Reinforcement part

Abstract

A boss (1000) for assembly with a part. The boss comprises a flange member (1002) arranged to abut a face of the part and a cylindrical body (1004). The cylindrical body of the boss arranged to be inserted into the part. The flange member is arranged to be removably mounted to the cylindrical body.

Description

[0001] REINFORCEMENT PART

[0002] FIELD OF THE INVENTION

[0003] The present invention relates to a structural reinforcement. More specifically, the invention relates to a boss for assembly with a part, and a method for structurally reinforcing a girder.

[0004] BACKGROUND OF THE INVENTION

[0005] In the construction of girder bridges, a plate of the girder, or a splice connection between multiple beams of a girder, may be under strengthened and thus require structural reinforcement. Existing methods of structural reinforcement require the girder(s) to be propped from below and / or the live load on the bridge to be restricted, while the under strengthened plate or splice connection is removed and a replacement is fitted, so as to ensure the bridge does not collapse.

[0006] The requirement that the bridge be propped in this way means that the structural reinforcement process is labour-intensive and time consuming. Furthermore, when the bridge being reinforced spans a road or a railway, the propping process will cause major disruption to the traffic on the road or railway below, as a propping mechanism must be set up beneath the bridge. Similarly, when the bridge being reinforced carries traffic, the requirement that the live load on the bridge be restricted (for example closing the bridge to road and rail traffic) is inconvenient and disruptive.

[0007] GB2268561 A describes a bolt security device that consists of a washer, hardened steel bush and a hardened steel bucket that is placed onto a bolt.

[0008] GB 2582840 A describes a boss for assembly with a part has a roughened portion for engaging a face of the part, and a method of reinforcing a girder.

[0009] SUMMARY OF THE INVENTION

[0010] According to an aspect of the invention, there is provided a boss for assembly with a part, the boss comprising a flange member arranged to abut a face of the part and a cylindrical body, the cylindrical body of the boss arranged to be inserted into the part, wherein the flange member is arranged to be removably mounted to the cylindrical body.

[0011] Optionally, the flange member has a smooth surface for engaging the face of the part.

[0012] Optionally, the smooth surface comprises a Greenkote® or Hot Dip Galvanised coating.

[0013] Optionally, the smooth surface is smooth to a surface finish roughness average (Ra) of less than 3.2 microns, preferably, to a surface finish roughness average of less than 1.2 microns.

[0014] Optionally, the smooth surface is in accordance with ISO 21920-1.

[0015] Optionally, the entire surface for engaging the face of the part is smooth.

[0016] Optionally, the flange member has a flange through hole, the cylindrical body has a cylindrical body through hole, wherein the flange and cylindrical body through holes align to define a boss through hole that extends through the boss, wherein the boss through hole is arranged to receive a bolt.

[0017] Optionally, the boss through hole is unthreaded.

[0018] Optionally, the flange through hole is chamfered.

[0019] Optionally, the cylindrical body through hole is chamfered.

[0020] Optionally, the chamfer of the flange through hole and / or the chamfer of the cylindrical body through hole is arranged to guide a bolt into the boss through hole.

[0021] Optionally, the chamfer on the flange through hole matches a chamfer between an underside of a head of the bolt and a shank of the bolt, wherein the bolt is arranged to be received in the boss through hole.

[0022] Optionally, the flange member and cylindrical body are formed from the same material.

[0023] Optionally, the flange member and cylindrical body are formed of material comprising different tensile strength.

[0024] Optionally, the boss comprises carbon steel.

[0025] Optionally, the boss comprises S355 Structural Steel.

[0026] In another aspect of the invention there is provided a kit of parts, or an assembly, comprising a boss according to any preceding claim, and a bolt arranged to fit within the boss.

[0027] Optionally, the bolt is a tension control bolt.

[0028] Optionally, the bolt is arranged to fit within the boss via a tolerance fit.

[0029] Optionally, the kit of parts, or an assembly described herein, comprises the boss described herein.

[0030] Optionally, the part is a strengthening member.

[0031] Optionally, the part is a strengthening plate.

[0032] Optionally, when the boss and the part are assembled, at least a part of the boss is inserted into said part.

[0033] Optionally, when the boss and the part are assembled, the cylindrical body of the boss is inserted into said part. Optionally, when inserted into said part, the cylindrical body of the boss extends into said part no further than the thickness of the part.

[0034] Optionally, the face of said part has a roughened portion arranged to engage with flange member, thereby to inhibit relative movement between the boss and said part.

[0035] Optionally, the flange member has a smooth surface to engage with the roughened portion of the part.

[0036] Optionally, the said part has at least one through hole arranged to receive a portion of the boss.

[0037] Another aspect of the invention provides a girder comprising: at least one understrengthened plate; one or more strengthening plates; and a boss as described herein assembled with the one or more strengthening plates.

[0038] Optionally, when assembled with the one or more strengthening plates, at least part of the boss is inserted into the one or more strengthening plates.

[0039] Optionally, the under-strengthened plate and the one or more strengthening plates are arranged one on top of the other, and wherein the part of the boss inserted into the strengthening plate extends through the one or more strengthening plates no further than the thickness of the strengthening plate or the combined thickness of the strengthening plates.

[0040] Another aspect of the invention provides a structure incorporating an assembly or a girder described herein.

[0041] Another aspect of the invention provides a method of manufacturing a boss for assembly with a part, the method comprising: providing a flange member arranged to abut a face of the part; separately providing a cylindrical body, wherein in use, the flange member is mountable to the cylindrical body. Optionally, providing the flange member comprises laser cutting a sheet of material.

[0042] Optionally, providing a cylindrical body comprises turning or machining a piece to form the cylindrical body on a lathe.

[0043] Optionally, providing a cylindrical body comprises cold forming a piece to form the cylindrical body.

[0044] Optionally, the method further comprises smoothing a surface of the flange member that is arranged to abut a face of the part.

[0045] Optionally, the smoothing a surface of the flange member comprises manufacturing the flange in accordance with ISO 21920-1.

