JP2018096184A - Steel plate floor instant bridge - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a steel plate floor instant bridge capable of suppressing the occurrence of fatigue crack from a welding line at the rib intersecting portion and also of reducing the installation period.MEANS FOR SOLVING THE PROBLEM: A steel plate floor instant bridge 100 has a main girder 40 made of a rolled H-shaped steel, a steel plate floor supporting material 50, and a steel plate floor panel 200. The steel plate floor panel 200 is equipped with a steel plate 11, a longitudinal rib 20 which is a flat plate 21, and a transverse rib 30 having a slit 33 formed therein. At the rib intersecting part, flat plate side surfaces 21s, 21t, and a flat plate lower end surface 21b are welded to slit side edges 33s, 33t, and a slit lower end edge 33b. The steel plate 11, a transverse rib web 31, and a transverse rib lower flange 32 are connected to a supporting material web 51, to a main-girder stiffener 43 and a supporting material stiffener 53 via a splice plate 74, and to a main-girder web 41 via a split tee 60 and a splice plate 74, respectively, by a bolt/nut 80.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a steel floor slab instant bridge, and more particularly to a steel floor slab instant bridge comprising a steel floor slab panel stiffened by vertical and horizontal ribs.

  In Japan, there are about 720,000 bridges, and about 74% of them have a bridge length of 2m or more and less than 15m (hereinafter referred to as the “small branch bridge”). A small span bridge has a floor slab (sometimes referred to as a floor slab) installed on a main girder arranged parallel to the bridge axis. The floor slab is mainly made of steel. There are concrete floor slabs mainly made of concrete, and composite floor slabs made of steel and concrete. Hereinafter, a bridge having a steel slab is referred to as a “steel slab bridge”, a bridge having a concrete slab is referred to as a “concrete slab bridge”, and a bridge having a composite slab is referred to as a “synthetic floor slab bridge”.

The steel plate forming the steel slab (same as the deck plate) is vertical ribs (sometimes called vertical beams) arranged in parallel to the main girder and perpendicular to the main girder (hereinafter referred to as “bridge width direction”). Are stiffened by transverse ribs (sometimes referred to as transverse beams) arranged on the interior. That is, the vertical rib and the horizontal rib are welded to the lower surface of the steel plate, and the intersection between the vertical rib and the horizontal rib (hereinafter referred to as “rib intersection”) is also welded. And the pavement of asphalt etc. is given to the upper surface of a steel plate.
On the other hand, in the composite floor slab, concrete is laid on the upper surface of the steel plate forming the composite slab, and the steel plate may be stiffened by vertical ribs and horizontal ribs in the same manner as the steel floor slab. At this time, the vertical rib and the horizontal rib are embedded in the concrete.

Vertical ribs are roughly classified into trapezoidal U-ribs that form closed spaces, and valve ribs and flat ribs that do not form closed spaces. The U-rib is a steel material having a side surface corresponding to the hypotenuse of the trapezoid and a lower surface corresponding to the upper side of the trapezoid, the upper edge of the side surface (side edge opposite to the lower surface) being welded to the steel plate, A closed space of a shape is formed.
The transverse rib has a T-shaped cross section, and one side edge (upper edge) of the web is welded to the steel plate, and the other side edge (lower edge) is provided with a flange. And the trapezoidal notch part which a vertical rib can penetrate | penetrate is formed in a web, and the both sides | surfaces of a U rib are weld-connected to a horizontal rib in a rib crossing part (notch part).

  A “lower scallop” is provided at the back of the notch. For this reason, the welding line between the U rib and the lateral rib is formed between the steel plate (deck plate) and the lower scallop, and the welding line on one side and the welding line on the other side sandwich the lower scallop. Separated. That is, a gap is formed between the lower surface of the U-rib and the innermost part of the notch. "have.

On the other hand, the flat rib is a flat plate, and at this time, a rectangular slit into which the flat plate can be inserted is formed in the horizontal rib, and an "upper scallop" is provided at the mouth of the slit, and at the back of the slit A “lower scallop” is provided.
Then, with the upper edge of the flat rib welded to the steel plate, the flat rib penetrates into the slit of the horizontal rib, and one side of the flat rib is welded to the horizontal rib at the rib intersection, A gap is formed between the other side surface and the lateral rib.
For this reason, the weld line between the flat rib and the lateral rib is formed between the upper scallop and the lower scallop on only one side surface and has a welding end point. In the upper scallop, the weld line between the flat rib and the horizontal rib is separated from the weld line between the flat rib and the steel plate, and is also separated from the weld line between the horizontal rib and the steel plate.

