KR102458323B1 - Steel composite girder and manufacturing method - Google Patents

Abstract

A steel composite girder is disclosed. According to the present invention, the steel composite girder comprises: a steel beam provided in an I-type or H-type and provided with a shear connector on an upper flange; a precast floor plate in which a shear pocket is provided in the center, into which the shear connector is inserted, and connected to an anchor reinforcing bar by grouting; and a cross beam connected to the web of the steel beam and extending in a direction perpendicular to the longitudinal direction of the steel beam. The end of the cross beam of the steel beam and the end of the cross beam of the adjacent steel beam are mutually fitted to eliminate connection errors during connection.

Description

STEEL COMPOSITE GIRDER AND MANUFACTURING METHOD

The present invention relates to a steel composite girder and a method for manufacturing the same, and more particularly, by assembling a steel beam introduced in advance and a precast floor plate manufactured for the purpose to provide a steel composite girder, thereby lowering the floor plate and the steel beam The present invention relates to a rigid girder and a method for manufacturing the same, in which prestress advantageous in terms of quality and performance is introduced in the stage.

Bridges are divided into composite structures and non-composite structures according to the connection status of the girder and the slab. The non-composite structure has a problem that the cross section of the girder must be enlarged because the girder bears all the load, whereas the synthetic structure has the advantage of efficiently sharing the load by integrating the girder and the bottom plate to act together. have. Such a composite structure requires a crossbeam between the girder and the girder, a shear connector is required to integrate the girder and the base plate, and a connecting reinforcing bar is required to connect the base plate and the base plate.

Crossbeams are installed to increase the lateral rigidity of the bridge, distribute the sectional force acting on the girder under the wheel load to the adjacent girder, and minimize the harmful effects of the deck or branch due to the effect of torsion. It is installed in the direction parallel to the teaching device.

Existing steel composite girder bridges are usually installed with girders on the abutments and piers, and then the deck is installed. Crossbeams can be installed when assembling the girder, or can be installed in the air after the girder is erected. In such a steel composite girder bridge, the girder bears the concrete weight of the deck, and this stress remains in the structural system afterwards, which is disappointing in terms of structural efficiency. If the girder and the deck are composited from the beginning, the composite structure of the girder and the bottom plate bears the weight of the deck, not the girder alone, so the structural efficiency is increased. However, if the girder and the bottom plate are synthesized from the beginning, the weight is heavy and the lifting operation becomes difficult.

In the case of a bridge composed of multiple girders, it is possible to reduce the lifting weight by constructing a single line composite girder unit. However, there is a problem in that it is impossible to access the lifting equipment to the crossbeam installation location due to the conflict of the bottom plate after the construction of the composite girder, so there is a problem that access through separate equipment or temporary facilities from the lower part occurs. If the lower space is limited, there is no other way to install crossbeams.

On the other hand, as a representative example of the connection method for connecting the existing precast bottom plate, there is a loop method as shown in FIG. The loop method is a method of overlapping two closed reinforcing bars and grouting the space. The loop method has the advantage that the section required for splicing is shorter than that of general rebar splicing, but it takes a considerable amount of grouting nonetheless. Also, there is a problem that the already hardened reinforcing bars interfere with each other.

Republic of Korea Patent Publication No. 10-2014-0026886 (2014.03.06)

The present invention has been devised to solve the problems of the prior art described above, and it is possible to assemble the crossbeam while eliminating the error of the crossbeam connection part so that the crossbeam assembly is possible on the assembled floorboard, and to improve the connection performance of the precast floorboard. To provide a composite girder and a method for manufacturing the same.

A steel composite girder according to an embodiment of the present invention for solving the above-described technical problem is provided in an I-type or H-shaped steel beam provided with a shear connector on the upper flange; a precast bottom plate coupled to the upper part of the steel beam, a shear pocket is provided in the central part, into which the shear connector is inserted, and connected to the anchor reinforcement by grouting; It includes a crossbeam connected to the abdomen of the steel beam and extending in a direction perpendicular to the longitudinal direction of the steel beam, and the crossbeam end of the steel beam and the crossbeam end of the adjacent steel beam are interfitted to solve the connection error when connecting characterized by being

The crossbeam, the crossbeam body connected to the steel beam; The cross section is provided in a 'C' shape and connected to the end of the crossbeam body, the lower part is closed and the upper part is an open box; and a connecting portion provided inside the box portion to connect the crossbeam end of the steel beam and the crossbeam end of the adjacent steel beam.

