JP2001303518A - Pressing member - Google Patents

Abstract

PROBLEM TO BE SOLVED: To solve a problem that a support member provided between the structural bodies of a structure such as a building or a bridge has little mitigating effect of impact force due to a high spring property in the vertical direction, constrains the movement of a bridge girder for the structural body, e.g. the bridge, transmits the excessive impact force between the structural bodies, thus causes the breakage of the structural body. SOLUTION: Hard plates and elastic bodies are stacked and buried in turn in an elastic body, and the rupture value or the plastic deformation value of the hard plates is determined in advance.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a pressing member having high seismic performance installed between structures such as a pier and a bridge girder.

[0002]

2. Description of the Related Art Conventionally, a bridge girder between a pier and a bridge girder exhibits a stable spring stiffness in a vertical direction and a rotation absorbing effect of a girder end due to advancing of a vehicle, and a change in ambient temperature in a horizontal (shear) direction. In order to realize this, there is a pressing member 30 in which a steel plate 20 is embedded in a rubber 10 as shown in FIG.

When a vertical load is applied to the pressing member 30, the lateral strain displacement of the rubber 10 between the steel plates 20 is restrained by the adhesive force between the steel plate 20 and the rubber 10, so that the pressing member 30 becomes high spring and a horizontal load is applied. In such a case, the rubber between the steel plates is displaced in the horizontal direction to lower the spring. According to the survey results after the Hyogoken-Nanbu Earthquake, most of the rubber bearings made of this pressed material did not suffer any damage. The specification related to the restoration of a damaged road bridge ”(February 1995, Japan Road Association) also recommends the installation of a pressing material using rubber bearings.

[0004]

However, the Hyogoken-Nanbu Earthquake caused damage to bearings and upper and lower connecting structures and breakage of mounting members on highway bridges, railway bridges, and general road bridges. In some cases, irreparable damage occurred, and the magnitude of a large earthquake that exceeded the design load of the conventional seismic design was shown. Therefore, various studies were conducted using this earthquake as a lesson, and in particular, in the case of road bridge structures, the necessity of cushioning materials to reduce seismic force and the role of cushioning materials added to devices to prevent bridge girders from falling were considered. The need for a system structure was required.

Therefore, in future seismic design, it is conceivable to increase the strength of the rubber pressing material itself or to increase the seismic force used as a design. On the other hand, in the rubber pressing material, the minimum guaranteed load and deformation amount of rubber are considered. With only the setting of, the final load of the rubber pressing member exceeds the structure, and the structure of the portion concerned is damaged more than expected, and the movement of the bridge girder becomes too large.

[0006]

Therefore, according to the present invention, a hard plate is laminated and embedded in an elastic body so as to alternate with the elastic body.
The structure was such that the fracture value or plastic deformation value of the hard plate was determined in advance. According to such a structure, when a hard plate with a rupture value point or a plastic deformation value is laminated inside the elastic body and used as a pressing material, if the seismic inertia force greater than the design seismic force is raised, In the vertical direction, the maximum pressure-receiving load is clarified and controlled by the destruction of the hard plate due to the strain force of the elastic body, and the load transmitted to the pier is reduced by the cushioning effect of the elastic body bearing, and the pressing material is broken By doing so, the function of preventing continuous movement of the bridge girder and preventing the pier from being destroyed due to concentration of inertia force at the time of a large earthquake on a specific pier will be exhibited.

[0007] Further, when the pressing member is broken, the strain energy of the elastic body consumes the energy associated with the destruction of the hard plate and the peeling of the adhesive, so that a large energy absorbing effect is exerted and extremely high toughness is exhibited. It also means
In any case, the maximum pressure (breaking) load and maximum deformation are quantified, and it is possible to set those points below the ultimate strength of the structure and the deformation in the final state. Designing a "supporting fuse theory" that is effective to prevent damage to the upper and lower structures of the bridge against seismic force exceeding the force Removes the uncertainty of the bridge during an earthquake while ensuring safety against seismic force It can be realized rationally in the form.

[0008]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is an explanatory view of a cross section, FIG. 2 is an explanatory view showing plastic deformation of a hard plate due to a vertical load, FIG. 3 is an explanatory view of an example used for bearing between a pier and a bridge girder, and FIG. 4 is used for a bridge girder prevention device FIG.

When a load is applied to a general rubber material, the ratio between the longitudinal strain and the transverse strain (Poisson's ratio) is set to 0.5, and even when the same rubber material is used, the compression spring applies a load when a load is applied. It is known that it changes depending on the shape ratio expressed by the ratio of the received pressure receiving area and the free area where the load does not act. When a restraining material is used inside, the surface is added to the pressure receiving area, so the compression spring improves. It is also known.

Therefore, a hard plate 2 made of metal, resin, FRP or the like is adhered to an elastic material 1 such as natural rubber, synthetic rubber or synthetic resin having elasticity so as to alternate with the elastic material 1. The pressing members 3 are formed by laminating in a state. The laminated state of the pressing member 3 by this laminated body is arranged in a direction orthogonal to the compression direction. The elastic member 1 and the hard plate 2 are adhered to each other. The laminating interval between the material 1 and the hard plate 2 is accurately maintained.

The factors relating to the spring in the compression direction are:
And the respective materials of the elastic material 1 and the hard plate 2. When a compressive load is applied to the laminated body, the lateral strain of the elastic member 1 between the hard plates 2 progresses with the progress of the load, and the hard plate 2 embedded therein has a strain force of the elastic member 1 in addition to the vertical load. Works. When a further load is applied and the strain displacement proceeds, the embedded hard plate 2 reaches the deformation limit, and undergoes plastic deformation as shown in FIG. When the plastic deformation of the hard plate 2 starts, the increase in the vertical load is suppressed sharply lower than the increase in the amount of deformation.

