g.
25 ¦ the flat plate and the corrugated plate.
26 ¦ According to another aspect of the present invention, 271 the strength of the bridge is increased, particularly for ~short 29 span bridges of greater length, e.g. having lengths of between 45 l 1~
1 to 60 feet by securing additional, lower corrugated plates to the 2 first mentioned, upper corrugated plate. The lower corrugated 3 ¦ plates may have the same length as the upper plate or they may be 4 shortened and centered relati~e to the length of the bridge so as 5¦ to give the bridge maximum strength at its center between its end 61 supports. Preferably, the lower corrugated plate is secured to 7 ¦ the upper corrugated plate so that the two define a plurality of 8 ¦ laterally spaced apart, longitudinally extending tubular members 9 ¦ to increase the strength and rigidity of the bridge while main-10 ¦ taining a relatively low overall weight. Further, the tubular 11 ¦ members may be utilized as protective conduits for cables, pipes ~ and the like while keeping them out of sight and thus increasing 13l the aesthetic overall appearance of the bridge. Ends of the 14¦ tubular member may be closed to prevent the accumulation of 15 ¦ moisture, debris, etc. therein.
16 ¦ For particular applications the flat plate may be 17 ¦ secured to the underside of the corrugated plate while the con-18 ¦ crete layer is poured directly onto the top of the corrugated 1~ ¦ plate and mechanically interlocked therewith. In such an in-20 ¦ stance the concrete layer alone effects the lateral distribution 21 ¦ of point loads over a plurality of corrugations while the (lower) 22 ¦ flat plate acts as the tie member for the corrugation. Addi-23 ¦ tional, lower corrugated plates are then secured to the upper 24 ¦ corrugated plate. This embodiment has the advantage that the 25 ¦ bridge has a relatively greater moment of inertia due to the 26 ¦ greater amount of concrete that is utilized since in such an 27 instance the concrete will fill the upwardly opening corrugations 228 I f the corrugated plate. In all other respects, however, this 31 ~
32 ~ A !
~ ~ 3()~
1~ aspect of the present invention is constructed and functions in li 21 the same manner.
3 ¦ Preferably, the metallic components of the bridge, 4 ¦ namely the corrugated plate and the flat plate are constructed of corrosion resistant materials such as stainless steel or copper 6 bearing steel as is marketed under the trade designation COR-TEN
7 by the U.S. Steel Corporation of Pittsburgh, Pennsylvania, for 8 example. sriefly, upon exposure to the atmosphere, copper bear-9 ing steel surface oxidizes and forms a self-protective coating, thereby providing far superior resistance to atmospheric cor-11 rosion. Accordingly, by constructing the plates of such l~l corrosion-resistant materials, thinner cross-section materials 13l can be employed which, in turn, are more readily worked and 14¦ enable one, for example, to corrugate the material at a lesser 15¦ cost by cold working it while requiring little or no maintenance 16¦ over the li^fe of the bridge.
17 ¦ Additionally, it is preferred to construct the corru-18 gated and flat plates used in the bridge of the present invention l9¦ of relatively high strength steel, for example, steel having a 201 yield strength of at least about 50,000 psi. This enables a 21¦ further reduction of the wall thicknesses for the plates at a 22¦ very modest increase in the per pound cost of the material which 2~1 is substantially out-weighed by reductions in the overall weight.
24 ¦ The perhaps greatest cost savings afforded by the 25 ¦present invention are encountered during the actual assembly and 26 ¦ erection of the bridge. To the extent the bridges employ flat 27 ¦plates, they are readily available at very reasonable prices.
28 T e corrugated plate, or the above-discussed flanged chanr.el .
~9(~512 1 members from which the corruga$ed plate is formed are readily 2 cold formed by corrugating flat sheet metal stock in suitable 3 corrugating machines. The corrugated plate and the flat plate 4 are then cut to the desired length and secured, e.g., spot-welded ~¦ to each other, or if channel members are used they are welded 61 together with high speed, automatic welding equipment or the 7 ¦ like.
8 ¦ Thereafter the bridge is ready for shipment to the 9 ¦ construction site and erection. To facilitate shipment the 10 ¦ bridge may be constructed in separate bridge modules of a prac-11 ¦ tical width, say 8 feet. To erect a bridge, all that is neces-12 ¦ sary is to hoist it into place. If modules are employed they are 13 hoisted into place and assembled, i.e., tied together with welds, 14 ¦ bolts or separate transverse tie-strips, for example. Lastly, 15 ¦ the thin layer of concrete is poured on top of the corrugated or 16 ¦ flat plate and the bridge is ready for use. Suitable guard rails 17 ¦ or similar lateral barriers can also be installed. If the bridge 18 is erected at a location where concrete is not available, each 19 module can be factory assembled and anti-skid material such as 20 ¦ l/4" or l/2" thick floor plate, diamond plate, etc., can be 21 ¦ secured to the flat plate (or form the flat plate as such) before 22 ¦ or after the modules are in place.
23 ¦ It will be observed that the construction and erection 24 ¦ of the bridge of the present invention does not rely on costly 25 ¦ profiles or the assembly of a low weight, high strength but 26 ¦ expensive framework made up of plates, angles, beams, channels 27 ¦ and the like. Instead, the bridge is constructed of cold.formed 228 ¦ plate ho1sted into place onto which a layer of concrete is ~Z9051Z
1 poured. The result is that the bridge can be manufactured and 2 installed at a cost which is substantially les~ than the manu-3 facturing and erection of a corresponding bridge constructed in 41 accordance with the prior art.
5l Further, the bridge of the present invention can be 61 stocked in standard lengths of, say, 5 or 10 feet increments, in 7 ¦ either standard widths or in the above-mentioned modular sizes.
8 ¦ For a given installation a standard bridge length can then be 9 ¦ chosen from stock and erected. If the actual bridge length is 10 ¦ less than the standard length, the bridge can be cut to the 11 ¦ desired length since the bridge structure, unlike prior art 1~ bridges, is uniform both in a longitudinal and a lateral direc-13 tion. Thus, a shortening of a stocked bridge in no way affects 14 its strength as rigidity, or for that matter, its appearance.
Consequently, the present invention also makes it 16 feasible to maintain an inventory of standard bridge lengths.
17 This in turn greatly speeds up delivery and installation times 1~ ; and ultlmatel owers the cost of bridges.
1 poured. The result is that the bridge can be manufactured and 2 installed at a cost which is substantially les~ than the manu-3 facturing and erection of a corresponding bridge constructed in 41 accordance with the prior art.
5l Further, the bridge of the present invention can be 61 stocked in standard lengths of, say, 5 or 10 feet increments, in 7 ¦ either standard widths or in the above-mentioned modular sizes.
