Method for manufacturing prefabricated bridge and prefabricated bridge manufactured thereby

Abstract

The purpose of the present invention is to provide a method for manufacturing a prefabricated bridge and a prefabricated bridge manufactured thereby, which can realize structural simplification by reducing the number of components, and can simplify a manufacturing process in accordance with a simplified structure and can greatly improve ease of manufacture.

Description

Method for manufacturing a prefabricated bridge and a prefabricated bridge manufactured thereby

[0001] The present invention relates to a method for manufacturing a prefabricated bridge and a prefabricated bridge manufactured thereby, and more specifically, to a method for manufacturing a prefabricated bridge and a prefabricated bridge manufactured thereby, which has a simple structure and thus can improve the convenience of manufacturing by simplifying the manufacturing process, and which can realize the convenience of manufacturing and the reduction of manufacturing costs by simplifying the structure by reducing the number of parts and reducing the manufacturing man-hours due to the simplification of the structure.

[0002] A bridge is a general term for a civil engineering structure built across a strait, bay, canal, sea, river, stream, etc. Bridges built over rivers or streams are smaller in scale than those built over the sea.

[0003] Bridges, for example, are a crucial means of transportation between regions across a river or stream. Indeed, in certain areas of South Korea, bridges are known to play such a crucial role that without them, travel between regions would be impossible.

[0004] These bridges are constructed by welding or bolting metal frames, so they have a sturdy structure, but they can be lost or damaged in the event of a natural disaster such as a typhoon or flood.

[0005] In this way, when a bridge is lost or damaged in a disaster such as a typhoon or flood, the loss or damage to the bridge can cause significant damage to not only material and human resources, but also social damage.

[0006] For example, according to the National Disaster and Safety Portal of the Ministry of the Interior and Safety, the amount of damage from disasters in South Korea over the past 10 years has been reported to be 3.6 trillion won, and the damage has generally increased by 30% to 40% annually.

[0007] According to disaster damage statistics, the amount increased from 300 billion won in 2009 to over 1 trillion won in 2012, and reached 2.3 trillion won in 2016.

[0008] As mentioned above, if a bridge is lost or damaged due to a disaster such as a typhoon or flood, emergency repairs are necessary. Only then can additional material and human resources as well as social damage be minimized.

[0009] Meanwhile, as conventional technologies related to prefabricated bridges, there are Korean Patent Registration No. 10-0722401 (prefabricated steel bridge: hereinafter referred to as “Prior Art 1”) and Korean Publication Patent No. 10-2022-0031166 (bridge device for emergency restoration: hereinafter referred to as “Prior Art 2”).

[0010] The above-mentioned prior art 1 is configured by connecting at least two or more steel girder segments, and includes a pressure block installed at a connecting end of each steel girder segment, a hinge unit installed at each connecting end, and a reinforcing unit installed to be connected to each connecting end to disperse a tensile force acting on the hinge unit.

[0011] The above-mentioned prior art 1 can prevent damage to the parts that are in contact with each other by installing pressure blocks and reinforcing units on the upper and lower surfaces of steel girder segments that are arranged to face each other so that they can sufficiently withstand compressive and tensile forces. In particular, one of the advantages is that the structure is very simple and thus easy to manufacture.

[0012] However, in the above-mentioned prior art 1, since the reinforcing unit is installed on the lower surface of the steel girder segment, the reinforcing unit protruding downward moves while scraping the floor during the process of transporting or transferring for installation, which causes damage to the reinforcing unit, raising concerns about breakage. In particular, in order to install a pressure block on the upper surface of the steel girder segment, there is the inconvenience of having to cut off part of the upper surface of the steel girder segment and then install the pressure block.

[0013] In addition, in the case of the prior art 1, in order to install the first hinge plate and the second hinge plate, a portion of the abdomen of the steel girder segment must be cut and then the first hinge plate and the second hinge plate must be installed, which causes a problem of cumbersome and inconvenient work.

[0014] That is, the prior art 1 has a problem in that it requires deformation of the steel girder segment in order to install the upper reinforcement and the first and second hinge plates.

[0015]

[0016] Referring to FIG. 12 of the above-mentioned prior art 2, the first and second reinforcing units are respectively connected to the leading ends of the first and second main girders having an 'I' shape, and the first and second pin connection units are respectively inserted between the first and second main girders and the first and second reinforcing units, and are placed on the upper surface of the horizontal wall portion and welded against the girder plate.

[0017] This prior art 2 has the advantage of reducing the risk of damage because there are no protruding members on the lower surface of the first and second main girders even when transported or moved for installation.

[0018] However, the above-mentioned prior art 2 has the following serious problems.

[0019] First, since the prior art 2 is a method in which the girder plate and the first and second pin connection units are welded while facing each other, there is no gap (space) at all between the girder plate and the first and second pin connection units, and thus, there is no space at all for welding.

[0020] Accordingly, the prior art 2 has a problem in that the work is cumbersome and inconvenient in that the upper surface of the first and second pin connection units and the lower surface of the first vertical reinforcement are separated from each other, and the rear surface of the first and second pin connection units and the front surface of the horizontal reinforcement are separated from each other to form a gap between each component so that the girder plate and the first and second pin connection units can be welded together.

[0021] Second, in the prior art 2, the tip of the first pin connection unit is sandwiched by the second pin connection unit and is placed against each other, and the first and second reinforcing units are structured to surround the first and second pin connection units inserted inward.

[0022] However, since the width of the first pin connection unit and the width of the second pin connection unit are different, the first and second reinforcement units must be manufactured separately in consideration of the width into which the first and second pin connection units are inserted, which may raise fundamental problems such as difficulties in manufacturing, an increase in components, and an increase in costs.