Since a complicated load (hereinafter referred to as “wheel load”) due to the traveling vehicle repeatedly acts on the steel deck, a complicated bending moment is repeatedly generated on the steel plate. At this time, the longitudinal rib stiffens the steel plate in the bridge axis direction and mainly generates stress in the bridge axis direction, and the lateral rib stiffens the steel plate in the bridge width direction and mainly generates stress in the bridge width direction. Therefore, both the deformation of the vertical rib and the deformation of the lateral rib are accumulated at the rib intersecting portion to cause extremely complicated local deformation, and concentrated local stress is generated.
Furthermore, the concentration of local stress in the longitudinal rib is further complicated by the form of the weld connection at the rib intersection as described above. For this reason, steel floor slab bridges tend to generate fatigue cracks particularly at the weld end points, and an invention is disclosed that attempts to suppress the occurrence of such fatigue cracks (see, for example, Patent Document 1).

JP2013-245459 (page 6-8, FIG. 5)

In the invention disclosed in Patent Document 1 (steel slab and steel slab bridge equipped with the same), the steel slab is formed with a U-rib and a trapezoidal notch into which the U-rib can enter in the web. The lower scallop is provided continuously to the innermost part of the notch.
In addition, a curved portion parallel to the side edge of the notch (corresponding to the hypotenuse of the trapezoid) is formed continuously from the innermost part of the notch (lower edge corresponding to the upper side of the trapezoid). A substantially strip-shaped narrow member is formed between the predetermined range on the back side and the curved portion.
Therefore, since the U rib is welded to the web of the lateral rib on the mouth side of the notch at the rib intersection and welded to the narrow member on the back side of the notch, the weld line is The welding end point facing the lower scallop at the lower end of the narrow member is continuous (overlapping) with the weld line between the steel plate and the steel plate.
As a result, the narrow member (particularly the back side) has a lower rigidity than the web and can be easily deformed. Therefore, stress concentration at the weld end point is reduced, so that the occurrence of fatigue cracks at the weld end point is suppressed. Yes.

However, the invention disclosed in Patent Document 1 has a problem in that a weld end point facing the lower scallop is formed at the rib intersection, and a weld crack is generated from the weld end point.
In addition, since the closed space is formed, one-side welding is performed, so that there is a possibility that the entire wall thickness does not melt, and there is a problem that fatigue cracks are generated from the weld line between the U rib and the lateral rib.
In addition, since the horizontal ribs are welded to the main girder, there is a problem that the construction period becomes long when replacing or newly installing.

  An object of the present invention is to provide a steel slab instant bridge capable of solving such a problem and capable of suppressing the occurrence of fatigue cracks from a weld line at a rib intersection and shortening the construction period.

(1) The steel deck slab instant bridge according to the present invention has a main girder arranged in the bridge axis direction, and a steel deck slab panel installed in the main girder,
The steel slab panel comprises a steel plate, longitudinal ribs in the bridge axis direction, and transverse ribs in the direction perpendicular to the bridge axis direction,
The vertical rib is a rectangular flat plate, the upper end surface of the vertical rib is welded to the steel plate,
The transverse rib is a steel material having a T-shaped cross section comprising a flat transverse rib web and a transverse rib flange provided at a lower end edge of the transverse rib web, and a rectangular slit is formed in the transverse rib flange,
The vertical rib penetrates into the slit, both side surfaces and the lower end surface of the vertical rib are welded to the horizontal rib web at the intersection of the slit and the vertical rib, and the upper end surface of the horizontal rib web is the steel plate. Welded to the
The main girder is a steel material rolled into an H-shaped cross section having a flat main girder web and a main girder upper flange and a main girder lower flange respectively provided at both ends of the main girder web. A main girder stiffener connecting the web, the main girder upper lunge and the main girder lower flange;
The steel plate is connected to the main girder upper flange by bolts / nuts,
The lower flange of the lateral rib is connected to the main girder web by a bolt / nut via a split tee,
The transverse rib web is connected to the main girder stiffener by a bolt / nut via a splice plate.

(2) The steel deck slab instant bridge according to the invention includes a flat support material web, a support material upper flange and a support material lower flange respectively provided at both ends of the support material web, the support material web, A steel slab support material comprising a support material stiffener for connecting the support material upper flange and the support material lower flange;
Instead of connecting the steel plate and the main girder upper flange, the steel plate is connected to the support material upper flange by a bolt / nut, and the main girder upper flange is connected to the support material lower flange by a bolt / nut,
The transverse rib web is connected to the support material stiffener by a bolt / nut via a splice plate.
(3) Furthermore, the welding start end and the welding end of the welding line that weld-connect the vertical rib and the horizontal rib are located on one side surface and the other side surface of the vertical rib, respectively.
(4) Furthermore, a weld line that welds and connects the vertical rib and the horizontal rib, a weld line that weld-connects the vertical rib and the steel plate, and a weld line that weld-connects the horizontal rib and the steel plate. Intersect.