8 ¦ For a given installation a standard bridge length can then be 9 ¦ chosen from stock and erected. If the actual bridge length is 10 ¦ less than the standard length, the bridge can be cut to the 11 ¦ desired length since the bridge structure, unlike prior art 1~ bridges, is uniform both in a longitudinal and a lateral direc-13 tion. Thus, a shortening of a stocked bridge in no way affects 14 its strength as rigidity, or for that matter, its appearance.
Consequently, the present invention also makes it 16 feasible to maintain an inventory of standard bridge lengths.
17 This in turn greatly speeds up delivery and installation times 1~ ; and ultlmatel owers the cost of bridges.
'30~1~
1 Brief Description of the Drawings 2 Fig. l is a schematic, side elevational view of a 3 bridge constructed in accordance with the present invention;
4 Fig. 2 is a fragmentary, enlarged front elevational view, in section, and is taken along line 2-2 of Fig. l;
6¦ Figs. 3-6 are fragmentary, front elevational views 7 similar to Fig. 2 but show other embodiments of the present 8 invention;
9 Fig. 7 is a side elevational view similar to Fig. l and illustrates a further embodiment of the present invention;
11 Fig. 8 is an enlarged, fragmentary front elevational I? view, in section, of the bridge illustrated in Fig. l and shows 13¦ the installation of lateral guard rails for the bridge;
14¦ Fig. 9 is a fragmentary bottom view, in section, and is j 15¦ taken on line 9-~ of Fig. 8; and 16¦ Fig. lO is an enlarged side elevational detail of the I7¦ portion of Fig. 7 enclosed by line lO-lO and illustrates the ZO c nnection of the bridge to a ~ridge aoutment.
1 Brief Description of the Drawings 2 Fig. l is a schematic, side elevational view of a 3 bridge constructed in accordance with the present invention;
4 Fig. 2 is a fragmentary, enlarged front elevational view, in section, and is taken along line 2-2 of Fig. l;
6¦ Figs. 3-6 are fragmentary, front elevational views 7 similar to Fig. 2 but show other embodiments of the present 8 invention;
9 Fig. 7 is a side elevational view similar to Fig. l and illustrates a further embodiment of the present invention;
11 Fig. 8 is an enlarged, fragmentary front elevational I? view, in section, of the bridge illustrated in Fig. l and shows 13¦ the installation of lateral guard rails for the bridge;
14¦ Fig. 9 is a fragmentary bottom view, in section, and is j 15¦ taken on line 9-~ of Fig. 8; and 16¦ Fig. lO is an enlarged side elevational detail of the I7¦ portion of Fig. 7 enclosed by line lO-lO and illustrates the ZO c nnection of the bridge to a ~ridge aoutment.
9051~ ~
1 I Description of Preferred Embodiments 2 ¦ Referring to Figs. 1 and 2, a bridge 2 constructed in 3 accordance with the present invention is shown suspended between 4 spaced-apart bridge abutments 4. The bridge comprises a corru-5i gated plate 6 having a multiplicity of parallel, side-by-side 6 ! corrugations 8 which extend in a longitudinal direction of the 71 bridge, that is which run from one ~ridge abutment 4 to the 81 other. The bridge further includes a flat plate 10 and a layer 9¦ of concrete 12 disposed on top of the flat plate and defining a 10¦ traffic carrying surface 14 of the bridge. Shear studs 16 are 11¦ secured, e.g. welded to the flat plate and they anchor the con-l?l crete layer to the flat plate to thereby form a mechanically 13l interlock between them.
14¦ In the embodiment of the bridge illustrated in Fig. 2, 15¦ the corrugated plate is defined by a multiplicity of channel 1~¦ members 18 each of which defines an upwardly opening, generally 17¦ V-shaped channel 2~, that is a channel having inclined sides 22.
18 ¦A first, relatively narrow horizontally disposed flange 24 pro-19 Ijects laterally from the upper end of one of the inclined channel 20 ¦sides while a second, relatively wide, horizontally disposed 21 ¦ flange 26 projects laterally from the upper end of the other 22 Iinclined channel side. Both flanges extend over the full length 23 ¦of the associated channel members. The wide flange of each 24 ¦channel member 18 is secured, e.g. spot, skip or continuously 25 ¦welded, or it is bolted to the narrow first flange 24 of the next 26 ¦ adjoining channel member.
27 Thus, in the illustrated embodiment, the corrugated 29 plate 6 is defined by the totality of channel members and the 3~1 ll ~290SlZ
wide flanges 26 define corrugation peaks 28 of the plate while 2 flat root sections 30 of the V-shaped channels 20 define corru-3 gation troughs 32.
4 In the embodiment of the invention illustrated in Fig.
~l 2, wid~ flanges 26 further define the flat plate 10 which is 61 structurally continuous over the full width of the corrugated 7 plate. For this purpose, the wide flanges include lateral, 8 outboard extensions 34 which are stepped up so as to accommodate 9 the narrow flanges of the next adjoining channel members and which have sufficient widths so as to overlap the wide flanges 26 11 of the adjoining channel members. In this manner, the outboard 12 extension 34 of one channel member covers and closes the upwardly 13 open V-shaped channel 20 of the adjacent channel member so that 14¦ when concrete is poured onto the resulting flat plate the fresh 15¦ concrete cannot enter the channel and the finished bridge ex-16 ¦ hibits a plurality of side-by-side, hollow tubular members which 17 ¦ extend over its full length.
18 The outermost edge of the outboard extension 34 is 1~¦ suitably secured, preferably welded to the wide flange 26 of the next adjoining channel member 18.
21 The embodiment of the invention illustrated in Fig. 2 22 is particularly adapted for short span bridges o-f relatively 23 lesser length. Thus, for a bridge having a length of 20 feet, 24 for example, the pitch of the corrugated plate, that is the spacing between adjacent corrugation peaks 28 or corrugation 26 ¦ troughs 32 is 30 inches while the corrugation height, that is the 27 distance between the corrugation peaks and corrugation troughs is 228 12 inches. The corrugated plate has a wall thickness of 3/16th l ~90~
inch and a root section 30 width of 4 inches. The concrete layer 21 height is between 3-1/2 to 4 inches while the shear studs 16 are 3 made of 1/2-inch diameter rod, the rod material and the plate 4 material having a minimum yield strength of 50,000 psi. Such a 5 ! bridge complies with AASHTO-HS 20-44 loading requirement.
6~ Referring now to Figs. 1 and 3 in another embodiment of 71 the invention, the bridge 2 is constructed in the above described 8¦ manner utilizing a plurality of side-by-side, parallel channel 9¦ members 18 which define corrugated plate 6 and flat plate 10 of 10¦ the bridge. Placed on top the flat plate 10 is a layer of con-11l crete 12 which defines traffic bearing surface 14. A multi-~ plicity of shear studs 16 welded to the flat plate 10 anchor the 13 I concrete layer to the flat plate and thereby form a mechanical 14 ¦ interlock between the two.
