JPH09310311A - Reinforcing structure of truss bridge - Google Patents

Abstract

PROBLEM TO BE SOLVED: To secure a necessary rigidity even though lower lateral structure is omitted and obtain a safe structure as a whole bridge by arranging diagonally extending structures from the support part of lower chord members in a truss bridge to upper chord members. SOLUTION: Diagonally extending truss structures 12 are installed in the plane including support part 2A, 2B and upper lateral girders 13, extending from the lower part of a truss bridge 10 to the upper part between a pair of the lower right and left chord members 2 and the upper right and left chord members 3, at both ends of the truss bridge 10. The diagonal structures 12 are provided with a shearing rigidity in both axial direction of the bridge and right-angled direction against the axis. In this truss bridge 10 with such a reinforced constitution, when a lateral force having an angle B against the bridge- axis acts on the truss bridge, the diagonal structures 12 and the vertical members 4 withstand the right-angled components against the bridge-axis of the lateral force cooperatively. And the diagonal structures 12 resist the components in the bridge-axial direction.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a reinforcing structure for a truss bridge, and more particularly to a reinforcing structure for a truss bridge in which a lower horizontal structure can be omitted.

[0002]

2. Description of the Related Art In the conventional construction work of a bridge, for example, for a truss type steel bridge (truss bridge), reduction of manufacturing man-hours in a factory based on rationalized design, shortening of on-site construction period, It is also required to reduce construction costs.

FIG. 8 is a side view of a conventional truss bridge 1 (for example, upper road truss bridge). The truss bridge 1 is a main structure truss including a lower chord member 2, an upper chord member 3, a vertical member 4 and a diagonal member 5. Have.

FIG. 9 is a plan view of a surface including a pair of left and right lower chord members 2 in the bridge axis direction. Within this surface, a supporting member 6 and a lower horizontal member 7 intersecting between the supporting members 6 are provided. (Oblique material in the horizontal plane) is provided. In addition, a pair of left and right upper chord members 3
In the surface including the
The upper horizontal girder is arranged at a position corresponding to the upper horizontal girder and the upper horizontal girder corresponding to the lower horizontal structure 7).

As shown in FIG. 8, the truss bridge 1 is constructed by laying a floor slab 8 such as a reinforced concrete floor slab or a steel floor slab on the upper chord member 3, but against the earthquake load and wind load. Conventionally, the design was carried out based on the basic idea of resisting each half by the lower horizontal structure 7 and floor slab 8 of the truss bridge 1.

Here, the case where the lower horizontal structure 7 obliquely arranged between the lower chord members 2 is omitted without changing the conventional structure will be outlined below. 10 and 11 show the lower lateral structure 7 shown in FIG.
A structural analysis model in which is omitted is shown. That is, FIG.
FIG. 3 is a plan view showing a model in which bending rigidity and shear rigidity of the lower chord member 2 are evaluated to be effective, and the lower chord member 2 is connected via a hinge portion 9. FIG. 11 is a plan view showing a model in which the bending rigidity is ignored on the safe side, and the lower chord member 2 is divided into a plurality of parts and connected by a hinge part 9.

As shown in the figure, although the lower chord member 2 and the supporting members 6 resist the seismic load with a slight angle, the lower part of the truss bridge 1 has an angle θ. The rigidity becomes extremely small against external force.

Therefore, when the truss bridge 1 has the conventional structure and the lower lateral structure 7 (oblique member in the horizontal plane) is omitted, it is attempted to reduce the number of manufacturing steps, the construction period, and the cost. However, there is a problem in that there is a structural defect, and there is a problem that partial plastic deformation may occur due to an external force such as an earthquake.

[0009]

SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and it is possible to maintain the required rigidity even if the lower horizontal structure (oblique member in the horizontal plane) is omitted. An object is to provide a reinforcement structure for a truss bridge.

Further, the present invention is a truss bridge which can resist a seismic load and a wind load having an angle in the axial direction of the bridge even if the lower lateral structure is omitted, so that the bridge as a whole can have a stable structure. It is an object to provide a reinforced structure of the.

Another object of the present invention is to provide a reinforcing structure for a truss bridge which can reduce the number of manufacturing steps, the construction period, the cost, and the like.