[0046] Another aspect of the invention provides a method of structurally reinforcing a girder, the method comprising: determining a section of the girder that requires strengthening, said section being joined together with at least one other section by a plurality of fasteners; positioning a strengthening member against the section that requires strengthening; and fastening the strengthening member to the girder without removing said section; wherein the fastening comprises removing and replacing at least one such fastener via an opening in the strengthening member.

[0047] Optionally, removing at least one such fastener comprises extracting the at least one fastener through the opening in the strengthening member.

[0048] Optionally removing at least one such fastener comprises drilling the at least one fastener through the opening in the strengthening member.

[0049] Optionally, replacing at least one fastener comprises, after removing the at least one fastener, inserting a boss into the opening of the strengthening member. Optionally, the boss comprises a flange member arranged to abut a face of the strengthening member and a cylindrical body, the cylindrical body arranged to be received within the opening of the strengthening member, wherein the flange member is arranged to be removably mounted to the cylindrical body.

[0050] Optionally, the flange member comprises a smooth surface for engaging the face of the strengthening member.

[0051] Optionally, when the boss is inserted into the opening of the strengthening member, the cylindrical body of the boss extends through the strengthening member to meet the section of the girder that requires strengthening.

[0052] Optionally, replacing at least one fastener further comprises, after inserting the boss into the opening of the strengthening member, inserting a replacement fastener through a through-hole of the boss, such that the replacement fastener is secured through the strengthening member and the section of the girder that requires strengthening.

[0053] Optionally, the boss is arranged to receive the replacement fastener through the through- hole via a tolerance fit.

[0054] Optionally, the replacement fastener is the same fastener that was previously removed.

[0055] Optionally, the strengthening member comprises a plurality of openings positioned to correspond with the positions of the plurality of fasteners.

[0056] Another aspect of the present invention provides a method of structurally reinforcing a girder, the method comprising: determining a section of the girder that requires strengthening, said section being joined together with at least one other section by a plurality of fasteners; positioning a strengthening member against the section that requires strengthening; and fastening the strengthening member to the girder without removing said section; wherein the strengthening member comprises a plurality of openings positioned to correspond with the positions of the plurality of fasteners. Optionally, the openings of the strengthening member are sized to accommodate heads of the fasteners.

[0057] Optionally, the method further comprises fabricating the strengthening member, wherein fabricating the strengthening member comprises forming openings in the strengthening member corresponding to the positions of the plurality of fasteners.

[0058] Optionally, forming openings comprises drilling the openings in the strengthening member.

[0059] Optionally, the said fastening comprises accessing the fasteners individually via their corresponding openings in the strengthening member to remove and replace the fasteners.

[0060] Optionally, the fasteners are removed and replaced individually in succession, or in successive groups.

[0061] Optionally, the method further comprises surveying the girder to identify the positions of at least some of the plurality of fasteners.

[0062] Optionally, the plurality of fasteners is a plurality of rivets and / or bolts.

[0063] Optionally, the at least one of the fasteners is replaced with a tension control bolt.

[0064] Optionally the strengthening member is fastened to the girder while the section of the girder that requires strengthening remains joined to the girder by at least one of the plurality of fasteners.

[0065] Optionally the method further comprises applying a layer of a self-levelling compound between the section of the girder that requires strengthening and the strengthening member. Optionally, a spacer plate is positioned between the section of the girder that requires strengthening and the strengthening member.

[0066] Optionally, the strengthening member is a strengthening plate.

[0067] Optionally, the section of the girder that requires strengthening is a splice connection between girders.

[0068] Optionally, the method is used to structurally reinforce one or more girders in a bridge.

[0069] Another aspect of the invention provides a girder structurally reinforced using a method as described herein.

[0070] Another aspect of the invention provides a structure such as a bridge incorporating a girder as described herein.

[0071] BRIEF DESCRIPTION OF THE DRAWINGS

[0072] Embodiments of the invention will now be described with reference to the accompanying drawings, in which:

[0073] Figure 1 shows a perspective view of an assembled boss;

[0074] Figure 2 shows a flange member;

[0075] Figure 3 shows a cylindrical body;

[0076] Figure 4 shows an underside perspective view of an assembled boss;

[0077] Figure 5 shows a side view of an assembled boss;

[0078] Figure 6 shows a top-down view of an assembled boss;

[0079] Figure 7 shows a girder which requires structural reinforcement;

[0080] Figure 8 shows the first step in a method of structurally reinforcing a girder;

[0081] Figure 9 shows the third step in the method of structurally reinforcing a girder;

[0082] Figure 10 shows a fourth step in the method of structurally reinforcing a girder;

[0083] Figure I la shows the fifth step in the method of structurally reinforcing a girder;

[0084] Figure 1 lb shows an exploded view of the girder; Figure 12 shows the sixth step in the method of structurally reinforcing a girder; Figure 13 shows a cross-sectional view of the girder which requires structural reinforcement;

[0085] Figure 14 shows a cross-sectional view of the girder, showing the result of the method.

[0086] Figure 15 shows a cross-sectional view of the girder which requires structural reinforcement.

[0087] Figure 16 shows a cross-sectional view of the girder, showing the result of the method.

[0088] DETAILED DESCRIPTION OF EMBODIMENT(S)

[0089] Figure 1 shows an assembled boss 1000. The boss 1000 is formed from two parts, a cylindrical body 1002 and a flange member 1004. As shown, in an assembled form, flange member 1004 is mounted on to the cylindrical body 1002. The boss 1000 has a boss through hole 1006 that is defined by a flange through hole 1008 (shown in Figure 2) and a cylindrical body through hole 1010 (shown in Figure 3). The boss through hole 1006 has a central axis A and is appropriately dimensioned to receive a bolt therein. The boss through hole 1006 extends through the boss 1000, i.e. through the flange member 1004 and the cylindrical body 1002. As shown in Figure 1, the boss through hole is unthreaded so as to receive a bolt. However, in other examples, the boss through hole may be threaded and the boss 1000 may be arranged to receive a threaded fastener instead.

