KR101140161B1 - Bridge bearing with spring - Google Patents

Abstract

PURPOSE: An elastic bearing is provided to maximally reduce a shear load even if the elastic bearing is installed in a limited space. CONSTITUTION: An elastic bearing comprises an upper plate, a lower plate(120), a rubber pad(200), and a damping member. The upper plate is arranged on an upper deck of a bridge. The lower plate is arranged on a pier of the bridge. The rubber pad is inserted between the upper and lower plates and comprises a rubber layer(201). The damping member is arranged inside the rubber pad and is integrally formed in the rubber layer. The damping member comprises a coil spring(600) vertically wound around the upper and lower plates.

Description

Elastic Stand {BRIDGE BEARING WITH SPRING}

The present invention relates to an elastic bearing for a bridge interposed between the top plate and the bridge of the bridge to absorb vibration and vibration.

In general, the upper and lower contact points of the bridge attenuate the impact energy in the event of temperature changes, earthquakes or wind loads, other vibrations and shocks, and allow the bridge to swing within an appropriate range so that the bridge is not destroyed. A seismic isolator is installed.

1 shows a conventional elastic foot. Referring to this, the upper plate 110 is disposed on the upper plate side of the bridge, the lower plate 120 is disposed on the pier side of the bridge. The upper plate 110 and the lower plate 120 prevents the vertical deviation of the pad 200 in the vertical direction, forms the appearance of the elastic bearing, and transmits a shear load to the pad 200.

The anchor socket 130 is fixed to the pier or the upper plate, the upper plate 110 and the lower plate 120 is fixed to a predetermined position of the pier or the upper plate by the anchor bolt 140 is fastened to the anchor socket 130.

Top and bottom surfaces of the pad 200 are firmly fixed to the upper plate 110 and the lower plate 120, respectively. For example, when the fixing member 150 penetrates the pad 200, the upper plate 110, and the lower plate 120, the pad 200 is fixed to each of the upper plate 110 and the lower plate 120. .

The pad 200 is sheared against vibration and shock acting on the bridge to attenuate the shear load, and the vibration and shock caused by the earthquake act as a shear load F acting in the lateral direction.

The intermediate plate 210 is inserted into the rubber layer 220 to reinforce the strength and elasticity of the rubber layer 220 so as to secure a shear modulus of the elastic support above a predetermined value.

However, when the magnitude of the shear load acting on the bridge is too large, such as an earthquake with high strength, even if the intermediate plate 210 is installed, the installation space of the elastic support is limited, and thus there is a limit to increasing the shear modulus. There is a limit to damping the shear load F without breakage or creep of the 200.

When the plastic deformation amount of the pad 200 exceeds an appropriate range before and after the action of the shear load F, the elastic bearing cannot move out of a predetermined position or exhibit a load damping performance. Therefore, the magnitude of the shear resistance at the same volume and size The elastic feet should be designed so that is the maximum.

In view of the above-described necessity, the present invention is characterized by the structure of the elastic support so as to attenuate the maximum shear load even when installed in a predetermined space, while the vertical load or the shear load repeatedly before and after the action In order to provide a sufficient damping performance in the present invention is to provide an elastic support is integrally included in the rubber layer to the exhaust member.

The elastic base of the present invention, the upper plate disposed on the upper plate side of the bridge; A lower plate disposed on the pier side of the bridge; A rubber pad interposed between the upper plate and the lower plate and including a rubber layer; A suction member made of an elastic material disposed inside the rubber pad and integrally formed with the rubber layer; It includes.

According to the present invention, the shear modulus can be increased without a large change in the total volume of the elastic bearing, and the strength against the vertical load and the shear load is strengthened, so that the repeated use reliability is improved and the damping force against the shear energy is increased.