The crossbeam body is provided with a reinforcing portion of a trapezoidal shape, and the box portion is provided to be connected to an end of the crossbeam body and the reinforcing portion.

The connecting portion may include: closed reinforcing bars provided in a 'U' shape at preset intervals up and down inside the box portion; a guide rail provided in the longitudinal direction of the box portion on the inner surface of the box portion; and a fitting plate that is simultaneously inserted into the guide rail provided at the crossbeam end of the steel beam adjacent to the guide rail of the connecting portion provided at the crossbeam end of the steel beam.

The fitting plate is provided in a 'C' shape in cross section, and the guide rail is provided in a 'C' shape so that the fitting plate is inserted.

The precast bottom plate may include a bottom plate body provided in a plate shape; an intaglio portion provided at an end of the bottom plate body and formed in a stud shape to insert the anchor reinforcing bar; and a protrusion provided at the lower end of the bottom plate body.

The engraved portion is provided to block out from the end of the bottom plate body to a predetermined length and depth in the direction of the shear pocket provided in the center of the bottom plate body, and an enlarged blockout portion is provided at one end of the intaglio reinforcing bar. It is characterized in that the addition is inserted.

The anchor reinforcing bar includes a pair of reinforcing bars having threads on both ends; a spacer connecting the pair of reinforcing bars in the vertical direction; and a fastening nut connecting the ends of the pair of reinforcing bars and the spacer.

In a steel composite girder manufacturing method according to another embodiment of the present invention for solving the above-described technical problem, a steel beam is mounted on a pre-flex steel beam production table and a soaring is introduced to the steel beam, and then to the lower portion of the steel beam. A first construction step of installing a steel beam support; On the upper part of the steel beam in which the soaring is introduced and the shear connector is provided on the upper part, a shear pocket is provided in the central part, the shear connector is inserted, and the precast floor plate connected by grouting with the anchor reinforcing bar is mounted, and the side of the steel beam A second construction step of providing a crossbeam to the; A third construction step of connecting the crossbeam by fitting the crossbeam end of the steel beam and the crossbeam end of the adjacent steel beam to each other; and a fourth construction step of performing grouting on the precast floor plate to connect the precast floor plate to each other.

The crossbeam is a crossbeam body connected to the steel beam, a cross-section is provided in a 'C' shape and is connected to the end of the crossbeam body, the lower part is closed and the upper part is an open box part and provided inside the box part of the steel beam It includes a connecting portion provided to connect the crossbeam end and the crossbeam end of the adjacent steel beam, wherein the crossbeam is simultaneously inserted into the guide rail provided at the crossbeam end of the crossbeam end and the guide rail of the connecting portion provided at the crossbeam end of the steel beam when connected It is characterized in that the connection error is adjusted by the fitting plate and the inside of the connection part is filled and connected by grouting.

The steel composite girder according to the present invention is prepared as a fully composite type during the girder manufacturing process, and the composite girder, which has about 3 to 4 times greater flexural stiffness compared to the steel beam, bears all its own weight, and by the soaring introduced into the steel beam before synthesis It is possible to introduce a linear compressive stress favorable to the composite girder base plate and the lower edge of the steel beam, so the structural efficiency and work safety are excellent.

In addition, according to the present invention, there is no need for on-site copper bars and formwork processes, and there is no risk of high-place work due to the installation, operation, and dismantling of copper bars and formwork.

