JP2003306908A - Connecting structure of superstructure work and substructure work of bridge and its construction method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide the connecting structure of the superstructure work and substructure work of a bridge, in which the substructure work and the superstructure work are fastened surely without hardly lowering the strength of the superstructure work, and its construction method. <P>SOLUTION: In the bridge composed of the substructure work 1 as a foundation and the superstructure work 3, which is placed on the top face of the substructure work 1, to which a box-shaped section 2 is formed partially and which is made of steel, steel frames 4 are buried on the substructure work 1 side in the vertical direction, one ends of PC steel materials 5 are fixed onto the steel frames 4 while the other ends of the PC steel materials 5 are exposed from the top face of the substructure work 1, and inserted into the box-shaped section 2 from inserting holes 6 formed to the box-shaped section 2, and the other ends of the PC steel materials 5 are fixed into the box-shaped section 2 and fastened onto anchors 7. <P>COPYRIGHT: (C)2004,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a connecting structure for a bridge superstructure and a substructure and a construction method thereof.

[0002]

2. Description of the Related Art Generally, when constructing a bridge such as an elevated highway, a structure is adopted in which a bridge pier as a substructure is erected from the ground and a superstructure to be a road is placed on the pier. .

In this case, the substructure may be made of concrete and the superstructure may be made of steel such as H steel. In such a structure, in order to ensure the strength of the substructure, the substructure is made of steel / reinforced concrete ( SRC) or steel concrete (SC) may be adopted.

When constructing a bridge having such a structure, as shown in FIG. 9, a support 52 is interposed between a lower work 50 and an upper work 51, and a flexible structure called a so-called continuous girder system is adopted. It has been.

[0005]

However, in the continuous girder method having the bearings 52 as described above, the lower work 50 and the upper work 51 are used.
There is a problem in that it is unavoidable that the connection with the bearing will be weakened, there is a risk that the bridge will be bridged in the event of an earthquake, and that the bearing 52 must be regularly maintained and managed.

Therefore, it is considered that the lower work 50 and the upper work 51 are rigidly connected to each other to form a so-called rigid frame structure to improve the strength.

However, the rigid connection structure has various problems in construction and is difficult to actually use. The reason is that when the entire bridge is made of concrete, it is possible to perform an integral construction, but in recent years, the substructure 50 is made of concrete, while the superstructure 51 is made of steel materials such as H steel and SRC structures. This is because it is often the case that the two materials of different materials cannot be easily rigidly connected.

For example, in the construction method shown in FIG.
A steel frame 53 of H steel or the like is provided in the inside of the machine, and an upper end portion 54 of the steel frame 53 is extended from the upper surface of the substructure 50. The opening 55 is provided in advance. At this time, as shown in the figure, the upper portion 54 of the steel frame 53 is positioned inside the superstructure 51. Then, by appropriately placing concrete in the superstructure 51, the superstructure 51 and the steel frame 53 are integrated.

In such a method, in order to introduce the steel frame 53 having a large cross-sectional area into the superstructure 51, a large area opening 55 must be provided and the strength of the lower flange 57 becomes low. There is.

As a method for solving such a problem, the construction method shown in FIG. 11 can be considered. In this construction method, a column portion 56 of H steel or the like is welded to the lower surface of the lower flange 57, and the column portion 56 is embedded in the substructure 50. This allows
The substructure 5 without lowering the strength of the lower flange 57.
It is possible to connect 0 and the superstructure 51.

However, in this construction method, the steel frame 53 in the substructure 50 and the column portion 56 interfere with each other, so that there are many cases where the construction cannot be carried out.

In any of the construction methods, the bridge is integrated by the adhesive force between the steel material such as H steel and the concrete, but originally, since the adhesive force between the steel material and the concrete cannot be expected to be large, originally both of them cannot be expected. It requires a considerable fixing length.