[0090] Figure 2 shows the flange member 1004 in greater detail. The flange member 1004 is ring-shaped with a diameter DI and a height hl. The flange member 1004 has a flat upper surface 1012 and an opposing flat lower surface 1014. The flange member 1004 has a flange through hole 1008 is formed through the centre of the flange member 1004 and extends from an opening in the upper surface 1012 to an opening in the lower surface 1014. The flat upper and lower surfaces 1012, 1014 of the flange member 1004 extend perpendicular to a central axis of the flange through hole 1008. The flange member 1004 is arranged to be removably mounted onto the cylindrical body 1002. Both openings of the flange through hole 1008 are chamfered, although the opening in the upper surface 1012 is shown to be chamfered in Figure 2. In other examples, only the opening in the upper surface 1012 may be chamfered, or alternatively, the opening in the lower surface 1014 may be chamfered. The chamfered opening(s) of the flange through hole 1008 help guide a bolt into the flange through hole 1008. Once the flange member 1004 is mounted onto the cylindrical body 1002 to form the boss 1000, the chamfered opening(s) of the flange through hole 1008 helps guide a bolt into the boss through hole 1006. In the instance where the opening in the upper surface 1012 is chamfered, preferably, the chamfer matches a chamfer between an underside of a head of the bolt and a shank of the bolt that is arranged to be received into the flange through hole 1008 (and ultimately, the boss through hole 1010). In this instance, the chamfered opening in the upper surface 1012 matches the angled surface between the bolt head and bolt shank. The bolt head can therefore be received in the flange through hole 1008 so that the bolt head sits flush against the part once the boss 1000 is installed.

[0091] Figure 3 shows the cylindrical body 1002 in greater detail. The cylindrical body 1002 is a hollow cylinder with a diameter D2 and a height h2. The cylindrical body 1002 has a flat upper surface 1016 and an opposing flat lower surface 1018. The cylindrical body 1002 has a cylindrical body through hole 1010 that is formed through the centre of the cylindrical body 1002 and extends from an opening in the upper surface 1016 to an opening in the lower surface 1018. The flat upper and lower surfaces 1016, 1018 of the cylindrical body 1002 extend perpendicular to a central axis of the cylindrical body through hole 1010.

[0092] Both openings of the cylindrical body through hole 1010 are chamfered, as shown in Figures 3 and 4 respectively. In other examples, only the opening in the upper surface 1016 may be chamfered, or alternatively, only the opening in the lower surface 1018 may be chamfered. Similarly, to the chamfered opening(s) of the flange through hole 1008, the chamfered opening(s) of the cylindrical body through hole 1010 are also arranged to help guide a bolt into the cylindrical body through hole 1010.

[0093] The flange member 1004 is arranged to be removably mounted to the cylindrical body 1002. The flange member 1004 is mounted to the cylindrical body 1002 by abutting the lower surface 1014 of the flange member 1004 with the upper surface 1016 of the cylindrical body 1002. The flange member 1004 is mounted to the cylindrical body 1002 so that a central axis of the flange through hole 1008 is aligned with a central axis of the cylindrical body through hole 1010. Preferably, the central axis of the flange through hole 1008 is collinear with the central axis of the cylindrical body through hole 1010. The boss 1000 is assembled once the flange member 1004 is mounted onto the cylindrical body 1002.

[0094] Once mounted, a part of the lower surface 1014 of the flange member 1004 contacts the upper surface 1016 of the cylindrical body 1002. The remaining, exposed part of the lower surface 1014 is arranged to contact a surface of a part that the boss 1000 is inserted, or at least partly inserted into. The exposed part of the lower surface 1014 that contacts the part is also called the faying surface of the boss, which is discussed in greater detail below. As shown in Figure 1, the diameter DI of the flange member 1004 is generally larger than the diameter D2 of the cylindrical body 1002 so that the lower surface 1014 of the flange member 1004 can contact the cylindrical body and the part.

[0095] Figure 4 shows the boss 1000 as viewed from below. The lower surface 1014 of the flange member 1004 has a smooth surface. Preferably, the entire lower surface 1014 is smooth, although only a part of the lower surface 1014 may be smooth.

[0096] Typically, it is known that providing a roughened surface in an engaging surface (i.e. between a first surface of a first component that contacts a second surface of a second component) is advantageous because it increases friction between the first and second surface, and consequently, between the first and second component. This is desirable in mechanical arrangements where longevity of the arrangement is desirable, as the frictional contact inhibits undesirable relative movement of the two components from external forces, such as vibration or torque, which could cause de-adjustment of the two components.

[0097] In the technical field of mechanical engineering, the skilled person has a strong technical prejudice to presume that providing a roughened surface is a requirement for providing a sufficiently secure mechanical arrangement. This is further particularly true within the industry of engineering where longevity of the arrangement is an important factor for a skilled person to consider, and the mechanical arrangement is used in an environment that is exposed to large amounts of external forces, such as vibration, during use.

[0098] The inventors, therefore, were particularly surprised to discover that providing a smooth lower surface 1014 provides adequate frictional grip between the flange member 1004 and the plate.

[0099] In the case where the boss 1000 is inserted, or at least part of the boss is inserted, in a through hole of a plate, and where the flange member 1004 is arranged to contact a surface of the plate, the smooth lower surface 1014 provides adequate frictional grip between the flange member 1004 and the plate.

[0100] The friction grip between the boss and the plate inhibits relative movement of the boss 1000 and the plate. The smooth surface of the faying surface ensures that the correct frictional engagement occurs between the boss and the plate underneath.

[0101] As the flange member 1004 is provided as a separate component from the cylindrical body 1002, it is easy to effectively smooth the whole of the lower surface 1014 of the flange member 1004. One method of preparing the smooth surface is to use a CNC machine in accordance with ISO 21920-1 to smooth a surface of the boss 1000. Alternatively, the smooth surface may be manufactured during the cold forming process. The methods smooths the lower surface 1014 of the flange member 1004 preferably to a surface finish roughness average (Ra) of less than 3.2 microns. Preferably, the lower surface 1014 of the flange has a surface finish roughness average of less than 1.2 microns. The smooth surface 1014 of the flange member 1004 is a faying surface for assembly of the boss with a part, such as a plate or girder.