[0023] Third, since the conventional technology 2 requires each component to be manufactured as a semi-finished product, the number of parts (number of sub-assemblies) is considerably large, making manufacturing cumbersome and inconvenient, and it is difficult to simplify the structure. In addition, there is a serious problem that the increase in the number of parts may lead to an increase in cost rather than a decrease in cost.

[0024] Accordingly, the present invention clearly recognizes the problems of the above-mentioned prior art 1 and prior art 2 and proposes a solution to solve them.

[0025] The purpose of the present invention is to provide a method for manufacturing an assembly bridge, which can realize simplification of the structure by reducing the number of parts, and can greatly improve the simplification of the manufacturing process and the convenience of manufacturing by a simple structure, and an assembly bridge manufactured thereby.

[0026] Another object of the present invention is to provide a method for manufacturing a prefabricated bridge, which can fundamentally solve the problem of an unwelded section occurring due to a deep depth from the tip of the first steel girder to the horizontal reinforcement member not being able to achieve a welding angle by forming a welding rod entrance in the lower flange, and a prefabricated bridge manufactured thereby.

[0027] The method for manufacturing a prefabricated bridge of the present invention to achieve the above purpose is as follows:

[0028] A step (S1) for installing link plates and horizontal reinforcements, in which the lower surface of a link plate spaced apart from the web of a steel girder is directly abutted against the upper surface of the lower flange of a steel girder forming an 'I' shape, a horizontal reinforcement is vertically placed between the upper flange and the lower flange of the steel girder, and the lower surface of the upper flange and the upper surface of the web and the lower flange are directly abutted against each other, and the link plate and horizontal reinforcement are welded and fixed at the boundary where the link plate and the horizontal reinforcement are directly abutted against each other;

[0029] A first vertical reinforcement installation step (S2) in which the lower surface of the first vertical reinforcement is directly abutted against the upper surface of the link plate, the edge surface of the first vertical reinforcement is directly abutted against the web and the horizontal reinforcement, and the boundary between the link plate and the first vertical reinforcement, the boundary between the horizontal reinforcement and the first vertical reinforcement, and the boundary between the web and the first vertical reinforcement are welded and fixed;

[0030] It is characterized by including a second vertical reinforcement installation step (S3) in which a second vertical reinforcement is vertically placed between the upper flange of the steel girder and the first vertical reinforcement, and the lower surface of the upper flange and the web and the upper surface of the first vertical reinforcement are directly abutted and welded.

[0031]

[0032] Here, before inserting a welding rod between the web and the link plate, a welding rod entrance cut downwardly open in the lower flange between the web and the link plate is provided, and the welding rod is inserted between the web and the link plate through the welding rod entrance, and the boundary between the link plate and the first vertical reinforcement, the boundary between the horizontal reinforcement and the first vertical reinforcement, and the boundary between the web and the first vertical reinforcement are welded and fixed.

[0033]

[0034] Here, the link plate is characterized in that a portion of the lower surface is cut to the thickness of the lower flange to provide a catch, and is welded and fixed directly against the upper surface and the end face of the lower flange.

[0035]

[0036] Here, a pair of pinholes are provided in the longitudinal direction of the link plate.

[0037]

[0038] The prefabricated bridge manufactured by the method for manufacturing a prefabricated bridge of the present invention to achieve the above purpose is:

[0039] In a prefabricated bridge, a first link plate integrally connected to the upper surface of the lower flange of a first steel girder in the shape of the letter 'I' and having a pinhole, a second link plate integrally connected to the upper surface of the lower flange of a second steel girder in the shape of the letter 'I' facing the first steel girder and having a pinhole, and an axis unit connected by penetrating the pinholes of the first link plate and the second link plate,

[0040] The first and second link plates are formed so that their upper and lower surfaces are horizontal to the lower flange, and one end surface where a pinhole is formed is formed in a semicircle, and the other end surface opposite to the pinhole is formed vertically so as to be perpendicular to the lower flange, and are arranged to be spaced apart from the webs of the first and second steel girders so that their lower surfaces are directly abutted against the upper surface of the lower flange and are welded and fixed;

[0041] A horizontal reinforcement member that is vertically placed between the upper and lower flanges of the first and second steel girders and is welded and fixed directly to the web, upper and lower flanges, and is welded and fixed directly to the vertical surface of the first and second link plates;

[0042] A first vertical reinforcement member that is welded and fixed directly to the upper surface of the first and second link plates so as to be perpendicular to the horizontal reinforcement member and is welded and fixed directly to the horizontal reinforcement member and the web of the first and second reinforcement girders;

[0043] It is characterized by further reinforcing a second vertical reinforcement member that is vertically arranged between the upper flange of the first and second steel girders and the first vertical reinforcement member and is directly welded to the web, upper flange, and first vertical reinforcement member.

[0044]

[0045] Here, the above axis unit,

[0046] An axle pin that is connected to the pinhole of the first and second link plates and has a screw portion provided on the outer surface through which it is penetrated,

[0047] It is characterized by comprising a nut that is fastened to the screw portion of the pivot pin.

[0048]

[0049] Here, a reinforcing bar integrally connected to the web of the first and second steel girders and the lower surface of the upper flange,

[0050] It is characterized by having a connecting unit that is further reinforced to suppress the spreading and warping between the first and second steel girders by being composed of a connecting member that interconnects the reinforcing bars.

[0051]

[0052] Here, a lower flange is cut open downward between the web of the first and second steel girders and the first and second link plates, and a welding rod entrance is provided through which a welding rod can be inserted so that the boundary between the first and second link plates and the first vertical reinforcement, the boundary between the horizontal reinforcement and the first vertical reinforcement, and the boundary between the web and the first vertical reinforcement can be welded and fixed via a welding rod inserted between the web and the first and second link plates.

[0053]

[0054] Here, the first and second link plates are characterized in that a portion of the lower surface is cut to the thickness of the lower flange to provide a catch, and the upper surface and the end surface of the lower flange are joined together as one piece.