However, since it is not possible to obtain a long fixing length by the above-mentioned construction method, it is difficult to obtain an ideal strength. That is, in the example shown in FIG. 10, a fixing length equal to or higher than the height of the superstructure 51 cannot be obtained in principle, so that the adhesive force becomes insufficient.

The present invention has been made in order to solve the above-mentioned conventional problems. A bridge superstructure for securely connecting the substructure to the superstructure without substantially lowering the strength of the superstructure. It is a technical object to provide a connecting structure of substructures and a construction method thereof.

[0015]

In order to solve the above-mentioned technical problems, the present invention has a structure in which a bridge superstructure and a substructure are connected as follows.

That is, in a bridge composed of a substructure 1 and a steel superstructure 3 placed on the upper surface of the substructure 1 and partially forming a box-shaped portion 2, a steel frame 4 is provided on the substructure 1 side. Was embedded in the vertical direction, one end of a PC steel material 5 made of high-tensile steel was fixed to the steel frame 4, and the other end of the PC steel material 5 was exposed from the upper surface of the substructure 1 and provided in the box-shaped portion 2. The box-shaped portion 2 is inserted through the insertion hole 6. After that, the other end of the PC steel material 5 is fastened to an anchor 7 fixed in the box-shaped portion 2.

It is desirable to provide a sleeve 8 on the PC steel material 5 so as to cover it so that concrete does not contact the surface of the PC steel material 5. The reason is that, in the present invention, the substructure and the superstructure are integrated by tensioning the PC steel material 5, so that when the PC steel material 5 is embedded in contact with concrete, the PC steel material 5 is tensioned. This is because the room is reduced and, as a result, sufficient strength cannot be obtained.

Next, as the construction method of the present invention, the substructure 1
And a steel superstructure 3 placed on the upper surface of the substructure 1 and partially forming a box-shaped portion 2, a steel frame 4 is vertically embedded in the substructure 1 side and the steel frame 4 Then, one end of the PC steel material 5 made of high-strength steel is fixed to and the concrete 11 is placed around the steel frame to form a substructure. In the step of fixing one end of the PC steel material 5 made of high-strength steel to the steel frame, it is desirable to provide a sleeve 8 on the PC steel material 5 so as to cover it so that concrete does not come into contact with the surface of the PC steel material 5.

From the upper surface of this substructure, PC steel material 5
While the other end of the box is projected, a box-shaped portion 2 in which an insertion hole 6 for inserting the PC steel material 5 and a window 9 located on an extension line of the insertion hole 6 are formed is prepared. It is mounted on the substructure 1 and the PC steel material 5 is introduced into the box-shaped portion 2.

Next, in a state where the anchor 7 is temporarily fixed to the other end of the PC steel material 5, a box-extracting frame 10 covering the upper surface of the anchor 7 is attached from the window, and then the concrete 12 is placed in the box-shaped portion 2. The anchor 7 is mounted and fixed in the box-shaped portion 2, and the box-out frame 10 is removed from the window 9 to expose the other end of the PC steel material 5 to the inside of the window 9.

Finally, the nut 13 is fastened to the other end of the PC steel material 5 to cause a tension force in the PC steel material 5, so that the lower work 1 and the upper work 3 are integrated.

The important components of the present invention will be further described below. [Substructure 1] A pier portion of a bridge, which can be made of steel / reinforced concrete (SRC) or steel concrete (SC).

[Box 2] is integrated with the superstructure 3,
It is provided in a portion of the superstructure 3 that is connected to the substructure 1. By welding an iron plate, it functions as a cross beam or a diaphragm, and by pouring concrete 12 inside, it becomes a strong structure.

[Superstructure 3] A part which is supported by the substructure 1 and becomes a road after completion, which is made of an iron plate of I-shape, H-shape, box-shape,
Alternatively, it may be made of steel products having a shape obtained by combining them.