15 ¦ In addition, however, and to increase the overall 16 ¦ strength of the bridge, a second, lower corrugated plate 36 is 17 ¦provided. In the illustrated embodiment, the lower corrugated 18 ¦plate is defined by side-by-side corrugated plate sections 38, 19 ¦ each of which defines two full corrugations, that is two corru-gation peaks 40 (which are relatively narrow) and two corrugation 21 ¦ troughs 42 (which are relatively wide). One lateral edge of each 22 ¦ corrugated plate section, say a righthand edge portion 44 is 23 ¦ stepped down to nest with a mating, relatively narrow, longi-24 ¦ tudinal side flange 46 of the adjoining corrugated plate section.
25 ¦The overlapping plate portions are suitably secured to each 26 ¦ other, preferably with intermittently placed bolts 48, although 27 ¦other means for fastening the plates together such as welds, 28 ¦ rivets and the like may, be substituted.
I l~9~ Z
i The structure illustrated in Fig~ 3 is functionally 2 ¦ similar to that illustrated in Fig. 2. Again, it defines mul-3 tiple, longitudinally extending tubular conduits which can be 4 utilized as above described and which render the bridge rela-5 ¦ tively lightweight while giving it great strength and rigidity.
6 ¦ The concrete layer is fully supported over its full width so that 7 ¦ its thickness can be kept t~ a minimum. Of course, the addition 8 of the lower corrugated plate 36 almost doubles the strength and 9 rigidity of the bridge illustrated in Figs. 3 over that illu-10 ¦ strated in Fig. 2.
111 The embodiment of the invention illustrated in Fig. 3 121 may, for example, be employed to conform a bridge having a span 13 ¦ of 30 feet with AASHTO-HS 20-44 loading requirements by providing 14 ¦ a 36-inch corrugation pitch, a corrugation height of 8 inches and 15 ¦ a concrete layer thickness of 6-1/4 inch. Again the corrugated 16 ¦ plate as well as the shear studs (dimensioned as discussed above) 17 I are constructed of steel having a yield strength of 50,000 psi.
18 In the example the upper corrugated plate has a (trough) root 19 ¦ section width of 2 inches and the lower corrugated plate has a 20 ¦ root section width of approximately 26 inches.
21 I Referring now to Fig. 4, in another embodiment of the 22 ¦ invention, the corrugated plate 6, flat plate 10-and concrete 23 ¦ layer 12 are constructed as above described. The bridge also 24 ¦ includes a lower corrugated plate 50 which is defined by the same 25 I channel members 18 which define the upper corrugated plate 6.
26 ¦ The only difference between the upper and lower corrugated plates 27 ¦ is that the channel members are inverted. Thus, the bridge 228 ~ illustrated in Fig. 4 also includes a lower flat plate 52 defined l ~;~90~1~
1 by wide flanges 26 together with corresponding outboard exten-2 sions 34. The upper and lower corrugated plates are suitably 3 secured to each other with welds, bolts, rivets or the like.
4 A bridge constructed as illustrated in Fig. 4 has a 5l somewhat greater strength and rigidity than the bridge illus-61 trated in Fig. 3, primarily because the bridge includes a con-7 tinuous lower flat plate 52. In all other respects the bridge is 8 constructed and functions as described above.
9 It will be observed that in the embodiments of the invention shown in Figs. 3 and 4, the upper and lower corrugated 11 plates are nested one within the other, that is the corrugation 12 peaks and corrugation troughs of the upper and lower corrugated 13l plates contact and are secured to each other. As a result, the 14¦ overall height of the portion of the bridge defined by the corru-15 ¦gated plates is substantially equal to the height of one corru-16 ¦gated plate plus one corrugated plate thickness. This construc-17 ¦ tion is particularly useful in connection with bridges having 18 ¦relatively high payloads yet relatively short spans where shear 19 ¦ forces are relatively high as compared to the bending momement.
20 ¦For bridges of greater spans, bending moments and the rigidity of 21 the bridge become of increasing significance and require a cor-22 responding strengthening of the bridge.
23 Referring now to Figs. 5 and 7, a bridge 54 is again 24 suspended between abutments 4, but it comprises a plurality of 251 corrugated plate layers which are stacked one on top of the other 26¦ by contacting and securing to each other corrugation troughs of 27 ¦ the upper corrugated plate with corrugation peaks of the Lower 28 ¦corrugated plate in the manner more fully described below.
l~O~
1¦ Referring now specifically to Fig. 5, an upper corru-2¦ gated plate 56 is constructed as above described from a plurality 31 of side-by-side channel members 18 which define upwardl~ open, 4l V-shaped channels 20 that are closed by wide, longitudinally 51 extending flanges 26 fitted with outboard extensions 34 so as to 6 Iclose the upwardly open channels. Overlapping portions of the 7 ¦outboard extensions and of the wide flange of adjoining channel 8 ¦members are again secured, e.g. welded together to define flat 9 ¦plate 10 which is structurally continuous over the width of the 1~ ¦corrugated plate. Placed on top of the flat plate 10 is the 11 ¦above described concrete layer 12 which defines traffic carrying l?l surface 14 of the bridge. Studs 16 are used to mechanically 13 ¦interlock the concrete layer to the flat plate.
14¦ A lower corrugated plate 58 may be constructed of 15 ¦mutliple corrugated plate sections 60 which define parallel, 16 ¦ side-by-side, longitudinally running corrugations having alter-17 ¦ nating, relatively narrow corrugation peaks 62 (of a width sub-18 ¦ stantially equal to the corrugation troughs of the upper corru-19 ¦ gated plate 56) and relatively wide corrugation troughs 64. One 20 ¦ of the lateral edge portions 66 is stepped down so as to nest 21 ¦ with short side flanges 68 of the adjoining corrugated plate 22 ¦ section so that the overlapping portions can be secured to each 23 ¦ other, for example, with bolts 70.
24 The embodiment of the invention illustrated in Fig. 5 is adapted for greater spans, say for a span of 45 feet. For 26 AASHTO-HS 20-44 loading requirements, the corrugated plates has a 27 23-inch pitch, a corrugation height of 8 inches and a plat,e 29 thickness of 3/16th with a yield strength of 50,000 psi. The I 1~90512 1 concrete layer thickness is 6~3/4 inch while the upper plate has 2 a ttrough) root section width of about 2 inches and the lower 3 plate has a root section width of about 13 inches. By increasing 4 the corrugation height to 12" and the plate thickness to 1/4" the bridge can have a span up to about 65 feet.
61 Referring to Figs. 5 and 7, the lower corrugated plate 7 I 58 may extend over the full length of the upper corrugated plate 8 56 as is shown for the first lower corrugated plate in Fig. 7.
9 The lower corrugated plates, however, may span a distance less than the full length of the upper corrugated plate as is the case 11 with lower corrugated plates 72, 74 and 76 shown in Fig. 7. In ? such an event, ends 78 of the lower corrugated plates terminate 13l short of abutments 4 and the plates are centered with respect to 14¦ the longitudinal extent of the bridge so that they strengthen the 15 ¦bridge where it ls subjected to greatest stress.