1 is a perspective view showing a partially cut conventional elastic support.
2 is an exploded perspective view of an elastic support including a coil spring as an embodiment of the present invention.
FIG. 3 is an assembled view illustrating a portion of FIG. 2 cut away. FIG.
4 is an exploded perspective view of an elastic support including a coil spring and a reinforcing iron plate according to another embodiment of the present invention.
FIG. 5 is an assembly view of a portion of FIG. 4 taken away. FIG.
Figure 6 is a side cross-sectional view briefly showing a low-load elastic base in the present invention.
Figure 7 is a side cross-sectional view briefly showing a high load elastic support in the present invention.
8 is a side cross-sectional view showing the deformation behavior of the elastic support under the shear load in the present invention.
9 is a side cross-sectional view of the case where the coil spring is installed in the transverse direction in the present invention.
10 and 11 are side cross-sectional views of the case where the leaf spring is installed in the transverse direction in the present invention.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings. In this process, the size or shape of the components shown in the drawings may be exaggerated for clarity and convenience of description. In addition, terms that are specifically defined in consideration of the configuration and operation of the present invention may vary depending on the intention or custom of the user or operator. Definitions of these terms should be made based on the contents throughout the specification.

Bridge structures usually have a vertical load on the vehicle or the bridge itself, but when an earthquake occurs, lateral loads occur. Thus, the seismic isolation design for the bridge is focused on elastically supporting lateral loads.

Since the elastic foot adopts the rubber pad 200, the horizontal rigidity is smaller than the vertical rigidity due to the characteristics of the rubber. Therefore, it is very advantageous for the seismic isolation design of bridge structures against lateral loads. The seismic isolation property of the elastic support is determined in the rubber pad 200. The elasticity of the rubber pad 200 is determined by a vulcanization treatment method for securing elasticity by connecting rubber molecules and sulfur molecules in a crosslinked form.

Looking at the design criteria of the elastic support, the rubber is designed so that the total shear strain obtained by adding the local shear strain for the vertical load, the local shear strain for the horizontal load, and the shear strain for the rotation is less than the maximum elongation of the rubber pad 200. Prevents damage or creep of the pad 200 and secures the safety of the elastic support.

Rubber, which is a raw material of the rubber pad 200, has a molecular structure of a high molecular compound in which one molecule is entangled with a ring. In order to add elasticity to the rubber molecules, a rubber raw material is mixed with an admixture such as sulfur, carbon, softener, and anti-aging material, and then heated at high temperature and high pressure, and the sulfur molecules form permanent crosslinks in the rubber molecules to give elasticity. Get this improved vulcanized rubber.

The quality of the vulcanized rubber is determined on the basis of the quality of the rubber raw material and is determined by the vulcanization treatment conditions including the heating temperature, the heating time and the pressure most suitable for the admixture used. Vulcanization conditions are the most important factors in determining the quality of rubber products.

On the other hand, natural rubber has a strong oxidation property compared to synthetic rubber, the elastic support uses a synthetic rubber or coating a durable coating rubber 220 on the outside of the rubber pad 200 about 5 ~ 10mm.

The suction member of the present invention includes at least one of the coil spring 600, the leaf spring (610a, 610b), the disc spring, the rubber pad 200 is characterized in that the suction member is vulcanized and bonded to the rubber layer 201 . Therefore, the rubber pad 200 including the suction member of the present invention has a vulcanization rate of the suction member and the rubber layer 201 as compared with the conventional elastic support made of only the rubber layer 201 or embedded with the reinforcing iron plate 210 in the horizontal direction. Good adhesion and increased vulcanized adhesion area increase shear modulus to enhance shear resistance and even elastically support vertical loads.

The rubber pad 200 of the present invention has a structure in which the suction member is vulcanized and adhered to the rubber layer 201 in which the rubber layer 201 or the reinforcing iron plate 210 is embedded. Upper and lower portions of the rubber pad 200 are provided with an upper plate 110 and a lower plate 120 for fixing to steel and concrete structures. At this time, the rubber layer 201 and the reinforcing iron plate 210 or the rubber layer 201 and the reinforcing iron plate 210 to suppress the sliding of the rubber molecular layer of the rubber pad 200 due to the lack of friction between the rubber layer 201 and the suction member. ) Or the rubber layer 201 and the suction member are vulcanized and bonded to have sufficient adhesiveness.

