JP6757160B2 - Structure for supporting bridge girder - Google Patents

Description

The present invention relates to a bridge girder support stopper and a bridge girder support structure including the stopper.

Conventionally, in order to prevent disasters such as the bridge girder, which is a superstructure, falling from the pier or pier, which is a substructure, when a large earthquake occurs, the bridge girder and the connecting part of the pier or pier are connected. It is known to provide a safety device.
For example, in Patent Document 1, in a movement limiting device for restricting the movement of a bridge girder installed on a substructure, a long steel material whose longitudinal direction is parallel to the moving direction of the bridge girder is provided to move the bridge girder. Accordingly, there is described a movement limiting device characterized in that the long steel material extends in the longitudinal direction to absorb energy that the bridge girder is about to move and restricts the movement of the bridge girder.
Further, in Patent Document 2, in a bearing structure provided at a contact point between an upper structure and a lower structure and transmitting a load from the upper structure to the lower structure, the bearing body has a shape in which the surface in the direction perpendicular to the bridge axis is not flat. The seismic bearing structure is described.

Japanese Unexamined Patent Publication No. 2014-173407 Japanese Unexamined Patent Publication No. 2014-218795

The movement restriction device described in Patent Document 1 described above absorbs the energy that the bridge girder is about to move by using a long steel material, and restricts the movement of the bridge girder.
Further, since the earthquake-resistant bearing structure described in Patent Document 2 described above has a bearing body having a shape whose surface is not flat in the direction perpendicular to the bridge axis, when a horizontal force during an earthquake is applied, the structure is perpendicular to the bridge axis. On the other hand, it can have sufficient proof stress and deformation performance.
An object of the present invention is a stopper for supporting a bridge girder including at least a concrete molded body, which can prevent the bridge girder from moving in the event of an earthquake and can be easily replaced after the occurrence of an earthquake. It is to provide a support stopper.

As a result of diligent studies to solve the above problems, the present inventor has found that the above object can be achieved by a bridge girder support stopper having a specific structure including a concrete molded body and a reinforcing member thereof. The invention was completed.

The present invention provides the following [1] to [8].
[1] In order to limit the horizontal movement of the pier or the pier with respect to the pier or the pier, one end is fixed to either the pier or the pier and the pier, and the pier or the pier can be horizontally moved within a specific range specified by the design. When the target of the fixation is the pier or the abutment, the bridge girder is used, and when the object of the fixation is the bridge girder, the movement is restricted when the upper limit of the specific range is exceeded. A stopper for supporting a bridge girder for use by attaching the other end to a pier or abutment so as to extend in the vertical direction. The stopper for supporting the bridge girder contains short fibers and has a bending strength (150 mm × 150 mm). Using a test piece of × 530 mm, when the pier length is 450 mm, the measured value under the condition of trisection loading) is 8 N / mm ² or more, and the concrete molded body is reinforced. The reinforcing member includes one or both of a reinforcing bar arranged in the concrete molded body and a tubular member arranged so as to accommodate the concrete molded body. A stopper for supporting the bridge girder, which is characterized by being.
[2] The bridge girder support stopper according to the above [1], wherein the bridge girder support stopper has a damping function due to plastic deformation and fracture absorption energy.
[3] The short fibers are steel fibers, the reinforcing bars are reinforcing bars, the tubular member is a steel pipe, and the concrete molded body is used as a binder material of cement, silica fine powder, and The stopper for supporting a bridge girder according to the above [1] or [2], which comprises intermediate particles having a particle size between the cement and the siliceous fine powder.
[4] The stopper for supporting the bridge girder according to any one of [1] to [3] above, and the restoring force is the mass of the bridge girder multiplied by 0.1 G (where G is the gravitational acceleration). A structure for supporting a bridge girder, which comprises a bearing which is equal to or more than a value and is arranged between the pier or the abutment and the bridge girder.
[5] The structure for supporting a bridge girder according to the above [4], wherein 10% or more of the restoring force of the bearing is obtained by gravity acting on the bridge girder.
[6] The bridge girder support structure according to the above [4] or [5], wherein the residual proof stress of the bridge girder support stopper after plastic deformation is 95% or less of the restoring force of the bearing.
[7] The bearing includes an upper shoe located near the bridge girder and a lower shoe located near the pier or the abutment, and the coefficient of friction between the upper shoe and the lower shoe is The bridge girder support structure according to any one of the above [4] to [6], which is 0.1 to 0.8.
[8] The structure for supporting a bridge girder according to the above [7], wherein a cushioning material is arranged between the upper shoe and the lower shoe.

