JPH09100510A - Construction method of bridge and rubber bearing body used in this method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce internal stress of a rubber bearing body produced by the aging dry shrinkage of bride girders and secure an instinct strength of a pier by heating the rubber bearing body interposed between concrete-made bride girders and the piers. SOLUTION: A rubber bearing body 4 interposed between an upper shoe 2 fixed with the bottom of a concrete-made bridge girder 20 and a lower shoe 3 fixed with the top of a pier 21, is formed with six rectangular board-shaped natural rubber-made boards and five stainless steel plates, which are alternately laminated and bonded with each other. The bridge girder 20 is moved resultant from aging dry shrinkage of the bridge girder 20 so that shearing strain may be produced on the rubber bearing body 4. In this case, a belt-like insulating material 17 is surrounded around the rubber bearing body 4 where a hot air is supplied thereto by driving a hot air generator 18, such as a blower, thereby heating the rubber bearing body so that the rubber of the bearing body 4 may be forcibly crept. It is, therefore, possible to remove the internal stress of the rubber bearing body 4 and reduce the reaction force to the pier 21.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for constructing a bridge of reaction force dispersion type and a rubber bearing used for the method.

[0002]

2. Description of the Related Art In recent years, bridge technology has been remarkably advanced, and the scale of bridges has been increasing year by year. Accordingly, many long bridges have been designed. As a bearing system for such a long bridge, conventionally, as shown in FIG. 16, a long span bridge girder 51 is used, and a rubber bearing 53 fixed to a large number of bridge piers 52.
Fixed support. Such a bridge of the support system is called a bridge of a distributed reaction force (horizontal force), and effectively utilizes the horizontal rigidity of the rubber bearing to arbitrarily distribute the inertial force of the bridge girder 51 to each pier 52. The pier 52
The cross-sectional shapes of the bridges have been made uniform to improve the balance of the entire bridge.

[0003]

However, in the case of a concrete long bridge, since the length of the bridge girder 51 is 300 m, the bridge girder 51 dries during the second half to 1-2 years after construction. The contraction contracts about 10 cm in the longitudinal direction (see arrow A in FIG. 16). Therefore, as shown in FIG.
The rubber bearing 53 is distorted in the longitudinal direction of the bridge girder 51 (toward the center of the bridge girder 51). As a result, a reaction force is applied to the pier 52 due to the deformation of the rubber bearing 53, and the bridge girder 51
After drying and shrinking, the bridge girder 52 is always subjected to a load in the lengthwise direction, which is disadvantageous in terms of strength of the bridge girder 52. Therefore, as a means for removing the distortion of the rubber support after the bridge girder 51 is dried and contracted, Japanese Patent Application Laid-Open No. 5-171 has been proposed.
A preliminary shearing deformation installation method disclosed in Japanese Patent No. 623 has been proposed. This method is as follows. That is, as shown in FIGS. 18 and 19, a bed plate 55 in which stoppers 56 are erected on both sides along the longitudinal direction of the bridge girder 51 and the like, and metal plates 59, 60 are fixed to the upper and lower surfaces of the rubber layer 58. As a result, a substantially rectangular parallelepiped rubber support 57 is prepared, and the rubber support 57 is positioned and fixed to the center of the bed plate 55 with bolts 61a and 61b. Next, the bridge pier 52 or the like is constructed, and the bed plate 55 is fixed to the upper portion of the bridge pier 52 or the like. Next, the locking projection 59a on the upper surface of the upper metal plate 59 of the rubber bearing 57 is fitted into the locking hole 62a on the lower surface of the sole plate 62, and the bridge girder 51 and the like are constructed in this state. Next, after removing the bolt 61a on the bridge girder 51 and the like in the drying shrinkage and creeping direction, the bolt 61b on the opposite side is tightened and rotated to rotate the rubber support 57.
The lower metal plate 60 is pressed and moved in the drying shrinkage and creep advancing direction of the bridge girder 51 and the like. In this way, after the rubber layer 58 of the rubber support 57 is pre-shear-deformed, the bolt 61b is removed, a spacer is arranged in the gap formed between the stopper 56 and the lower metal plate 60, and bolted. ing.