16 I To prevent the accumulation of moisture and debris 17 ¦ within and to prevent animals from gaining access to the hollow 18 ¦interior of the lower corrugated plate through their open ends 19 178, Z-shaped end plates 79 or L-shaped end plates 81 may be 20 ¦suitably placed over the open ends as is illustrated in Fig. 7 21 ¦ and secured to the adjoining corrugation.
22 ¦ Figs. 7 and 10 also illustrate the manner in wich 23 ¦bridge 2 is supported by abutments 4. Each abutment includes a 24 ¦protruding ledge 120 on which is formed a pedestal 122. Ends 124 25 Iof the uppermost corrugated plate 56 and, as illustrated in Figs.
26 7 and 10 of the next lower corrugated plate 58, overlap the 27 pedestals and rest thereon. An elastomeric bearing pad 126 is 29~ interposed between the corrugated plates and the pedestal.
~ ~90~2 l Preferably, each corrugated plate end 124 is defined by ¦
2 a generally L-shaped end plate 128 which is suitably secured, 3 e.g. welded to the corrugated plates 56, 58 and which includes a 4 lower, horizontal leg 130 which rests on the elastomeric bering 51 pad. Anchor bolts 132 protrude from the abutment led~e 120 and 6 ¦ extend through suitably placed holes in the horizontal leg of the 7 ¦ end plate. Nuts attach the end plate and, therewith, the cor-8 ~ rugated plates and the entire bridge to the anchor bolts and the 9 ¦ abutment. To permit thermal expansions of the bridge the anchor 10 ¦bolt holes in the horizontal leg 130 of one of the end plates 128 11 ¦ are elongated in the direction of the length of the bridge.
l? Referring now to Fig. 6, in yet another embodiment of 13 the invention, a bridge 80 is constructed of at least one upper 14 carrugated plate 82 and one lower corrugated plate 84, each of which is constructed of corrugated plate sections 86 which define l& alternating corrugation peaks and corrugation troughs 88, 90 17 which are laterally offset by one-half corrugation pitch so that 18 corrugation troughs of the upper plate are aligned with corru-l9 gation peaks of the lower plate. Placed directly on top of the upwardly facing surface of the upper corrugated plate is a con-21 crete layer 92 which defines traffic carrying surface 14 of the 22 bridge.
23 To anchor the concrete layer to the corrugated plate, 24 the latter is constructed of so-called checkered plate, arranged for example in a diamond pattern so that raised protrusions 94 26 which are uniformly distributed over the corrugated plate and 27 depressions defined by them face upwardly. The need for concrete 2B a choring st~ds (sho~n in Figs. 2-5) is there~y eliminated. The ~1 22 .
l.~9~)Sl~ I
I protrusiOns, which typically extend upwardly from a remainder of 2 the plate by up to l/8th inch or more, form a uniform, i.e.
3 evenly distributed mechanical interlock between the concrete 4 layer and the corrugated plate and thus, integrate the latter 5¦ with the former into a load bearing structure.
61 Since concrete has little tensional strength and since 71 the corrugations of the upper and lower plates have little trans-I verse strength, a flat plate 96 defined by a plurality of inter-9¦ connected flat plate sections 98 is used so as to render the flat 10¦ plate structurally continuous over the width of the corrugated 11¦ plate. The flat plate is interposed between the upper and lower ?~ corrugated plates 82, 84 to prevent the corrugations of the 13 plates from being opened, that is from being spread apart in a 14¦ lateral bridge direction when the bridge is subjected to its 5¦ design load. Thus, flat plate 96 performs the same function as ,61 the flat plates illustrated in Figs. 2-5 but, in the embodiment 17 ¦ ill~strated in Figs. 6, it is spaced apart from the concrete 18 ¦ layer by the upper corrugated plate. The flat plate itself is 19 ¦suitably secured to the corrugation troughs and peaks of the 20 ¦ upper and lower corrugated plates, respectively, as by welding or 21 ¦bolting it thereto.
22 ¦ For a sectional or modular construction of the bridge, 23 ¦ that is for a construction in which each corrugated plate section 24 ¦ has a width less than the overall width of the bridge, each 25 ¦section is fitted with a longitudinally extending, relatively 26 ¦ short side flange 100 along one edge of the section and a longi-27 ¦ tudinally extending, relatively wide side flange 102 on the 29 jopposite side of the section so that portions of the relatively l ~.~9()53LZ
1~ wide flanges of the upper and lower sections overlap and can be 21 secured, e.g. bolted to each other.
3l In the embodiment of the invention illustrated in Fig.
4 6, the upper corrugated plate is preferably constructed of 5' checkered steel plate while the lower corruga~ed plate is con-6 ¦ structed of regular steel plate, both of which have a yield 7 ¦ stress of 50,000 psi. For the AASHTO-HS 20-44 loading require-81 ments the plates have a thickness of 3/16th inch a corrugation 9 ¦ pitch of between 16 to 18 inches, and a corrugation depth of 10 ¦ between 6 and 8 inches. The flat plate 96 also has a 3/16th inch 11 ¦ thickness while the concrete protrudes 2 to 3 inches above the ~ ¦ corrugation peaks of the upper corrugated plate. Such a struc 13 ¦ ture is suitable for span lengths of between 20 to 40 feet. Of 14 course, by adding additional lower corrugated plates the span length of the bridge can be increased as may be required.
16 I Referring now briefly to Figs. 8 and 9, a longitu-17 ¦ dinally extending guard rail 104 may be installed along lateral 18 ¦ edges 106 of the bridge by arranging over the length of the 19 ¦ bridge a plurality of generally L-shaped channel members 108 20 ¦ (which may have the same profile as the corrugations of corru-21 I gated plate 6). Each channel member includes a horizontal por-22 ¦ tion 110 secured to the underside of corrugations 8 of the corru-23 I gated plate with bolts 112, for example~ A vertical portion 114 24 ¦ of the channel member protrudes above road bed 14 and the guard 25 I rail is secured, e.g. bolted to its upper end. A gusset plate 26 I 116 is preferably bolted to the corrugated plate in alignment 27 ¦ with the channel member and welded to the latter. It includes a 28 I protruding section 118 which is secured, e.g. welded to the 29 channel member to rigidify its vertical portion.
1 I Description of Preferred Embodiments 2 ¦ Referring to Figs. 1 and 2, a bridge 2 constructed in 3 accordance with the present invention is shown suspended between 4 spaced-apart bridge abutments 4. The bridge comprises a corru-5i gated plate 6 having a multiplicity of parallel, side-by-side 6 ! corrugations 8 which extend in a longitudinal direction of the 71 bridge, that is which run from one ~ridge abutment 4 to the 81 other. The bridge further includes a flat plate 10 and a layer 9¦ of concrete 12 disposed on top of the flat plate and defining a 10¦ traffic carrying surface 14 of the bridge. Shear studs 16 are 11¦ secured, e.g. welded to the flat plate and they anchor the con-l?l crete layer to the flat plate to thereby form a mechanically 13l interlock between them.