The present invention also provides the following [9] to [13].
[9] A stopper for supporting the bridge girder for supporting the bridge girder by attaching one end to the pier or the bridge and attaching the other end to the bridge girder, and a restoring force of 0.1 G to the mass of the bridge girder (however, G is gravity). A structure for supporting a bridge girder, which includes a bearing arranged between the pier or the pier and the bridge girder, which is equal to or more than a value multiplied by (acceleration).
[10] The structure for supporting a bridge girder according to the above [9], wherein 10% or more of the restoring force of the bearing is obtained by gravity acting on the bridge girder.
[11] The structure for supporting a bridge girder according to the above [9] or [10], wherein the residual proof stress of the stopper for supporting the bridge girder after plastic deformation is 95% or less of the restoring force of the bearing.
[12] The bearing includes an upper shoe located near the bridge girder and a lower shoe located near the pier or the abutment, and the coefficient of friction between the upper shoe and the lower shoe is The bridge girder support structure according to any one of the above [9] to [11], which is 0.1 to 0.8.
[13] The structure for supporting a bridge girder according to the above [12], wherein a cushioning material is disposed between the upper shoe and the lower shoe.

According to the stopper for supporting the bridge girder of the present invention, it is possible to prevent the bridge girder from moving in the event of an earthquake.
Further, the stopper for supporting the bridge girder of the present invention can be easily replaced after an earthquake or the like.

It is sectional drawing which shows the state which cut in the vertical plane an example of the structure (road bridge) including the stopper for supporting a bridge girder of this invention. FIG. 5 is a cross-sectional view showing a state in which an example of a bridge girder support stopper in the structure (road bridge) shown in FIG. 1 is cut in a horizontal plane. It is sectional drawing which enlarges and shows the bearing in the structure (road bridge) shown in FIG. 1 and the peripheral structure thereof. It is a perspective view which shows the bearing body (rubber shoe) which is the component part (component member) of the bearing in the structure (road bridge) shown in FIG. It is a side view of the structure (road bridge) shown in FIG. It is a side view which shows an example of a road bridge schematically.

In FIG. 1, the bridge girder support stopper 3 has one end fixed to the pier 1 in order to limit the horizontal movement of the bridge girder 2 with respect to the pier 1, and is capable of horizontal movement within a specific design-defined range. The other end is attached to the recess 6 of the bridge girder 2 so as to extend in the vertical direction so that the movement is restricted when the upper limit of the specific range is exceeded.
Here, the direction in which the bridge girder 2 can move horizontally with respect to the pier 1 is at least the direction perpendicular to the longitudinal direction of the bridge girder (the direction in which the bridge girder extends; hereinafter also referred to as the longitudinal direction of the bridge girder) (the direction of the width of the bridge girder; hereinafter, Also referred to as the bridge girder width direction). FIG. 1 shows that the bridge girder 2 can move horizontally in the bridge girder width direction because the dimension of the recess 6 of the bridge girder 1 in the bridge girder width direction is larger than the diameter dimension of the bridge girder support stopper 3. There is.
In this way, since the bridge girder 2 can move horizontally in the bridge girder width direction in the bridge girder support stopper 3, even if the bridge girder 2 moves in the bridge girder width direction in the bearing 4 within a specific range described later in the event of an earthquake. The bridge girder support stopper 3 does not break.

The dimension of the recess 6 in the longitudinal direction of the bridge girder can be set to be larger than the diameter of the stopper 3 for supporting the bridge girder. In this case, the dimension of the recess 6 in the longitudinal direction of the bridge girder is determined in consideration of the magnitude of the change in the length of the bridge girder 2 which is assumed when the bridge girder 2 expands and contracts in the longitudinal direction due to a change in temperature or the like. Can be done.
Examples of the shape of the recess 6 include a rectangular parallelepiped shape, a hemispherical shape, a hemispherical shape, and the like.