[0102] The flange member 1004 and cylindrical body 1002 may be independently manufactured prior to assembly. For example, the flange member 1004 may be formed by using a laser cutter or by turning a piece on a CNC machine or lathe. In this example, a piece of material may be provided with a height hl that corresponds with the desired height hl of the flange member 1004. The material may then be mounted on a laser cutter, before the piece of material is cut to the correct size (i.e. diameter DI) of the flange member 1004. Secondly, the laser cutter forms the flange through hole 1008 by cutting through the centre of the flange member 1004.

[0103] The cylindrical body 1002, on the other hand, may be formed using a lathe. In this example, a piece of material is machined to a diameter D2 to form the cylindrical body 1002. Then, a cylindrical body through hole 1010 is created by boring through the centre of the cylindrical body 1002. Alternatively, the cylindrical body 1002 may be formed by a cold forming process using a cold forming wire. Typically, the cold forming wire has a different diameter than the final diameter (D2), as the material is forced into the die to form the cylindrical body 1002.

[0104] The flange member 1004 and cylindrical body 1002 may be formed from the same material, such as carbon steel. Alternatively, the flange member 1004 and cylindrical body 1002 may be formed from similar materials with differing tensile strengths, such as EN8A and S355. The boss 1000 may be tailored depending on the part that the boss is inserted in to. Preferably, the boss 1000 comprises carbon steel, or any suitable metal with a yield strength of at least 355N / mm2 such as S355 Structural Steel.

[0105] Forming the boss 1000 from two separate components (i.e. providing the flange member 1004 and the cylindrical body 1002 separately) enables the boss 1000 to be manufactured easier and quicker in comparison to a boss 1000 that is formed from as a single, unitary part. In this arrangement, the flange member 1004 and cylindrical body 1002 can be manufactured independently in simple manufacturing processes. The manufacturing processes for forming the flange member 1004 and the cylindrical body 1002 also generates less the waste material in comparison to the manufacturing process required to form a boss part from one piece of material. Furthermore, the two-part boss 1000 shown in Figures 1-6 may be easily manufactured using readily available cylindrical components and bodies. Manufacturing the boss 1000 using two parts also enables the size of the boss 1000 to be customised. The cylindrical body 1002 and the flange member 1004 can be manufactured to accommodate different sizes of bolts, or to ensure that the cylindrical body 1002 is received correctly in the part.

[0106] The cylindrical body 1002 and the flange member 1004 may have a layer of surface protection coating applied. The surface protection coating is preferably Greenkote®. The Greenkote® coating can be applied on to the cylindrical body 1002 and / or flange member 1004 without the need for an etching primer layer being used, which provides advantages over zinc based plated coatings, which do require an etching primer layer. Applying fewer layers of coating to the smooth surface of the boss enhances the smoothing effect of the coating, As described. In addition, bolts (specifically, tension control bolts which are preferably used for assembly of the boss with a part) are typically also coated with Greenkote®. Instead of Greenkote®, the cylindrical body 1002, flange member 1004 and / or bolt may have a surface protection coating formed by hot dip galvanising, painting or electro zinc plating.

[0107] As described above, the cylindrical body 1002 of the boss 1000 is arranged to be inserted into a part, while the lower surface 1014 of the flange member 1004 being arranged to abut against a face of the part. The face of the part that contacts the lower surface 1014 of the flange is a corresponding faying surface to the boss 1000. The faying surface of the part is a face of the part. The smooth, lower surface 1014 of the flange member 1004 therefore engages the face of the part. In some examples, only part of the flange faying surface that engages the face of the part may be smooth, but preferably, the entire surface of the flange that engages the face of the part is smooth. The faying surface of the part may be roughened, by for example, abrasive blasting (such as sand or grit blasting), knurling the faying surface or machining surface features to the faying surface to form peaks and troughs in the surface. The smooth surface of the flange member 1004 and the rough surface of the part promotes better adhesion between the flange member 1004 and the part so the boss 1000 is less likely to rotate.

[0108] Roughening the faying surface of the part increases the relative friction between the lower surface 1014 of the flange member 1004 and the faying surface of the part when they are in contact to achieve an optimal friction grip between the boss 1000 and the part.

[0109] Figure 5 shows a side view of the boss 1000, while Figure 6 shows the boss 1000 as viewed from above. In the case where the boss 1000 is inserted through hole of a plate, the height h2 of the cylindrical body 1002 is the same or less than the thickness of the plate, so that the lower surface 1018 of the cylindrical body 1002 is flush against the bottom surface of the plate. The flange member 1004 engages with a surface of the plate so as to retain the boss 1000 in position. The outer diameter D2 of the cylindrical body 1002 is substantially the same as the diameter of the through hole of the plate. The inner diameter of the cylindrical body 1002 is substantially the same as the bolt which is received within the through hole so that the bolt has a friction or close tolerance fit within the boss 1000.

[0110] While Figures 1 to 6 show the flange member 1004 of the boss 1000 being circular, the flange could instead be any other appropriate shape, preferably a tessellatable shape. In one example, the circular flange could have segments removed from opposing sides of the circle. In another example, the flange member could be square or hexagonal. In these given examples, the distance from the centre of the boss to the outer edge of the flange is reduced in certain directions. Reducing the distance from the centre of the boss 1000 to the outer edge of the flange member 1004 provides the advantage of reducing the necessary spacing between two bosses which are positioned next to one another, thereby allowing for a higher density of bosses. The boss through hole 1006 would still have a shape and dimensions appropriate to receive a bolt irrespective of the shape of the flange member 1004.

[0111] Figure 7 shows a girder 6000 prior to strengthening; the girder comprises first and second beams 6002 and 6004. The beams each have web plates 6008 and two flange plates 6010 and 6012, where 6010 are the upper flange plates and 6012 are the lower flange plates. The flange plates 6010 and 6012 are coupled to the web plates 6008 by means of angled sections 6014. The angled sections 6014 are coupled to the upper flange plates by means of a plurality of rivets 6016 and the lower flange plate by means of a plurality of rivets 6018. For each flange plate, the rivets 6016 and 6018 which couple the angled sections 6014 to the flange plates 6010 and 6012 are arranged in two columns, where one column of rivets is arranged to couple one of the angled sections 6014 to the flange plate on one side of the web plate 6008, and the other column of rivets are arrange to couple one of the angled sections 6014 to the flange plate on the other side of the web plate 6008.