The suction member includes at least one of the coil spring 600, the leaf springs 610a and 610b, and the dish spring. The spring has the intrinsic elastic modulus E and the transverse elastic modulus G as intrinsic physical properties. When the shear force is applied to the material, a sliding resistance is applied to the cross section, and this resistance is denoted by τ. The vertical stress sigma acts in the direction perpendicular to the material. τ is a stress generated in the plane of the cross section and is referred to as shear stress and denoted by τ. Since the strain with respect to the shear stress τ is a change in the shear angle, this angular displacement is called the shear strain and is expressed by γ. The lateral elastic modulus G = (shear stress / shear strain) and the longitudinal elastic modulus E = (vertical stress / vertical strain).

2 and 3, the elastic support of the present invention includes an upper plate 110, a lower plate 120, a rubber pad 200, and a suction member. In the illustrated example, the rubber pad 200 does not include the reinforcing iron plate 210 and is made of only the rubber layer 201, and is wound in a lengthwise direction perpendicular to the upper plate 110 and the lower plate 120. Coil spring 600 is shown as an example of the suction member. The suction member may be vulcanized and adhered to the rubber pad 200, and may be mounted in plurality for each portion of the rubber pad 200.

The suction member serves to increase the initial stiffness and the restoring force, which is a basic performance that the seismic isolation device should have. Initial stiffness refers to the stiffness that can withstand a constant vertical load without damage in the initial state where shear load (F) is not applied.Resilience is the degree of restoration to the original position without creep or yield when shear load (F) is lowered. Say.

The coil spring 600, which is an embodiment of the suction member, is elastically deformed together with the rubber pad 200 to support the vertical load of the bridge in the longitudinal direction of the coil spring 600, thereby reducing the load on the rubber pad 200. When the elastic deformation of the rubber pad 200 prevents buckling or lateral yield deformation of the rubber pad 200 and prevents the rubber pad 200 from twisting in a direction other than the load direction. It guides the deformation path and prevents the rubber pad 200 from tearing due to excessive deformation by external force.

Damping force is generated by the internal friction of the rubber pad 200 when an earthquake acts as a shear load F, and the coil spring 600 is also part of the external force in the form of intermolecular friction, viscous deformation, elastic deformation, and heat generated during deformation. Since it consumes the reinforcement of the damping force of the rubber pad 200.

In addition, the coil spring 600 is elastically deformed in the lateral direction of the coil spring 600 perpendicular to the longitudinal direction as well as the longitudinal direction, as well as improving the vulcanization adhesion between the coil spring 600 and the rubber layer 201, the rubber pad ( The shear modulus of 200) is increased and the anti-vibration or shear strength is reinforced. In the present specification, 'shear load (F)' is used in the same sense as the 'earthquake load' acting in the cross direction of the bridge.

When the vulcanized rubber having a large internal friction is coated on the metal exhaust member, the amplitude of the shear load F or the seismic load is reduced. The rubber layer 201 of the rubber pad 200 coated on the suction member is designed to have a shape and a thickness that can withstand large displacements, and suppresses excessive deformation, fatigue failure, and plastic deformation of the suction member.

The rubber layer 201 of the rubber pad 200 consumes a part of external force in various forms such as intermolecular friction, viscous friction, coulomb friction, viscous deformation, elastic deformation, and heat generated during deformation, and at the same time by internal friction of rubber. It acts as a damping, protects the absorbing member when the external force is applied, and prevents the absorbing member from being exposed to the outside to prevent corrosion or contamination of the absorbing member, and the suction member is fixed by freezing in cold paper, so that the shear resistance is weakened. And preventing surging of the dust collecting member. When the coil spring 600 is used as the suction member, the surging effect occurring in the coil spring 600 can be prevented by the covering rubber. The surging effect refers to a phenomenon in which natural vibration of the coil spring 600 is induced when the coil spring 600 receives a variable load close to the natural frequency.

The relationship between the load and the displacement of the suction member shows the nonlinear behavior characteristics due to the viscous deformation and elastic deformation theory of the coated rubber vulcanized to the suction member and the shape effect of the viscous deformation of the rubber. Therefore, even if the load changes, the natural frequency of the spring system is almost constant.