FIG. 5 is a graph showing the compressive performance characteristics of the laminated body. When attention is paid to the load, the standard value regarding the load is given only the minimum guaranteed value with the above-mentioned ordinary pressing material. Then, the structure may be damaged before the destruction of the pressing member. By paying attention to this point, the invention of the present application breaks the pressing member 3 by exceeding the design load of the elastic bearing, so that the pressing member 3 acts like a fuse and damage to the structure can be avoided.

FIGS. 6 to 11 show examples in which the stress concentration phenomenon is generated in the inner hard plate to further clarify and control the breaking point. FIGS. 6 and 7 show grooves and the like in a part of the hard plate 2. 8 and 9 show the fractured part 4 formed by connecting materials having low strength, and FIGS. 10 and 11 show the fractured part 4 formed by discontinuous holes. Yes, the discontinuous holes may be open front and back, but if they are sealed with the elastic material 1, the water tightness of the hard plate can be maintained.

In any of the above cases, the strain force of the elastic member 1 ruptures the hard plate 2 to make the pressing member clarify and control the maximum pressure receiving load. According to the main pressing member 3,
For example, as shown in FIG. 3, a pressing member 3 between a pier 5 and a bridge girder 6 is provided.
When used as a vertical load, when the load is excessive with respect to the vertical load, the internal hard plate 2 breaks to exhibit an energy absorbing effect, and suppresses the generation of an impact load, thereby lowering the height of the bridge. Will be reasonably prevented.

As described above, the pressing member 3 exhibits a large amount of energy absorption because the breaking energy of the hard plate 2 is added to the external energy that has been applied, in addition to the strain energy of the elastic member 1. The maximum reaction force is set to be less than the ultimate strength or proof strength of the structure because the maximum pressure receiving load (reaction force) does not exceed the initial upper limit and can be quantified. As a result, it can be used as a cushioning material to protect the structure from destruction, it can be practiced by removing the uncertainty of "supporting fuse theory", and excessive damage to the upper and lower structure of the bridge It is an indispensable cushioning material for construction to prevent it.

[0016]

According to the present invention described in detail above, a hard plate is buried in an elastic body alternately with the elastic body, and when a compressive load exceeding a predetermined value is applied in the vertical direction, the hard plate is hardened. The break point can be quantified and controlled by employing a structure in which the breaking load is set in advance so that the plate breaks, whereby the member below the pressing member in the vertical direction, for example, the bridge pier in the bridge When an excessive load due to a transmitted earthquake, etc. is applied, the load can be reduced by losing the supporting force of the pressing material with a compressive load exceeding the specified value, thereby reducing the mass and dispersing the mass. In addition, a large mass load has an effect of preventing breakage of a pier in a basic portion of a structure, that is, a bridge.

In any case, the maximum load (breaking) load can be quantified and set to a value lower than the ultimate strength or proof strength of the structure. It is effective to reduce.

[Brief description of the drawings]

FIG. 1 is an explanatory sectional view showing an embodiment;

FIG. 2 is an explanatory view showing plastic deformation of a hard plate due to a vertical load.

FIG. 3 is an explanatory view of an example used for bearing between a pier and a bridge girder.

FIG. 4 is an explanatory view of an example used in a bridge girder prevention device for a bridge girder.

FIG. 5 is a graph showing compression performance characteristics of a laminate.

FIG. 6 is a plan view showing a configuration example of another hard plate.

FIG. 7 is a side view of the same.

FIG. 8 is a plan view showing a configuration example of another hard plate.

FIG. 9 is a side view of the same.

FIG. 10 is a plan view showing a configuration example of another hard plate.

FIG. 11 is a side view of the same.

FIG. 12 is an explanatory diagram showing a conventional example.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Elastic material 2 Hard plate 3 Pressing material 4 Breaking part

 ────────────────────────────────────────────────── ─── Continued on the front page (72) Inventor Miwa Kotani 1058 Nakao, Uozumi-cho, Akashi-shi, Hyogo F-term in Shibata Industry Co., Ltd. (reference) 2D059 AA03 AA05 GG01 GG05 GG30 GG35 GG56 3J048 AA01 BA08 BC09 CB07 DA01 DA04 EA38 3J059 AA10 BA43 BC04 BC06 GA42 3J066 AA26 AA30 BA04 BB04 BD10 BE06 BF11 BF20 BG02 BG04

Claims (6)

[Claims] 1. A pressing member characterized in that a hard plate is laminated and buried in an elastic body so as to be alternated with the elastic body, and the breaking value of the hard plate is set in advance. 2. A pressing member, wherein a hard plate is laminated and buried in an elastic body so as to be alternated with the elastic body, and a plastic deformation value of the hard plate is set in advance. 3. A structure in which a hard plate is laminated and buried in an elastic body so as to alternate with the elastic body, and a breaking load is predetermined so that the laminated portion is broken when a predetermined load is applied in a shearing direction. Pressing material characterized by doing. 4. A pressing material according to claim 1, wherein a breaking portion is formed in a part of the hard plate and a breaking load in a vertical direction is determined. 5. The pressing member according to claim 1, wherein the hard plate is a synthetic resin plate. 6. The pressing member according to claim 1, wherein the elastic body is rubber.