14¦ In the embodiment of the bridge illustrated in Fig. 2, 15¦ the corrugated plate is defined by a multiplicity of channel 1~¦ members 18 each of which defines an upwardly opening, generally 17¦ V-shaped channel 2~, that is a channel having inclined sides 22.
18 ¦A first, relatively narrow horizontally disposed flange 24 pro-19 Ijects laterally from the upper end of one of the inclined channel 20 ¦sides while a second, relatively wide, horizontally disposed 21 ¦ flange 26 projects laterally from the upper end of the other 22 Iinclined channel side. Both flanges extend over the full length 23 ¦of the associated channel members. The wide flange of each 24 ¦channel member 18 is secured, e.g. spot, skip or continuously 25 ¦welded, or it is bolted to the narrow first flange 24 of the next 26 ¦ adjoining channel member.
27 Thus, in the illustrated embodiment, the corrugated 29 plate 6 is defined by the totality of channel members and the 3~1 ll ~290SlZ
wide flanges 26 define corrugation peaks 28 of the plate while 2 flat root sections 30 of the V-shaped channels 20 define corru-3 gation troughs 32.
4 In the embodiment of the invention illustrated in Fig.
~l 2, wid~ flanges 26 further define the flat plate 10 which is 61 structurally continuous over the full width of the corrugated 7 plate. For this purpose, the wide flanges include lateral, 8 outboard extensions 34 which are stepped up so as to accommodate 9 the narrow flanges of the next adjoining channel members and which have sufficient widths so as to overlap the wide flanges 26 11 of the adjoining channel members. In this manner, the outboard 12 extension 34 of one channel member covers and closes the upwardly 13 open V-shaped channel 20 of the adjacent channel member so that 14¦ when concrete is poured onto the resulting flat plate the fresh 15¦ concrete cannot enter the channel and the finished bridge ex-16 ¦ hibits a plurality of side-by-side, hollow tubular members which 17 ¦ extend over its full length.
18 The outermost edge of the outboard extension 34 is 1~¦ suitably secured, preferably welded to the wide flange 26 of the next adjoining channel member 18.
21 The embodiment of the invention illustrated in Fig. 2 22 is particularly adapted for short span bridges o-f relatively 23 lesser length. Thus, for a bridge having a length of 20 feet, 24 for example, the pitch of the corrugated plate, that is the spacing between adjacent corrugation peaks 28 or corrugation 26 ¦ troughs 32 is 30 inches while the corrugation height, that is the 27 distance between the corrugation peaks and corrugation troughs is 228 12 inches. The corrugated plate has a wall thickness of 3/16th l ~90~
inch and a root section 30 width of 4 inches. The concrete layer 21 height is between 3-1/2 to 4 inches while the shear studs 16 are 3 made of 1/2-inch diameter rod, the rod material and the plate 4 material having a minimum yield strength of 50,000 psi. Such a 5 ! bridge complies with AASHTO-HS 20-44 loading requirement.
6~ Referring now to Figs. 1 and 3 in another embodiment of 71 the invention, the bridge 2 is constructed in the above described 8¦ manner utilizing a plurality of side-by-side, parallel channel 9¦ members 18 which define corrugated plate 6 and flat plate 10 of 10¦ the bridge. Placed on top the flat plate 10 is a layer of con-11l crete 12 which defines traffic bearing surface 14. A multi-~ plicity of shear studs 16 welded to the flat plate 10 anchor the 13 I concrete layer to the flat plate and thereby form a mechanical 14 ¦ interlock between the two.
15 ¦ In addition, however, and to increase the overall 16 ¦ strength of the bridge, a second, lower corrugated plate 36 is 17 ¦provided. In the illustrated embodiment, the lower corrugated 18 ¦plate is defined by side-by-side corrugated plate sections 38, 19 ¦ each of which defines two full corrugations, that is two corru-gation peaks 40 (which are relatively narrow) and two corrugation 21 ¦ troughs 42 (which are relatively wide). One lateral edge of each 22 ¦ corrugated plate section, say a righthand edge portion 44 is 23 ¦ stepped down to nest with a mating, relatively narrow, longi-24 ¦ tudinal side flange 46 of the adjoining corrugated plate section.
25 ¦The overlapping plate portions are suitably secured to each 26 ¦ other, preferably with intermittently placed bolts 48, although 27 ¦other means for fastening the plates together such as welds, 28 ¦ rivets and the like may, be substituted.
I l~9~ Z
i The structure illustrated in Fig~ 3 is functionally 2 ¦ similar to that illustrated in Fig. 2. Again, it defines mul-3 tiple, longitudinally extending tubular conduits which can be 4 utilized as above described and which render the bridge rela-5 ¦ tively lightweight while giving it great strength and rigidity.
6 ¦ The concrete layer is fully supported over its full width so that 7 ¦ its thickness can be kept t~ a minimum. Of course, the addition 8 of the lower corrugated plate 36 almost doubles the strength and 9 rigidity of the bridge illustrated in Figs. 3 over that illu-10 ¦ strated in Fig. 2.
111 The embodiment of the invention illustrated in Fig. 3 121 may, for example, be employed to conform a bridge having a span 13 ¦ of 30 feet with AASHTO-HS 20-44 loading requirements by providing 14 ¦ a 36-inch corrugation pitch, a corrugation height of 8 inches and 15 ¦ a concrete layer thickness of 6-1/4 inch. Again the corrugated 16 ¦ plate as well as the shear studs (dimensioned as discussed above) 17 I are constructed of steel having a yield strength of 50,000 psi.
18 In the example the upper corrugated plate has a (trough) root 19 ¦ section width of 2 inches and the lower corrugated plate has a 20 ¦ root section width of approximately 26 inches.
21 I Referring now to Fig. 4, in another embodiment of the 22 ¦ invention, the corrugated plate 6, flat plate 10-and concrete 23 ¦ layer 12 are constructed as above described. The bridge also 24 ¦ includes a lower corrugated plate 50 which is defined by the same 25 I channel members 18 which define the upper corrugated plate 6.
26 ¦ The only difference between the upper and lower corrugated plates 27 ¦ is that the channel members are inverted. Thus, the bridge 228 ~ illustrated in Fig. 4 also includes a lower flat plate 52 defined l ~;~90~1~
1 by wide flanges 26 together with corresponding outboard exten-2 sions 34. The upper and lower corrugated plates are suitably 3 secured to each other with welds, bolts, rivets or the like.
4 A bridge constructed as illustrated in Fig. 4 has a 5l somewhat greater strength and rigidity than the bridge illus-61 trated in Fig. 3, primarily because the bridge includes a con-7 tinuous lower flat plate 52. In all other respects the bridge is 8 constructed and functions as described above.
