KR20110126566A - Composite truss girder with high strength node - Google Patents

Abstract

PURPOSE: A complex truss girder having a connection structure of a chord for improving pressing stress and bond stress is provided to secure enough resisting cross section against twisting. CONSTITUTION: A complex truss girder having a connection structure of a chord comprises an upper panel point connecting structure(30), a lower panel point connecting structure, and a composite concrete girder. The upper panel point connecting structure is attached to a top panel point of a web diagonal member(10). The upper panel point connecting structure is composed of a finishing board(31), an anchor plate(32), a gusset board(33), and a flange plate(34). The composite concrete girder is combined in the upper and lower panel point connecting structure.

Description

COMPOSITE TRUSS GIRDER WITH HIGH STRENGTH NODE}

The present invention is a shear force for mitigating the stress concentration caused by the transfer of the force of the concrete bottom plate to the gap connection structure and the abdominal material which is very effective in increasing the attachment stress and the acupressure stress between the upper and lower bottom plate and the gap connection structure And a composite truss girder provided with a synthetic concrete girder having a resistance section against torsional moments.

Patents 423757 and 794443 and Korean Patent Laid-Open Publication No. 2009-55530 are directed to improving the structure of a gap portion where a top bottom plate and a bottom bottom plate are synthesized at the top and bottom of a composite truss girder made of steel.

The former point structure consists of a vertical plate integrated connecting plate attached to the bottom of the abdominal member, a stirrup reinforcing bar attached to the bottom of the connecting plate, and a reinforcing bar for lower concrete slab connected to the stirrup reinforcing bar.

However, with a simple connecting plate with a vertical plate corresponding to the rib, the gap strength of the composite truss girder is insufficient to cope with the enormous dynamic load of a traffic vehicle frequently crossing the composite truss girder bridge. This is because the torsion stress is weak. Therefore, in the composite truss girder bridge of the aforementioned point structure, an undesired phenomenon of cracking shortly after completion of the bottom bottom plate of the point portion is frequent.

The gap structure shown in Fig. 6 of the core is drilled by a gusset plate fitted to the bottom of a circular steel pipe abdominal member with a slit in the center of the width and a hole into which a rebar is connected to the reinforcing bar of the bottom plate. It is a vertical connecting plate welded to the slits of the gusset plate with the upper end touching the lower end of the abdominal member.

However, the gusset plate is prone to wheel force due to the external force acting in the axial direction, and the vertical connecting plate is weak to vibrations acting in the cross direction, and the synthetic force with the lower sole plate is weak. It is not much different from the former, and the manufacturing difficulty of the slitting plate fitting slits at the lower end of the abdominal member is high.

In the latter point structure, an inner member longer than the circular steel pipe abdominal member is inserted into the abdominal member, and a flat end connecting plate wider than the outer diameter of the abdominal member is attached to the lower end of the inner member. At the side end, a side connecting plate having a plurality of transverse reinforcing bar holes connected to the reinforcing steel bar of the bottom plate is attached. The inner member has a pair of ribs side by side attached to both sides of the substrate having the same width as the inner diameter of the abdominal member. In consideration of the reality of welding operation in which the welding rod cannot be welded into the long abdominal member, the fixing point (welding point) of the inner member to the abdominal member is limited to the upper and lower ends of the abdominal member.

In order for the inner member to contribute to substantially increasing the strength of the abdominal member, at least the substrate of the inner member must be welded over the entire length of the abdominal member. However, the effect of increasing the abdominal member strength by the inner member is extremely unlike that of the inventor. I doubt it.

In addition, since the end connecting plate and the side connecting plate are embedded in the lower bottom plate in the diagonal direction and the longitudinal direction, the synthetic force with the lower bottom plate against the external force acting on the top is weak. And the side connecting plate is able to bear some degree of external force acting in the bridge direction on the lower floor plate, but the stress on the external force acting vertically is low. For this reason, the synthetic force for synthesizing the bottom plate by the end connecting plate and the side connecting plate does not seem to be very high. It is natural that the strength of the composite truss girder bridge will be raised.