In the steel slab instant bridge according to the present invention, the vertical rib is formed of a flat plate, and both side surfaces and the lower end surface of the vertical rib that have entered the slit formed in the horizontal rib are welded to the horizontal rib.
That is, since the gap between the lower end surface of the vertical rib and the innermost part of the slit is blocked by the weld line and there is no gap corresponding to the lower scallop, the stress concentration due to the wheel load generated in the part is alleviated. The occurrence of fatigue cracks is suppressed and the life is extended.
In addition, since the end points (welding start end and welding end) of the weld line connecting the vertical rib and the horizontal rib are not located between the lower end surface of the vertical rib and the innermost end of the slit, fatigue cracks from the relevant part Generation is further suppressed.
Furthermore, the weld line between the vertical rib and the horizontal rib, the weld line between the vertical rib and the steel plate, and the weld line between the horizontal rib and the steel plate intersect at the slit mouth (the same as the upper end surface of the vertical rib). A gap corresponding to the upper scallop is not formed. Therefore, stress concentration due to the wheel load in the portion is alleviated, so that the occurrence of fatigue cracks from the portion is suppressed and the life is extended.
Further, the vertical rib is a flat plate and is welded and connected to the horizontal rib and the steel plate on both sides of the flat plate (same as double-sided welding), so that the connection is sound.

Further, since the connection between the main girder and the steel deck is a bolt / nut through a split tee and a splice plate, the installation is facilitated and the construction is quick. Also, the removal work becomes quick.
Moreover, since the steel deck support material is installed in the main girder, the freedom of installation increases. That is, even when using a pre-standardized steel deck panel and a pre-standardized main girder, the height of the existing substructure can be increased by adjusting the height of the steel deck support material. The steel slab (upper surface of the pavement provided on the steel slab panel) can be set to a desired height without being affected by the height (the height including the supporting means of the pier).
Furthermore, since the main girder is formed of rolled H-section steel, it becomes easy to standardize, and the manufacturing cost can be reduced and the construction time can be shortened. In other words, by adopting steel floor slab panels and rolled H-section steel, it is possible to expect a reduction in life cycle costs from production to maintenance management by combining standardized products, design-less, and implementation of some paving factories. The existing substructure can be diverted.

It is the perspective view which looked at the steel-slab slab instant bridge concerning Embodiment 1 of this invention from diagonally upper front to diagonally downward. It is a perspective view which expands and shows a part of steel deck slab instant bridge shown in FIG. It is the perspective view which looked at the member (steel slab panel) which comprises the steel deck slab instant bridge shown in FIG. 1 from the diagonally downward direction to the diagonally upward direction. It is a front view which shows a part (a steel plate and a vertical rib) of the member (steel slab panel) which comprises the steel slab instant bridge shown in FIG. It is a front view which shows a part (lateral rib) of the member (steel slab panel) which comprises the steel slab instant bridge shown in FIG. It is a perspective view which expands and shows a part (rib crossing part) of the member (steel slab panel) which comprises the steel slab instant bridge shown in FIG. It is the perspective view which looked at the test material for testing the characteristic of the steel-slab slab instant bridge shown in FIG. 1 from diagonally upward to diagonally downward. It is a front view which shows a part of test material shown in FIG. It is a front view which shows a part of comparison material for comparing with the test material shown in FIG. It is a bar graph which compares the concentrated stress total of the test material for testing the characteristic of the steel deck slab instant bridge shown in FIG. 1, and a comparison material. It is a "load-loading number curve" which shows the result of the fatigue test for testing the characteristic of the steel floor slab instant bridge shown in FIG.

[Embodiment 1]
Next, Embodiment 1 according to the present invention will be specifically described with reference to the drawings. In addition, the following drawings are drawn typically, and this invention is not limited to the drawn form, It can change suitably.

(Steel slab instant bridge)
1 to 6 are diagrams for explaining a steel floor slab instant bridge according to Embodiment 1 of the present invention, in which FIG. 1 is a perspective view seen from diagonally upward to diagonally downward, and FIG. 3 is an enlarged perspective view, FIG. 3 is a perspective view of a constituent member (steel floor slab panel) seen from diagonally downward from the front, and FIG. 4 is one of the constituent members (steel floor panel). FIG. 5 is a front view showing a part (lateral rib) of a constituent member (steel floor slab panel), and FIG. 6 is one of the constituent members (steel floor slab panel). It is a perspective view which expands and shows a part (rib crossing part).