[Steel 4] It is buried inside the substructure 1, and for example, H steel can be used. In addition, PC steel material 5
A fixing plate for fixing one end of the PC steel material 5 may be welded, and a hole for inserting one end of the PC steel material 5 may be formed in the fixing plate. The PC steel material 5 and the steel frame 4 are fixed to each other by tightening a nut or the like on one end of the PC steel material 5 inserted into the hole. [PC steel material 5] This is a general term for high-strength steel materials, and fixing means such as screws for fixing is provided at both ends. In addition to the rod, a wire or a cable can be used as the form, but a PC steel rod is preferable.

[Insertion Hole 6] It is formed on the bottom surface of the box-shaped portion 2 and has a minimum diameter through which the PC steel material 5 can be inserted. The reason for the minimum diameter is that the box-shaped portion 2,
That is, the strength of the superstructure 3 that is integral with the box-shaped portion 2 is not reduced.

[Anchor 7] This is to give the fastening force of the PC steel material 5 to concrete, and is composed of a fixing plate and a nut.

[Sleeve 8] A relatively thin iron pipe, so-called sheath pipe can be used. The purpose of using this sleeve 8 is to store the PC steel material 5 inside, and when the concrete 11 is placed, the concrete 1 is directly attached to the PC steel material 5.
This is for preventing 1 from touching. Therefore, high strength is not required, and a thin pipe may be used. By using this sleeve 8, when the PC steel material 5 is tightened with the nut, the entire PC steel material 5 is pulled without stress, so that the elasticity of the PC steel material 5 can be used for fixing.

[Window 9] It is located on the upper surface of the box-shaped portion 2, that is, on the superstructure 3, and is coaxial with the position of the insertion hole 6.
This window 9 is used as a jack space for putting in and out the box-out form 10 and fastening the PC steel material 5, and it is desirable to fill it with concrete after the work.

[Box Forming Form 10] A space is formed above the anchor 7 so that the anchor 7 is not buried in the concrete 12, and is formed in a shape such that the upper part of a cone or a pyramid is cut. , Reverse this and anchor 7
So that it adheres to the upper surface of the. When the concrete is cured and then removed, a mortar-like space is formed above the anchor 7. This material is preferably a synthetic resin having good releasability.

As described above, since the box-shaped portion 2 of the superstructure 3 is merely provided with the insertion hole 6 through which the PC steel material 5 can be inserted, the strength reduction of the superstructure 3 can be almost ignored. It's done.

Further, by tensioning the PC steel material 5, the lower work 1 and the upper work 3 can be securely fastened, and stronger integration can be achieved as compared with the conventional one in which the steel frame is simply embedded. .

[0033]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, a connecting structure for a bridge upper work and a lower work and a construction method thereof according to the present invention will be described in more detail with reference to the embodiments shown in FIGS. 1 to 8.

FIG. 1 is a side view of a lower work 1 and an upper work 3 placed on the upper surface of the lower work 1, which is a partial cross section.

The substructure 1 is a concrete bridge pier constructed as follows.

As shown in FIG. 4, first of all, the vertical 4 made of H steel is used.
Two horizontal steel lines and a total of eight steel frames 4 are erected vertically. A fixing plate 4a is fixed to the steel frame 4 by welding as shown in FIG. 2, and a rod hole is provided in the fixing plate 4a. In this rod hole, a PC steel rod 5c made of PC steel material 5
Is to be inserted. Screws 5a5b are formed on both ends of the PC steel rod 5c. By inserting one end of the PC steel rod 5c into the rod hole and tightening it with the nut 20,
The PC steel rod 5c and the steel frame 4 are integrally fixed.

In such a state, as shown in FIG.
The sleeve 8 is put on the C steel rod 5c so as to cover it. Next, a predetermined formwork is installed around the steel frame 4, and concrete 11 is placed inside the formwork. At this time, the PC steel rod 5c is made to project from the upper surface of the concrete 11 together with the sleeve 8.