In addition, to increase the composite force between the abdominal member and the bottom plate, transverse bars must be penetrated through the holes of the side connecting plates.

In the conventional prior art described above, when the concrete for the bottom plate is poured, it does not have any structure to prevent a part of the concrete from flowing into the bottom of the abdominal member, and thus there is no waste factor of the concrete for forming the bottom concrete slab.

For this reason, the prior art gap structure is questioned about the reliability of construction quality of the composite truss girder bridge.

Conventional composite truss girders are dedicated to the synthesis of the upper chord plate attached to the upper gap point. In this structure, there is a limit to increase the composite strength of the upper end of the abdominal material and the upper bottom plate of the composite truss girder. In order to build a stronger and safer composite truss girder bridge, it is also necessary to reconstruct this part.

An object of the present invention is to provide a high resistance stress against external forces such as shear force and bending moment and torsion moment acting on the upper and lower gap points, and sufficient resistance to stress concentration and crack generation torsion moments at the upper and lower gap points. It is to provide a composite truss girder having a junction structure for increasing the attachment stress and acupressure stress provided.

In order to achieve the above object, the present invention, in the composite truss girder, having a finishing plate and anchor plate and gusset plate and flange plate, and an upper reinforcing material coupled to the front and rear ends of the anchor plate is attached to the upper end of the abdominal yarn An upper gap point connection structure; A lower gap point connection structure coupled to a closing plate, an anchor plate, a gusset plate, and a flange plate to be attached to the bottom of the abdominal yarn; Proposes a composite concrete girder coupled to the upper and lower junctions.

The upper point connection structure consisting of the closing plate, anchor plate, gusset plate, and flange plate provides a structure that can strongly resist external forces such as shear force, bending moment, and torsion moment acting on the upper point.

Synthetic concrete girders, in addition to the upper point connection, provide sufficient cross section to resist cracking torsion moments at the upper point.

The lower point connection structure consisting of the closing plate, anchor plate, gusset plate, and flange plate provides a structure that can strongly resist external forces such as shear force, bending moment, and torsion moment acting on the lower point.

As a result, the construction quality of the composite truss girder bridge can be improved and a longer life composite truss girder bridge can be provided.

1 is a partial cutaway example of a bridge constructed of a composite truss girder according to the present invention
Figure 2 is an exploded perspective view of a portion of the upper gap point connection structure to which the anchor anchor plate is applied
Figure 3 is a perspective view of the abdominal yarn and the finishing plate and gusset plate
4 is an exploded perspective view of a part of the modified upper gap junction structure;
5 is an enlarged view taken along the line AA of FIG.
Figure 6 is an illustration of the case where the upper stiffener is welded to the upper gap point connection structure
7 is an exemplary view when the upper gap point connection structure and the upper reinforcement is fastened with bolt-nuts;
Figure 8 is a partial cutaway cross-sectional view of the stiffener reinforced concrete composite girders
9 is a perspective view of the stiffener reinforcement bar installed for the composite concrete girder
Figure 10 is an exemplary view for each type of hyeonsang reinforcement is introduced wire tension material
11 is an illustration of various connections between the anchor plate and the reinforcement web and reinforcing bars
Figure 12 is a perspective view of the bolt-nut connection of the junction structure
Figure 13 is a perspective view of the concrete inlet hole of the junction structure and the stiffeners

      In Figure 1, the gap point connection structure of the upper end of the abdominal yarn 10 of the steel truss is provided with an stiffener 20 and concrete upper plate 50 connected in the axial direction. The stiffener 20 is illustrated as a ㅛ type steel in which a narrow flange plate is integrated on a pair of parallel web tops, but is not limited thereto, and may be replaced with a type I steel or P type steel according to the specification of a composite truss girder bridge. have.

The U-shaped rebar 40 is attached upside down at regular intervals on the upper surface of the upper stiffener 20. Type reinforcing bar 40 can be adjusted according to the size of the shear force acting on the composite surface of the concrete top plate 50 and the stiffener 20. Above the concrete bottom plate 51 installed at the bottom of the abdominal material 10 is seen the closing plate 31 of the lower gap connection structure.