The bridge girder support stopper 3 contains short fibers and has a bending strength (measured value under the condition of trisection loading when the span length is 450 mm using a test piece of 150 mm × 150 mm × 530 mm). Includes a concrete molded body of 8 N / mm ² or more, and a reinforcing member for reinforcing the concrete molded body.
Examples of short fibers include metal fibers and the like.
Examples of metal fibers include steel fibers, stainless steel fibers, amorphous fibers and the like.
The dimensions of the short fibers are preferably 0.05 to 0.5 mm in diameter and 5 to 25 mm in length, more preferably 0.1 to 0.3 mm in diameter and 8 to 20 mm in length. .. The aspect ratio (fiber length / fiber diameter) of the metal fiber is preferably 20 to 200, more preferably 40 to 150, and particularly preferably 50 to 100.
The bending strength of the concrete molded body (measured value under the condition of trisection loading when the span length is 450 mm using a test piece of 150 mm × 150 mm × 530 mm) is preferably 8 N / mm ² or more. the 12N / mm ² or more, more preferably 15N / mm ² or more, more preferably 18N / mm ² or more, and particularly preferably 21N / mm ² or more.

The reinforcing member is one or both of a reinforcing bar arranged in the concrete molded body and a tubular member arranged so as to accommodate the concrete molded body.
Examples of reinforcing bars include reinforcing bars and the like.
Examples of reinforcing bars include deformed reinforcing bars and the like.
Examples of deformed reinforcing bars include deformed steel bars, deformed coil reinforcing bars and the like.
As a form of the reinforcing bar, as shown in FIG. 2, one spiral reinforcing bar is formed on six linear reinforcing bars (reinforcing bars) 3c arranged parallel to each other located at each apex of the hexagon. Reinforcing bars (reinforcing bars) 3d are fixed so as to abut from the outside (reinforcing bar structure including spiral reinforcing bars), or (not shown) arranged parallel to each other located at each apex of a square. A plurality of square annular reinforcing bars (reinforcing bars) are fixed to the four linear reinforcing bars (reinforcing bars) at appropriate intervals in the longitudinal direction so as to abut from the outside (annular). Reinforcing bar structure including the reinforcing bar of the above) and the like.
Examples of the tubular member include a cylindrical steel pipe and the like.
As an example of a reinforcing member in which the reinforcing member includes both a reinforcing bar and a tubular member, as shown in FIG. 2, a reinforcing bar structure (straight line) containing the above-mentioned spiral reinforcing bar in a cylindrical steel pipe 3a. A combination of six shaped reinforcing bars 3c and a spiral reinforcing bar 3d) is accommodated. In FIG. 2, the internal space of the cylindrical steel pipe 3a is filled with mortar 3b. The bridge girder support stopper 3 is composed of a reinforcing member (steel pipe 3a, reinforcing bars 3c, 3d) and a mortar 3b.

The concrete molded body preferably contains cement, silica fine powder, and intermediate particles having a particle size between cement and silica fine powder as the material of the binder. By using siliceous fine powder and intermediate particles in addition to cement, the yield strength and toughness can be further enhanced.
Examples of the siliceous fine powder include silica fume, silica dust, silica sol, precipitated silica and the like.
Examples of the intermediate particles include silica stone powder (quartz powder), limestone powder, alumina powder, fly ash, etc. The grain size of the cement is preferably 16 to 70 μm in an amount of 50% by mass or more of the particles constituting the cement. It has a grain size within the range.
The particle size of the siliceous fine powder is preferably such that 50% by mass or more of the particles constituting the siliceous fine powder have a particle size in the range of 0.01 to 0.5 μm.
The particle size of the intermediate particles is preferably such that 50% by mass or more of the particles constituting the intermediate particles have a particle size in the range of 1 to 15 μm.
The material of the concrete molded body contains fine aggregate and water in addition to the short fibers and the binder, and may also contain a water reducing agent, a coarse aggregate and the like, if necessary. In addition, in this specification, the term "concrete compact" shall include those containing coarse aggregate (concrete) and those not containing coarse aggregate (mortar).
Examples of the water reducing agent include a high-performance water reducing agent, a high-performance AE water reducing agent, and the like.
The blending amount of the water reducing agent varies depending on the type of the water reducing agent, but is preferably 0.001 to 5 parts by mass in terms of solid content with respect to 100 parts by mass of cement.
The water reducing agent can be used in either liquid form or powder form.

