JP3866194B2 - Grade structure of steel truss web PC bridge - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a grading structure of a steel truss web PC bridge in which concrete upper and lower floor slabs are connected by a steel truss web, and more particularly to a grading structure embedded and fixed in a concrete girder.
[0002]
[Prior art]
The steel truss web PC bridge has a structure using concrete for the upper and lower floor slabs of the main girder and a steel truss for the web, and can reduce its own weight and lengthen the span compared to the conventional concrete bridge.
In this steel truss web PC bridge, the critical part (joint part of the truss material (diagonal material) that constitutes the steel truss) is an important structural component that integrates the concrete member and the steel member and serves as a cross-sectional force transmission mechanism. Part.
[0003]
A gusset rating structure as shown in FIG. 7 has been conventionally proposed as a rating structure of concrete and steel truss.
This gusset rating structure is a structure in which a gusset plate 16 is embedded in a concrete girder 15, and a compression side truss member 17 and a tension side truss member 18 are frictionally joined to the gusset plate 16 with a high-strength bolt 19. Reference numeral 20 denotes a stud fused to the gusset plate 16, which is fixed to the concrete.
Specifically, an auxiliary plate for increasing the joint area with the gusset plate is welded to the circumferential surface of the truss material, and the auxiliary plate and the truss material are sandwiched between two front and rear gusset plates. In addition, the gusset plate and the auxiliary plate are each friction-joined (fastened) with high-strength bolts (see, for example, Non-Patent Document 1).
[0004]
[Non-Patent Document 1]
“Prestressed concrete” published by Japan Prestressed Concrete Technology Association, March 1999, Vol. 41, no. 2, P41-47
[0005]
[Problems to be solved by the invention]
However, the above-described conventional gusset rating structure has the restriction that the truss material must be a square steel pipe with a surface that is surface-bonded to the gusset plate, because the truss material is secured with a gusset plate and bolted. is there.
Further, since the truss material is joined to the gusset plate, it is difficult to adjust the angle of the truss material.
Furthermore, gusset plates of various sizes are required depending on the size of the truss bridge, and there is a problem that construction efficiency is poor.
Moreover, since the bolt joining location of the truss material in the gusset plate is a portion exposed from the concrete, the exposed portion of the gusset plate needs to be painted.
As a result as described above, there is a problem that the rating part is enlarged.
[0006]
The present invention has been made in view of the problems of the above-described conventional techniques, and an object of the present invention is to provide a grading structure capable of achieving a compact grading.
[0007]
[Means for Solving the Problems]
The technical means taken by the present invention to achieve the above object is a grading structure in a steel truss web PC bridge in which concrete upper and lower floor slabs are connected by a steel truss web, and is constituted by a steel pipe. each end portion of the compression side truss member and the tension side truss member, opposed parallel phase a pair of gusset plates to the circumferential wall of the steel pipe, and the extended projection in the axial direction outwardly of the truss member from the end of the truss member The pair of gusset plates protruding from the ends of the compression side truss members and the pair of gusset plates protruding from the ends of the tension side truss members are arranged in parallel with the plane formed by the truss members to be joined. sandwiched between the spliced plate, characterized by being fastened to package insert contact plate with high strength bolts (claim 1).
The truss material on the compression side and the tension side may be either a round steel pipe or a square steel pipe in order to fix the gusset plate.
With the above configuration, the gusset plates fixed to the compression side truss material and the tension side truss material are joined by high-strength bolts by two-surface friction. Thereby, the rating point can be made compact, and therefore the gusset plate can be embedded inside the concrete girder.
In addition, the angle of the truss member can be adjusted at the time of installation by manufacturing an attachment plate (position of the mounting hole of the high-strength bolt) reflecting the measured value.
[0008]
Further, a round steel pipe used as a steel pipe that constitutes the compression side truss member and the tension side truss member, fixation of the gusset plate of a pair against its round steel pipe, the axis of the peripheral wall of the steel pipe from the side end portion A predetermined length along the notch, and a mounting protrusion integrally formed on the gusset plate may be joined and welded to the notch (claim 2).
[0009]
Further, the peripheral wall of the round steel pipe sandwiched between the mounting protrusion of the gusset plates of the upper Symbol a pair, the reinforcing bars to be arranged in the bridge axis direction may be opened through hole penetrating arrangement (claim 3).
With this configuration, in addition to the arrangement of reinforcing bars in the bridge axis direction, it is possible to improve the filling property of the concrete into the truss material (steel pipe).
[0010]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings.