On the upper surface of the substructure 1 thus constructed, the superstructure 3 is placed as shown in FIG. Superstructure 3
As shown in FIG. 8, 2 is attached to the lower surface of the main girder 3a which becomes the road.
It has a shape provided with a steel girder 3b. Then, a box-shaped portion 2 is formed in a portion corresponding to the substructure 1. This box-shaped portion 2 is formed in a box shape by welding two horizontal girders 2b between steel girders 3b and 3b, and by welding a bottom plate 2b to a bottom portion surrounded by the lateral girders 2b and steel girders 3b. It is a thing. An insertion hole 6 is formed in the bottom plate 2b so as to correspond to the position of the PC steel rod 5. Further, a window 9 located on the extension line of the insertion hole 6 is formed on the upper surface of the box-shaped portion 2, substantially on the upper surface of the superstructure 3.

The upper structure 3 having the above-mentioned structure is suspended by a crane and placed on the lower structure 1 while aligning the positions of the insertion holes 6 and the sleeve 8. It should be noted that the bottom plate 2b is preliminarily welded with a slip-preventing tack 21 on the lower surface thereof so that no slippage occurs between the two.

Subsequently, as shown in FIG. 6, concrete 12 is placed in the box-shaped portion 2. Prior to this, the anchor 7 formed in the shape of a perforated disc in the screw 5b portion of the PC steel rod 5c. Through. Then, the box-out form 10 is attached so as to hide the upper surface of the anchor 7. In addition, this anchor 7
The shape of is not limited to the disk shape, and other shapes may be used.

The box-out form 10 is for forming a space above the anchor 7 so that the anchor 7 is not buried in the concrete 12, and is formed, for example, in the shape of a truncated cone. To do. And this is reversed and it is made to adhere to the upper surface of the anchor 7. It should be noted that the box-shaped portion 2 is provided with a large number of shift-preventing tacks 21 on the inner wall thereof.

Next, as shown in FIG. 7, concrete 12 is placed in the box-shaped portion 2, and after curing, the box-extracting formwork 1 is opened through the window 9.
To remove. In this state, the screw 5b portion of the PC steel rod 5c is exposed on the anchor 7 inside the window 9, and the nut 13 is tightened to this screw 5b portion. By this tightening, the lower work 1 and the box-shaped portion 2, that is, the upper work 3, are firmly integrated. After tightening the nuts, the mortar-shaped holes formed by the box-out mold 1 are filled with concrete 12.

Next, the mutual relation of the stresses acting on the respective parts will be briefly described with reference to FIG.

In FIG. 1, the bending moment M from the superstructure 3 is transmitted to the substructure 1 via the tensile force T of the PC steel material 5. If the distance between the PC steel materials 5 is L, then M
= T * L holds.

Further, the horizontal force S in the upper work 3 is transmitted to the lower work 1 via the shift-preventing tacks 21 provided on the lower surface of the bottom plate 2b (SR). Therefore, here S
= SR. The axial force N from the superstructure 3 is transmitted to the substructure 1 via the compressive force of the bottom plate 2b. Box-shaped part 2
The integration of the concrete 12 with the concrete 12 is ensured by the slip-preventing studs 21 provided on the inner surface of the box-shaped portion 2.

By selecting the PC steel material having a higher strength, the same fastening force can be obtained even if the number of PC steel rods 5c is reduced. By doing so, the number of the insertion holes 6 can be reduced, so that it is possible to minimize a slight decrease in strength caused by providing the insertion holes 6. Further, since the amount of construction can be reduced, the work period can be shortened as a whole.

[0047]

According to the present invention, since the substructure and the superstructure can be securely fastened by tensioning the PC steel material, as compared with the conventional one in which the steel frame is simply buried. More powerful integration of substructure and superstructure can be achieved.

Further, the tension of the PC steel material is applied to the PC through the window.
The workability is excellent because it can be easily done by inserting a nut into the other end of the steel material.

Further, since the box-shaped portion of the superstructure is merely provided with an insertion hole through which the PC steel material can be inserted, the strength of the superstructure can be almost neglected.