9 It will be observed that in the embodiments of the invention shown in Figs. 3 and 4, the upper and lower corrugated 11 plates are nested one within the other, that is the corrugation 12 peaks and corrugation troughs of the upper and lower corrugated 13l plates contact and are secured to each other. As a result, the 14¦ overall height of the portion of the bridge defined by the corru-15 ¦gated plates is substantially equal to the height of one corru-16 ¦gated plate plus one corrugated plate thickness. This construc-17 ¦ tion is particularly useful in connection with bridges having 18 ¦relatively high payloads yet relatively short spans where shear 19 ¦ forces are relatively high as compared to the bending momement.
20 ¦For bridges of greater spans, bending moments and the rigidity of 21 the bridge become of increasing significance and require a cor-22 responding strengthening of the bridge.
23 Referring now to Figs. 5 and 7, a bridge 54 is again 24 suspended between abutments 4, but it comprises a plurality of 251 corrugated plate layers which are stacked one on top of the other 26¦ by contacting and securing to each other corrugation troughs of 27 ¦ the upper corrugated plate with corrugation peaks of the Lower 28 ¦corrugated plate in the manner more fully described below.
l~O~
1¦ Referring now specifically to Fig. 5, an upper corru-2¦ gated plate 56 is constructed as above described from a plurality 31 of side-by-side channel members 18 which define upwardl~ open, 4l V-shaped channels 20 that are closed by wide, longitudinally 51 extending flanges 26 fitted with outboard extensions 34 so as to 6 Iclose the upwardly open channels. Overlapping portions of the 7 ¦outboard extensions and of the wide flange of adjoining channel 8 ¦members are again secured, e.g. welded together to define flat 9 ¦plate 10 which is structurally continuous over the width of the 1~ ¦corrugated plate. Placed on top of the flat plate 10 is the 11 ¦above described concrete layer 12 which defines traffic carrying l?l surface 14 of the bridge. Studs 16 are used to mechanically 13 ¦interlock the concrete layer to the flat plate.
14¦ A lower corrugated plate 58 may be constructed of 15 ¦mutliple corrugated plate sections 60 which define parallel, 16 ¦ side-by-side, longitudinally running corrugations having alter-17 ¦ nating, relatively narrow corrugation peaks 62 (of a width sub-18 ¦ stantially equal to the corrugation troughs of the upper corru-19 ¦ gated plate 56) and relatively wide corrugation troughs 64. One 20 ¦ of the lateral edge portions 66 is stepped down so as to nest 21 ¦ with short side flanges 68 of the adjoining corrugated plate 22 ¦ section so that the overlapping portions can be secured to each 23 ¦ other, for example, with bolts 70.
24 The embodiment of the invention illustrated in Fig. 5 is adapted for greater spans, say for a span of 45 feet. For 26 AASHTO-HS 20-44 loading requirements, the corrugated plates has a 27 23-inch pitch, a corrugation height of 8 inches and a plat,e 29 thickness of 3/16th with a yield strength of 50,000 psi. The I 1~90512 1 concrete layer thickness is 6~3/4 inch while the upper plate has 2 a ttrough) root section width of about 2 inches and the lower 3 plate has a root section width of about 13 inches. By increasing 4 the corrugation height to 12" and the plate thickness to 1/4" the bridge can have a span up to about 65 feet.
61 Referring to Figs. 5 and 7, the lower corrugated plate 7 I 58 may extend over the full length of the upper corrugated plate 8 56 as is shown for the first lower corrugated plate in Fig. 7.
9 The lower corrugated plates, however, may span a distance less than the full length of the upper corrugated plate as is the case 11 with lower corrugated plates 72, 74 and 76 shown in Fig. 7. In ? such an event, ends 78 of the lower corrugated plates terminate 13l short of abutments 4 and the plates are centered with respect to 14¦ the longitudinal extent of the bridge so that they strengthen the 15 ¦bridge where it ls subjected to greatest stress.
16 I To prevent the accumulation of moisture and debris 17 ¦ within and to prevent animals from gaining access to the hollow 18 ¦interior of the lower corrugated plate through their open ends 19 178, Z-shaped end plates 79 or L-shaped end plates 81 may be 20 ¦suitably placed over the open ends as is illustrated in Fig. 7 21 ¦ and secured to the adjoining corrugation.
22 ¦ Figs. 7 and 10 also illustrate the manner in wich 23 ¦bridge 2 is supported by abutments 4. Each abutment includes a 24 ¦protruding ledge 120 on which is formed a pedestal 122. Ends 124 25 Iof the uppermost corrugated plate 56 and, as illustrated in Figs.
26 7 and 10 of the next lower corrugated plate 58, overlap the 27 pedestals and rest thereon. An elastomeric bearing pad 126 is 29~ interposed between the corrugated plates and the pedestal.
~ ~90~2 l Preferably, each corrugated plate end 124 is defined by ¦
2 a generally L-shaped end plate 128 which is suitably secured, 3 e.g. welded to the corrugated plates 56, 58 and which includes a 4 lower, horizontal leg 130 which rests on the elastomeric bering 51 pad. Anchor bolts 132 protrude from the abutment led~e 120 and 6 ¦ extend through suitably placed holes in the horizontal leg of the 7 ¦ end plate. Nuts attach the end plate and, therewith, the cor-8 ~ rugated plates and the entire bridge to the anchor bolts and the 9 ¦ abutment. To permit thermal expansions of the bridge the anchor 10 ¦bolt holes in the horizontal leg 130 of one of the end plates 128 11 ¦ are elongated in the direction of the length of the bridge.
l? Referring now to Fig. 6, in yet another embodiment of 13 the invention, a bridge 80 is constructed of at least one upper 14 carrugated plate 82 and one lower corrugated plate 84, each of which is constructed of corrugated plate sections 86 which define l& alternating corrugation peaks and corrugation troughs 88, 90 17 which are laterally offset by one-half corrugation pitch so that 18 corrugation troughs of the upper plate are aligned with corru-l9 gation peaks of the lower plate. Placed directly on top of the upwardly facing surface of the upper corrugated plate is a con-21 crete layer 92 which defines traffic carrying surface 14 of the 22 bridge.
23 To anchor the concrete layer to the corrugated plate, 24 the latter is constructed of so-called checkered plate, arranged for example in a diamond pattern so that raised protrusions 94 26 which are uniformly distributed over the corrugated plate and 27 depressions defined by them face upwardly. The need for concrete 2B a choring st~ds (sho~n in Figs. 2-5) is there~y eliminated. The ~1 22 .
l.~9~)Sl~ I
I protrusiOns, which typically extend upwardly from a remainder of 2 the plate by up to l/8th inch or more, form a uniform, i.e.
3 evenly distributed mechanical interlock between the concrete 4 layer and the corrugated plate and thus, integrate the latter 5¦ with the former into a load bearing structure.