When an earthquake occurs and there is a big shake on the ground, all objects lying on the ground will be forced, but objects close to the frequency of the earthquake will cause resonance and face the risk of collapse. Therefore, it is necessary to understand the frequency characteristics of the earthquake and to design the natural frequency and seismic isolation characteristics of the structure.

Until the 1950s, when the seismic design of the earthquake was not accurately understood, the earthquake wave was designed to prepare for the earthquake only by solid design.However, the earthquake wave contained less energy in the long period than the short period. Since the early days, it has begun to realize that isolating designs that smoothly design structures and make their own periods long are safe.

As a method of designing a structure smoothly as described above, there is a method of lengthening a unique period by increasing the height as in a high-rise structure, but since the low-rise building and the general bridge structure must satisfy the load supporting conditions in normal use, the minimum cross-sectional area of the supporting member There is a limit to the long period of the natural period of this cursor structure.

Therefore, as a method for artificially lengthening the intrinsic period of the structure while maintaining the cross-sectional area of the support member of the structure, it is preferable to use a viscoelastic material such as rubber or to add a high-elasticity suction member to the support member of the structure as in the present invention. It's a good way.

The natural period of the structure is determined by the mass and elastic modulus of the structure and in principle is not affected by the damping factor. It is virtually impossible to control the mass of the bridge structure, but adjusting the elastic modulus or boundary conditions of the structure can be achieved through the suction member of the present invention.

Therefore, the elastic support of the present invention has a powerful effect on the seismic design of low-rise buildings or bridges, and can control the elastic modulus and boundary conditions to make the period of the natural period of the structure long, and the seismic energy delivered to the structure is intermolecular friction In the form of viscous deformation, elastic deformation, etc. to prevent collapse.

According to the present invention, by adjusting the elastic modulus of the coil spring 600, which is an embodiment of the suction member, or by adjusting the boundary condition determined by the fastening condition and the fastening position of the rubber pad 200 or the suction member, Long periods can be easily longed.

Conventional elastic feet made of rubber only or elastic feet made of rubber and reinforcing iron plate 210 is based on the damping component control, so it is difficult to make the long period of the natural cycle of the bridge structure. On the other hand, the rubber pad 200 of the present invention can prolong the intrinsic period of the structure by using the periodic characteristics of the seismic wave, so the resonance suppression effect is excellent.

4 and 5 illustrate a rubber pad 200 composed of a suction member, a reinforcing iron plate 210, and a rubber layer 201. The suction member includes a coil spring 600, the coil spring 600 is wound in a direction perpendicular to the upper plate 110, the coil spring 600 supports the vertical load and the load capacity for the shear load (F) To strengthen.

Since the reinforcing iron plate 210 is inserted into the rubber layer 201 and vulcanized and bonded to the rubber layer 201, the lateral strength is reinforced and the shear modulus of the rubber pad 200 is increased to a predetermined value or more. In the embodiment of FIGS. 4 and 5 in which a reinforcing iron plate 210 is added compared to FIGS. 2 and 3. The vertical load bearing force as well as the shear load F bearing force are enhanced.

According to the present invention, the strength of the shear resistance by the vulcanized adhesive strength of the reinforcing steel plate 210 is replaced or further improved by the vulcanized adhesive strength of the dust absorbing member, and the strength of the vertical load is also enhanced because the dust absorbing member elastically supports the vertical load. If necessary, the natural period of the bridge structure can be adjusted.

6 is a side cross-sectional view briefly showing the elastic support for the low load F1 in the present invention. The suction member includes a plurality of coil springs 600 wound in a direction perpendicular to the upper plate 110. The vertical extension length Ls of the coil spring 600 extends beyond the height Lr of the rubber pad 200. The coil spring 600 has its end exposed when viewed from the upper or lower surface of the rubber pad 200, and is in contact with the upper plate 110 or the lower plate 120 to elastically support the vertical load.