However, in this case, the bolt 61
Since it is very difficult to set the distance for tightening and rotating b to press and move the lower metal plate 60 of the rubber bearing 57, the accurate distance cannot be set, and the rubber bearing 57 does not dry even after the bridge girder 51 or the like shrinks. There is a problem in that the shearing deformation continues to act on the rubber layer 58 and the rubber bearing 57 is damaged early. Moreover, in this structure, shear deformation acts on the rubber layer 58 of the rubber support 57 from the initial state, and the bolt 61
Since the shearing deformation is rapidly given by the tightening of b, there is a problem that the rubber layer 58 is likely to be cracked. further,
Since it is necessary to perform fine manual work such as the tightening work of the bolt 61b and the mounting work of the spacer in a narrow place, it takes time and effort.

The present invention has been made in view of the above circumstances, and reduces the internal stress of the rubber support and reduces the internal stress of the bridge pier without the need for construction work for readjustment of the bridge girder after drying and shrinking. It is an object of the present invention to provide a bridge construction method capable of ensuring strength and a rubber support used for the method.

[0006]

In order to achieve the above object, the present invention comprises a step of fixing a rubber bearing on the upper part of a bridge pier, and a step of placing and fixing a bridge girder on the rubber bearing. First, there is provided a bridge construction method including a step of heating the rubber support after a predetermined period of time to remove internal stress thereof.
The second gist of the present invention is a rubber bearing used for the method of constructing a bridge, in which at least one intermediate plate is embedded inside the rubber body.

[0007]

BEST MODE FOR CARRYING OUT THE INVENTION That is, a method of constructing a bridge according to the present invention comprises a step of fixing a rubber bearing on an upper part of a pier, a step of placing and fixing a bridge girder on the rubber bearing, and a predetermined period. And the step of heating the rubber bearing to remove the internal stress after the passage. Therefore, when the bridge girder moves for a predetermined distance in the longitudinal direction due to drying shrinkage of its constituent materials, etc., the rubber bearing undergoes shear deformation due to this movement, but heating the rubber bearing causes creep of the rubber to occur. The internal stress of the rubber bearing can be removed. Therefore, the reaction force applied to the pier becomes significantly small when the bridge girder is dried and contracted. Further, in the present invention, the heating conditions at the time of heating are not so difficult as the setting of the pressing movement distance in the conventional example, and the internal stress of the rubber bearing can be removed by setting the accurate heating conditions. Moreover, in this product, the shear deformation acting on the rubber bearing gradually occurs during the predetermined period, and the means for removing the internal stress of the rubber bearing is heating, so that the rubber bearing is cracked during work. Etc. will not occur. Further, since the heating work does not require the finer work as the tightening work and the mounting work as in the conventional example, the heating work can be easily performed even in a narrow place. In the present invention, the predetermined period generally refers to a period from the latter half year to 3 years of concrete bridge girder construction, for example, in the case of a concrete bridge girder having a length of about 300 m, the latter half year of bridge girder construction
It's been about a year or two. On the other hand, the rubber bearing of the present invention is used in the construction method of the present invention, and the method of the present invention can be easily realized. Further, in the present invention, the longitudinal side surfaces of the bridge girder of the rubber bearing are formed to incline at a predetermined angle with respect to the vertical direction, and in that state, the initial mounting state is achieved, and after the bridge girder is dried and contracted, the side surfaces are substantially In the case of a vertical surface, the pressure receiving area of the rubber portion increases substantially after the bridge girder is dried and contracted (L in FIG. 13 showing the length of the effective pressure receiving area in the initial mounting state and the dry contraction after the contraction). Figure 7 showing it
L'is longer than L, which means that the effective pressure receiving area increases after drying and shrinking), and the compressive stress due to the load during actual use decreases. .

Next, an embodiment of the present invention will be described with reference to the drawings.

FIG. 1 shows an embodiment of a bearing device 1 used in the present invention. The bearing device 1 includes an upper shoe 2 attached to the lower surface of a concrete bridge girder and a lower shoe 3 attached to the upper surface of a bridge pier, and the rubber shoe 4 of the present invention is attached to the upper shoe 2. Is fixed. FIG. 2 is a view looking up from below. The upper shoe 2 is, as shown in FIG.
The main body 5 is composed of a rectangular flat plate made of iron, and four anchor bolts 6 (two of which are hidden and invisible) are erected on the upper surface of the main body 5.