[0055]

[0056] Here, a pair of pinholes is provided in the longitudinal direction of the first and second link plates.

[0057] The present invention has a simple structure, so that the convenience of manufacturing can be improved by simplifying the manufacturing process, and the structure can be simplified by reducing the number of parts, and the manufacturing process can be reduced by simplifying the structure, so that the convenience of manufacturing and the reduction of manufacturing costs can be realized.

[0058] In addition, in the present invention, when the depth from the tip of the first steel girder to the horizontal reinforcement is deep and the welding angle cannot be achieved, the welding work had to be performed only in a certain area, but as in this embodiment, if the welding rod is inserted through the welding rod entrance opened downward, a sufficient welding angle and work field of view can be secured, so that the lower boundary of the web and the first vertical reinforcement, the lower right boundary of the first link plate and the first vertical reinforcement, and the lower boundary of the horizontal reinforcement and the first vertical reinforcement can be thoroughly and completely welded and fixed, and accordingly, the welding work becomes very convenient and easy, so there is an advantage of further improving workability.

[0059] Figures 1 to 4 are drawings illustrating step-by-step the manufacturing method of an assembly bridge according to the present invention.

[0060] Figure 5 is a perspective view of a combined assembly of a prefabricated bridge according to a first embodiment of a prefabricated bridge manufactured by a method for manufacturing a prefabricated bridge of the present invention.

[0061] Figure 6 is an exploded perspective view of Figure 5.

[0062] Figure 7 is a cross-sectional view taken along line A-A of Figure 5.

[0063] Fig. 8 is a partial view of Fig. 5.

[0064] Figure 9 is a drawing for explaining the operation of a prefabricated bridge according to the first embodiment of the present invention.

[0065] Figure 10 is a drawing for explaining problems in the manufacture of a prefabricated bridge according to the first embodiment of the present invention.

[0066] Fig. 11 is a bottom perspective view of a prefabricated bridge according to a second embodiment of the present invention.

[0067] Figure 12 is a drawing showing the side and front views of Figure 11.

[0068] Fig. 13 is a bottom perspective view of a prefabricated bridge according to a third embodiment of the present invention.

[0069] Figures 14 and 15 are a bottom perspective view and a front view of a prefabricated bridge according to a fourth embodiment of the present invention.

[0070]

[0071] - Explanation of symbols -

[0072] 10,20: 1st and 2nd steel girders 11,12: Web 12,22: Upper flange

[0073] 13,23: Lower flange 14: Welding rod entrance

[0074] 30,30': 1st and 2nd link plates 31: Pinhole 32: Hook

[0075] 40: Axle unit 41: Axle pin 41a: Screw part

[0076] 41b: Bolt hole 50: Locking hole 51: Stud bolt

[0077] 52: Nut 60,60': Horizontal reinforcement

[0078] 70,70': First vertical reinforcement 80,80': Second vertical reinforcement

[0079] 90: connecting unit 91,91': reinforcing bar 91a: L-shaped steel

[0080] 91a-1: Bolt hole 91b: End plate 92: Connection port

[0081] 92a: Stud bolt 92b: Nut

[0082] Figures 1 to 4 are drawings illustrating step-by-step the manufacturing method of an assembly bridge according to the present invention, and the following description will be made with reference to these drawings.

[0083]

[0084] In order to minimize redundant explanations when explaining the method for manufacturing a prefabricated bridge according to the present invention, the manufacturing method is explained based on the first steel girder (10), and the second steel girder (20) is substantially the same as the first steel girder (10) except for the number of second link plates (30'), so the contents related to the second steel girder (20) are replaced with the description of the first steel girder (10).

[0085]

[0086] 1) Link plate and horizontal reinforcement installation stage (S1)

[0087] The above link plate and horizontal reinforcement installation step (S1) is a step of installing the first link plate (30) and horizontal reinforcement (60) on the first steel girder (10) in the shape of the letter 'I'.

[0088] Referring to (a) and (b) of FIG. 1, the first steel girder (10) is a steel material having an upper flange (12) and a lower flange (13) horizontally arranged on the upper and lower surfaces of a vertically arranged web (11) to form an 'I' shape.

[0089] The lower surface of the first link plate (30) placed spaced apart from the web (11) of the first steel girder (10) is directly placed against the upper surface of the lower flange (13) of the first steel girder (10), and the boundary between the lower flange (13) and the first link plate (30) is welded and fixed based on the first link plate (30).

[0090] Next, a horizontal reinforcement member (60) is vertically placed between the upper flange (12) and the lower flange (13) of the first steel girder (10), and the lower surface of the upper flange (12) and the upper surface of the web (11) and the lower flange (13) are directly abutted against each other. With the horizontal reinforcement member (60) as a reference, the boundary between the lower surface of the upper flange (12) and the horizontal reinforcement member (60), the boundary between the web (11) and the horizontal reinforcement member (60), and the upper surface of the lower flange (13) and the horizontal reinforcement member (60) are welded and fixed.

[0091] In addition, the boundary where the first link plate (30) and the horizontal reinforcement (60) are directly in contact with each other is welded and fixed based on the first link plate (30).

[0092]

[0093] 2) First vertical reinforcement installation stage (S2)

[0094] The above first vertical reinforcement installation step (S2) is a step of installing the first vertical reinforcement (70) between the upper flange (12) of the first steel girder (10) and the first link plate (30).

[0095] Referring to (a) and (b) of FIG. 2, a first vertical reinforcement (70) is inserted between the upper flange (12) of the first steel girder (10) and the first link plate (30).

[0096] Next, the lower surface of the first vertical reinforcement (70) is placed so that it directly abuts against the upper surface of the first link plate (30), and the side and back surfaces of the first vertical reinforcement (70) are placed so that they directly abut against the web (11) and the horizontal reinforcement (60), respectively.