At this time, when the vertical load is excessive, the deformation amount of the suction member due to the vertical load is large, so that a crack occurs in the vulcanization adhesion between the rubber and the suction member, or a large difference occurs between the vertical deformation amount of the rubber and the vertical deformation amount of the suction member, or a rubber pad ( There is room for the vertical load to be evenly distributed over the entire surface of the upper surface of 200). Therefore, when the magnitude | size of the vertical load is the fall weight F1 less than a predetermined value (for example, 600 tons), the suction member has the vertical extension length Ls which is more than the height Lr of the rubber pad 200, and the suction member The ends of the are in contact with the upper plate 110 or lower plate 120.

Figure 7 is a side cross-sectional view briefly showing the elastic support for high load (F2) in the present invention. The suction member includes a coil spring 600 wound in a direction perpendicular to the upper plate 110 or the lower plate 120. The vertical extension length Ls of the suction member is smaller than the height Lr of the rubber pad 200, and the suction member is disposed to be locked in the rubber pad 200.

With respect to the vertical load of the high load F2 equal to or greater than a predetermined value (for example, 600 tons) transmitted to the elastic support, the vertical load is distributed evenly over the entire area of the upper or lower surface of the rubber pad 200 so that the concentrated load is applied to the suction member. This does not occur. In addition, since the vertical load uniformly distributed over the entire area of the rubber pad 200 acts first on the rubber part of the rubber pad 200 without first acting on the suction member, only a part of the primarily damped distribution load is applied to the suction member. Works. Therefore, there is no problem in the vulcanization adhesion between the rubber layer 201 and the suction member, and much difference is not caused in the deformation amount of the rubber layer 201 and the deformation amount of the suction member.

8 is a side cross-sectional view showing the deformation behavior of the elastic support under the shear load (F) in the present invention. When the shear load F is applied, the rubber pad 200 is sheared transversely in the transverse direction, and the coil spring 600, which is a suction member, is also elastically deformed in the lateral direction. If the vertical elastic modulus of the coil spring 600 is large, the lateral elastic modulus is also increased in proportion to this, and the coil spring 600 vulcanized and adhered to the rubber layer 201 elastically moves in a lateral direction, and thus a rubber pad 200 made of simple rubber. ), The bearing capacity for the shear load (F) is enhanced.

9 is a side cross-sectional view of the case where the coil spring 600 is installed in the transverse direction in the present invention. A coil spring 600 vulcanized and bonded to the rubber layer 201 is used as the suction member, and the coil spring 600 is wound in the lateral direction of the rubber pad 200 to maximize the shear modulus increase effect. When the coil spring 600 is disposed laterally, the bearing force for the shear load F is much stronger than the bearing force for the vertical load. The lateral extension length of the coil spring 600 extends more than half of the lateral length of the rubber pad 200. According to this embodiment, it may be necessary to maximize the shear resistance when the size of the elastic bearing is determined.

10 is a side cross-sectional view of the case in which the leaf springs 610a and 610b are installed in the transverse direction. The leaf member includes leaf springs 610a and 610b which are vulcanized and adhered to the rubber layer 201. The illustrated leaf springs 610a and 610b are formed by bending a pair of elastic plates to each bend in an arch shape. The pair of elastic plates face each other, and both ends thereof are in contact with each other, and the center portions are spaced apart from each other. During the action of the shear load F, the convex portion of the center portion is flat and elastically deformed to absorb the shear load F while the contact portions at both ends are supported. The load capacity for the vertical load is strengthened by the vulcanized adhesion between the leaf springs 610a and 610b and the rubber layer 201. A plurality of rubber pads 200 may be arranged at regular intervals over the lateral length of the rubber pad 200.

11 is a side cross-sectional view of the case in which the leaf springs 610a and 610b are installed in the vertical direction. The leaf springs 610a and 610b which are vulcanized and adhered to the rubber layer 201 as the dust absorbing member have an arch shape in which both ends thereof contact and spaced apart from each other. When the vertical load is applied, the convex portion of the center portion is flat and elastically deformed to absorb the vertical load, with the contact portions at both ends serving as support points.