1 and 2, a steel deck slab instant bridge 100 includes a main girder 40 installed on a support device installed on a pier (not shown), a steel deck slab support 50 installed on the main girder 40, and a main girder. 40 and a steel deck slab panel 200 attached to a steel deck support 50.
The main girders 40 are arranged in four rows in the bridge width direction, and the three steel deck panels 200 forming the steel deck are installed in the bridge width direction. However, the present invention is not limited to this. It can be in rows or any number. The longitudinal direction of the main girder 40 is “bridge axis direction (Y direction)”, the direction perpendicular to the bridge axis direction is “bridge width direction (X direction)”, and the direction perpendicular to the XY plane is “vertical”. Direction (Z direction) ".

(Main digit)
The main girder 40 is a steel material rolled into a H-shaped section (referred to as “rolled H-shaped steel” in the present invention), and includes a main girder web 41 (located in the YZ plane) and a main girder web 41. The main girder upper flange 42a (located on the XY plane) and the main girder lower flange 42b (located on the XY plane) respectively formed on the both side edges. Further, a plurality of main girder stiffeners 43 (located on the XZ plane) for connecting the main girder web 41, the main girder upper flange 42a, and the main girder lower flange 42b are provided at intervals in the longitudinal direction.

(Steel slab support material)
The steel slab support material 50 is a steel material having an H-shaped cross section, and includes a support material web 51 (located on the YZ plane) and support material upper flanges 52a (X -Located on the -Y plane) and a support lower flange 52b (located on the XY plane).
Further, a plurality of support material stiffeners 53 (located on the XZ plane) connecting the support material web 51, the support material upper flange 52a, and the support material lower flange 52b are provided at intervals in the longitudinal direction. In addition, although the steel deck support 50 is formed by welding a steel plate to have a H-shaped cross section, it may be a rolled H-shaped steel.

(Steel floor panel)
In FIG. 1, a steel deck slab panel 200 includes a steel deck 10, longitudinal ribs 20 in the bridge axis direction, and lateral ribs 30 in the bridge width direction (X direction). Although the factory construction pavement 12 is applied to the upper surface of the steel plate 11 constituting the steel floor slab 10 and the site construction pavement 13 is applied at the construction site, the construction time is reduced. The pavement 12 may be performed at the construction site.

(Vertical ribs constituting the steel floor panel)
3 and 4, the vertical rib 20 is formed by a rectangular flat plate 21, and the flat plate upper end surface 21 a is welded to the steel plate 11 (the weld line of such weld connection is referred to as “W21”).
For convenience of explanation, the distance between the flat plate upper end surface 21a and the flat plate lower end surface 21b is “flat plate height H”, and the distance between the flat plate side surface 21s and the flat plate side surface 21t is the same as the thickness of the flat plate 21. "T", one side surface is referred to as "flat plate side surface 21s", and the other side surface is referred to as "flat plate side surface 21t".

(Horizontal ribs that make up the steel slab panel)
3 and 5, the lateral rib 30 includes a substantially rectangular lateral rib web 31, a lateral rib lower flange 32 provided at the lateral rib lower end 31 b of the lateral rib web 31, and the lateral rib upper end surface 31 a to the lateral rib lower end 31 b. The lateral rib upper end surface 31a is weld-connected to the steel plate 11 (the weld line of such weld connection is referred to as “W31”). The vertical rib 20 can enter the slit 33. For convenience of explanation, the slit 33 has an opening of “slit upper edge 33 a”, the innermost “slit lower edge 33 b”, one side edge “slit side edge 33 s”, and the other side surface “slit side edge”. 33t ".
At the mouth of the slit 33, a C chamfer 34s is formed at the corner between the slit side edge 33s and the lateral rib upper end surface 31a, and a C chamfer 34t is formed at the corner between the slit side edge 33t and the lateral rib upper end surface 31a. .
When the distance between the slit upper end 33 a and the slit lower edge 33 b is referred to as “slit depth D”, the slit depth D is slightly larger than the flat plate height H. Further, the gap between the slit side edge 33s and the slit side edge 33t (same as the width of the slit 33, hereinafter referred to as “slit width S”) is slightly larger than the flat plate thickness H.

(Rib crossing of steel slab panel)
3 and 6, the flat plate 21 enters the slit 33. At the rib intersection, the flat plate lower end surface 21b is the slit lower end edge 33b, the flat plate side surface 21s is the slit side edge 33s, and the flat plate side surface 21t is the slit side edge 33t. (The weld line of such a weld connection is referred to as “W23”). That is, the weld line W23 is “all-around welding” in a range excluding the upper end surface 21a of the flat plate. At this time, the welding end point (not shown) of the weld line W23 is not located at the flat plate lower end surface 21b (same as the slit lower end edge 33b), but the flat plate side surface 21s (same as the slit side edge 33s) and the flat plate side surface 21t (slit side edge). 33t).
The C chamfer 34s and the C chamfer 34t are, for example, as small as “C10”, so the weld line W21, the weld line W31, and the weld line W23 intersect (overlapping) at the C chamfer 34s and the C chamfer 34t. ), The initially formed triangular gap is closed. Therefore, a gap corresponding to the upper scallop and a gap corresponding to the lower scallop are not formed at the rib intersection.