[0097] As described above, in a state of direct contact, the upper boundary of the web (11) and the first vertical reinforcement (70), the lower left boundary of the first link plate (30) and the first vertical reinforcement (70), and the upper boundary of the horizontal reinforcement (60) and the first vertical reinforcement (70) are welded and fixed based on the first vertical reinforcement (70), and the web (11), the lower flange (13), the first link plate (30), the horizontal reinforcement (60), and the first vertical reinforcement (70) are mutually connected, so that the remaining portion except the front is formed in a closed shape.

[0098] When the above welding is completed, a welding rod is inserted between the web (11) and the first link plate (30) through the opened front, and the lower boundary of the web (11) and the first vertical reinforcement (70), the lower right boundary of the first link plate (30) and the first vertical reinforcement (70), and the lower boundary of the horizontal reinforcement (60) and the first vertical reinforcement (70) are welded and fixed based on the first vertical reinforcement (70).

[0099]

[0100] 3) Second vertical reinforcement installation stage (S3)

[0101] The above second vertical reinforcement installation step (S3) is a step of installing at least one second vertical reinforcement (80) between the upper flange (12) of the first steel girder (10) and the first vertical reinforcement (70).

[0102] Referring to (a) and (b) of FIG. 3, a second vertical reinforcement (80) is inserted between the upper flange (12) of the first steel girder (10) and the first vertical reinforcement (70), and the second vertical reinforcement (80) is vertically arranged so as to be perpendicular to the longitudinal direction of the first vertical reinforcement (70).

[0103] At this time, the upper surface, side surface (surface facing the web) and lower surface of the second vertical reinforcement (80) are directly abutted against the lower surface of the upper flange (12) and the upper surface of the web (11) and lower flange (13), respectively.

[0104] In the above arrangement, the boundary between the lower surface of the second vertical reinforcement (80) and the upper flange (12), the boundary between the second vertical reinforcement (80) and the web (11), and the upper surface boundary of the second vertical reinforcement (80) and the lower flange (13) are fixed by welding, regardless of the left or right, based on the second vertical reinforcement (80).

[0105]

[0106] Meanwhile, after the second vertical reinforcement installation step (S3), as shown in FIG. 4, a reinforcement bar (91) is installed on the lower surface of the web (11) and upper flange (12) constituting the first steel girder (10). If necessary, the installation work of the reinforcement bar (91) may be performed in advance before the link plate and horizontal reinforcement installation step (S1).

[0107]

[0108] Meanwhile, after the second vertical reinforcement installation step (S3) or after the step of installing the reinforcement bar (91), the first and second steel girders (10, 20) are arranged facing each other so that the pin holes (31) of the first and second link plates (30, 30') are connected to each other through the shaft unit (40) that penetrates the pin holes (31).

[0109]

[0110] According to this embodiment, there is an advantage in that the simplification of the structure due to the reduction in the number of parts can be realized, and the simplification of the manufacturing process due to the simple structure and the convenience of manufacturing can be greatly improved.

[0111]

[0112] Meanwhile, if the width between the web (11) and the first link plate (30) is narrow and the depth from the tip of the first steel girder (10) to the horizontal reinforcement (60) is deep, even if the welding rod is inserted through the front opening, the welding angle (θ1: see FIG. 11) does not come out, so it is quite difficult to weld and fix the lower boundary of the web (11) and the first vertical reinforcement (70), the lower right boundary of the first link plate (30) and the first vertical reinforcement (70), and the lower boundary of the horizontal reinforcement (60) and the first vertical reinforcement (70), and even if welding is performed, welding is possible only in the part where the welding angle comes out and welding is not possible in the remaining parts, so there is a problem that the welding result is bound to be unsatisfactory.

[0113] In this embodiment, it is to be noted that the above problem is solved by providing a welding rod entrance (14) formed by cutting the lower flange (13) between the web (11) and the link plate (30) so as to be open downward before welding and fixing the lower boundary of the web (11) and the first vertical reinforcement (70), the lower right boundary of the first link plate (30) and the first vertical reinforcement (70), and the lower boundary of the horizontal reinforcement (60) and the first vertical reinforcement (70) by inserting a welding rod between the web (11) and the first link plate (30).

[0114] Referring to FIGS. 1 and 2, the welding rod entrance (14) is a passage through which the welding rod can enter and exit, and may be formed only in the lower flange (13) between the web (11) and the first link plate (30), or may be formed throughout the entire lower flange (13) as in the present embodiment.

[0115] For example, the welding rod entrance (14) is naturally provided by forming the front end length of the lower flange (13) constituting the first steel girder (10) to be relatively shorter than the front end length of the upper flange (12).

[0116] Here, shortening the tip length of the lower flange (13) does not mean forming it infinitely short, and it is recommended that the welding rod entrance (14) be freely formed within half (e.g., ⅓ to ½ - the length cut from the tip of the lower flange) of the length (depth) from the tip of the lower flange (13) to the horizontal reinforcement (60). It is recommended that the welding rod entrance (14) be formed by comprehensively judging the depth from the tip of the first steel girder (10) to the horizontal reinforcement (60), securing the work field of view, welding angle, etc.

[0117] In addition, when forming the above welding rod entrance (14), the lower part and lower flange (13) of the web (11) constituting the first steel girder (10) may be cut together (see Fig. 11) to form the welding rod entrance (14).

[0118]

[0119] According to the present embodiment, when the depth from the tip of the first steel girder (10) to the horizontal reinforcement (60) is deep and the welding angle (θ1: see Fig. 11) cannot be achieved, the welding work can only be performed in a part of the area, making it difficult to weld the entire area. However, as in the present embodiment, if the welding rod is inserted through the welding rod entrance (14) opened downward, a sufficient welding angle (θ2: see Fig. 12) and work field of view can be secured, so that the lower boundary of the web (11) and the first vertical reinforcement (70), the lower right boundary of the first link plate (30) and the first vertical reinforcement (70), and the lower boundary of the horizontal reinforcement (60) and the first vertical reinforcement (70) can be thoroughly and comprehensively welded and fixed, and accordingly, the welding work becomes very convenient and easy, so that the workability is further improved.