[0112] The two beams 6002 and 6004 are connected via first and second splice connections 6020a and 6020b. The splice connections 6020a and 6020b comprise multiple splice plates which overlap with, and are fastened to, existing plates of the beams 6002 and 6004.

[0113] Taking the first splice connection 6020a as an example, the connection comprises a splice plate 6024 which is positioned on the top surface of upper flange plates 6010 of each of the two beams 6002 and 6004. The splice plate 6024 overlaps with the upper flange plates 6010 and the left hand portion of the splice plate 6024 is coupled to the upper flange plate 6010 of the first beam 6002 while the right hand portion of the splice plate 6024 is coupled to the upper flange plate 6010 of the second beam 6004. The second splice connection 6020b also comprises a similar splice plate (not shown) which is positioned on the bottom of the lower flange plates 6012 of the two beams 6002 and 6004.

[0114] Taking the second splice connection 6020b as an example, the connection comprises at least one additional splice plate 6026 which is positioned on the upper surface of the lower flange plates 6012 so as to overlap with both lower flange plates 6012. The left hand portion of the additional splice plate 6026 is coupled to the lower flange plate 6010 of the first beam 6002 while the right hand portion of the additional splice plate 6026 is coupled to the lower flange plate 6010 of the second beam 6004. The first splice connection 6020a also comprises similar additional splice plates (not shown) which are positioned on the bottom of the upper flange plates 6010 of the two beams 6002 and 6004. The splice plate 6024 is coupled to the upper flange plates 6010 of the two beams 6002 and 6004 via a plurality of rivets 6028, which form two columns, one column on either side of the rivets 6016 which couple the flange plates 6010 to the web plates 608 via the angled sections 6014. The additional splice plate 6026 is coupled to the lower flange pate 6012 via a plurality of rivets 6030 which form a single column adjacent the column of rivets 6014 which couple the lower flange plate 6012 to the web plate 6008.

[0115] In construction, a girder such as is shown in Figure 7 may require structural reinforcement, for example because the splice connection between the two beams may be under strengthened. When the girder is used in the construction of a bridge, and the splice connection requires structural reinforcement, the beams may need to be propped from below, and / or the live load on the bridge may need to be restricted, in order to prevent the bridge from collapsing when removing the under strengthened splice plates to fit stronger splice plates.

[0116] While Figure 7 shows a girder comprising two beams which are connected by a splice connection, the girder could instead comprise one single beam. In this case, the girder may require structural reinforcement if either the upper or lower flange plate is under strengthened. Again, when the girder is used in the construction of a bridge, the beam may need to be propped from below, and / or the live load on the bridge may need to be restricted, in order to prevent the bridge from collapsing when removing the under strengthened flange plate in order to fit a stronger flange plate.

[0117] Similarly, while Figure 7 shows the two beams to have a splice connection between their upper and lower flange plates, the two beams could instead have a splice connection elsewhere, for example between their web plates.

[0118] Figure 8 shows a girder 7000. The girder 7000 is the result of the first step of a method of structurally reinforcing a girder being performed on the girder 6000 of Figure 7, where the splice connection 6020a between the upper flange plates 6010 of the beams 6002 and 6004 is under strengthened. In the first step of the method, every other row of rivets 6016 and 6028 is replaced by bolts 7002. The bolts 7002 replace the rivets 6016 and 6028, which couple the upper flange plates 6010 to the web plate 6008 (via the angled sections 6014), and the splice plate 6024 to the upper flange plates 6010, respectively. In order to ensure that the upper flange plates 6010 and the splice connection 6020a are not weakened by the removal of the rivets 6016 and 6028, the rivets 6016 and 6028 are replaced individually so that, when one rivet is removed, a bolt 7002 is fitted in its place before the next rivet is removed. In this way, the rivets 6016 and 6028 can be removed and replaced with bolts 7002 without weakening the bridge, thereby negating the need for the bridge to be propped from below, or for the live load on the bridge to be restricted. Alternatively, one row of rivets 6016 and 6028 may be removed before bolts 7002 are fitted in their place. The rivets 6016 and 6028 are removed by drilling, and the replacement bolts 7002 are installed and tightened in accordance with the manufacturer’s specifications before the next rivet is drilled out.

[0119] The girder 7000 has remaining rivets 6016 and 6028 and bolts 7002 positioned in alternate rows along the girder 7000. The bolts 7002 are tension control bolts of approximately the same diameter as the removed rivet, so that the bolts 7002 have a close tolerance fit within the hole left by the removed rivet. In this example, the bolts are M24 high strength friction grip bolts. The bolts are secured from below by a nut.

[0120] In the case where the method is used to structurally reinforce a girder of a road or rail bridge, where the bridge carries traffic such as cars or trains, this step of the method provides the advantage of reducing the amount of time the bridge needs to be closed to that traffic. This is because the rivets are replaced individually with bolts 7002 while the under-strengthened portion of the girder remains attached. Therefore, the structural integrity of the bridge is not compromised while the rivets 6016 and 6028 are replaced. In this way, the process of replacing the rivets 6016 and 6028 can be interrupted, or completed in stages, so as to allow traffic to flow when required and thus negating the need to restrict the live load on the bridge. In one example, where the bridge is a rail bridge, the process of replacing the rivets 6016 and 6028 with bolts 7002 can be completed across multiple nights during the period where trains are not running over the bridge.

[0121] Additionally, in the case where the method is used to reinforce structurally a girder of a bridge that spans a road or a railway, this step of the method provides the advantage that the bridge does not need to be propped or supported from below while the rivets 6016 and 6028 are replaced with bolts 7002. Therefore, the traffic flowing on the road or railway beneath the bridge need not be interrupted during this step of the method.

[0122] In addition to the replacement of rivets 6016 and 6028 with bolts 7002, this step of the method may include, or be preceded by, a surface preparation of the upper flange plates 6010. The surface preparation may include the application of a self-levelling compound to the top of the upper flange plates 6010.

[0123] In the second step of the method, the girder 7000 is surveyed to locate the positions of the rivets 6016 and 6028 and the bolts 7002.