The blending amount of each material of the concrete molded body is as follows.
The blending amount of the short fibers is a volume percentage in the total amount of the composition for forming the concrete molded product, and is preferably 4% or less, more preferably 0.5 to 3%, and particularly preferably 1 to 3%. ..
The blending amount of the siliceous fine powder is preferably 5 to 50 parts by mass, more preferably 10 to 40 parts by mass, and particularly preferably 20 to 40 parts by mass with respect to 100 parts by mass of cement from the viewpoint of strength development after curing. It is 40 parts by mass.
The blending amount of the intermediate particles having a particle size between the cement and the siliceous fine powder is preferably 5 to 90 parts by mass, more preferably 10 parts by mass with respect to 100 parts by mass of the cement from the viewpoint of strength development after curing. It is -80 parts by mass, more preferably 20 to 75 parts by mass, and particularly preferably 30 to 70 parts by mass.
The blending amount of the fine aggregate is preferably 50 to 400 parts by mass, more preferably 80 to 250 parts by mass, and particularly preferably 80 to 200 parts by mass with respect to 100 parts by mass of cement from the viewpoint of strength development after curing. It is a mass part.
The amount of water is preferably 10 to 35 parts by mass, more preferably 15 to 32 parts by mass, and particularly preferably 20 to 30 parts by mass with respect to 100 parts by mass of cement.

In general, bridge girder support stoppers tend to have a small toughness ratio because the shear span ratio is small. If the cross-sectional area of the bridge girder support stopper is reduced in order to increase the shear span ratio, the yield strength will be reduced. Therefore, assuming that a sufficiently large yield strength is secured, for example, when the shear span ratio is 1, the above-mentioned spiral reinforcement is provided in the internal space of the steel angle (cylindrical steel pipe having a square cross section). A stopper for supporting a bridge girder, which accommodates a reinforcing bar structure including reinforcing bars and is filled with ordinary concrete (which does not correspond to the concrete molded body used in the present invention), cannot secure a sufficiently large toughness ratio.
In this respect, the toughness ratio can be increased by using the stopper for supporting the bridge girder of the present invention.
As a result, due to the large toughness obtained by using the stopper for supporting the bridge girder of the present invention, the safety (the structure is the user or the user) which is the performance required for the structure in the event of a large-scale earthquake. Performance to avoid threatening the lives of people in the vicinity) is improved.

The stopper for supporting the bridge girder preferably has a damping function due to plastic deformation and fracture absorption energy. By having such a damping function, the proof stress and toughness can be further enhanced.

FIG. 3 shows the bearing 4 in FIG. 1 and its peripheral structure.
The bearing 4 is arranged so as to be interposed between the pier 1 and the bridge girder 2, and is a laminated body composed of an upper shoe 4b, a bearing main body 4a, and a lower shoe 4c.
The upper shoe 4b and the lower shoe 4c can be formed by, for example, mortar. In this case, the anchor 5 can also be used for fixing the upper shoe 4b to the bridge girder 2 and fixing the lower shoe 4c to the pier 1.
The bearing body 4a is made of a cushioning material (for example, rubber), and is manufactured as a tile-shaped molded body, for example, as shown in FIG. In FIG. 4, the arc-shaped curved direction of the bearing body 4a coincides with the bridge girder width direction (see FIGS. 1 and 3). Further, the direction in which the height of the bearing body 4a does not change coincides with the longitudinal direction of the bridge girder (the direction perpendicular to the width direction of the bridge girder).

When the bearing body 4a has a tile-like shape, the upper shoe 4b fixed to the bridge girder 2 tries to move diagonally upward along the upper surface of the bearing body 4a when a large earthquake occurs, but the bridge girder 2 itself. Due to its heavy weight, a very large amount of energy (earthquake energy) is required in the process of moving toward the apex of the upper surface of the bearing body 4a. Further, before the lower end of the upper shoe 4b reaches the apex of the upper surface of the bearing body 4a, the bridge girder support stopper 3 comes into contact with the side wall of the recess 6 (see FIG. 1) of the bridge girder 2, and the play (gap) is eliminated. For example, the energy of the earthquake will be consumed for the destruction of the bridge girder support stopper 3. After that, even if the bridge girder support stopper 3 is broken (broken), a very large amount of energy (earthquake energy) is required for the lower end of the upper shoe 4b to reach the apex of the upper surface of the bearing body 4a. .. Therefore, the lower end of the upper shoe 4b does not reach the apex of the upper surface of the bearing body 4a even in a large earthquake. In this way, the fall of the bridge girder 2 from the bearing 4 is prevented more effectively than before. Further, even if the bridge girder support stopper 3 is destroyed, only the bridge girder support stopper 3 needs to be replaced with a new one, so that restoration work after an earthquake can be easily performed.