The rubber bearing 4 is, as shown in FIG.
It is formed in a substantially rectangular parallelepiped shape, and a rectangular flat plate-shaped iron upper fixing plate 8 is fixed to the upper surface of the rubber support 4 by adhesion or the like, and a rectangular flat plate-shaped iron lower side is bonded to the lower surface by adhesion or the like. The fixed plate 9 is fixed. On the lower surface of the lower fixing plate 9, a fixing plate 10 made of an iron square plate is provided by welding or the like. As shown in FIG. 5, the rubber bearing 4 is made of six rectangular flat plate-shaped rubber plates 4 (or elastic material such as chloroprene rubber which can greatly relieve shear stress).
a and five rectangular flat plate-shaped stainless steel plates 4b are alternately laminated and bonded. As shown in FIG. 2, such a rubber bearing 4 has its upper fixing plate 8
Is fixed to the upper shoe 2 integrally by screwing it to the lower end surface of the upper shoe 2 with eight mounting bolts 11.

The lower shoe 3 is composed of a main body 12 made of an iron flat plate, and four anchor bolts 13 (two of which are hidden and invisible) which are provided upright on the lower surface of the main body 12 ( (See FIG. 1). As shown in FIG. 6, the main body 12 is formed in a square shape, and a square recess 14 that fits into the fixing plate 10 of the rubber bearing 4 is formed in the central portion thereof. In the figure, reference numeral 15 is a guide plate formed at four corners of the upper surface of the main body 12 to guide the lower fixed plate 9 in the left-right direction.

In the above construction, the upper and lower gears 2, 3 are positioned so that the fixing plate 10 of the rubber bearing 4 mounted on the upper gear 2 is located right above the recess 14 of the lower gear 3. When the upper shoe 2 is lowered and placed on the lower shoe 3, the fixing plate 10 of the upper shoe 2 is fitted into the concave portion 14 of the lower shoe 3 automatically as shown in FIG. Positioned and fixed to. From this state, when the upper shoe 2 moves a predetermined distance in the right direction (arrow direction) in FIG. 7 due to the drying shrinkage of the concrete of the bridge girder attached to the upper shoe 2, the rubber support 4 shifts from the vertical state to the inclined state. (See FIG. 8). In this state, internal stress is generated in each rubber plate 4a of the rubber support 4, and the rubber support 4 is heated as a method of removing this internal stress.

When a bridge is produced using such a supporter device 1, for example, the fixing plate 10 of the upper shoe 2 is fitted into the recess 14 of the lower shoe 3 in advance so that the upper shoe 2 is lowered. Place it on the top and temporarily fix it with a temporary fixing tool such as a string or wire in that state,
Bring it to the work site. After this loading, the lower shoe 3 fixed temporarily by the above-mentioned temporary fixture is temporarily installed by a temporary means such as a plate material in the lower shoe fixing portion 21 formed by being surrounded by a frame material or the like on the upper portion of the pier formed in advance. (See Figure 9). Then, a concrete material is poured into the lower shoe fixing portion 21 to produce the lower shoe fixing portion 21. At this time, at the same time, the lower shoe fixing portion 21
The lower shoe 3 is fixed by embedding the bolt 13 in the concrete portion of the lower shoe fixing portion 21 on the upper surface of the. Next, the upper shoe 2 is temporarily provided with a plate material or the like in a state of facing the lower shoe 3 to the upper shoe fixing portion 20 formed by being surrounded by the frame material or the like on the lower surface of the bridge girder formed in advance. Prior to this, the temporary fixing of the temporary fixing device is released, but the mutual positional relationship between the lower shoe 3 and the upper shoe 2 is maintained as it is (that is, the fixing plate 10 is fixed to the lower shoe 3). It remains fitted in the recess 14). Next, a concrete material is cast into the upper shoe fixing portion 20 to integrally produce the upper shoe fixing portion 20 on the bridge girder, and the upper shoe 2 and the bolt 6 of the upper shoe fixing portion 20 are fixed to the upper shoe fixing portion 20. It is embedded and fixed in the concrete part of the part 20. In this way, the bridge can be completed by sequentially attaching the bridge girders to the piers. In the bridge manufactured in this way, the bridge girder moves toward the right side (the direction of the arrow in FIG. 9) due to the drying shrinkage of the concrete material, etc., during a period of 1 or 2 years from the latter half of this construction. Along with this movement, the rubber support 4 shifts from the illustrated vertical state to the inclined state (see FIG. 10). After this transition,
As shown in FIG. 2, the belt-shaped heat insulating material 17 is arranged in an annular shape with a predetermined space left between the rubber bearing 4 and the rubber bearing 4, so that the heat insulating material 17 surrounds the rubber bearing 4. After that, hot air is blown into the space from a hot air generator 18 with a temperature controller such as a blower to heat the rubber support 4. The heating conditions for this heating are heating at 50 to 90 ° C. for 24 to 400 hours, and preferably at 60 to 80 ° C. for 48 to 200 hours. In this embodiment, heating is performed at 70 ° C. for about 96 hours. By such heating, the rubber of the rubber support 4 is forced to creep, the internal stress generated inside the rubber is removed, and the reaction force to the pier can be reduced.