[0120]

[0121] Meanwhile, a catch (32) can be optionally applied to the first link plate (30), which will be described in detail later in the assembly bridge manufactured by the manufacturing method.

[0122] In addition, a pair of pinholes (31) can be optionally applied to the first link plate (30) in addition to a catch (32), which will be described in detail later in the assembly bridge manufactured by the manufacturing method.

[0123]

[0124] Meanwhile, in explaining the prefabricated bridge of the present invention, two steel girders were used as a fragmentary example, but multiple steel girders may be applied as needed and constructed through the process mentioned above.

[0125]

[0126] FIG. 5 is a perspective view of a combined assembly bridge according to a first embodiment of a prefabricated bridge manufactured by a method for manufacturing a prefabricated bridge of the present invention, FIG. 6 is an exploded perspective view of FIG. 5, FIG. 7 is a cross-sectional view taken along line A-A of FIG. 5, and FIG. 8 is a partial view of FIG. 5.

[0127]

[0128] Referring to FIGS. 5 to 8, the prefabricated bridge manufactured by the manufacturing method of the present invention is composed of first and second steel girders (10, 20), first and second link plates (30, 30'), an axis unit (40), horizontal reinforcements (60, 60'), first vertical reinforcements (70, 70'), and second vertical reinforcements (80, 80'), and thus has a simple structure, which can improve the convenience of manufacturing by simplifying the manufacturing process, and has a technical feature that can realize the convenience of manufacturing and the reduction of manufacturing costs by simplifying the structure due to the reduction in the number of parts, and reducing the manufacturing man-hours due to the simplification of the structure.

[0129]

[0130] The above first and second steel girders (10, 20) are composed of a vertically arranged web (11), an upper flange (12) and a lower flange (13) that are horizontally arranged on the upper and lower surfaces of the web (11) and integrally joined, and form an 'I' shape.

[0131] These first and second steel girders (10, 20) are arranged so that their cross-sections face each other.

[0132]

[0133] The first and second link plates (30, 30') above are plates having one end formed as a rectangular parallelepiped (the lower and upper surfaces that abut against the lower flange and the first vertical reinforcement, respectively, are horizontal, and the surface that abuts against the horizontal reinforcement is vertical) and the other end formed as a semicircle (arc shape). In the present embodiment, they are directly abutted against the upper surfaces of the lower flanges (13, 23) of the first and second steel girders (10, 20) and are fixed integrally by welding.

[0134] Additionally, a pinhole (31) is provided in the semicircular portion of the first and second link plates (30, 30').

[0135] As an example, the second link plate (30') may be installed only in the second steel girder (20), or a pair may be installed as shown in FIG. 6.

[0136]

[0137] The above-mentioned shaft unit (40) is composed of a shaft pin (41) and a nut (42), and in the present embodiment, it is coupled to the pin hole (31) of the first and second link plates (30, 30') to interconnect the first and second link plates (30, 30').

[0138] The above-mentioned pivot pin (41) is connected to penetrate the pin hole (31) of the first and second link plates (30, 30'). A stopper is provided at one end of the pivot pin (41) to limit excessive movement in the inserted direction, and a screw portion (41a) is provided on the outer surface of the other end to enable a nut (42) to be fastened.

[0139] The above nut (42) is fastened to the screw portion (41a) of the shaft pin (41) and serves to limit the departure of the shaft pin (41) from the pin hole (31).

[0140] Meanwhile, if vibration is repeatedly applied while the above-mentioned axle pin (41) and nut (42) are mutually fastened, there is a problem that the nut (42) is likely to loosen, which causes the fastening force to weaken.

[0141] Accordingly, in this embodiment, the above problem was solved by further reinforcing the anti-loosening device (50).

[0142] The above anti-loosening device (50) is composed of a stud bolt (51) and a nut (52).

[0143] In order to install the above anti-loosening device (50), a bolt hole (41b) is formed through the screw portion (41a) of the shaft pin (41).

[0144] The above stud bolt (51) is a member having threads formed at both ends, and in the case of this embodiment, it is connected to penetrate the bolt hole (41b), and if necessary, a known bolt may be applied instead of the stud bolt (51).

[0145] The above nut (52) is fastened to the screw threads provided at both ends of the stud bolt (51), and a split pin may be installed to penetrate instead of the nut (52).

[0146] As described above, if the anti-loosening device (50) is installed on the shaft pin (41), the nut (52) can be prevented from loosening even under repeated vibrations.

[0147]

[0148] The above horizontal reinforcement (60, 60') is a plate having a predetermined width and thickness, and in the case of the present embodiment, it is inserted between the upper flange (12, 22) and the lower flange (13, 23) of the first and second steel girders (10, 20) and is vertically arranged, and the side surface and the upper and lower surfaces of the horizontal reinforcement (60, 60') are directly abutted against the web (11, 21) and the upper flange (12, 22) and the lower flange (13, 23) of the first and second steel girders (10, 20), respectively, and are fixed integrally by welding.

[0149] In addition, the horizontal reinforcement (60, 60') is directly abutted against the vertical surface formed at one end of the first and second link plates (30, 30') and is integrally joined by welding, so that it supports the first and second link plates (30, 30') from moving in the transverse direction (the longitudinal direction of the girder), and it is also expected to have the effect of suppressing deformation of the first and second steel girders (10, 20).

[0150]

[0151] The above first vertical reinforcement (70, 70') is a plate having a predetermined width and thickness, and in the case of the present embodiment, it is arranged parallel to the lower flange (13, 23) and perpendicular to the horizontal reinforcement (60, 60') so that the lower surface thereof is directly abutted against the upper surface of the first and second link plates (30, 30') and is fixed integrally by welding.