FIG. 1 is an external view showing a steel truss web PC bridge, and steel truss members constituting the web B, in which the upper and lower floor slabs A and A ′ of the main girder are connected by the web B of the steel truss. The grading part of is embedded in concrete.
[0011]
FIG. 2 is a perspective view showing the stencil structure on the upper floor slab side, and the steel truss constituting the web B is a combination of a compression side truss material 1 and a tension side truss material 1 ′ made of a round steel pipe in a substantially V shape, The joint portion, that is, the grading portion, is a pair of gusset plates 2, 2 ', 3, and 3' before and after the side portions of the compression side truss member 1 and the tension side truss member 1 'are welded and fixed. 2, 2 ', 3 and 3' are friction-joined with high-strength bolts 5 via the attachment plate 4.
[0012]
As shown in FIG. 5, the welding and fixing of the gusset plates 2, 2 ', 3, and 3' to the compression-side truss member 1 and the tensile-side truss member 1 'of the round steel pipe are as shown in FIG. A substantially U-shaped cutout portion 6 is formed on the peripheral wall by relatively bending. The notch 6 can be formed by scraping the peripheral wall, and the depth of scraping is the thickness of the gusset plate to be welded.
On the other hand, the pair of front and rear gusset plates 2, 2 ', 3, 3' is formed of a steel plate, and is fitted on one side of the gusset plate with a notch 6 formed on the side of the truss member 1, 1 '. The matching mounting protrusions 7 are formed to protrude in the same body.
Then, the mounting protrusion 7 formed continuously with the pair of front and rear gusset plates 2, 2 ', 3, 3' is fitted into the notch portion 6 of the compression side truss member 1 and the tension side truss member 1 ', and the joint portion is inserted. By welding, both are firmly integrated. That is, as described above, the mounting protrusions 7 on the gusset plates 2, 2 ', 3, 3' side are fitted into the notches 6 formed on the peripheral wall of the truss material and welded, so the welding area of both members is large. In addition, welding can be performed by joining the surfaces, and the surface of the round steel pipe and the surface of the mounting protrusion can be arranged flush with each other. In addition, fatigue resistance can be considered by processing the front-end | tip part of the attachment protrusion piece 7 into a R surface, and also carrying out the R process of the shape of the notch part 6 by the side of a truss material.
[0013]
The gusset plates 2, 2 ′, 3, 3 ′ are provided with a number of through holes 8 for inserting the high-strength bolts 5 in a lattice shape, and further holes for arranging the penetration reinforcing bars 10. A perforated steel plate gibber (abbreviation: PBL gibber) 9 is integrally formed.
[0014]
The attachment plate 4 that frictionally joins the pair of front and rear gusset plates 2 and 2 ′ of the compression side truss member 1 and the pair of front and rear gusset plates 3 and 3 ′ of the tension side truss member 1 ′ with a high-strength bolt 5 is a compression side truss. The gusset plates 2 and 2 'of the material 1 and the gusset plates 3 and 3' of the tension side truss material 1 'are formed to have a size, and a mounting hole 11 through which the high-strength bolt 5 passes is provided in the surface. Like the holes 8, they are opened in a lattice pattern. In addition, the opening position of the mounting hole 11 can be adjusted to reflect the measured value, so that the angle of the truss member can be adjusted at the time of installation.
[0015]
Further, the peripheral wall of the truss material (round steel pipe) sandwiched between the mounting projection pieces 7 of the pair of front and rear gusset plates 2, 2 ', 3, 3' in the compression side truss material 1 and the tension side truss material 1 'described above. The through hole 12 is opened. The through-hole 12 passes through a reinforcing bar 13 and a PC cable (not shown) arranged along the bridge axis direction in the concrete upper and lower floor slabs A and A ′, and fills the truss with concrete. Can be increased.
[0016]
Due to the grading structure described above, the pair of front and rear gusset plates 2, 2 ', 3, 3' fixed to the compression-side truss member 1 and the tension-side truss member 1 'are fastened by the attachment plate 4, respectively. Since it is fastened with a bolt, it becomes a two-surface friction welding, and the rating part can be configured compactly. Thereby, the said score part can be embedded in the concrete 14.
In addition, since the entire scoring portion can be embedded in the concrete as described above, the painted area of the truss material (the painted area of the exposed portion) is reduced compared to the conventional configuration where the joint between the gusset plate and the truss material is exposed. Can also be expected economic effect.