[0124] Figure 9 shows a girder 8000. The girder 8000 is the result of the third step of the method of structurally reinforcing a girder being performed on the girder 7000 of Figure 8.

[0125] In the third step of the method of structurally reinforcing a girder, two spacer plates 8002 and 8004 are positioned on the top surface of the upper flange plates 6010. The spacer plates 8002 and 8004 are substantially identical to one another, where one plate is positioned on one side of the splice plate 6024 and one plate is positioned on the other side. The spacer plates 8002 and 8004, along with the splice plate 6024, provide a level surface upon which additional plates may be positioned.

[0126] The spacer plates 8002 and 8004 have an array of holes 8006 through the plates. The locations of the holes 8006 correspond to the locations of the rivets 6016 and 6028 and the bolts 7002 of the upper flange plate 6010. The locations of the rivets 6016 and 6028 and bolts 7002 are determined by the surveying of the beam as described with reference to step two of the method. The rivets 6016 and 6028 and the bolts 7002 have heads which form projections above the top surface of the upper flange plates 6010. When the spacer plates 8002 and 8004 are positioned on the top surface of the upper flange plates 6010, the heads of the rivets 6016 and 6028 and bolts 7002 protrude into the holes 8006 of the spacer plates 8002 and 8004 thereby to retain the spacer plates 8002 and 8004.

[0127] The holes 8006 of the spacer plates 8002 and 8004 are circular, and have a diameter which is larger than the diameter of the heads of the rivets 6016 and 6028 and bolts 7002. In this way, the heads of the rivets 6016 and 6028 and the bolts 7002 are able to protrude into the holes 8006 thereby to retain the spacer plates 8002 and 8004 without the need for additional fasteners. Furthermore, the rivets 6016 and 6028 and the bolts 7002 can be removed through the holes 8006 while the spacer plates are in place. In one example, a rivet 6016 can be drilled out by accessing the rivet 6016 through one of the holes 8006. In another example, a bolt 7002 can be unfastened by removing the corresponding nut, and the bolt 7002 can be extracted through the opening provided by the hole 8006. The spacer plates 8002 and 8004 are fabricated, including the drilling of the array of holes 8006, prior to their being transported to the girder to be strengthened.

[0128] As well as the addition of the spacer plates 8002 and 8004 at this step of the method, any gaps between the existing upper flange plates 6010 and the added spacer plates 8002 and 8004 are filled with a self-levelling compound to ensure that any areas of the corrosion of the upper flange plates 6010 are filled to provide a level surface upon which the spacer plates 8002 and 8004 can be fixed.

[0129] In the case where a plate of the girder, rather than a splice connection, requires structural reinforcement, this step of the method may not be necessary, as the plate to be strengthened should already have a level surface.

[0130] Figure 10 shows a girder 9000. The girder 9000 is the result of the fourth step of the method of structurally reinforcing a girder being performed on the girder 8000 of Figure 8.

[0131] In the fourth step of the method of structurally reinforcing a girder, a strengthening member, which is a strengthening plate 9002, is positioned on top of the level surface provided by the splice plate 6024 and spacer plates 8002 and 8004. The strengthening plate 9002 is shaped so as to cover exactly the surfaces of the splice plate 6024 and the spacer plates 8002 and 8004.

[0132] The strengthening plate 9002 has an array of holes 9004 through the plate. The locations of the holes 9004 correspond to the locations of the rivets 6016 and 6028 and the bolts 7002 of the upper flange plate 6010, and are thus aligned with the holes 8006 of the spacer plates 8002 and 8004. The locations of the rivets 6016 and 6028 and bolts 7002 are determined by the surveying of the beam as described with reference to step two of the method. The rivets 6016 and 6028 and the bolts 7002 have heads which form projections above the top surface of the upper flange plates 6010. The heads of the rivets 6016 and 6028 and bolts 7002 may protrude into the holes 9004 of the strengthening plate 9002 when it is in place, thereby to retaining the strengthening plate 9002.

[0133] The holes 9004 of the strengthening plate 9002 are circular, and have a diameter which is larger than the diameter of the heads of the rivets 6016 and 6028 and bolts 7002. In this way, the rivets 6016 and 6028 and the bolts 7002 can be removed through the holes 9004 while the spacer plates are in place. In one example, a rivet 6016 can be drilled out by accessing the rivet 6016 through one of the holes 9004. In another example, a bolt 7002 can be unfastened by removing the corresponding nut, and the bolt 7002 can be extracted through the opening provided by the hole 9004. The strengthening plate 9002 is fabricated, including the drilling of the array of holes 9004, prior to it being transported to the girder to be strengthened.

[0134] This step of the method provides a number of advantages over existing methods of structural reinforcement. Firstly, as the holes 9004 of the strengthening plate 9002 are large enough that the rivets 6016 and 6028 and the bolts 7002 can be removed through the holes 9004, the strengthening plate 9002 can be fixed to the girder without removing the under strengthened section of the girder (for example, the splice plate 6024 or upper flange plate 6010) and thus without weakening the bridge. Therefore, the girder does not need to be propped from below while the strengthening plate is fitted. This is particularly advantageous in the case where the girder is part of a bridge which spans a road or railway, as a propping structure will not have to be erected below the bridge and thus the road or railway will not need to be closed. This is also advantageous where the bridge spans a body of water. Similarly, the live load on the bridge need not be restricted while the strengthening plate is fitted, therefore avoiding the inconvenience and disruption which would be caused by closing the bridge to traffic.

[0135] Secondly, as the under strengthened section of the girder does not need to be removed for the strengthening plate 9002 to be attached, the structural integrity of the girder is not compromised at any step of the method. Therefore, the method can be performed in stages or interrupted at any point. In the case where the girder is part of a bridge which carries car or rail traffic, this is particularly advantageous because the method can be carried out over multiple nights meaning the bridge will not need to be closed at times when traffic is not flowing.

[0136] It should be noted that the advantages provided by the pre-fabricated strengthening plate 9002 apply equally to the pre-fabricated spacer plates 8002 and 8004 as described with reference to Figure 9.