In FIG. 2, a gap point connecting structure 30 is attached to an upper gap point of the abdominal yarn 10. The upper gap point connection structure 30 mainly includes a closing plate 31 and an anchor plate 32, a gusset plate 33, and a flange plate 34.

In FIG. 3, the upper end of the abdominal yarn 10 has a connection hole 11 bored in the axial direction along the oblique direction on the circumferential wall of the abdominal yarn lying on an imaginary line passing through the center of the cross section. The connecting hole 11 is a seat to be welded and fixed by inserting the gusset plate 33 to be attached to the anchor plate 32 in an oblique direction. In the gusset plate 33 to be attached to the anchor plate 32, a connecting hole 33a to which the anchor plate 32 is inserted and welded is drilled.

The closing plate 31 is a flat thick steel plate, and the bottom surface of the closing plate 31 and the end of the abdominal yarn 10 are cut and welded to each other in an oblique direction, and in the oblique direction of the attached abdominal yarn 10. The connection hole 31a to be welded by penetrating the gusset plate 33 at the same position as the drilled connection hole 11 is drilled.

The upper part of the abdominal yarn 10 is welded to the bottom of the closing plate 31, and the gusset plate 33 welded by inserting the anchor plate 32 into the connecting hole 33a is connected to the bottom plate of the closing plate 31. When it is inserted into the connection hole 11 of the ball 31a and the abdominal yarn material 10 and welded, it becomes the upper gap part connection structure 30 of the form as shown in FIG.

When assembled in this way, the upper gap point connecting structure 30 and the abdominal yarn material 10 formed of the closing plate 31, the anchor plate 32 and the gusset plate 33 are integrated to act on the shear point and bending moment, It has a structure that can effectively resist external forces such as torsion moment.

The flange plate 34 is attached to the upper end of the anchor plate 32. The flange plate 34 improves the acupressure stress for the load acting on the joint surface between the concrete bottom plate and the flange plate upper surface generated due to the axial force between the abdominal yarn material 10 through the gap connecting portion 30. The anchor plate 32 is attached throughout the longitudinal direction, and the width thereof can be adjusted according to the magnitude of the applied load.

The upper surface of the flange plate 34 attaches a connecting member such as a U-shaped reinforcing bar 40 to improve adhesion between the concrete floor plate and the junction connecting structure 30, thereby effectively preventing local buckling and lateral buckling of the flange plate. Cope with it.

4 shows a modified embodiment in which a pair of anchor plates 32a in which the gusset plate 33a is integrally attached to both sides of the upper end of the abdominal yarn material 10 is shown. In the finishing plate 31 welded to the upper end of the abdominal yarn 10, a connection hole 31a corresponding to the thickness and width of the gusset plate 33a is drilled, and the connection hole 31a is used to form the gusset plate 33a. In this way, the two sides of the abdominal yarn material 10 are welded to the connecting hole 11a perforated in accordance with the width of the gusset plate 33a to be integrated.

As described above, the upper point connection structure 30 of this modified embodiment can also be strongly resistant to external forces such as shear force, bending moment, and torsion moment acting on the gap point.

The gusset plate 33a, which is wider and flatr than the gusset plate 33 of the first embodiment and thicker than the steel pipe abdominal material 10, has a higher welding difficulty with the connection hole 11a of the steel pipe abdominal material 10. A decrease in weld strength is also expected. In consideration of this point, as shown in FIG. 5, the gusset plate 33a is inserted into the connecting hole 11a so that the outer surface of the connecting portion 11 is in line with the tangential direction, and the shear surface penetration groove is welded to strengthen the coupling state.

In FIG. 6, the upper reinforcement 20 is connected to both ends of the upper gap point connection structure 30 formed of the closing plate 31, the connecting plate 32, the gusset plate 33, and the flange plate 34. have. The upper stiffener 20 is constructed when the upper flange plate 21, the lower flange plate 22 and the web 23 are welded to each other and connected to each other at the site where the composite truss girder is to be constructed. The cross-sectional shape is selected to be the same as the cross-sectional shape of the upper gap point connection structure 30, and the joint between the upper gap point connection structure 30 and the upper reinforcing reinforcement member 20 Weld and weld by end face penetration groove.