61 Since concrete has little tensional strength and since 71 the corrugations of the upper and lower plates have little trans-I verse strength, a flat plate 96 defined by a plurality of inter-9¦ connected flat plate sections 98 is used so as to render the flat 10¦ plate structurally continuous over the width of the corrugated 11¦ plate. The flat plate is interposed between the upper and lower ?~ corrugated plates 82, 84 to prevent the corrugations of the 13 plates from being opened, that is from being spread apart in a 14¦ lateral bridge direction when the bridge is subjected to its 5¦ design load. Thus, flat plate 96 performs the same function as ,61 the flat plates illustrated in Figs. 2-5 but, in the embodiment 17 ¦ ill~strated in Figs. 6, it is spaced apart from the concrete 18 ¦ layer by the upper corrugated plate. The flat plate itself is 19 ¦suitably secured to the corrugation troughs and peaks of the 20 ¦ upper and lower corrugated plates, respectively, as by welding or 21 ¦bolting it thereto.
22 ¦ For a sectional or modular construction of the bridge, 23 ¦ that is for a construction in which each corrugated plate section 24 ¦ has a width less than the overall width of the bridge, each 25 ¦section is fitted with a longitudinally extending, relatively 26 ¦ short side flange 100 along one edge of the section and a longi-27 ¦ tudinally extending, relatively wide side flange 102 on the 29 jopposite side of the section so that portions of the relatively l ~.~9()53LZ
1~ wide flanges of the upper and lower sections overlap and can be 21 secured, e.g. bolted to each other.
3l In the embodiment of the invention illustrated in Fig.
4 6, the upper corrugated plate is preferably constructed of 5' checkered steel plate while the lower corruga~ed plate is con-6 ¦ structed of regular steel plate, both of which have a yield 7 ¦ stress of 50,000 psi. For the AASHTO-HS 20-44 loading require-81 ments the plates have a thickness of 3/16th inch a corrugation 9 ¦ pitch of between 16 to 18 inches, and a corrugation depth of 10 ¦ between 6 and 8 inches. The flat plate 96 also has a 3/16th inch 11 ¦ thickness while the concrete protrudes 2 to 3 inches above the ~ ¦ corrugation peaks of the upper corrugated plate. Such a struc 13 ¦ ture is suitable for span lengths of between 20 to 40 feet. Of 14 course, by adding additional lower corrugated plates the span length of the bridge can be increased as may be required.
16 I Referring now briefly to Figs. 8 and 9, a longitu-17 ¦ dinally extending guard rail 104 may be installed along lateral 18 ¦ edges 106 of the bridge by arranging over the length of the 19 ¦ bridge a plurality of generally L-shaped channel members 108 20 ¦ (which may have the same profile as the corrugations of corru-21 I gated plate 6). Each channel member includes a horizontal por-22 ¦ tion 110 secured to the underside of corrugations 8 of the corru-23 I gated plate with bolts 112, for example~ A vertical portion 114 24 ¦ of the channel member protrudes above road bed 14 and the guard 25 I rail is secured, e.g. bolted to its upper end. A gusset plate 26 I 116 is preferably bolted to the corrugated plate in alignment 27 ¦ with the channel member and welded to the latter. It includes a 28 I protruding section 118 which is secured, e.g. welded to the 29 channel member to rigidify its vertical portion.
Claims (19)
1. A bridge for carrying traffic comprising as essentially the sole load carrying members of the bridge between spaced apart supports for the bridge, a corrugated plate having side-by-side, parallel corruga-tions defined by alternating corrugations peaks and corrugation troughs, the corrugations being oriented in the direction of the length of the bridge and plate;
plate means connected to the corrugation peaks, defin-ing a traffic carrying surface of the bridge, being structurally continuous over substantially the full width of the corrugated plate, and having a sufficient strength and rigidity for distributing a point load applied to the traffic carrying surface in a lateral direction over a plurality of adjoining corrugations to thereby prevent a spreading apart of the corrugations under the point load; the corrugated plate being de-fined by multiple, side-by-side corrugated members, each such member being defined by a generally V-shaped upwardly open channel section and first and second, laterally protruding flanges continuous with the chan-nel section, the flanges extending over the full length of the section, the first flange having a lateral ex-tent which is less than the lateral extent of the sec-ond flange, the lateral extent of the second flange being further sufficient so as to completely cover an adjoining V-shaped channel section and overlap the sec-ond flange of such adjoining section; and means for securing overlapping portions of the second flanges of adjoining sections to each other; whereby the joined second flanges defined a second plate means.
plate means connected to the corrugation peaks, defin-ing a traffic carrying surface of the bridge, being structurally continuous over substantially the full width of the corrugated plate, and having a sufficient strength and rigidity for distributing a point load applied to the traffic carrying surface in a lateral direction over a plurality of adjoining corrugations to thereby prevent a spreading apart of the corrugations under the point load; the corrugated plate being de-fined by multiple, side-by-side corrugated members, each such member being defined by a generally V-shaped upwardly open channel section and first and second, laterally protruding flanges continuous with the chan-nel section, the flanges extending over the full length of the section, the first flange having a lateral ex-tent which is less than the lateral extent of the sec-ond flange, the lateral extent of the second flange being further sufficient so as to completely cover an adjoining V-shaped channel section and overlap the sec-ond flange of such adjoining section; and means for securing overlapping portions of the second flanges of adjoining sections to each other; whereby the joined second flanges defined a second plate means.
2. A bridge longitudinally suspended be-tween spaced apart abutments for carrying traffic and comprising as the sole load carrying members between the abutments: a corrugated plate including a plurality of side-by-side corrugations extending longi-tudinally between the abutments and having a generally trapezoidal cross section, the corrugations being de-fined by alternating corrugation peaks and corrugation troughs each of which includes a generally flat, rela-tively narrow peak section; and a correspondingly shaped and oriented trough section; plate means rigidly secured to the corrugated plate and including a layer of concrete defining a traffic carrying surface of the bridge and a flat plate disposed substantially parallel and spaced apart from the surface, the concrete layer and the flat plate means being rigidly interconnected and having a sufficient rigidity so that the plate means distributes a point load applied to the traffic carrying surface in a lateral direction over a plurality of corrugations.
3. A bridge according to claim 2 wherein the flat plate is disposed generally above the corru-gated plate, and including means for rigidly connecting the concrete layer directly to the flat plate.
4. A bridge according to claim 2 wherein the flat plate is disposed generally beneath the corru-gated plate, and including means for rigidly securing the flat plate to an underside of the corrugated plate, and means for rigidly securing the concrete layer to an upper side of the corrugated plate.
5. A bridge according to claim 2 including at least one lower corrugated plate disposed generally beneath the first mentioned corrugated plate, the lower corrugated plate having longitudinally extending, side-by-side corrugations, and means for rigidly securing the lower corrugated plate to the upper corrugated plate so as to define between the corrugated plates a plurality of longitudinally extending tubular members.