1 is a schematic diagram showing a loop method among precast connection methods according to the prior art;
2 is a perspective view showing a state in which a beam of a rigid composite girder is connected in a transverse direction according to an embodiment of the present invention;
3a is an exploded perspective view of a crossbeam of a rigid composite girder according to an embodiment of the present invention;
Figure 3b to Figure 3d is a perspective view showing the connection sequence of the crossbeam of the steel composite girder according to an embodiment of the present invention;
4A and 4B are perspective views showing a precast bottom plate of a steel composite girder according to an embodiment of the present invention;
5a to 5c are perspective views showing a process and state in which a steel composite girder is connected in a transverse direction according to an embodiment of the present invention;
6A to 6C are conceptual views illustrating a method of manufacturing a rigid composite girder according to an embodiment of the present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings so that those of ordinary skill in the art can easily implement them. However, the present invention may be embodied in several different forms and is not limited to the embodiments described herein. And in order to clearly explain the present invention in the drawings, parts irrelevant to the description are omitted, and similar reference numerals are attached to similar parts throughout the specification.

Throughout the specification, when a part "includes" a certain component, it means that other components may be further included, rather than excluding other components, unless otherwise stated.

Hereinafter, a rigid girder according to the present invention will be described in detail with reference to the drawings.

Figure 2 is a perspective view showing a state in which the beams of the composite girder are connected in the transverse direction according to the embodiment of the present invention, Figure 3a is an exploded perspective view of the crossbeam of the composite girder according to the embodiment of the present invention, Figures 3b to 3d is a perspective view showing the connection sequence of the crossbeams of the steel composite girder according to the embodiment of the present invention, Figures 4a and 4b are perspective views showing the precast bottom plate of the steel composite girder according to the embodiment of the present invention, Figure 5a 5c to 5c are perspective views showing the process and state in which the steel composite girder is connected in the transverse direction according to the embodiment of the present invention, and FIGS. 6a to 6c are conceptual views showing the construction method of the steel composite girder according to the embodiment of the present invention. to be.

2 to 6c, the steel composite girder according to an embodiment of the present invention includes steel beams 110 and 120, crossbeams 130 and 140, and a precast bottom plate 150.

The steel beams 110 and 120 are provided in I-shape or H-shape and include upper flanges 111 and 121, lower flanges 115 and 125, and abdomens 113 and 123, and shear on the upper flanges 111 and 121. Connection members 117 and 127 are provided.

The shear connectors 117 and 127 are provided to be vertically connected to the upper flanges 111 and 121, and may be provided in a straight rib or perforbond shape.

The shear connectors 117 and 127 are inserted into the shear pockets 157 of the precast bottom plate 150 to connect the steel beams 110 and 120 and the precast bottom plate 150 .

The cross beams 130 and 140 are connected to the abdomens 113 and 123 of the steel beams 110 and 120 and extend in a direction perpendicular to the longitudinal direction of the steel beams 110 and 120 to form any one of the steel beams 110 and It is to connect the adjacent steel beams 120 in the transverse direction in the transverse direction.

The crossbeam 130 end of the steel beam 110 and the crossbeam 140 end of the adjacent steel beam 120 are coupled to each other, so that the connection error can be solved when connecting.

The crossbeams 130 and 140 are cross beam bodies 131 and 141 connected to the steel beams 110 and 120, the cross-section is provided in a 'C' shape and connected to the ends of the crossbeam bodies 131 and 141, and the lower part is closed and the upper part is provided inside the open box parts 135 and 145 and the box parts 135 and 145 to connect the end of the crossbeam 130 of the steel beam 110 and the end of the crossbeam 140 of the adjacent steel beam 120 It includes a connection portion (J) provided to do so.

The crossbeam body (131, 141) is connected so that one end is fixed to the abdomen of the steel beams (110, 120), the other end is provided with a connecting portion (J) and reinforcing portions (133, 143).

The crossbeam body (131, 141) is provided in an I-shape or H-shape like the steel beams (110, 120), and at one end a protruding connection part (132b) coupled to the abdomen (113, 123) and the upper flange (111, 121). , 142b) and the lower flanges (115, 125) are seated on the upper surface of the fixed support connection (132a, 142a) is provided.

The reinforcing parts 133 and 143 are provided to be spaced apart at a preset interval between the upper and lower flanges of the other ends of the crossbeam bodies 131 and 141, and their shape is a triangular or trapezoidal shape that increases in width toward the other end. can be formed.