[0152] In addition, the outer surface (see Fig. 6) of the first vertical reinforcement (70, 70') is directly abutted against the web (11, 21) of the first and second steel girders (10, 20) and the horizontal reinforcement (60, 60'), respectively, and is fixed integrally by welding.

[0153] Meanwhile, when welding is completed up to the first vertical reinforcement (70, 70'), the remaining portions except the front are formed in a closed shape by mutual connection (welding fixation) of the web (11, 21), the lower flange (13, 23), the first and second link plates (30, 30'), the horizontal reinforcement (60, 60'), and the first and second vertical reinforcements (70, 70').

[0154] By inserting a welding rod between the web (11) and the first link plate (30) through the front opening in this manner, the lower boundary of the web (11) and the first vertical reinforcement (70), the lower right boundary of the first link plate (30) and the first vertical reinforcement (70), and the lower boundary of the horizontal reinforcement (60) and the first vertical reinforcement (70) are welded and fixed based on the first vertical reinforcement (70).

[0155]

[0156] The second vertical reinforcement (80, 80') is a plate having a predetermined width and thickness, and in the case of the present embodiment, it is inserted between the upper flanges (12, 22) of the first and second steel girders (10, 20) and the first vertical reinforcement (70, 70') so as to be arranged parallel to the horizontal reinforcement (60, 60') and perpendicular to the first vertical reinforcement (70, 70'), and is arranged vertically, and the side surface and upper surface and lower surface of the second vertical reinforcement (80, 80') are directly abutted against the webs (11, 21) and the lower surfaces of the upper flanges (12, 22) of the first and second steel girders (10, 20) and the upper surface of the first vertical reinforcement (70, 70'), respectively, and are integrally joined by welding.

[0157] In this embodiment, two second vertical reinforcements (80, 80') are applied to each of the first and second steel girders (10, 20), and the number can be increased or decreased as needed.

[0158]

[0159] Meanwhile, the prefabricated bridge according to the first embodiment of the present invention may further include a connecting unit (90).

[0160] The above connecting unit (90) is composed of a reinforcing bar (91, 91') and a connecting member (92), and in the present embodiment, it serves to connect the first and second steel girders (10, 20) to each other and prevents the first and second steel girders (10, 20) from spreading out and warping.

[0161] Referring to Fig. 8, the reinforcing bar (91, 91') is composed of a L-shaped steel (91a) and a finishing plate (91b).

[0162] The above L-shaped steel (91a) is joined to the web (11, 21) and upper flange (12, 22) of the first and second steel girders (10, 20) by welding.

[0163] And, a bolt hole (91a-1) is integrally formed in the L-shaped steel (91a) through which a stud bolt (92a) of a connecting member (92) penetrates.

[0164] The above closing plate (91b) is integrally formed on the side of the L-shaped steel (91a).

[0165] Referring to Fig. 6, the connecting member (92) is composed of a stud bolt (92a) and a nut (92b), and in the present embodiment, is detachably installed on the reinforcing bars (91, 91') and serves to connect them to each other.

[0166] The above stud bolt (92a) is a member having screws provided at both ends and is connected to the bolt hole (91a-1) of the reinforcing bar (91, 91') so as to penetrate therethrough.

[0167] As described above, by fastening nuts (92b) to both ends of the combined stud bolts (92a), the reinforcing bars (91, 91') are interconnected, and as a result, the spreading and warping between the first and second steel girders (10, 20) are naturally suppressed.

[0168]

[0169] FIG. 9 is a drawing for explaining the operation of a prefabricated bridge according to the first embodiment of the present invention, and the following description will be made with reference to this.

[0170] First, when a vertical load (F1) is applied to the first and second steel girders (10, 20) in a state where a prefabricated bridge according to the first embodiment of the present invention is erected, the first steel girder (10) rotates clockwise (R1) around the axis pin (41) via the first link plate (30), and the second steel girder (20) rotates counterclockwise (R2) around the axis pin (41) via the second link plate (30'). The first steel girder (10) and the second steel girder (20) rotated in this manner are brought into strong contact while applying a lateral force (F2) toward each other's cross-sections.

[0171] Meanwhile, when a vertical load is applied to the above-mentioned axis pin (41), the load is transferred to the first and second link plates (30, 30') connected to the axis pin (41), the load transferred to the first and second link plates (30, 30') is transferred and distributed to the first vertical reinforcement member (70, 70'), and the load transferred to the first vertical reinforcement member (70, 70') is again transferred and distributed to the upper flange (12, 22) through the second vertical reinforcement member (80, 80').

[0172] Therefore, when a vertical load is applied to the above-mentioned axial pin (41), the damage to the tip of the first and second steel girders (10, 20) can be drastically reduced through the load transfer and distribution effect between each member, and it is also quite advantageous from an economical perspective when considering the possibility of future reuse.

[0173]

[0174] FIG. 10 is a drawing for explaining problems in the production of a prefabricated bridge according to the first embodiment of the present invention, and the following description is made with reference to this drawing.

[0175] And to avoid redundant explanation, the first steel girder (10) is used as an example to explain in detail, and the welding rod entrance (14) described below is also applied to the lower flange (23) of the second steel girder (20).

[0176] As shown in Fig. 10, it is also preferable to fix the boundary between the first link plate (30) and the first vertical reinforcement (70), the boundary between the horizontal reinforcement (60) and the first vertical reinforcement (70), and the boundary between the web (11) and the first vertical reinforcement (70) by welding.

