JP3335598B2 - Fall prevention device combined with displacement limiting device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a bridge prevention device provided on a bridge or the like, and more particularly, to a multi-function displacement limiting device combined with a multi-function displacement limiting device capable of coping with a displacement during an ordinary earthquake. About.

[0002]

Conventionally, in order to prevent falling from the bridge girder of the bridge or bridge provided on a large earthquake, the girder prevention device A as shown in FIG. 13, for example, as shown in FIGS. 14 to 16, It is provided between the concrete bridge 20, the steel bridge 21, and the bridges 22 and 22.

The fall prevention device A is provided between the bridge girders or between the bridge girder and the abutment. The bridge girder is prevented from falling by the connecting cable 4 in which the PC steel rod or the PC steel stranded wire is PE-coated.

[0004]

However, since the purpose of the conventional bridge fall prevention device is to prevent the fall when an unexpected large earthquake occurs, the displacement of the bridge girder during a normal small and medium earthquake is limited. And has no effect on absorption of seismic energy. Regarding this, the displacement prevention device has been required in the road bridge specification as well, and in this case, conventionally, the upper structure and the lower structure are relatively fixed by an anchor bar or a steel angle stopper. Since the displacement is limited and provided separately from the bridge prevention device, it is difficult from the viewpoint of the structure and maintenance of the bearing portion, and the cost is increased. Furthermore, the conventional fall prevention device is
There is also a problem that the cushioning material for alleviating the shocking seismic force becomes large. The displacement limiting device combined type bridge prevention device according to the present invention is proposed to solve such a problem.

[0005]

The gist of the present invention to solve the above-mentioned problem of the device for preventing a bridge from falling with a displacement limiting device according to the present invention is to bridge a connecting member of a predetermined length and to provide stoppers at both ends of the connecting member. A falling bridge prevention device provided to prevent a bridge girder from dropping from an abutment or a pier, wherein the bridge girder is engaged with the connecting member and is plastically deformed by displacement of the connecting member, and horizontal displacement of the bridge girder is caused by the plastic deformation. A displacement limiting device is provided between the stoppers , and the displacement limiting device is made of a metal loosely fitted to the connecting member.
A cylindrical body, and a stopper is inserted into the connecting member on the stopper side of the cylindrical body.
To expand the diameter of the tubular body when the bridge girder is displaced.
Wedge plate, wedge plate and stopper
Between the hold plate and the wedge plate
Between the rate and hold plate
And an elastic body for maintaining the interval between the plates .

The wedge plate is pushed into the inside from a stopper side opening of the cylindrical body to a required position, and a part of the cylindrical body is attached to a bridge girder in a state where the diameter of the cylindrical body is expanded and preloaded in advance; The wedge plate is provided with a tapered portion for expanding the diameter of the cylindrical body on the outer peripheral surface, and the angle of the tapered portion is set to 2 ° to 20 °; the elastic body and the hold plate are preloaded. The wedge plate of the tubular body is assembled with bolts, and after the tubular body is attached to the bridge girder, the bolts are removed and attached.

According to the bridge-preventing device combined with the displacement limiting device according to the present invention, the elastic body between the wedge plate and the hold plate is expanded and contracted to cope with the expansion and contraction of the bridge girder due to the temperature change. During an earthquake, the cylindrical body is expanded by the movement of the wedge plate inside the cylindrical body and the seismic energy is absorbed as the bridge girder moves in the horizontal direction. Therefore, the horizontal movement of the bridge girder is stopped at an appropriate position depending on the magnitude of the seismic energy.

In the case of large seismic energy which cannot be absorbed even by the expansion of the cylindrical body, the cylindrical body is broken and the displacement of the bridge girder is stopped by the stopper at the end of the connecting member. In this manner, a bridge-fall prevention device combined with a displacement limiting device in response to a request from a road bridge specification book is obtained.

In addition, since the wedge plate is pushed in from one end opening and preloaded, the metal cylindrical body has a load-displacement curve shown by a solid line in the figure as shown in FIG. The part becomes almost flat from a small displacement, and can absorb large seismic energy. If the cylindrical body is not preloaded, the load-displacement curve shown by the broken line in the figure will be obtained, and will be greatly deformed by a small load, and it will be impossible to sufficiently absorb the seismic energy.

Further, since the angle of the tapered portion of the wedge plate for expanding the diameter of the cylinder is set to 2 ° to 20 °, the diameter of the cylinder can be easily expanded and plastically deformed.

The elastic body and the hold plate in the displacement limiting device combined with fall prevention device are assembled with a wedge plate of a preloaded cylinder by bolts, and after the cylinder is attached to the bridge girder, the bolts are removed and attached. Therefore, at the work site of the bridge girder, the bolts need only be removed and the number of man-hours can be reduced, and the parts can be transported as a single sub-assembly part, making it easier to handle.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, a displacement prevention device combined with a displacement limiting device according to the present invention will be described with reference to the drawings.
To facilitate understanding of the present invention, portions corresponding to those of the conventional example will be denoted by the same reference numerals as those of the conventional example.