Further, in the case where the PC steel material is provided with a sleeve so as to cover it and the concrete is not in contact with the surface of the PC steel material, tension can be applied without stress when tightening the nut of the PC steel material, and the strength is increased. It can be maintained for many years.

[Brief description of drawings]

FIG. 1 is a side view with a partial cross section showing a connecting structure of a superstructure and a substructure of a bridge according to an embodiment of the present invention.

FIG. 2 is a partial cross-sectional view showing the periphery of a lower end portion of a PC steel material having a connection structure of a superstructure and a substructure.

FIG. 3 is a partial cross-sectional view showing a periphery of an upper end portion of a PC steel material having a connection structure of a superstructure and a substructure.

FIG. 4 is a side view with a partial cross section showing an initial stage of construction of a method for connecting superstructure and substructure.

FIG. 5 is a side view with a partial cross section showing the first half of construction of the method for connecting the upper work and the lower work.

FIG. 6 is a side view with a partial cross-section showing the latter half of the construction of the method for connecting the upper work and the lower work.

FIG. 7 is a side view with a partial cross section showing the latter half of the construction in the method of connecting the upper work and the lower work.

FIG. 8 is an overall perspective view showing a connecting structure of a superstructure and a substructure.

[Fig. 9] Fig. 9 is a side view showing a connection structure of a conventional bridge superstructure and substructure.

FIG. 10 is a side view with a partial cross-section showing a connection structure between a superstructure and a substructure of a conventional bridge.

FIG. 11 is a partial cross-sectional side view showing another example of a conventional bridge superstructure and substructure connection structure.

[Explanation of symbols]

1 substructure 2 box-shaped parts 3 superstructure 4 steel frame 5 PC steel 6 insertion holes 7 anchor 8 sleeves 9 windows 10 Boxing formwork 11,12 concrete 13 nuts

Claims (5)

[Claims] 1. A bridge consisting of a substructure that is a foundation and a steel superstructure that is placed on the upper surface of the substructure and partially forms a box-shaped portion, in which a steel frame is vertically installed on the substructure side. The other end of the PC steel material is embedded and fixed at one end to this steel frame, and the other end of this PC steel material is exposed from the upper surface of the substructure and inserted into the superstructure through an insertion hole previously drilled in the box-shaped part. A structure for connecting bridge superstructures and substructures, characterized in that the bridge is fastened to an anchor fixed in the box-shaped part. 2. The connection structure of a bridge superstructure and a substructure according to claim 1, wherein a sleeve is provided so as to cover the PC steel material so that concrete does not come into contact with the surface of the PC steel material. . 3. A bridge consisting of a substructure that is the foundation and a steel superstructure that is placed on the upper surface of the substructure and partially forms a box-shaped portion, in which a steel frame is vertically installed on the substructure side. It is embedded, and while fixing one end of the PC steel material to this steel frame, concrete is cast around the steel frame as a substructure, and the other end of the PC steel material is projected from the upper surface of the substructure while the PC steel material is Prepare a box-shaped portion in which an insertion hole to be inserted and a window located on an extension line of the insertion hole are respectively prepared, and the box-shaped portion is placed on the lower work to introduce the PC steel material into the box-shaped portion, With the anchor temporarily fixed to the other end of the PC steel material, a boxing mold that covers the upper surface of the anchor from the window is mounted, and then concrete is placed in the box-shaped part to fix the anchor in the box-shaped part, Remove the boxing form from the other end of the PC steel It allowed exposed inside the window, P and fastening the nut to the other end of the PC steel
A method for connecting bridge superstructure and substructure, characterized in that the substructure and superstructure are integrated by causing tension in the C steel material. 4. In the step of fixing one end of the PC steel material to the steel frame, a sleeve is provided on the PC steel material so as to cover it, and P
The method for connecting the bridge superstructure and substructure according to claim 3, wherein concrete is prevented from coming into contact with the surface of the C steel material. 5. The connection structure and its construction method according to claim 1, wherein the PC steel material is a PC steel rod.