       Type reinforcing bars 40 and 41 are attached to the upper surface of the flange plate 34 of the upper point connecting portion 30 and the upper surface of the upper flange plate 21 of the upper reinforcing material 20. Although the U-shaped reinforcing bar 40 is illustrated as having horizontal bars 42 and 43 installed in the axial and axial directions, the U-shaped reinforcing bar 40 is also applied to the U-shaped reinforcing bars attached to the upper reinforcement 20. Accordingly, the horizontal reinforcing bars 42 and 43 may be reinforced in the throttling and throttling directions.

The type reinforcing bar 40 of the upper point connection structure 30 increases the adhesion with the concrete top plate in the point area, and the reinforcing reinforcement 20 side type reinforcing bar 41 has the upper point connection structure 30. It will strengthen the adhesion with the concrete top plate except the area of.

On the other hand, after the truss girder segment manufactured at the factory is transported to the construction site of the composite truss girder bridge, the installation work on the pier is performed in the cantilever temporary construction method such as FCM. The difficulty of the high and very dangerous, the work of connecting the upper junction connecting structure 30 and the stiffener 20 on the ground also needs to consider the required equipment, working time and welding difficulty of thick thick plates.

       Considering this point, the same position as the fastening hole and the same number on the joint surface of the anchor plate 32 and the upper reinforcement 20 and the web 23 having the fastening holes at regular intervals horizontally and vertically when manufacturing the girder as shown in FIG. 7. To connect to the bolt-nut 61 by abutting the connecting plate (60) punched in the fastener. Construction by this method shortens the construction period, improving construction efficiency and reducing construction costs.

In FIG. 8, each of the upper gap-point connecting structures 30 attached to the abdominal yarn 10 of the composite truss girder is connected in the axial direction by the upper reinforcement 20. Due to the structural characteristics of the composite truss, the composite concrete girder has a cross section of resistance to shear and torsional moments to alleviate the stress concentration caused by the transfer of the force of the upper and lower base plates 50 and 51 to the abdominal yarn 10. Install (80) in the axial direction. The synthetic concrete girder 80 improves the function and durability of the point by resisting the crack of the concrete member between the point generated by the shear force and the torsion moment transmitted from the sand at the point.

     As shown in FIG. 9, the concrete composite girder 80 is provided with a rebar network 70 for concrete composite concrete girder. Reinforcement net 70 for the composite concrete girder reinforces the main reinforcing bar 71 and the stirrup reinforcing bar 72 for resistance to external loads, such as shear force and torsion moment. Stirrup reinforcing bar 72 is a bar-shaped reinforcement when the bar is interfered with the anchor plate 32 of the upper gap point connection structure 30 and the lower end of the web 23 of the stiffener 20.

    In this case, the method of reinforcing the stirrup reinforcement 72 using the reinforcing bar coupler 73 as shown in Fig. 11C, and the anchor plate 32 and the abdominal plate 23 as shown in Fig. 11D. Perforated reinforcing bar 37 to penetrate through the stub reinforcing bar 72 through a combination method. In case of reinforcing the stirrup reinforcement 72 using the reinforcing coupler 73, the stirrup reinforcement 72 is divided into upper and lower parts for convenience, and the lower stirrup reinforcement 72b is welded and installed in the manufacture of the girder, and then the upper stirrup in the truss girder field. The construction efficiency is increased by connecting the reinforcing bar 72a with the reinforcing bar coupler 73 to be integrated.