[0137] Figure 10a shows a girder 1100. The girder 1100 is the result of the fifth step of the method of structurally reinforcing a girder being performed on the girder 9000 of Figure 10.

[0138] In the fifth step of the method of structurally reinforcing a girder, the bolts 7002 are removed through the holes 9004 of the strengthening plate 9002. Each bolt 7002 is removed individually. Once a bolt 7002 has been removed, the boss 1000 is inserted into the hole 9004 in the strengthening plate. The cylindrical body 1002 is inserted into the hole 9004, before the flange member 1004 is mounted on top of the upper surface of the cylindrical body. As described previously, the flange member 1004 and the cylindrical body 1002, once assembled, define a boss through hole which is arranged to receive a bolt. Once the boss 1000 has been inserted, another bolt 1102 is inserted into the through hole of the boss 1000 and secured from below by a nut (not shown). This process is completed before another bolt 7002 is removed so as not to compromise the structural integrity of the girder. As previously described, the through hole 1006 of the boss 1000 has a diameter which is substantially the same as the hole of the upper flange plate 6010 through which the bolt 7002 was previously attached.

[0139] Once this fifth step of the method has been completed, the girder has assemblies 1104 of bolts 1102 and bosses 1000 at every other row of holes along the top surface of the girder.

[0140] As only the bolts 7002 are removed, the splice plate 6024 remains fastened to the beams 6002 and 6004 by the rivets 6016 and 6028 which were not replaced by bolts 7002 in the first step of the method. Furthermore, each bolt 7002 is removed individually, and another bolt 1102 is fitted before the next bolt 7002 is removed. In this way, the splice connection 6020a is not weakened while the strengthening plate 9002 is attached. Therefore, the strengthening plate 9002 can be fastened to the girder without removing the splice plate 6024 and thus the girder does not need to be propped from below nor does the live load on the bridge need to be restricted.

[0141] Figure 1 lb shows an exploded view of the girder 1100. Figure 1 lb shows a section of the girder which is not part of the splice connection 6020a. Figure 1 lb shows the upper flange plate 6010 being coupled to the angled section 6014 via rivets 6016. There are also vacant holes 1106 in the upper flange plate 6010 which are left by the removal of the bolt 7002. The spacer plate 8002 is shown having holes 8006 which are aligned with the location of the rivet and bolt holes in the upper flange plate 6010. The strengthening plate 9002 is shown also having holes 9004 which are aligned with the holes 8006 of the spacer plate 8002. The boss 1000 is arranged to be received in a hole 9004 of the strengthening plate 9002, and the bolt 1102 is arranged to fit within the through hole 1006 of the boss 1000. The through hole 1006 of the boss has substantially the same diameter as the holes 1106 in the flange plate 6010 which were previously occupied by rivets 6016.

[0142] As previously described, the surface of the flange member 1004 of the boss 1000 is smoothed so as to provide a friction grip with the upper surface of the strengthening plate 9002. The upper surface of the strengthening plate 9002 may also be roughened so as to cooperate and with the smooth portion of the boss 1000. In this way, the boss 1000 will be engaged by the surface of the plate 9002 so that it cannot rotate within the hole 9004. This is particularly advantageous when a bolt 1102 is fitted within the boss 1000 as the rotational movement of the bolt 1102 will not cause the boss to rotate.

[0143] Figure 12 shows a girder 1200. The girder 1200 is the result of completing all of the steps of the method of structurally reinforcing a girder. The girder 1200 has a number of additional bolts 7002 which strengthen further the coupling between the strengthening plate 9002 and the girder 1200. In this step of the method, the holes 9004 which do not host a boss 1000 and bolt 1102 assembly 1104 are optionally filled with metal repair putty, or a similar substance, and levelled off prior to the application of paint onto the girder.

[0144] Figures 13 and 14 show cross sectional views of a part of the girder which is not part of the splice connection 6020a.Figure 13 shows the girder 6000 of Figure 6, before any steps of the method of structurally reinforcing a girder have been performed. Figure 12 shows the upper flange plate 6010 having rivets 6016 which couple the upper flange plate 6010 to the angled sections 6014. The angled sections 6014 are coupled to the web plate 6008 via a rivet 1202.

[0145] Figure 14 shows the girder 1200 of Figure 12, after all steps of the method of structurally reinforcing a girder have been performed. Figure 14 shows the girder 1200 therefore having the upper flange plate 6010, the spacer plate 8002, and the strengthening plate 9002. The holes 8006 of the spacer plate 8002 and the holes 9004 of the strengthening plate 9002 are aligned so as to form a through hole. The rivets 6016 have been removed and replaced with bolts 1102, which are fastened through the through holes and secured from below by nuts 1302.

[0146] Referring back to the fourth step of the method as described previously, the holes 8006 of the spacer plate 8002 and the holes 9004 of the strengthening plate 9002 have diameters which are larger than the diameters of the heads of the bolts 7002. This is because the bolts 7002 are extracted through the holes 8006 and 9004. The holes 8006 and 9004 shown in Figure 14 are therefore wider than the heads of the bolts 7002 and 1102.

[0147] The cylindrical body 1002 of the boss 1000 has a height h2 which is equal to or less than the combined thickness of the spacer plate 8002 and strengthening plate 9002. The flange member 1004 of the boss 1000 engages the top surface of the strengthening plate 9002 via the smooth portion of the flange, thereby to inhibit rotation of the boss 1000 when the bolt 1102 is fitted. Additional bolts 7002 are fitted towards the edges of the girder; as the bolts do not pass through as many plates they are not as long as the bolts 1102. The bolts 1102 and 7002 are arranged to secure the spacer plate 8002 and strengthening plate 9002 to the girder via the same coupling points that were previously occupied by the rivets which secured the flange plate 6010 to the girder. In this way, the strengthening plate 9002 is secured to the girder without removing any existing sections of the girder.

[0148] Figure 14 also shows the boss 1000 providing a through hole which receives the bolt 1102. The boss 1000 is required to line the holes 8006 to 9004 and thereby narrow the diameter of the holes to the appropriate diameter so that the bolts 1102 form a close tolerance within the through hole of the boss 1000.

[0149] Figures 15 and 16 show cross sectional views of a part of the girder which is part of the splice connection 6020a.