As described above, in the bearing device 1, the creep (permanent distortion) of the rubber plate 4a itself constituting the rubber bearing 4 is carried out.
Is used positively, and a highly damping material (this highly damping material generally has large creep) is selectively used as the rubber material of the rubber plate 4a. By heating such a rubber bearing 4 after drying and shrinking the concrete material of the bridge girder, internal stress generated in the rubber bearing 4 can be sufficiently removed. In this case, it is easy to set the heating conditions and the work details for the above heating,
It can be done easily even in a narrow space. Moreover, in this case, since the shear deformation acting on the rubber bearing 4 gradually occurs,
During this period, the rubber bearing 4 is not cracked,
Further, the rubber bearing 4 is not cracked during the heating operation.

FIG. 12 shows a modification of the present invention. In this example, as a method of heating the rubber bearing 4, the electric blanket 19 is wound around the outer circumference of the rubber bearing 4 and heated. The heating conditions in this case are the same as the heating conditions with the hot air.

FIG. 13 shows a modified example of the rubber bearing 4. In this example, as shown in FIG. 14, the rubber bearing 4 is formed by inclining a substantially rectangular parallelepiped shape with respect to the vertical direction (in the direction of inclination, the bridge girder constitutes the concrete). The direction in which the material shrinks due to the drying shrinkage [the direction of the arrow in the figure] is the opposite direction, and the inclination angle is set to the angle calculated in advance), and is attached to the upper surface of this rubber bearing 4 by adhesion or the like. A rectangular plate-shaped iron upper fixing plate 8 is fixed, and a rectangular plate-shaped iron lower fixing plate 9 is adhered to the lower surface.
Has been fixed. The rubber bearing 4 is formed by forming side surfaces 4c (left and right side surfaces in the drawing) orthogonal to the contraction direction of the bridge girder (that is, the longitudinal direction of the bridge girder, indicated by an arrow in the drawing) as shown in the drawing. The upper surface is opposite to the lower surface in the direction opposite to the above contraction direction (direction opposite to the arrow in the figure)
6 rectangular flat plate made of natural rubber (or made of elastic material such as chloroprene rubber that can greatly relieve shear stress) rubber plate 4a and 5 rectangular flat plate made of stainless steel It is configured by alternately laminating and adhering flat plates 4b (the left and right and front and rear four side surfaces are formed as vertical surfaces). In this structure, after the bridge girder is dried and contracted, the side surface 4c orthogonal to the contraction direction of the bridge girder becomes a vertical surface. In this case, after the bridge girder is dried and contracted, the pressure receiving area of the rubber portion is substantially increased (L in FIG. 13 and FIG.
L'is longer than L, which means that the effective pressure receiving area increases after drying and shrinking), and the compressive stress due to the load during actual use decreases. .