10 shows an example in which the wire tension member 90 is installed in the stiffener 30. (A) Attach the vertical reinforcing material 24, the perforated tension material 25 is punctured at equal intervals along the direction of the axial axial reinforcement 20, and through the tension material 25 of all the vertical reinforcement material (24). It is installed through one or more wire-like tension member 90. After installing the composite truss girder with wire-type tension member 90 on the pier, the prestress is introduced in the axial direction, so that the structure can effectively resist the tensile force acting on the stiffener and the sagging of the girder, and especially the extrusion method or the cantilever. In case of constructing the composite truss girder bridge by the construction method, the efficiency is much greater, which can reduce other construction cost. The vertical stiffener 24 is a local buckling by the combined action of the bending stress and shear stress acting on the web 23 of the upper stiffener 20, as well as the role of fixing the position of the wire tension member in the vertical and horizontal direction Play a role in resisting.

(B) is the case where the wire tension member 90 is introduced by attaching the vertical reinforcement 24 to both sides of the web 23 in the I-shaped upper reinforcement 20, and (c) is the This is the case where the vertical reinforcing material 24 is attached between both webs 23 and the wire tension material 90 is introduced. The introduction result is the same even if the prestress is introduced by installing the wire type tension member 90 in the type of stiffener 20 of any type.

FIG. 11 illustrates a method of connecting the reinforcing bar for the concrete upper plate with the anchor plate 32 of the upper point connection structure 30 and the web 23 of the stiffener 20. (A) is a case in which the hook reinforcing bar 100 is attached to the side of the anchor plate 32 and the web 23 to be hooked to the hook formed at the end of the reinforcing bar 71, and (B) is the anchor plate 32. In the case of attaching the type attachment reinforcement 101 to the side of the web 23 and hooking the hook of the end of the reinforcing bar 71, (C) is straight to the outer surface of the anchor plate (32) and the web (23) Attached reinforcing bars 102 and connected to the reinforcement 71 using the reinforcing bar coupler (73), (D) is a reinforcing bar at the same interval as the reinforcing bar interference with the anchor plate 32 and the web 23 This is the case where 37 is drilled and the rebar 71 is penetrated. At this time, the shape of the reinforcing hole 37 may be any shape of a circular hole, an elliptical hole, a square hole. In any embodiment, the anchor plate 32 and the web 23 and the reinforcing bar 71 may be easily connected by a method other than welding.

FIG. 12 shows a modified embodiment in which the upper gap junction connection structure 30 attached to the end of the truss girder segment is connected with bolt-nuts. Welding the junction structure of each segment by transporting the truss girder segment made of the length and weight to be transported to the bridge construction site while the upper junction portion connecting structure 30 is welded and attached to the end of the abdominal yarn 10. This is a common method, but in this case, construction difficulties due to required equipment, working time, and difficulty of welding thick thick plates often occur.

In consideration of this point, in the case of a composite truss girder in which a load capable of connecting the junction connection structure to the bolt-nut 61 is applied, the anchor plate 32 having the perforated holes at regular intervals horizontally and vertically Abutting the anchor plate 32 of each truss girder attached to each other, the connection plate 60 with the fastening hole perforated at the same position as the fastening hole on both sides of the anchor plate and then fastened with the bolt-nut 61 When assembled, it is possible to improve the construction efficiency and economic efficiency due to the shortening of the construction and construction of the girder.

FIG. 13 shows an example in which the concrete inlet hole 38 is drilled in the upper gap-point connection structure 30 and the phase reinforcement 20 using the P-type steel. Due to the upper flange plate 31 and the upper flange plate 21, the upper flange plate 22 of the upper reinforcing member connecting structure 30, the upper reinforcing member 20, and the upper reinforcing member connecting structure 30 and the upper reinforcement when placing concrete There is a fear that voids may occur because the concrete does not flow smoothly into the interior of the 20, resulting in a drop in member strength due to concrete cracking.

In order to solve this, the concrete inlet hole 38 is drilled into the flange plate 31 of the upper point connecting portion 30, the upper flange plate 21 of the upper reinforcing material 20, and the lower flange plate 22, and then poured. The concrete is smoothly flowed into the interior of the upper gap point connection structure 30 and the stiffener 20 through the concrete inlet hole 38 to prevent the occurrence of voids to prevent cracking in advance and enhance the member force. .