[0177] However, when looking at the prefabricated bridge according to the first embodiment of the present invention, if the width between the web (11) and the first link plate (30) is narrow and the depth from the tip of the first steel girder (10) to the horizontal reinforcement (60) is deep, even if a welding rod is inserted, it is difficult to secure a field of vision and the welding angle (θ1) is not achieved, so it is practically difficult to weld and fix the lower boundary of the web (11) and the first vertical reinforcement (70), the lower right boundary of the first link plate (30) and the first vertical reinforcement (70), and the lower boundary of the horizontal reinforcement (60) and the first vertical reinforcement (70), and even if welding is performed, there is a problem that only a part of the area where the welding angle is achieved can be welded, and the rest cannot be welded.

[0178] In this embodiment, it is to be noted that the above problem is solved by providing a welding rod entrance (14) formed by cutting the lower flange (13) between the web (11) of the first steel girder (10) and the link plate (30) so as to be open downward.

[0179]

[0180]

[0181] *Figure 11 is a bottom perspective view of a prefabricated bridge according to a second embodiment of the present invention, and Figure 12 is a drawing showing the side and front views of Figure 11, and the following description will be made with reference to these.

[0182] Referring to FIGS. 11 and 12, the welding rod entrance (14) is a passage through which the welding rod can enter and exit, and may be formed only in the lower flange (13) between the web (11) and the first link plate (30), or may be formed throughout the entire lower flange (13) as in the present embodiment.

[0183] For example, the welding rod entrance (14) is naturally provided by forming the front end length of the lower flange (13) constituting the first steel girder (10) to be relatively shorter than the front end length of the upper flange (12).

[0184] Here, since the tip length of the lower flange (13) cannot be formed infinitely short, the welding rod entrance (14) can be freely formed within half (e.g., ⅓ to ½ - the length cut from the tip of the lower flange) of the length (depth) from the tip of the lower flange (13) to the horizontal reinforcement (60), and the cut length can also be changed as needed.

[0185] And it is advisable to form the above welding rod entrance (14) by taking into account the depth from the tip of the first steel girder (10) to the horizontal reinforcement (60) and the welding angle accordingly.

[0186] In addition, when forming the above welding rod entrance (14), the lower part and lower flange (13) of the web (11) constituting the first steel girder (10) may be cut together (see Fig. 11) to form the welding rod entrance (14).

[0187]

[0188] According to the present embodiment, when the depth from the tip of the first steel girder (10) to the horizontal reinforcement (60) is deep and the welding angle cannot be achieved, the welding work had to be performed only in a certain area. However, as in the present embodiment, if the welding rod is inserted through the welding rod entrance (14) opened downward, a sufficient welding angle (θ2: see FIG. 12) and work field of view can be secured compared to the previous embodiment, so that the lower boundary of the web (11) and the first vertical reinforcement (70), the lower right boundary of the first link plate (30) and the first vertical reinforcement (70), and the lower boundary of the horizontal reinforcement (60) and the first vertical reinforcement (70) can be meticulously welded and fixed, and accordingly, the welding work becomes very convenient and easy, so there is an advantage of further improving workability.

[0189]

[0190] Fig. 13 is a bottom perspective view of a prefabricated bridge according to a third embodiment of the present invention, and the following description will be made with reference to this.

[0191] In the case of the above embodiment, the upper surfaces of the first and second link plates (30, 30') are directly abutted against the upper surfaces of the lower flanges (13, 23) and are integrally fixed by welding. However, these first and second link plates (30, 30') have the following problems: first: they are not easy to install, and second: when force is applied to the first and second link plates (30, 30') in the transverse direction (the longitudinal direction of the girder) after installation, there is a problem that a slight transverse force is applied to the welded area despite the fact that the horizontal reinforcement (60) and each member are mutually fixed by welding.

[0192] In this embodiment, it is to be noted that the above problem is solved by forming a catch (32) on the lower surface of the first and second link plates (30, 30').

[0193] Referring to Fig. 13, a portion of the lower surface of the first and second link plates (30, 30') was cut to the thickness of the lower flange (13, 23) to form a catch (32).

[0194] And, the first and second link plates (30, 30') with the catch (32) formed in this way were fixed by welding while directly abutting against the tip and upper surface of the lower flange (13, 23).

[0195] According to the present embodiment, when installing the first and second link plates (30, 30'), since the catch (32) catches the front end surface of the lower flange (13, 23), the depth of the first and second link plates (30, 30') does not need to be considered, and only the left and right widths need to be considered, thereby improving the convenience of installation. In addition, even if force is applied to the first and second link plates (30, 30') in the transverse direction (in the longitudinal direction of the girder) after installation, the catch (32) of the first and second link plates (30, 30') can sufficiently withstand the force in the transverse direction (lateral force) because it catches the front end surface of the lower flange (13, 23).

[0196]

[0197] FIG. 14 and FIG. 15 are a bottom perspective view and a front view of a prefabricated bridge according to a fourth embodiment of the present invention, and the following description will be made with reference to these.

[0198] Referring to FIG. 14, the fourth embodiment according to the present invention is substantially the same as the structure of the third embodiment above, except that a pair of pinholes (31) are provided in the longitudinal direction of the first and second link plates (30, 30').

[0199] For example, as illustrated in FIG. 15, the first and second link plates (30, 30') are opposed to each other in an alternating manner so that the pin holes (31) are mutually connected, and an axis unit (40: see FIG. 2) is respectively coupled to a pair of pin holes (31) mutually connected in this manner.

[0200] As needed, multiple pinholes (31) may be formed.

[0201]

[0202] Although the present invention has been described in detail only with respect to the described specific embodiments, it will be apparent to those skilled in the art that various modifications and variations can be made within the technical scope of the present invention, and it will be apparent that such modifications and variations fall within the scope of the appended claims.