[0012]

That is, the present invention focuses on providing a diagonally inclined structure from the fulcrum portion of the lower chord member to the upper chord member instead of the lower lateral structure (oblique member in the horizontal plane). A reinforcement structure for a truss bridge having a form,
This is a reinforcing structure for a truss bridge, in which a diagonally inclined structure is obliquely arranged from the fulcrum portion of the lower chord member to the upper chord member in the truss bridge.

The oblique-to-tilt structure may have a truss structure, a satiety structure, or a rigid frame structure.

The above diagonally tilted structure can also be constituted by using a main structure truss such as a lower chord member, an upper chord member, a vertical member, and a diagonal member, or a member of an anti-tilt structure on a fulcrum of the lower chord member.

Considering the shear rigidity in the plane of the upper horizontal structure of the slab such as the reinforced concrete slab and the steel slab to be laid on the truss bridge, even if the upper horizontal structure is omitted, this inclined structure Can be dealt with.

It should be noted that it is also possible to use a shear connector such as a stud dowel to integrate it with the above-mentioned reinforced concrete floor slab, or to directly connect an oblique structure to the floor slab such as a steel floor slab with a welding structure or a bolt structure. it can.

In the truss bridge reinforcement structure according to the present invention, the diagonally inclined structure is provided from the fulcrum portion of the lower chord member to the upper chord member. Therefore, when an external force such as an earthquake or a side wind acts on the truss bridge, the diagonally inclined structure is provided. The external force is effectively transmitted to the lower chord member, the upper chord member, and the floor slab having high shear rigidity via the. Therefore, even if the lower horizontal structure is omitted, the rigidity of the entire truss bridge can be maintained and a stable structure can be obtained.

[0018]

BEST MODE FOR CARRYING OUT THE INVENTION Next, a reinforcing structure 11 for a truss bridge 10 according to an embodiment of the present invention will be described with reference to FIGS. However, the same parts as those in FIGS. 8 to 11 are designated by the same reference numerals, and the detailed description thereof will be omitted. FIG.
2 is a side view of the truss bridge 10, FIG. 2 is a plan view of a surface including a pair of left and right lower chord members 2 in the bridge axis direction, and FIG.
In the truss bridge 10, a fulcrum portion 2A, 2B of the lower chord member 2 to a point 3A of the upper chord member 3,
Toward 3B (specifically 2A-3B, and 2B-
3A) Reinforcing structure 11 is formed by providing diagonally inclined structure 12.

That is, the diagonally inclined structure 12 is a fulcrum between the lower left and right lower chord members 2 and the upper left and right upper chord members 3 at both ends of the truss bridge 10 from the lower side to the upper side of the truss bridge 10. On the surface including the parts 2A, 2B and the upper cross beam 13, this is provided obliquely in a truss form.

However, the diagonally inclined structure 12 does not necessarily have to be constructed by connecting the fulcrums 2A, 2B of the lower chord member 2 to the points 3A, 3B of the upper chord member 3, and as shown by the phantom line in FIG.
If the external force applied to the diagonal anti-tilt structure 12 can be transmitted to the floor slab 8 such as a reinforced concrete floor slab or a steel floor slab, and preferably at the left and right ends of the truss bridge 10, the upper chord member 3 is optional. It is enough to connect this to the part of.

The diagonally inclined structure 12 has shear rigidity in the bridge axis direction and in the direction perpendicular to the bridge axis. As shown in FIG. 2, as the reinforcing structure 11, the conventional lower lateral structure 7 (oblique member in the horizontal plane, 9) is omitted.

In the present invention, part of the diagonally inclined structure 12 may also serve as a main structure truss such as the lower chord member 2, the upper chord member 3, the vertical member 4 and the diagonal member 5, or the fulcrums 2A, 2
The member of the inclined structure above B (actually, the fulcrum portions 2A, 2
A member for connecting B, that is, a supporting member 6) may also be used.

Further, considering the shear rigidity in the upper horizontal structure 14 (dotted line in FIG. 3) of the floor slab 8, the upper horizontal structure 14
The present invention can be applied to the case where is omitted.

The diagonal structure 12 of the reinforcing structure 11
Can be any structure such as a truss structure that can be reduced in weight, a full structure that can provide greater rigidity, and a rigid frame structure similar to a steel frame. That is, FIG.
5 is a perspective view of a main portion showing a diagonally inclined structure 12A of another truss structure, FIG. 5 is a perspective view of a main portion of a diagonally inclined structure 12B of a full structure, and FIG.
FIG.