(Operation effect of steel slab panel)
As described above, in the steel floor slab panel 200, a gap corresponding to the upper scallop and a gap corresponding to the lower scallop as in the conventional case are not formed at the rib crossing portion. The stress concentration at the position of the slit lower edge 33b is relieved, and the occurrence of fatigue cracks from the portion is suppressed.
In addition, since there are no end points (start and end) of the weld line W23 at the position of the flat plate lower end surface 21b (same as the slit lower end edge 33b), the occurrence of fatigue cracks from this position is further suppressed.
Therefore, the life of the steel deck panel 200 is extended (this will be described in detail separately).

(Mounting the steel deck panel to the main girder)
1 and 2, the steel deck support 50 is placed on the main girder 40, and the main girder upper flange 42a and the support lower flange 52b are connected by bolts / nuts 80. And the side edge part of the steel plate 11 which comprises the steel floor slab panel 200 is mounted in the support material upper flange 52a, and both are connected by the volt | bolt / nut 80. FIG.
Further, the lateral rib lower flange 32 of the lateral rib 30 constituting the steel floor slab panel 200 is connected to the main girder web 41 by a bolt / nut 80 via a split tee 60 and a splice plate 61.
Further, the transverse rib web 31 of the transverse rib 30 is connected to the main girder stiffener 43 via a splice plate 74 by a bolt / nut 80 and also connected to the support material stiffener 53 via a splice plate 75 by a bolt / nut 80. ing.

  The horizontal rib lower flange 32 is connected to the splice plate 61, the splice plate 61 is connected to the split tee 60 having a T-shaped cross section, and the split tee 60 is connected to the main girder web 41. However, the present invention is not limited to this, and the splice plate 61 is removed, and the inner and outer surfaces of the lower rib 32 of the lateral rib are sandwiched between the split-tees having the L-shaped cross section. May be connected by a bolt / nut 80.

(bolt and nut)
The bolt / nut 80 is a fastening means including a bolt that penetrates a predetermined through hole (not shown) and a nut that is screwed to the bolt, and is accompanied by a washer and a locking device as necessary. The materials, shapes, and dimensions of the bolts and nuts forming the bolt / nut 80 are not limited, and are appropriately selected according to the installation location. For example, if the bolt in the bolt / nut 80 that connects the steel plate 11 and the support upper flange 52a is a “dish-type high strength bolt”, it is suitable for the on-site construction pavement 13 on the upper surface of the steel plate 11.

(Effects of steel slab instant bridge)
As described above, the steel deck slab instant bridge 100 has the steel deck slab panel 200, and the steel deck slab panel 200 is suppressed from the occurrence of fatigue cracks as described above. To do. Further, since the connection between the steel deck slab panel 200 and the main girder 40 and the steel deck support 50 is a bolt / nut 80 and welding is not required, the work is simplified and the construction time is shortened.
The above is the case where the steel deck support 50 is provided, but the present invention is not limited to this, and the steel deck support 50 is removed and the steel plate 11 is directly attached to the main girder upper flange 42a. They may be placed and connected by bolts / nuts 80.

(Example of steel slab panel)
The steel floor slab panel 200 is manufactured to the following dimensions, and a plurality of sheets are arranged.
The steel plate 11 constituting the steel deck 10 has a bridge axis direction (Y direction) length of 4500 mm, a bridge width direction (X direction) length of 2560 mm, and a thickness (Z direction) of 16 mm.
The flat plate forming the vertical rib 20 is a rectangular steel plate having a flat plate height H of 256 mm and a flat plate thickness T of 16 mm. And seven sheets are arranged at intervals of 320 mm in the bridge width direction (X direction).
The lateral rib 30 has a distance from the lateral rib upper end surface 31a to the lower surface of the lateral rib lower flange 32 (hereinafter referred to as “lateral rib height”) of 600 mm, and the lateral rib web 31 has a thickness of 9 mm. The slits 33 are formed at seven places at intervals of 330 mm, the slit depth D is 258 mm, and the slit width S is 20 mm.