Between the reinforcing parts 133 and 143, an end hole 134 to which the end of the closed reinforcing bar is coupled is provided so as to be struck up and down at a preset interval.

The box portions 135 and 145 are provided in a rectangular parallelepiped shape so that their heights correspond to the heights of the ends of the crossbeam bodies 131 and 141, and are provided to open in the direction of the upper and other ends.

The box portion 135 of any crossbeam 130 is provided so that only the upper portion is opened when meeting the box portion 145 of the adjacent crossbeam 140 , and a connection portion J is provided in the box portions 135 and 145 .

The connection part (J) is a box part ( The guide rails 139 and 149 provided in the longitudinal direction of 135 and 145, the guide rail 139 of the connecting portion provided at the end of the crossbeam 130 of the steel beam 110 and the crossbeam 140 of the steel beam 120 adjacent to It includes a fitting plate 137 that is simultaneously inserted into the guide rail 149 provided at the end.

The closed reinforcing bars 138 and 148 are provided to be vertically spaced apart, and the straight portions of the U-shaped closed reinforcing bars 138 and 148 in a plan view are provided to overlap.

A nut portion N is provided at the ends of the closed reinforcing bars 138 and 148 to fix the ends of the closed reinforcing bars 138 and 148 passing through the end holes 134 and 144 with respect to the box portions 135 and 145.

The guide rails 139 and 149 are provided in pairs, one on each inner side of the box portions 135 and 145, and are provided in a 'C' shape to facilitate insertion of the fitting plate 137, but the width of the upper part is It may be provided such that the width becomes relatively wide and becomes constant as it goes down.

The fitting plate 137 has a 'C' shape in cross section, and the protruding portions of both sides are provided to be inserted into the guide rails 139 and 149, respectively.

Referring to FIGS. 3B to 3D , a process of canceling an error when connecting the cross beams 130 and 140 in the transverse direction perpendicular to the longitudinal direction of the steel beams 110 and 120 will be described.

The errors that may be generated between the cross beams 130 and 140 are a vertical error, a lateral error, and a longitudinal error. The vertical error and the transverse error can be adjusted relatively easily through the pushing and/or pulling process in the precast floor plate, but the longitudinal error generated between the cross beams 130 and 140 is relatively difficult to match.

In the case of the present invention, it is provided so that the longitudinal error disappears by the fitting of the fitting plate 137 and the guide rails 139 and 149.

First, as shown in FIG. 3b, the longitudinal error between the crossbeams 130 and 140 is checked, and the fitting plate 137 is simultaneously inserted into the guide rails 139 and 149 as shown in FIG. 3c and pushed in by hitting or hydraulic pressure. By completing the insertion of the fitting plate 137 as shown in 3d, the error of the crossbeam is eliminated. Thereafter, an injection material such as concrete is poured into the inside of the box portions 135 and 145 .

Since the crossbeams 130 and 140 according to the embodiment of the present invention are prefabricated hybrid crossbeams in which a steel box and reinforced concrete are combined, they basically have a steel structure type, so they are relatively light and are not connected through bolts or welding, but precast floor plates. At 150, an injection-type composite structure is applied so that the crossbeam connection work can be performed.

The precast bottom plate 150 is coupled to the upper portion of the steel beams 110 and 120, and a shear pocket 157 is provided in the central portion to insert the shear connectors 117 and 127, and anchor reinforcement 160 and grouting will be connected

When the steel beams 110 and 120 are provided as a pre-flex, the precast bottom plate 150 may be formed to have a curvature corresponding to the curvature of the steel beams 110 and 120 .

The precast bottom plate 150 is a bottom plate body 151 provided in a plate shape, and is provided at the end of the bottom plate body 151, and is formed in a stud shape to insert an anchor reinforcing bar 160. An intaglio part 153 is provided. , a protrusion 159 provided on the lower end of the bottom plate body 151 , a shear groove 154 provided as a groove on the end side of the bottom plate body 151 and grouted, and protruding from the bottom of the bottom plate body 151 . It includes a heonchi portion 155 provided to be so, a cross-sectional extension 158 provided on the side of the lower surface of the bottom plate body 151.