In the present invention, the bearing 4 preferably has a restoring force equal to or greater than a value obtained by multiplying the mass of the bridge girder 2 by 0.1 G (where G is a gravitational acceleration) (hereinafter, also referred to as a preferred form 1 of the bearing). It says.). With this configuration, even in the case of a large earthquake, the upper shoe 4b fixed to the bridge girder 2 does not get over the apex of the upper surface of the bearing body 4a, and after the earthquake, the original before the earthquake occurs. You can expect to return to the position (great resilience).
Further, the bearing 4 is preferably one in which 10% or more of its restoring force is obtained by gravity acting on the bridge girder 2 (hereinafter, also referred to as a preferable form 2 of the bearing).
Further, the bridge girder support stopper 3 preferably has a residual proof stress after plastic deformation of 95% or less of the restoring force of the bearing 4 (hereinafter, also referred to as a preferable form 1 of the bridge girder support stopper).
In the present invention, the coefficient of friction between the upper shoe 4b and the lower shoe 4c in the bearing 4 is preferably 0.1 to 0.8. If the coefficient of friction is within this range, damping due to friction can be expected. In order to keep the coefficient of friction within this range, the bearing body is preferably formed of a cushioning material (eg, rubber). Further, by combining such a friction coefficient with any one or both of the above-mentioned preferred forms 1 and 2 of the bearing and the preferred form 1 of the bridge girder support stopper, a synergistic effect for preventing the bridge girder from falling is expected. can do.
By using the bridge girder support stopper 3 and the bearing 4 having a restoring force together, the recoverability (maintaining the function of the structure in a usable state or in a short period of time), which is the performance required for the structure in the event of an earthquake, is achieved. Performance to keep it in a recoverable state) is improved.

FIG. 5 shows a state in which the structure shown in FIG. 1 (pier 1, bridge girder 2, etc.) is viewed from the side. In FIG. 5, each of the two bridge girders 2 has one end mounted on the pier 1 via a bearing 4.
FIG. 6 shows an example of a bridge using a support portion (fixed portion 12 and movable portion 13) including a bridge girder support stopper and a bearing of the present invention. Each of the two bridge girders 2 is mounted by placing one end on the abutment 10 with a fixed portion 12 interposed therebetween and the other end on the pier 1 with a movable portion 13 interposed therebetween. It is bridged between two piers 10. A road 11 is formed on the two bridge girders 2.
The fixing portion 12 is formed by forming a recess 6 (see FIG. 1) of the bridge girder 2 so that the bridge girder 2 can move horizontally with respect to the bridge girder support stopper 3 only in the bridge girder width direction.
The movable portion 13 is formed so that the recess 6 of the bridge girder 2 can move horizontally with respect to the bridge girder support stopper 3 in both the bridge girder width direction and the bridge girder longitudinal direction.

[Example 1]
Ordinary Portland cement 630 kg / m ³ , silica fume 200 kg / m ³ , silica stone powder (intermediate particles) 390 kg / m ³ , silica sand (grain size: 75-600 μm) 880 kg / m ³ , steel fiber (diameter: 0.2 mm, length: Each material of (13 mm) 115 kg / m ³ , high-performance water reducing agent 30 kg / m ³ , and water 180 kg / m ³ was mixed to prepare a mortar.
The particle size of ordinary Portland cement was such that 50% by mass or more of its constituent particles had a particle size in the range of 16 to 70 μm.
The particle size of silica fume was such that 50% by mass or more of its constituent particles had a particle size in the range of 0.01 to 0.5 μm.
The particle size of the silica stone powder was such that 50% by mass or more of the constituent particles had a particle size in the range of 1 to 15 μm.
The proportion of steel fibers in the mortar was in the range of 1-3% by volume.
The bending strength of the concrete molded body obtained by hardening this mortar (measured value under the condition of trisection loading when the span length is 450 mm using a test piece of 150 mm × 150 mm × 530 mm). Was 21 N / mm ² or more.