Therefore, the vertical rib 20 can completely enter the slit 33, and is between the flat plate lower end surface 21b and the slit lower end edge 33b, between the flat plate side surface 21s and the slit side edge 33s, and between the flat plate side surface 21t and the slit side edge 33t. In the design, a gap of 2 mm is generated between them.
In addition, since the machining accuracy has improved due to the development of machine tools (such as NC laser processing machines), even if the gap value fluctuates due to manufacturing errors or mounting errors, a design that does not hinder welding connection It has become.
And the factory construction pavement 12 of 80 mm of pavement thickness is provided in a manufacturing factory in the rectangular range except the both-sides edge and both-ends edge of the upper surface of the steel plate 11. FIG. In addition, in the range excluding the factory construction pavement 12 (same for both side edges and both end edges), after the installation of the steel floor slab panel 200 to the main girder 40 is completed at the construction site, the on-site construction pavement 13 having a pavement thickness of 80 mm. Is provided (see FIG. 1). The factory construction pavement 12 may be provided at the construction site.

(Example of main girder)
The main girder 40 is manufactured in three levels with a span distance of 10 m, 15 m, and 20 m. That is, when the span distance is 10 m, it is a rolled H-section steel having a web height of 600 mm, a flange width of 300 mm, a web thickness of 14 mm, and a flange thickness of 28 mm. When the distance between the supports is 15 m, the rolled H-section steel has a web height of 850 mm, a flange width of 300 mm, a web thickness of 19 mm, and a flange thickness of 32 mm. Further, when the span distance is 20 m, the rolled H-section steel has a web height of 1000 mm, a flange width of 300 mm, a web thickness of 19 mm, and a flange thickness of 28 mm. The material is SM400 or SM490, but is not limited to this.

(Test material)
FIGS. 7 to 9 each illustrate the steel deck slab instant bridge according to Embodiment 1 of the present invention, and FIG. 7 shows a test material for testing the characteristics of the test material from diagonally upward to diagonally downward. FIG. 8 is a front view showing a part thereof, and FIG. 9 is a front view showing a part of a comparative material for comparison.
In addition, about the same site | part as the steel deck board 200, the same code | symbol is attached | subjected and description is abbreviate | omitted. In order to facilitate understanding, the member dimensions, the gaps between the members, and the width of the weld line are exaggerated.

7 and 8, in the test material 300, the steel deck slab panel 200 is directly installed on the pair of main girders 40, the main girder upper flange 42a and the steel deck slab support 50 are removed, and the steel plate 11 is removed. Is the same as that directly welded to the main girder web 41 and the main girder stiffener 43.
The transverse rib lower flange 32 is not connected via the splice plate 61 and the split tee 60, and the transverse rib web 31 is directly connected to the main girder web 41 at the position of the main girder stiffener 43 without the splice plate 74. ing.
At this time, the main girder 40 has a length (distance in the bridge axis direction) of 5000 mm and a girder height of 1000 mm, and the main girder 40 is provided with four main girder stiffeners 43 at equal intervals in the bridge axis direction. Further, the main girders 40 are arranged with an interval (distance in the bridge width direction) of 2000 mm.
The steel deck panel 200 includes six vertical ribs 20 in the bridge width direction and four horizontal ribs 30 in the bridge axis direction. And the dimension of a rib crossing part etc. are the same as the value of the said Example.

(Comparison material)
In FIG. 9, the comparative material 900 has a steel plate 11, longitudinal ribs 20 in the bridge axis direction, and comparative lateral ribs 90 in the bridge width direction, and the form of the rib intersection is different from that of the test material 300. The shape and dimensions of the parts excluding the same are the same as those of the test material 300. That is, it differs from the slit 33 formed in the test material 300 in that the comparative slit 93 is formed in the comparative material 900 and further the comparative scallop 95 is formed in the innermost part of the comparative slit 93. Hereinafter, differences between the two will be described.

(Comparison material horizontal rib)
The comparative horizontal rib 90 includes a comparative web 91 that is a rectangular flat plate, and a comparative slit 93 that is formed from the comparative upper end 91 a to the comparative lower end 91 b of the comparative web 91. Is formed. The longitudinal rib 20 can enter the comparison slit 93, and the width of the comparison slit 93 is larger than the flat plate thickness T. A comparative C chamfer 94s is formed at the mouth of the comparative slit 93.
For convenience of explanation, the mouth of the comparative slit 93 is “comparison slit upper end 93a”, the innermost part is “comparison slit lower end edge 93b”, one side edge is “comparison slit side edge 93s”, and the other side is These are referred to as “comparison slit side edges 93t”, respectively. The distance between the comparative slit upper end 93a and the comparative slit lower end edge 93b is larger than the flat plate height H.
The comparison scallop 95 is substantially circular in contact with the comparison slit lower end edge 93b, and forms a gap having a distance larger than the distance between the comparison slit side edge 93s and the comparison slit side edge 93t.