The intaglio part 153 is provided to block out from the end of the bottom plate body 151 to a predetermined length and depth in the direction of the shear pocket provided in the center of the bottom plate body 151, and one end of the intaglio part 153 ( An enlarged block-out portion (153a) is provided at the inner end of the bottom plate body), and one end of the anchor reinforcing bar (160) is inserted.

Both ends of the anchor reinforcing bars 160 are inserted into both ends of the enlarged block-out portion 153a of one bottom plate 150 and the enlarged block-out portion 153a of the neighboring bottom plate 150, and by grouting Any one of the bottom plates 150 and the adjacent bottom plate 150 are connected.

In the lower end of the bottom plate 150 (the lower surface of the bottom plate body), a cross-section extension 158 is provided in consideration of the cross-sectional loss of the portion where the grouting cannot be filled when the bottom plates 150 are connected, and the bottom A protrusion 159 is provided at the lowermost end of the end of the plate body 151 (ie, the lowermost end of the end of the base plate body or the uppermost part of the cross-sectional extension) to block the grouting leakage.

Although not shown, a protrusion may be provided at the edge of the bottom plate body 151 to block grouting leakage, and a backup material for preventing grouting leakage may be attached to the protrusion. The backup material is made of an elastic material, and the protrusions of the bottom plate 150 that are connected to the protrusions of any one of the bottom plates 150 meet and elastically contract within the clearance generated to further block leakage.

Anchor reinforcing bar 160 is a pair of reinforcing bars 161, 163 with threads at both ends, a spacer 165 connecting the pair of reinforcing bars 161, 163 in the vertical direction, a pair of reinforcing bars 161, It includes a fastening nut 167 connecting the end of the 163 and the spacer 165 .

The pair of reinforcing bars 161 and 163 includes an upper reinforcing bar 161 and a lower reinforcing bar 163, and the pair of reinforcing bars 161 and 163 and the spacer 165 are provided in a rectangular shape, and the bottom plate 150 ) When manufacturing, the reinforcing bars corresponding to the anchor reinforcing bars 160 have standard hooks or closed ends, thereby ensuring continuity with the anchor reinforcing bars 160 .

The bottom plate 150 is generally provided in a rectangular parallelepiped shape, but when it is provided for an outer mold as shown in FIG. 5A , it may include an edge end curb 170 and a firewall anchor (not shown) at the end.

With reference to Figures 6a to 6c, the construction method of the steel composite girder according to an embodiment of the present invention will be described in detail.

In the construction method of the steel composite girder according to the embodiment of the present invention, the steel beam 110 is mounted on the preflex steel beam production table 10 and the soaring is introduced into the steel beam 110 of the steel beam 110 . The first construction step of installing the steel beam support 40 in the lower part, the shear connector 117 is provided in the upper part of the steel beam 110 in which the soaring is introduced and the shear connector is provided in the upper part, the shear pocket 157 is provided in the center part. A second construction step of mounting the precast bottom plate 150 that is inserted and connected by the anchor reinforcing bar 160 and grouting, and providing the crossbeams 130 and 140 on the side of the steel beam 110, the steel beam 110 ) of the crossbeam 130 end and the crossbeam 140 end of the adjacent steel beam 120 are mutually fitted to each other to connect the crossbeams 130 and 140, the third construction step, grouting on the precast bottom plate 150 and a fourth construction step of connecting the precast floor plates 150 to each other by carrying out.

In the first construction step, the steel beam may be provided so that the pre-flex is introduced, it is also possible to be provided so that the pre-flex is not introduced.

For the introduction of the preflex, the steel beam 110 is mounted on the preflex steel beam making table 10 as shown in FIG. 6a, and the transverse buckling prevention bar 20 may be provided, and the lower portions of both ends of the steel beam 110 are A negative reaction force fixing anchor 30 may be provided.

Introduce the spur to the steel beam 110 through the hydraulic jack (S), and the swell is designed in advance to about 0.2 to 0.3% of the span.