       The description of the upper point connection structure described above uses the lower point connection structure as well, and attaches it to the lower end of the abdominal yarn material 10 to produce a composite truss girder. However, in the case of the lower gap part, only the compressive force is applied during the construction, so that the lower beam reinforcement in the same aspect as the top reinforcement 20 connecting the connection part of each gap part is omitted, and the reinforcing bar having a resistance section against shear force and torsion moment in the axial direction is omitted. Only concrete girder can be installed. 2, 4 to 12 can be easily understood by looking upside down.

10: Abdominal material
11,11a: connector
20: ordinary reinforcement
30: connecting structure of upper gap
31: finish plate
32: anchor plate
33: gusset
34: flange plate
37: concrete inlet hole
70: (for composite concrete girder) rebar network
80: synthetic concrete girder
90: tension

Claims (10)

A composite truss girder that combines an upper concrete bottom plate and a lower concrete bottom plate at the top and bottom of the truss steel abdominal material,
The upper gap connection structure in which the upper concrete bottom plate is coupled to the upper connection end of the abdominal yarn interconnected in the axial direction between the closing plate attached to the top of the abdominal yarn and the anchor plate to which the flange plate is attached, and the upper gap connection structure It consists of an ordinary reinforcement that is reinforced with connecting wire tension material,
The lower gap connection structure consists of an anchor plate with a closing plate and a flange plate attached to the bottom of the abdominal yarn.
Where the upper concrete bottom plate and the upper end of the abdominal yarn meet each other, the composite concrete girder which is synthesized with the stiffener having the shear force and the cross section of resistance to cracking torsional moment, which is centered on the axial direction of the upper gap point is installed.
Where the lower concrete deck and the lower end of the abdominal yarn meet, the reinforced concrete girder is installed with a reinforced concrete girder which has a shearing force centered on the axial direction of the lower gap and resistance to cracking torsion moment. Composite truss girder with gap junction structure. The method of claim 1,
An anchor plate with a flange plate is a composite truss girder with an attachment point welded at the center of the connection end of the cut abdominal material and a point connection for increasing acupressure stress. The method of claim 1,
An anchor plate with a flange plate is a composite truss girder having a junction structure for increasing attachment stress and acupressure stress, which is welded to the outside of the cut-out portion of the abdominal yarn end. The method of claim 1,
The anchor plate with flange plate for acupressure stress increase of upper and lower point connection structure is attached one or two or more types of reinforcing bars, hook bars, lattice bars, and bending studs in horizontal and vertical directions. Composite truss girder with connection structure of gap point for increasing the attachment stress and acupressure stress, in which the ellipse hole for concrete casting is mounted on the flange plate. The method of claim 1,
Anchor plate and upper reinforcement with flange plate of upper connection point connection structure have bolt connection and welding structure in consideration of manufacturing and construction convenience with anchor point connection structure anchor plate attached to abdominal yarn. Composite truss girder with stress point connection structure. The method of claim 5,
The stiffener is an I, ㅛ or 형 steel that can cope with the tensile force applied to the phase current, and at least one wire tension member is disposed on both or inside the web to minimize deflection in the girder. And a composite truss girder having a point connection structure for acupressure stress increase. The method of claim 1,
Composite truss girder with connecting point and connecting point for increasing acupressure stress with synthetic concrete girders in the axial direction of upper and lower points. The method of claim 1,
Anchor plate with flange plate of connecting structure of upper point and lower point is used to increase attachment stress and acupressure stress of one or two or more of U-type reinforcing bars, hook reinforcing bars and reinforcing bar couplers. Composite truss girder with point connection structure. In the first aspect,
The anchor plate with the flange plate of the upper point and the lower point connection structure is a composite truss girder with the connection point of the point structure for increasing the attachment stress and the acupressure stress, which is formed by the oval hole for the rebar passage. The method of claim 1,
The composite truss girder transports the truss girder segment with the length and weight that can be transported while the upper concrete bottom plate and the bottom concrete bottom plate embedded anchor plate are welded to the steel abdominal material to the bridge construction site. Composite truss girder with bolt-nut connection structure with bolt-nut connection structure to improve construction efficiency and economic efficiency due to shortening of air.

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