In response to the shear load F, the rubber pad 200 has a stronger shear coefficient due to the vulcanized adhesion between the rubber layer 201 and the leaf springs 610a and 610b, compared to the case where only the rubber layer 201 is provided. The transverse strength is further improved upon the action of the shear load F.

According to the suction member of the present invention, the coil spring 600 or the leaf spring (610a, 610b) is disposed in the vertical direction or the transverse direction can see the effect of reducing the seismic force. The suction member increases the load capacity for the transverse shear load F as well as the load capacity for the vertical load.

The suction member may be used together with the reinforcing iron plate 210, and in this case, the load bearing capacity of the rubber pad 200 may be increased because it can withstand a greater vertical load. In the rubber pad 200, in which the reinforcing iron plate 210 is not employed, the shear reinforcing plate 210 replaces the shear reinforcing function of the reinforcing iron plate 210 alone.

When the earthquake acts as the shear load F, the rubber pad 200 has a structure in which the vulcanized rubber having a large internal frictional force is coated on a metal member, and thus the amplitude damping effect of the earthquake is excellent. Such a covering structure can prevent surging effects occurring in the coil spring 600, and in particular, since the vulcanized rubber absorbs vibration by interaction between intermolecular molecular fillers, it is well suited for absorption of high frequency vibration or earthquake.

The relationship between the load and the displacement in the rubber pad 200 is a nonlinear elastic characteristic due to the elastic theory of the rubber and the shape effect of the viscous deformation, so the natural frequency of the spring system is almost constant even if the working load is changed.

On the other hand, since the absorbing member can adjust the natural period or natural frequency of the bridge structure in which the elastic bearing is installed, by adjusting the elastic modulus or boundary condition of the absorbing member, the natural period of the structure is not a short period by avoiding the natural period of the seismic wave. It has the advantage of long periods of time. The boundary conditions of the suction member are adjusted according to the vulcanization adhesion conditions, the installation position, the number of installations, the installation shape, and the like of the suction member and the rubber layer 201.

By adjusting the extension length of the dust-absorbing member with respect to the height Lr of the rubber pad 200, it can appropriately correspond to the magnitude of the vertical load. For example, in the elastic support to which the high load (F2) of 600 tons or more acts, the coil spring 600 is recessed in the rubber pad 200 so that the vertical load does not directly act on the coil spring 600.

In the elastic bearing to which the low load F1 acts, the length of the coil spring 600 is equal to or greater than the thickness of the rubber pad 200 so that both ends of the coil spring 600 are connected to the upper plate 110 and the lower plate 120. Make direct contact. Therefore, the vertical load primarily concentrates on the coil spring 600, thereby strengthening the bearing capacity against the vertical load.

Although embodiments according to the present invention have been described above, these are merely exemplary, and it will be understood by those skilled in the art that various modifications and equivalent embodiments of the present invention are possible therefrom. Therefore, the true technical protection scope of the present invention will be defined by the following claims.

110 ... upper plate 120 ... lower plate
200..rubber pad 201 ... rubber layer
210 ... steel plate 220 ... coating rubber
600 ... coil spring 610a, 610b ... leaf spring
F ... Shear Load Ls ... Vertical Extension Length
Lr ... height of rubber pad F1 ... low load
F2 ... High load

Claims (10)

An upper plate disposed on the upper plate side of the bridge;
A lower plate disposed on the pier side of the bridge;
A rubber pad interposed between the upper plate and the lower plate and including a rubber layer;
A suction member made of an elastic material disposed inside the rubber pad and integrally formed with the rubber layer; Including,
The suction member includes a coil spring vulcanized to the rubber layer,
The coil spring is wound in the transverse direction of the rubber pad, and extends in the transverse direction of the rubber pad,
And the transverse extending length of the coil spring is at least half of the transverse length of the rubber pad.
delete The method of claim 1,
The rubber pad having the suction member and the rubber layer integrated therein has a non-linear elastic behavior.
The method of claim 1,
According to the adjustment of the elastic modulus of the suction member, the boundary condition determined by the fastening condition or the fastening position of the rubber pad or the suction member, the intrinsic period of the bridge structure is a long period of elasticity support.
delete delete delete delete delete delete

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