(Rib crossing part of comparative material)
The upper end surface of the flat plate of the vertical rib 20 is connected to the steel plate 11 by a weld line W21, the upper end of comparison 91a of the comparison web 91 is connected to the steel plate 11 by a weld line W91, and the flat plate 21 penetrates the comparison slit 93.
At this time, a gap is formed between the flat plate lower end surface 21b and the comparative slit lower end edge 93b, and the flat plate side surface 21s is welded in a range excluding the comparative scallop 95 of the comparative slit side edge 93s (welding of such a welded connection). The line is called “W93”). On the other hand, the flat plate side surface 21s faces the comparative slit side edge 93t and is separated from each other without being welded.
At this time, the upper end of the weld line W93 overlaps with the weld line W21 and the weld line W91 and closes the comparative C chamfer 94s, but the lower end of the weld line W93 is located on the comparative scallop 95 and is compared. The scallop 95 is not blocked. That is, the welding end point of the weld line W93 is located at the comparative scallop 95. In addition, any of the welding line W91 and the welding line W93 may be formed first.

(FEA)
Prior to the fatigue test, (a) the critical loading position was confirmed by FEA (finite element method analysis), and (b) fatigue resistance detail was examined. The support condition is four-point support that supports both ends of the pair of main girders 40.

(Critical loading position)
Concentrated tensile stress and concentrated compressive stress are generated in the vertical rib 20 of the steel deck panel 200 depending on the traveling position of the vehicle. That is, when the concentrated stress generated in the longitudinal rib (assumed to be “R1”) whose loading position has been changed is obtained and the concentrated stress for each loading position is compared, the loading position (hereinafter referred to as “the maximum tensile loading position”) is referred to. ) The maximum concentrated tensile stress (σ1 +) is generated when loaded on F1, and the maximum concentrated compressive stress (σ1-) is generated when loaded on the loading position (hereinafter referred to as “compressed maximum loading position”) Q1. I understand that. The sum of the absolute value of the maximum concentrated tensile stress (σ1 +) and the maximum concentrated compressive stress (σ1−) for the longitudinal rib R1 is defined as “total concentrated stress (σ1 ±)”.
Similarly, for each of the other longitudinal ribs R2, R3,..., The maximum tensile loading positions F2, F3..., The compression maximum loading positions Q2, Q3.・ Ask for.
Therefore, the longitudinal rib Rj corresponding to the concentrated stress sum σj ± having the largest value among the obtained concentrated stress sums σ1 ±, σ2 ±, σ3 ±... The maximum tensile loading position Fj is referred to as a “critical loading position” of the steel deck panel 200.

(Total concentrated stress)
FIG. 10 is a bar graph comparing the concentrated stress sums of the test material and the comparative material for testing the characteristics of the steel deck slab instant bridge according to Embodiment 1 of the present invention. Note that the concentrated tensile stress is indicated by a downward sloping line, and the absolute value of the concentrated compressive stress is indicated by a right upward slanting line.
In FIG. 10, when 100 kN is loaded on the maximum tensile loading position Fj of the target longitudinal rib Rj in the test material 300, a concentrated tensile stress (σj +) of 25 N / mm ² is generated, and the compression maximum loading position Qj is generated. when the loading of 100 kN, 55N / mm ² concentration compressive stress (σj-) is generated, stress concentration sum (.SIGMA.j ±) is set to 80 N / mm ^2.
On the other hand, for the comparative material 900, when the target longitudinal rib is specified in the same manner as the test material 300 and 100 kN is loaded at each of the maximum tensile loading position and the maximum compression loading position, the concentrated tensile stress in the target longitudinal rib is increased. 92N / mm ^2, concentrated compressive stress 85N / mm ² occurs, stress concentration sum is in 177N / mm ^2.
That is, the test material 300 is 58% lower in total concentrated stress than the comparative material 900, and particularly the concentrated tensile stress is 73% lower. Therefore, since the test material 300 did not have a gap corresponding to the lower scallop, it was confirmed that the total concentrated stress was significantly reduced.

(Fatigue test)
FIG. 11 is a “load-loading number curve” showing a result of a fatigue test for testing the characteristics of the steel deck slab instant bridge according to the first embodiment of the present invention. The vertical axis represents the repeated load loaded at the critical loading position, and the horizontal axis represents the number of repetitions (referred to as “fatigue life” in FIG. 11).
In FIG. 11, when a load of 200 kN is repeatedly loaded at the critical loading position of the test material 300 and the critical loading position of the comparative material 900, fatigue cracks do not occur in the test material 300 even after repeated about 70 million times. Whereas (indicated by a black square with a black arrow in the upper right direction), the comparative material 900 has fatigue cracks generated by repetition of about 2 million times (indicated by a white square).
Further, even when a load of 340 kN is repeatedly loaded about 1 million times on the test material 300, fatigue cracks are not generated (indicated by a black square with a black arrow in the upper right direction).
In addition, the diagonal line in a figure has shown "10 million times of T load conversion."
From the above, it was confirmed that the test material 300 has excellent fatigue durability. That is, in the test material 300, the longitudinal ribs 20 and the transverse ribs 30 are welded over the entire circumference at the rib intersection, and there is no gap corresponding to the lower scallop. Is suppressed.