[0017]
FIG. 6 is a diagram showing a modified application example of the grading structure of the present invention. In the above-described embodiment, the steel truss web connects the upper and lower floor slabs made of concrete, but the steel truss web may be connected and fixed to the upper and lower chords made of steel.
As shown in the figure, connecting plates 21 and 21 'are integrally formed on the front and back sides of the upper chord material C made of steel, and the above-described operation is performed between the front and rear connecting plates 21 and 21'. Each truss material having the same configuration as shown in the example, that is, each gusset of a compression side truss material (round steel pipe) 23 welded with a gusset plate 22 and a tension side truss material (round steel pipe) 25 welded with a gusset plate 24. The plate is inserted, and the contact plate 26 is joined to the inside of the gusset plates 22, 24, and is friction-joined with a high-strength bolt 27. Thereby, the gusset plate 22 of the compression side truss member 23 and the gusset plate 24 of the tension side truss member 25 are attached by the attachment plate, respectively.
With the above configuration, a round steel pipe can be used for the truss member connected to the upper and lower chord members. The upper and lower chord members are optional, such as being embedded in a concrete floor slab or partially embedded.
[0018]
The present invention is not limited to the above-described embodiment, and can be changed without changing the gist of the invention.
(1) The welding of the gusset plate to the truss material of the round steel pipe may be performed by attaching a receiving seat to the back surface of the gusset plate without applying a slit to the truss material.
(2) The truss material may be a square steel pipe.
[0019]
【The invention's effect】
The grading structure of the steel truss web PC bridge according to the present invention can be a two-surface friction high-strength bolt joint with the structure of claim 1, thereby making the grading part compact compared to the conventional structure. . Therefore, it becomes possible to embed the rating part in the concrete, and the concrete member and the steel member can be firmly integrated. Moreover, even if the truss material is a round steel pipe, the gusset plate can be firmly fixed. Therefore, compared with the conventional gusset rating structure using a square steel pipe, a general round steel pipe can be used, which is economically advantageous.
Furthermore, according to the structure of claim 3, in addition to the arrangement of reinforcing bars in the direction of the bridge axis, it is possible to improve the filling property of the concrete into the truss material (steel pipe) and further strengthen the integration of the concrete member and the steel member. Can do.
[Brief description of the drawings]
FIG. 1 is a perspective view showing an appearance of a steel truss web PC bridge according to the present invention.
FIG. 2 is an enlarged perspective view showing a grading point structure portion.
FIG. 3 is an enlarged plan view of a rating part.
4 is an enlarged sectional view taken along line (4)-(4) of FIG.
FIG. 5 is an exploded perspective view of members constituting the rating part.
FIG. 6 is a perspective view showing a modified application example of the grading structure of the present invention.
FIG. 7 is a front view showing a conventional gusset rating structure.
[Explanation of symbols]
A, A '... Upper / lower floor slab B ... Web (steel truss)
DESCRIPTION OF SYMBOLS 1 ... Compression side truss material 1 '... Tensile side truss materials 2, 2' ... Gusset plate 3, 3 '... Gusset plate 4 ... Connecting plate 5 ... High strength bolt 6 ... Notch part 7 ... Mounting protrusion 12 ... Through Hole

Claims (3)

A steel truss web PC bridge structure in which concrete upper and lower floor slabs are connected by a steel truss web,
Each end portion of the compression side truss member and the tension side truss member is constituted by a steel pipe, in parallel with a phase opposed gusset plates a pair in the circumferential wall of the steel pipe, and the axial direction of the truss member from the end of the truss member A pair of gusset plates projecting from the ends of the compression-side truss members and a pair of gusset plates projecting from the ends of the tension-side truss members are formed of a truss material that is bonded by extending outwardly protruding and fixing. sandwiched between spliced plate arranged parallel to the plane, Case point of the steel Torasuuebu PC bridge, characterized in that it has fastened the package insert contact plate with high strength bolts. Steel tube that constitutes the compression side truss member and the tension side truss member is a round steel pipe, the gusset plate secured one pair against its round steel pipe, along the axis of the peripheral wall of the steel pipe from the side end portion predetermined The steel truss web PC bridge grading structure according to claim 1, wherein a length notch and an attachment protrusion integrally formed with the gusset plate are joined and welded to the notch. The peripheral wall of the round steel pipe sandwiched between the mounting protrusion of the upper Symbol a pair gusset plate, according to claim 1 or, characterized in that the through-hole penetrating placing rebar to place the bridge axis direction is established 2. Rating structure of steel truss web PC bridge described in 2.

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