Six linear diameters arranged parallel to each other located at each apex of the hexagon in a cylindrical steel pipe (diameter: 115 mm, length: 300 mm, thickness: 4.5 mm) After accommodating one spiral deformed coil reinforcing bar with a diameter of 6 mm so as to abut from the outside on a 13 mm deformed steel pipe), the above-mentioned prepared mortar is placed in the internal space of this steel pipe. Was poured into the steel pipe to prepare a stopper for supporting the bridge girder having the cross section shown in FIG.
Next, when a positive / negative alternating bending loading test was performed using this bridge girder support stopper, the level was obtained from the obtained data (graph in which the horizontal axis represents the central displacement (mm) and the vertical axis represents the load (kN)). It was found that it can be used as a disposable bridge girder support stopper that can withstand two earthquakes.

1 Pier 2 Bridge girder 3 Stopper for supporting bridge girder 3a Steel pipe 3b Mortar 3c Straight reinforcing bar (deformed bar)
3d spiral reinforcing bar (deformed coil reinforcing bar)
4 Bearing 4a Bearing body (rubber shoe)
4b Upper shoe 4c Lower shoe 5 Anchor 6 Recess 10 Abutment 11 Road 12 Fixed part 13 Moving part

Claims (6)

A bridge girder support stopper and a bridge girder support structure including bearings.
The stopper for supporting the bridge girder is
In order to limit the horizontal movement of the pier or the pier with respect to the pier or the pier, one end is fixed to either the pier or the pier and the pier and one end is fixed.
If the target of the fixation is the pier or the abutment, the bridge girder will be able to move horizontally within the specified range specified by design and the movement will be restricted if the upper limit of the specific range is exceeded. If the target of the fixation is the bridge girder, attach the other end to the pier or the abutment.
A stopper for supporting bridge girders that is arranged so as to extend in the vertical direction.
Concrete containing short fibers and having a bending strength (measured value under the condition of trisection loading when the strut length is 450 mm using a test piece of 150 mm × 150 mm × 530 mm) of 8 N / mm ² or more. moldings, and a reinforcing member for reinforcing the concrete molded body, a reinforcement which is disposed within the concrete molded body, a cylindrical shape is arranged to accommodate the concrete molded body A stopper for supporting a bridge girder that includes a reinforcing member that is one or both of the members.
The bearing is arranged so as to be interposed between the pier or the abutment and the bridge girder whose restoring force is equal to or more than the value obtained by multiplying the mass of the bridge girder by 0.1 G (where G is the gravitational acceleration). It is a bearing to be done
A bearing body composed of an upper shoe located near the bridge girder, a lower shoe located closer to the pier or the abutment, and a cushioning material disposed between the upper shoe and the lower shoe, and The bearing body has a tile-like shape, the upper shoe has a lower surface having the same curved shape as the upper surface of the bearing body, and the lower shoe has the same curved upper surface as the lower surface of the bearing body. A structure for supporting bridge girders, which is characterized by having a bearing . The bridge girder support structure according to claim 1, wherein the bridge girder support stopper has a damping function due to plastic deformation and fracture absorption energy. The short fiber is a steel fiber, the reinforcing bar is a reinforcing bar, the tubular member is a steel pipe, and the concrete molded body is a cement, a siliceous fine powder, and the cement as materials for a binder. The bridge girder support structure according to claim 1 or 2, which contains intermediate particles having a particle size between the siliceous fine powders. The bridge girder support structure according to any one of claims 1 to 3 , wherein 10% or more of the restoring force of the bearing is obtained by gravity acting on the bridge girder. The bridge girder support structure according to any one of claims 1 to 4, wherein the residual proof stress of the bridge girder support stopper after plastic deformation is 95% or less of the restoring force of the bearing. The bridge girder support structure according to any one of claims 1 to 5 , wherein the friction coefficient between the upper shoe and the lower shoe is 0.1 to 0.8.

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