  As mentioned above, although this invention was demonstrated based on Embodiment 1 about the steel floor slab instant bridge, these are illustrations and various modifications are possible, and such a modification is also in the scope of the present invention. This will be understood by those skilled in the art.

  The steel floor slab instant bridge according to the present invention is not limited to small-scale bridges and can be widely used for various bridges because fatigue cracks from the weld line are suppressed and construction is quick. Can do.

DESCRIPTION OF SYMBOLS 10: Steel floor slab 11: Steel plate 12: Factory construction pavement 13: Field construction pavement 20: Vertical rib 21: Flat plate 21a: Flat plate upper end surface 21b: Flat plate lower end surface 21s: Flat plate side surface 21t: Flat plate side surface 30: Horizontal rib 31: Horizontal Rib web 31a: Horizontal rib upper end surface 31b: Horizontal rib lower end 32: Horizontal rib lower flange 33: Slit 33a: Slit upper end 33b: Slit lower edge 33s: Slit side edge 33t: Slit side edge 34s: C chamfering 34t: C chamfering 40: Main girder 41: Main girder web 42a: Main girder upper flange 42b: Main girder lower flange 43: Main girder stiffener 50: Steel plate support material 51: Support material web 52a: Support material upper flange 52b: Support material lower flange 53: Support material stiffener 60: Split tee 61: Splice plate 74: Splice Rate 75: Splice plate 80: Bolt / nut 90: Comparison lateral rib 91: Comparison web 91a: Comparison upper end surface 91b: Comparison lower end 92: Comparison lower flange 93: Comparison slit 93a: Comparison slit upper end 93b: Comparison slit lower end edge 93s: Comparative slit side edge 93t: Comparative slit side edge 94s: Comparative C chamfer 95: Comparative scallop 100: Steel deck slab instant bridge 200: Steel deck slab panel 300: Test material 900: Comparative material W21: Welding line W31: Welding line W23: Welding line W91: Welding line W93: Welding line

Claims (4)

A main girder arranged in the direction of the bridge axis, and a steel slab panel installed in the main girder,
The steel slab panel comprises a steel plate, longitudinal ribs in the bridge axis direction, and transverse ribs in the direction perpendicular to the bridge axis direction,
The vertical rib is a rectangular flat plate, the upper end surface of the vertical rib is welded to the steel plate,
The transverse rib is a steel material having a T-shaped cross section comprising a flat transverse rib web and a transverse rib flange provided at a lower end edge of the transverse rib web, and a rectangular slit is formed in the transverse rib flange,
The vertical rib penetrates into the slit, both side surfaces and the lower end surface of the vertical rib are welded to the horizontal rib web at the intersection of the slit and the vertical rib, and the upper end surface of the horizontal rib web is the steel plate. Welded to the
The main girder is a steel material rolled into an H-shaped cross section having a flat main girder web and a main girder upper flange and a main girder lower flange respectively provided at both ends of the main girder web. A main girder stiffener connecting the web, the main girder upper lunge and the main girder lower flange;
The steel plate is connected to the main girder upper flange by bolts / nuts,
The lower flange of the lateral rib is connected to the main girder web by a bolt / nut via a split tee,
The transverse rib web is an steel bridge slab instant bridge connected to the main girder stiffener by a bolt / nut through a splice plate. A flat support material web, a support material upper flange and a support material lower flange respectively provided at both ends of the support material web, and a support material for connecting the support material web, the support material upper flange and the support material lower flange Having a steel deck support with a stiffener;
Instead of connecting the steel plate and the main girder upper flange, the steel plate is connected to the support material upper flange by a bolt / nut, and the main girder upper flange is connected to the support material lower flange by a bolt / nut,
2. The steel deck slab instant bridge according to claim 1, wherein the transverse rib web is connected to the support material stiffener by a bolt / nut through a splice plate.   3. The steel according to claim 1, wherein a welding start end and a welding end of a weld line that weld-connects the vertical rib and the horizontal rib are located on one side surface and the other side surface of the vertical rib, respectively. Floor version instant bridge.   A weld line that welds and connects the vertical rib and the horizontal rib, a weld line that weld-connects the vertical rib and the steel plate, and a weld line that weld-connects the horizontal rib and the steel plate intersect. The steel bridge slab instant bridge according to any one of claims 1 to 3.

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