[0150] Figure 15 shows the girder 6000 as in Figure 7, before any steps of the method of structurally reinforcing a girder have been performed. Figure 15 shows the upper flange plate 6010 having rivets 6016 which couple the upper flange plate 6010 to the angled sections 6014. The angled sections 6014 are coupled to the web plate 6008 via a rivet 1202. The flange plate 6016 is also coupled to the splice plate 6024 and the additional splice plate 6026 via the rivets 6028. Figure 16 shows the girder 1200 as in Figure 12, after all steps of the method of structurally reinforcing a girder have been performed. Figure 16 shows the girder 1200, having the strengthening plate 9002 fastened to the girder. Referring to the steps which were performed to transform the girder 6000 into the girder 1200, the rivets 6016 and 6028 were firstly removed and replaced by bolts 7002 (as described in the first step of the method with reference to Figure 7). The strengthening plate 9002 was then positioned on top of the splice plate 6024 (as described with reference to Figure 10). The bolts 7002 were then removed and extracted through the holes 9004 and a boss 1000 was inserted into the holes 9004 so as to narrow the holes and restore the through hole to a diameter appropriate to receive the bolts 1102 (as described with reference to Figure 10). The bolts 1102 were secured from below using the nuts 1302. In this way, the splice plates 6024 and 6026 remain coupled to the upper flange plate 6010 and the additional splice plate 6026 while the strengthening plate 9002 is fastened to the girder.

[0151] It will be understood that the invention has been described above purely by way of example, and modifications of detail can be made within the scope of the invention. In particular, although the invention has been described with reference to the structural reinforcement of a splice connection, the invention could also be applied to the structural reinforcement of any other plate of a girder, for example a flange plate. In this case, the strengthening plate is attached directly to the flange plate without the need for spacer plates.

[0152] Similarly, while the invention has been described with reference to the use of such girders in bridges, the invention could also be applied to other structures which incorporate girders, such as office buildings.

[0153] Furthermore, while the boss has been described as being arranged to receive a bolt via a friction or close tolerance fit, where the bolt is secured by a nut, the boss could also be arranged with a screw thread interior of the through hole where the bolt is threaded through the through hole.

[0154] Each feature disclosed in the description, and (where appropriate) the claims and drawings may be provided independently or in any appropriate combination.

[0155] Where the word 'or' appears this is to be construed to mean 'and / or' such that items referred to are not necessarily mutually exclusive and may be used in any appropriate combination. Although the invention has been described above with reference to one or more preferred embodiments, it will be appreciated that various changes or modifications may be made without departing from the scope of the invention as defined in the appended claims.

Claims

P604295PC00CLAIMS1. A boss for assembly with a part, the boss comprising a flange member arranged to abut a face of the part and a cylindrical body, the cylindrical body of the boss arranged to be inserted into the part, wherein the flange member is arranged to be removably mounted to the cylindrical body.

2. A boss according to claim 1, wherein the flange member has a smooth surface for engaging the face of the part.

3. A boss according to any preceding claim wherein the smooth surface comprises a Greenkote ® or Hot Dip Galvanised coating.

4. A boss according to any preceding claim, wherein the smooth surface is smooth to a surface finish roughness average (Ra) of less than 3.2 microns, preferably, to a surface finish roughness average of less than 1.2 microns.

5. A boss according to any preceding claim, wherein the entire surface for engaging the face of the part is smooth.

6. A boss according to any preceding claim, wherein the flange member has a flange through hole, the cylindrical body has a cylindrical body through hole, wherein the flange member and cylindrical body through holes align to define a boss through hole that extends through the boss, wherein the boss through hole is arranged to receive a bolt.

7. A boss according to claim 6, wherein the boss through hole is unthreaded.

8. A boss according to claim 6 or 7, wherein the flange through hole is chamfered.

9. A boss according to any one of claims 6-8, wherein the cylindrical body through hole is chamfered.

10. A boss according to claims 8 or 9, wherein the chamfer of the flange through hole and / or the chamfer of the cylindrical body through hole is arranged to guide a bolt into the boss through hole.

11. A boss according to any preceding claim, wherein the flange member and cylindrical body are formed from the same material or wherein the flange and cylindrical body are formed of materials of differing tensile strengths.

12. A boss according to any preceding claim, wherein the boss comprises carbon steel.

13. A kit of parts, or an assembly, comprising a boss according to any preceding claim, and a bolt arranged to fit within the boss.

14. A kit of parts, or an assembly, according to claim 13, wherein the bolt is a tension control bolt.

15. A kit of parts, or an assembly, according to claim 13 or 14, comprising the boss according to any of claims 1 to 12.

16. A kit of parts, or an assembly, optionally according to claim 13, wherein the part is a strengthening member.

17. A kit of parts, or assembly according to claims 13 or 14, wherein, when the boss and the part are assembled, at least a part of the boss is inserted into said part.

18. A kit of parts, or an assembly, comprising a boss according to claim 13, wherein when the boss and the part are assembled, the cylindrical body of the boss is inserted into said part.

19. A kit of parts, or an assembly, according to any of claims 13 to 18, wherein the face of said part has a roughened portion arranged to engage with flange, thereby to inhibit relative movement between the boss and said part.

20. A kit of parts, or an assembly, according to claim 19, wherein the flange has a smooth surface to engage with the roughened portion of the part.

21. A kit of parts, or an assembly, according to any of claims 13 to 20, wherein said part has at least one through hole arranged to receive a portion of the boss.

22. A girder comprising: at least one under-strengthened plate; one or more strengthening plates; and a boss according to any of claims 1 to 12 assembled with the one or more strengthening plates.

23. A girder according to claim 22, wherein, when assembled with the one or more strengthening plates, at least part of the boss is inserted into the one or more strengthening plates.

24. A method of manufacturing a boss for assembly with a part, the method comprising: providing a flange member arranged to abut a face of the part; separately providing a cylindrical body, wherein in use, the flange member is mountable to the cylindrical body.

25. A method of manufacturing a boss according to any one of claim 24, further comprising smoothing a surface of the flange member that is arranged to abut a face of the part.

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