Claims

1. The lower surface of the link plate, which is spaced apart from the web of the steel girder, is directly abutted against the upper surface of the lower flange of the steel girder forming an 'I' shape, and is fixed by welding, and a horizontal reinforcement is vertically placed between the upper flange and the lower flange of the steel girder and is welded and fixed while directly abutting the lower surface of the upper flange and the upper surface of the web and the lower flange, and the link plate and horizontal reinforcement installation step (S1) is performed by welding and fixing the boundary where the link plate and the horizontal reinforcement are directly abutted; A first vertical reinforcement installation step (S2) in which the lower surface of the first vertical reinforcement is directly abutted against the upper surface of the link plate, the edge surface of the first vertical reinforcement is directly abutted against the web and the horizontal reinforcement, and the boundary between the link plate and the first vertical reinforcement, the boundary between the horizontal reinforcement and the first vertical reinforcement, and the boundary between the web and the first vertical reinforcement are welded and fixed; A method for manufacturing a prefabricated bridge, characterized by including a step (S3) of installing a second vertical reinforcement by vertically arranging a second vertical reinforcement between the upper flange of the steel girder and the first vertical reinforcement and welding and fixing the second vertical reinforcement so that the lower surface of the upper flange and the web and the upper surface of the first vertical reinforcement are directly abutted against each other.

2. In paragraph 1, A method for manufacturing a prefabricated bridge, characterized in that, before inserting a welding rod between the web and the link plate, a welding rod entrance is provided in a lower flange between the web and the link plate, which is cut to be open downward, and the welding rod is inserted between the web and the link plate through the welding rod entrance, and the boundary between the link plate and the first vertical reinforcement, the boundary between the horizontal reinforcement and the first vertical reinforcement, and the boundary between the web and the first vertical reinforcement are welded and fixed.

3. In paragraph 2, A method for manufacturing an assembly bridge, characterized in that the link plate has a lower portion cut to the thickness of the lower flange to provide a catch, and is welded and fixed directly to the upper surface and end face of the lower flange.

4. In paragraph 3, A method for manufacturing an assembly bridge, characterized in that a pair of pinholes are provided in the longitudinal direction of the above link plate.

5. In a prefabricated bridge comprising a first link plate (30) integrally connected to the upper surface of the lower flange (13) of a first steel girder (10) in the shape of the letter 'I' and having a pin hole (31), a second link plate (30') integrally connected to the upper surface of the lower flange (23) of a second steel girder (20) in the shape of the letter 'I' facing the first steel girder (10) and having a pin hole (31), and an axis unit (40) connected by penetrating the pin holes (31) of the first link plate (30) and the second link plate (30'), The first and second link plates (30, 30') are formed so that the upper and lower surfaces are horizontal to the lower flange (13, 23), and one end surface where the pinhole (31) is formed is formed in a semicircular shape, and the other end surface opposite to the pinhole (31) is formed vertically so as to be perpendicular to the lower flange (13, 23), and are arranged apart from the webs (11, 21) of the first and second steel girders (10, 20) so that the lower surface is directly abutted against the upper surface of the lower flange (13, 23) and is fixed by welding; Horizontal reinforcement (60, 60') that is vertically arranged between the upper flange (12, 22) and the lower flange (13, 23) of the first and second steel girders (10, 20) and is welded and fixed directly to the web (11, 21), the upper flange (12, 22) and the lower flange (13, 23) while being welded and fixed directly to the vertical surface of the first and second link plates (30, 30'); A first vertical reinforcement (70, 70') that is directly welded and fixed to the upper surface of the first and second link plates (30, 30') so as to be perpendicular to the horizontal reinforcement (60, 60') and is directly welded and fixed to the horizontal reinforcement (60, 60') and the web (11, 21) of the first and second steel girders (10, 20); A prefabricated bridge manufactured by a method for manufacturing a prefabricated bridge, characterized in that a second vertical reinforcement (80, 80') is further reinforced by being vertically arranged between the upper flange (12, 22) of the first and second steel girders (10, 20) and the first vertical reinforcement (70, 70') and directly abutting and welding the web (11, 21), the upper flange (12, 22) and the first vertical reinforcement (70, 70').

6. In paragraph 5, The above axis unit (40) is An axle pin (41) that is connected to penetrate the pin hole (31) of the first and second link plates (30, 30') and has a screw portion (41a) provided on the outer surface thereof through which it is penetrated, An assembly bridge manufactured by a method for manufacturing an assembly bridge, characterized by comprising a nut (42) fastened to a screw portion (41a) of an axle pin (41).

7. In paragraph 6, A reinforcing bar (91, 91') integrally connected to the lower surface of the web (11, 21) and the upper flange (12, 22) of the first and second steel girders (10, 20), A prefabricated bridge manufactured by a method for manufacturing a prefabricated bridge, characterized in that a connecting unit (90) is further reinforced to suppress the spreading and warping between the first and second steel girders (10, 20) by being composed of a connecting member (92) that interconnects reinforcing bars (91, 91').

8. In any one of paragraphs 5 to 7, A prefabricated bridge manufactured by a method for manufacturing a prefabricated bridge, characterized in that a lower flange (13, 23) is cut to be open downward between the web (11, 21) of the first and second steel girders (10, 20) and the first and second link plates (30, 30'), and a welding rod entrance (14) is provided through which a welding rod can be inserted so that the boundary between the first and second link plates (30, 30') and the first vertical reinforcement (70, 70'), the boundary between the horizontal reinforcement (60, 60') and the first vertical reinforcement (70, 70'), and the boundary between the web (11, 21) and the first vertical reinforcement (70, 70') can be welded and fixed.

9. In paragraph 8, A prefabricated bridge manufactured by a method for manufacturing a prefabricated bridge, characterized in that a portion of the lower surface of the first and second link plates (30, 30') is cut to the thickness of the lower flange (13, 23) to provide a catch (32), and is integrally joined by being in contact with the upper surface and the end surface of the lower flange (13, 23).

10. In paragraph 9, An assembly bridge manufactured by a method for manufacturing an assembly bridge, characterized in that a pair of pinholes (31) are provided in the longitudinal direction of the first and second link plates (30, 30').

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