6. A bridge according to claim 5 wherein the lower corrugated plate is also defined by corruga-tion peaks and corrugations troughs defining flat peak sections and corresponding trough sections, and wherein the corrugation trough sections of the first mentioned corrugated plate are connected to the peak sections of the lower corrugated plate.
7. A bridge according to claim 5 wherein the lower corrugated plate is also defined by corruga-tion peaks and corrugation troughs defining flat peak sections and corresponding trough sections, and wherein the corrugation peak sections of the first mentioned corrugated plate are connected to the trough sections of the lower corrugated plate.
8. A bridge according to claim 2 wherein the corrugated plate and the flat plate are constructed of a corrosion resistant steel.
9. A bridge according to claim 2 including a plurality of lower corrugated plates disposed beneath and rigidly secured to the first mentioned corrugated plate, at least some of the lower corrugated plates having a length less than the spacing between the abut-ments and having ends terminating short of the abut-ments.
10. A bridge according to claim 2 wherein the corrugated plate and the flat plate are constructed of stainless steel.
11. A bridge for suspension between spaced apart abutments comprising as the sole load carrying and distributing members a material layer defining a generally flat traffic carrying surface, a plurality of longitudinally extending, parallel and upwardly opening channel members arranged side-by-side, each channel member including a generally horizontally disposed flange protruding laterally from an upper end of the channel member and extending over the full length of the channel member, the flange having a width greater than the lateral spacing between adjoining channel mem-bers so that portions of the flanges of adjoining mem-bers overlap and means for rigidly securing overlapping portions of the flanges of adjoining channel members to each other to thereby define a corrugated plate having longitudinally extending corrugations and a sub-stantially flat plate immediately beneath the concrete layer, the bridge further including means defining a mechanical interlock between the material layer and the flat plate so as to form a rigid, lightweight, uniform structure.
12. A bridge for carrying vehicular traffic between spaced-apart abutment means comprising as sub-stantially the sole load carrying members of the bridge between the abutment means a corrugated metal plate having side-by-side, parallel corrugations defined by alternating corrugation peaks and corrugation troughs, the corrugations being oriented in the direction of the length of the bridge; a flat metal plate having an effective width substantially equal to the width of the corrugated plate; means securing the flat plate to ad-joining corrugations to thereby tie together adjoining corrugations and prevent them from spreading apart in a lateral direction, a layer of concrete placed on top of the corrugated plate and extending over the full length and width thereof for defining a traffic bearing sur-face for the bridge, the layer and the flat plate to-gether having a sufficient rigidity so as to distribute a vehicular point load acting on the traffic bearing surface in a lateral direction over a plurality of cor-rugations; the corrugated plate, the flat plate and the layer of concrete being further formed and dimensioned so that the concrete layer is stressed in compression only when the bridge carries the vehicular traffic; and means forming a rigid interlock between the layer of concrete, the flat plate and the corrugated plate.
13. A bridge according to claim 12 wherein the flat plate is disposed on top of the corrugated plate and wherein the layer of concrete is disposed on top of the flat plate.
14. A bridge according to claim 13 including a plurality of post means secured to the corrugated plate and having an upwardly extending portion disposed lateral of the corrugated plate and protruding upwardly above the traffic bearing surface, and a guard rail extending parallel to the corrugations and secured to the upwardly extending portion of the post means proxi-mate an uppermost end thereof.
15. A bridge according to claim 14 wherein the post means has an L-shaped configuration and in-cludes a substantially horizontal portion, and includ-ing means for securing the horizontal portion to corru-gation troughs of the corrugated plate.
16. A bridge according to claim 12 including at least one lower corrugated plate secured to the un-derside of the first mentioned corrugated plate, the lower plate having a lesser length than the first men-tioned corrugated plate, and means for closing open ends of the lower corrugated plate so as to prevent the accumulation of moisture and debris therein.
17. A bridge according to claim 12 wherein the abutment means defines a generally horizontally oriented ledge for receiving the supporting respective ends of the corrugated plate, and further including a generally L-shaped end plate secured to the corrugated plate for defining the ends of the latter, the end plate including a horizontally disposed leg carried by the ledge.
18. A bridge according to claim 17 including anchor bolts protruding upwardly from the ledge; and wherein the horizontal leg is secured to the anchor bolts.
19. A bridge according to claim 18 including means defining a bearing surface for the horizontal leg interposed between the ledge and the horizontal leg.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CA000544919A CA1290512C (en) | 1987-08-19 | 1987-08-19 | Lightweight bridge structure |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CA000544919A CA1290512C (en) | 1987-08-19 | 1987-08-19 | Lightweight bridge structure |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1290512C true CA1290512C (en) | 1991-10-15 |
Family
ID=4136307
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA000544919A Expired - Lifetime CA1290512C (en) | 1987-08-19 | 1987-08-19 | Lightweight bridge structure |
Country Status (1)
| Country | Link |
|---|---|
| CA (1) | CA1290512C (en) |
-
1987
- 1987-08-19 CA CA000544919A patent/CA1290512C/en not_active Expired - Lifetime
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| US4706319A (en) | Lightweight bridge structure | |
| US4129917A (en) | Bridge structure | |
| US4300320A (en) | Bridge section composite and method of forming same | |
| US4120065A (en) | Lightweight modular, truss-deck bridge system | |
| US9163392B2 (en) | Reinforcement rib and overhead structure incorporating the same | |
| US4211504A (en) | High strength corrugated metal plate and method of fabricating same | |
| US4099359A (en) | High strength corrugated metal plate and method of fabricating same | |
| US4186541A (en) | High strength corrugated metal plate and method of fabricating same | |
| US4220423A (en) | High strength corrugated metal plate and method of fabricating same | |
| US3894370A (en) | Reinforced structures incorporating strip deck material | |
| US7069614B1 (en) | Modular span multi-cell box girder bridge system | |
| US6467223B1 (en) | Composite concrete and steel floor/carrier for modular buildings | |
| US5152112A (en) | Composite girder construction and method of making same | |
| CN209923769U (en) | Section steel-UHPC combined plate and bridge deck | |
| US5966764A (en) | Roll beam girder system for bridges | |
| EP0010733A1 (en) | Guideway units for elevated guideways | |
| CA1290512C (en) | Lightweight bridge structure | |
| US4742591A (en) | Cable stayed bridge having box edge beams and method of construction | |
| CN112281656A (en) | Combined multi-span bridge plate connecting structure | |
| EP0685018B1 (en) | Bridge structure | |
| EP0393091B1 (en) | A load-bearing horizontal structural system for a building | |
| CN212956124U (en) | Combined multi-span bridge plate connecting structure | |
| EP0385998B1 (en) | Floor structure for buildings | |
| CN218541131U (en) | Pretensioned prestressing floor | |
| JPH0230492Y2 (en) |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| MKLA | Lapsed |