Thereafter, as shown in FIG. 6b , the steel beam support 40 is provided at the lower part of the steel beam 110 in which the soaring is introduced, and the steel beam support 40 may be provided with a screw jack or the like. The steel beam support 40 is provided so that the composite cross-section bears the weight of the precast bottom plate 150 .

The cross beams 130 and 140 may be provided after the soaring is introduced into the steel beam 110 , and may be provided on the steel beam 110 at the same time as the precast bottom plate 150 is mounted.

Thereafter, in the second construction step as shown in FIG. 6c , the precast bottom plate 150 is connected to the adjacent precast bottom plate 150 and the anchor reinforcing bars 160 and grouting, and the grouting is performed with cross beams as in the fourth construction step. It can be carried out all at once in a connected state, but after grouting is performed in the second construction stage, the rigid composite girder can be completed by connecting the crossbeams in the third construction stage.

When the beam 110 is provided for the outer mold as shown in Fig. 5a, the cross section of the precast bottom plate 150 is provided asymmetrically, so that the bottom plate cross-section design is applied so that the shear center is in the center of the beam 110. can This is because, if the shear centers are mismatched, there is a risk that a torsion moment may occur when the girder is removed.

In the third construction step, the vertical error and lateral error are corrected through the push & pulling operation on the upper part of the precast floor plate 150, and the fitting plate 137 is inserted into the guide rails 139, 149 to insert the cross beam 130, 140) to correct the longitudinal error. In addition, non-shrinkage concrete grouting is performed inside the box parts 135 and 145 to finish the connection of the crossbeams 130 and 140 .

The steel composite girder according to the present invention is prepared as a fully composite type during the girder manufacturing process, and the composite girder, which has about 3 to 4 times greater flexural rigidity than the steel beam, bears all its own weight. It is possible to introduce favorable linear compressive stress to the composite girder bottom plate and the lower edge of the steel beam, so the structural efficiency and work safety are excellent.

In addition, according to the present invention, there is no need for on-site copper bars and formwork processes, and there is no risk of high-place work due to the installation, operation, and dismantling of copper bars and formwork.

For general steel composite girder, the floor plate is installed by the cast-in-place method after the steel beam is installed. In this case, the steel beam bears the sole weight of the sole plate. In addition, there is a disadvantage in that the construction process is complicated and it is necessary to work in a dangerous environment because the installation of formwork and copper bars is required.

In the rigid composite girder according to the present invention, since tensile stress is not generated in the precast floor plate, reinforcing bars can be omitted from the longitudinal connection. In the rigid cross section, the sole plate corresponds to the upper edge and is structurally compressed. However, tensile stress may be generated in the floor plate due to the concrete drying shrinkage and restraint effect. Since a predetermined compressive stress is introduced into the precast floor plate of the present invention, longitudinal reinforcing bars can be usually omitted in the connection of the precast floor board, and reinforcing bars required only for positions where tensile stress is large, such as the right leg of the ramen structure. A rational design for arranging can be applied.

In addition, when the steel composite girder according to the present invention is applied to the Ramen bridge, it is possible to prevent lateral cracking, which is a chronic problem of the steel composite Ramen bridge. Transverse cracks are occurring in many steel composite ramen bridge decks in common use. In particular, this transverse crack is occurring in the portion where the sub-structure and the super-structure, which belong to the rapidly changing section of the ramen structure, connect. This crack is caused by the drying shrinkage restraint of the concrete floor plate to which the cast-in-place method is applied. Since the steel composite girder according to the present invention basically has a precast bottom plate and a fully composite girder is provided, the drying shrinkage of the bottom plate is very small, and the harmful binding force is insignificant. It has the advantage of being able to prevent defects by taking

The foregoing description of the present invention is for illustration, and those of ordinary skill in the art to which the present invention pertains can understand that it can be easily modified into other specific forms without changing the technical spirit or essential features of the present invention. will be. Therefore, it should be understood that the embodiments described above are illustrative in all respects and not restrictive. For example, each component described as a single type may be implemented in a distributed manner, and likewise components described as distributed may also be implemented in a combined form.