FIG. 15 shows another embodiment of the present invention. In this embodiment, instead of attaching the fixing plate 10 to the lower fixing plate 9 of the rubber bearing 4, the recess 14 formed on the upper surface of the lower shoe 3 is made large enough to fit the lower fixing plate 9. The lower fixing plate 9 is formed in the recess 1
The rubber bearing 4 is fixed to the lower shoe 3 by fitting the rubber bearing 4 to the lower shoe 3. The other parts are the same as those in the above embodiment, and the same parts are denoted by the same reference numerals. This structure has a simpler structure than the above embodiment.

In each of the above-mentioned embodiments, the rubber bearing 4 is fixed to the upper shoe 2 and the recess 14 is formed in the lower shoe 3. However, the present invention is not limited to this, and the recess is provided in the upper shoe 2. 14 may be formed, and the rubber bearing 4 may be fixed to the lower shoe 3.

Further, in each of the above-mentioned embodiments, the six layers of rubber plates 4a constituting the rubber support 4 are made of the same material, but the present invention is not limited to this, and they are made of different materials. You may do it. In this case, it is preferable that the rubber material of each rubber plate 4a has the same spring constant in the shearing direction and that the strain of each rubber plate 4a is constant. Further, as the constituent material of the rubber bearing 4,
Natural rubber (NR), synthetic rubber (SBR, BR, IR, C
R, IIR, NBR, EPDM, etc.) and elastic synthetic resins such as urethane resins. Also, the above-mentioned rubber bearing 4
May be composed of one type of rubber alone.

[Brief description of the drawings]

FIG. 1 is an explanatory diagram of an embodiment of a bearing device used in the present invention.

FIG. 2 is a view of an upper shoe with a rubber bearing as viewed from below.

FIG. 3 is a side view of the upper shoe.

FIG. 4 is a side view of the rubber bearing.

FIG. 5 is a structural explanatory view of the main body of the rubber bearing.

FIG. 6 is a plan view of a lower shoe.

FIG. 7 is a cross-sectional view of the main parts showing the operation of the above-mentioned support device.

FIG. 8 is a cross-sectional view of an essential part showing the operation of the bearing device.

FIG. 9 is an explanatory diagram of a main part of a bridge using the support device.

FIG. 10 is an explanatory diagram of a main part of a bridge using the support device.

FIG. 11 is an explanatory diagram of a heating means of the rubber bearing.

FIG. 12 is an explanatory diagram showing a modified example of the heating means.

FIG. 13 is a side view showing a modified example of the rubber bearing.

FIG. 14 is a cross-sectional view showing a main body of a rubber bearing of the modified example.

FIG. 15 is an explanatory diagram showing another embodiment of the present invention.

FIG. 16 is an explanatory diagram of a conventional example.

FIG. 17 is a diagram showing an operation of the conventional example.

FIG. 18 is an explanatory diagram of another conventional example.

FIG. 19 is an explanatory diagram showing a construction method of another conventional example.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 support device 2 upper shoe 3 lower shoe 4 rubber bearing 17 heat insulating material 18 hot air generator 19 electric blanket 21 lower shoe fixing part

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Sadaji Kumaoka 4 13 Arakicho Shinjuku-ku, Tokyo Sumitomo Construction Co., Ltd. (72) Inventor Shinichiro Kumagai 13 13 Arakicho Shinjuku-ku Tokyo Sumitomo Construction Co., Ltd. (72) Inventor Kazumichi Sasaki 4 13-Araki-cho, Shinjuku-ku, Tokyo Sumitomo Construction Co., Ltd.

Claims (3)

[Claims] 1. A step of fixing a rubber bearing to an upper part of a bridge pier, a step of placing and fixing a bridge girder on the rubber bearing, and heating the rubber bearing after a predetermined period of time to internal stress thereof. And a bridge removing method. 2. The side surface of the rubber girder in the longitudinal direction of the bridge girder is formed so as to be inclined at a predetermined angle with respect to the vertical direction, and in that state, the initial mounting state is achieved, and the side surface is substantially vertical after the bridge is dried and contracted. The method for constructing a bridge according to claim 1, which is a surface. 3. A rubber bearing used in the bridge construction method according to claim 1 or 2, wherein at least one intermediate plate is embedded inside the rubber body. body.