Further, in the present invention, the diagonally inclined structure 12 can be directly connected to the floor slab 8. That is, FIG.
It is an expanded side view which shows the other example of the diagonal structure 12 connection, as shown, the stud dovetail 15 is installed in the part of the upper transverse girder 13, and a shearing force is transmitted from the diagonal structure 12 to the floor slab 8. In this way, the upper cross member 14 can be omitted or the cross section thereof can be made thin.

In the truss bridge 10 having the reinforcing structure 11 having such a structure, as shown in FIG. 3, when a lateral force having an angle θ acts on the bridge axis direction, The diagonal structure 12 and the vertical member 4 work together to resist the component force.

Further, in the component force in the bridge axis direction (the force to displace the main girder in the bridge axis direction, that is, the pair of lower chord member 2 and upper chord member 3, the vertical member 4 and the diagonal member 5), the diagonally inclined structure 12 is used. resist.

Therefore, in the conventional truss bridge 1 (FIG. 8), the floor slab 8 and the lower horizontal structure 7 are designed to share the seismic load and the wind load, respectively. In the reinforcement structure 11 of the bridge 10, the lower lateral structure 7
Even if omitted, as described above, the diagonally inclined structure 12 resists the component force in the bridge axis direction, and this component force can be transmitted in the direction of the floor slab 8; The floor slab 8 having an extremely high shear rigidity can resist 100%.

[0029]

As described above, according to the present invention, since the diagonally inclined structure is provided between the fulcrum portion of the lower chord member and the upper chord member, the lower lateral structure is omitted and the number of manufacturing steps is reduced. The construction period and cost can be reduced, and the truss bridge can maintain the required rigidity and stability.

[Brief description of drawings]

FIG. 1 is a side view of a truss bridge 10 including a reinforcing structure 11 according to an embodiment of the present invention.

FIG. 2 is a plan view of a plane including a pair of left and right lower chord members 2 in the bridge axis direction.

FIG. 3 is a perspective view of relevant parts.

FIG. 4 is a perspective view of relevant parts showing a diagonally inclined structure 12A according to another truss structure.

FIG. 5 is a perspective view of relevant parts showing a diagonally inclined structure 12B having a full structure.

FIG. 6 is a perspective view of relevant parts showing a diagonally inclined structure 12C having a rigid frame structure.

FIG. 7 is an enlarged side view showing another example of the diagonally-inclined structure 12 connection portion of the same.

FIG. 8 is a side view of a conventional truss bridge 1 (for example, upper road truss bridge).

FIG. 9 is a plan view of a plane including a pair of left and right lower chord members 2 in the bridge axis direction.

FIG. 10 is a plan view showing a model in which the bending rigidity and the shear rigidity of the lower chord member 2 are evaluated to be effective.

FIG. 11 is a plan view showing a model in which the bending rigidity is ignored on the safe side.

[Explanation of symbols]

 1 truss bridge (for example, upper road truss bridge, Fig. 8) 2 lower chord member 2A fulcrum part of lower chord member 2 (Figs. 1, 2, 3) 2B fulcrum part of lower chord member 2 (Figs. 1, 2, 3) 3 Upper chord member 3A Upper chord member 3 point (Figs. 1, 2 and 3) 3B Upper chord member 3 point (Figs. 1, 2 and 3) 4 Vertical member 5 Diagonal member 6 Support member 7 Lower horizontal structure (in horizontal plane) Oblique material) 8 Floor slabs such as reinforced concrete floor slabs and steel floor slabs 9 Hinge section 10 Truss bridges (Figs. 1, 2 and 3) 11 Reinforcement structure of truss bridges 12 Diagonal tilt structure 12A Diagonal tilt structure by other truss structure (Fig. 4) 12B Diagonal structure with full structure (Fig. 5) 12C Diagonal structure with ramen structure (Fig. 6) 13 Upper girder 14 Upper lateral structure 15 Stud bell

Claims (4)

[Claims] 1. A reinforcement structure for a truss bridge having a truss type, characterized in that a diagonally inclined structure is obliquely arranged from the fulcrum portion of the lower chord member to the upper chord member of the truss bridge. Construction. 2. The reinforcement structure for a truss bridge according to claim 1, wherein the diagonally inclined structure is a truss structure. 3. The reinforcement structure for a truss bridge according to claim 1, wherein the diagonally inclined structure has a full structure. 4. The reinforcing structure for a truss bridge according to claim 1, wherein the diagonally inclined structure has a rigid frame structure.