The scope of the present invention is indicated by the following claims rather than the above detailed description, and all changes or modifications derived from the meaning and scope of the claims and their equivalent concepts should be interpreted as being included in the scope of the present invention. do.

110: steel beam
120: steel beam
130: cross beam
140: cross beam
150: precast bottom plate
160: anchor reinforcement

Claims (10)

A steel beam provided in I-shape or H-shape and provided with a shear connector on the upper flange;
a precast bottom plate coupled to the upper part of the steel beam, a shear pocket is provided in the central part, into which the shear connector is inserted, and connected to the anchor reinforcement by grouting;
A cross beam connected to the abdomen of the steel beam and extending in a direction perpendicular to the longitudinal direction of the steel beam; includes,
The crossbeam end of the steel beam and the crossbeam end of the adjacent steel beam are mutually fitted to solve the connection error when connecting,
The crossbeam, the crossbeam body connected to the steel beam; The cross section is provided in a 'C' shape and is connected to the end of the crossbeam body, the lower part is closed and the upper part is an open box; and a connecting portion provided inside the box portion and provided to connect the crossbeam end of the steel beam and the crossbeam end of the adjacent steel beam.
The connecting portion may include: closed reinforcing bars provided in a 'U' shape at preset intervals up and down inside the box portion; a guide rail provided in the longitudinal direction of the box portion on the inner surface of the box portion; and a fitting plate that is simultaneously inserted into the guide rail of the connecting portion provided at the crossbeam end of the steel beam and the guide rail provided at the crossbeam end of the steel beam adjacent to the guide rail. delete According to claim 1,
The crossbeam body is provided with a reinforcing part of a trapezoidal shape, and the box part is a rigid girder, characterized in that it is provided to be connected to an end of the crossbeam body and the reinforcement part. delete According to claim 1,
The fitting plate is provided in a 'C' shape in cross section, and the guide rail is provided in a 'C' shape so that the fitting plate is inserted. synthetic girders. According to claim 1,
The precast bottom plate,
a bottom plate body provided in a plate shape;
an intaglio portion provided at an end of the bottom plate body and formed in a stud shape to insert the anchor reinforcing bar; and
A rigid girder comprising a; a protrusion provided at the lower end of the bottom plate body. 7. The method of claim 6,
The intaglio portion is provided to block out from the end of the bottom plate body to a predetermined length and depth in the direction of the shear pocket provided in the center of the bottom plate body,
An enlarged block-out portion is provided at one end of the intaglio, and one end of the anchor reinforcing bar is inserted. 8. The method of claim 7,
The anchor reinforcement is
A pair of reinforcing bars with threads on both ends;
a spacer connecting the pair of reinforcing bars in the vertical direction; and
A rigid girder comprising a; a fastening nut connecting the end of the pair of reinforcing bars and the spacer. A first construction step of installing a steel beam support in the lower part of the steel beam after mounting the steel beam on the preflex steel beam production table and introducing the soaring to the steel beam;
On the upper part of the steel beam in which the soaring is introduced and the shear connector is provided on the upper part, a shear pocket is provided in the central part, the shear connector is inserted, and the precast floor plate connected by grouting with the anchor reinforcing bar is mounted, and the side of the steel beam A second construction step of providing a crossbeam to the;
A third construction step of connecting the crossbeam by fitting the crossbeam end of the steel beam and the crossbeam end of the adjacent steel beam to each other; and
A fourth construction step of performing grouting on the precast floor plate to connect the precast floor plate to each other; including,
The crossbeam is a crossbeam body connected to the steel beam, a cross-section is provided in a 'C' shape and connected to the end of the crossbeam body, the lower part is closed and the upper part is an open box part and provided inside the box part of the steel beam It includes a connecting portion provided to connect the crossbeam end and the crossbeam end of the adjacent steel beam,
When the crossbeam is connected, the connection error is adjusted by a fitting plate that is simultaneously inserted into the guide rail provided at the crossbeam end of the steel beam adjacent to the guide rail of the connecting portion provided at the crossbeam end of the steel beam, and the inside of the connecting portion is filled by grouting A method of manufacturing a rigid girder, characterized in that it is connected. delete

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