As shown in FIG. 1, a bridge-preventing device 1 with a displacement limiting device according to a first embodiment of the present invention comprises a connecting member between a parapet 2a of an abutment 2 and a cross beam 3a of a bridge girder 3. A connecting cable 4 made of PC steel stranded wire, the surface of which is covered with PE (polyethylene), and a thread groove for fixing a nut is engraved at both ends, is provided in a free-fit state with a predetermined length, and both sides of the bridge girder. At two locations.

As shown in FIG. 2, the connecting cable 4 has a metal apartment 4a crimped to both ends of the cable.
A thread groove 4b is formed in the outer periphery of the apartment 4a, and nuts 5 and 6 serving as stoppers are screwed therein.

Between the nuts 5 and 6 serving as the stoppers, there is provided a displacement limiting device 7 which is a main part of the present invention.
In the embodiment shown in FIG. 1, an example in which the displacement limit storages 7, 7 are provided on both sides has been described. However, in this case, the set displacement amount in the displacement limiting device 7 is doubled.

As shown in FIG. 2, the displacement limiting device 7 is a metal cylinder (for example, loosely fitted to the connecting cable 4).
There is a cylindrical steel pipe) 8 and a wedge plate 9 provided at the stopper side of the cylindrical body 8 so as to be fitted into the connecting cable 4 and increasing the diameter of the cylindrical body 8 when the bridge girder 3 is displaced.

The diameter, length, wall thickness and the like of the cylindrical body 8 are appropriately determined by setting seismic energy to be absorbed by plastic deformation. For example, the diameter is 100-30
About 0 mm, length is 700-1000 mm as an example
It is about. As shown in FIG. 3, a flat fixing plate 8a for attachment and fixing is fixed to the cross beam side of the cylindrical body 8 by means such as welding. A cable through hole 8b is provided in the center of the fixing plate 8a, and four mounting holes 8d for bolt insertion are provided around the cable through hole 8b. A guide pipe 4c for preventing damage to the PE coating is fitted in the connecting cable 4 inserted into the through hole 8b in advance. In addition, a hanging metal fitting 8c for transportation may be provided on the outer peripheral surface of the cylindrical body 8 according to the size and weight of the cylindrical body.

The wedge plate 9 is a ring-shaped metal plate having a required width, which is loosely fitted to the condominium 4a of the connecting cable 4. On its outer peripheral surface, in FIG.
A tapered portion 9a that tapers from the nut 5 toward the cross beam 3a is provided. The degree of inclination of the tapered portion 9a is in the range of 2 ° to 20 °.

A concave portion 9b for an elastic body is provided on the rear end surface of the wedge plate 9, and a spring 10 as an elastic body is fitted therein. And wedge plate 9
A ring-shaped hold plate 11 having a through hole 11a for a cable is provided at the center in the opposite direction, and one end of the spring 10 is fitted into the concave portion 11b for the spring 10.

At the rear of the hold plate 11, a nut 5 is screwed into the thread groove 4b of the condominium 4a from the rear side, and the nut 5 is screwed to the hold plate 11 with its front end surface abutting.

In the displacement limiting device 7 shown in FIG. 2, the wedge plate 9 is pushed into the cylinder 8 from the opening on the nut side to preload, and the spring 10 and the hold plate 11 are mounted thereon as shown in FIG. Then, the wedge plate 9 and the hold plate 11 are temporarily fixed to each other with the hexagon socket head bolts 12 while maintaining the interval S ₂ (see FIG. 2), and are assembled. Therefore, after attaching the displacement limiting device 7 assembled to the connection cable 4 and screwing the nut 5 into the screw groove 4b, the bolt 12 is removed by the operator.

A cap 13 made of synthetic resin is fitted to the rear end of the cylindrical body 8. In the case of expansion and contraction due to a temperature change, in the case of a small-to-medium-scale earthquake, or in the case of a large earthquake, the displacement limiting device 7 The operation will be described.

First, as shown in FIG. 5, in the case of a temperature change or a small-to-medium-scale earthquake, the spring 10 as the elastic body responds by expanding and contracting according to the amount of movement of the bridge girder 3. When the cylinder 8 is plastically deformed within a certain range due to a middle-scale earthquake, the displacement limiting device 7 is replaced with a new one after the earthquake has subsided.

Next, in the case of a large earthquake, as shown in FIG. 6, the bridge girder 3 is largely displaced rearward, and the bearing portion B is broken, and as shown in FIG. The plate 9 moves in the direction of the arrow while expanding the diameter of the cylindrical body 8 along the tapered portion 9a. As shown in FIG. 8, seismic energy is absorbed by the pre-loaded cylinder 8 according to the solid line of the load-displacement curve. The broken line in FIG. 8 shows a weight-displacement curve when no preloading is performed.

Due to the diameter-expanding action of the cylinder 8, the cylinder 8 is plastically deformed almost uniformly, and seismic energy is absorbed in accordance with the displacement of the bridge girder 3. Then, the rearward displacement of the bridge girder 3 is stopped according to the seismic energy.

Further, when the bridge girder 3 is displaced backward, as shown in FIG. 9, the displacement limiting device 7 is broken, and thereafter the displacement is limited backward by the nut 5 as a stopper, so that the fall from the abutment 2 is prevented. Is to be prevented. In this embodiment, the fall prevention device 1 combined with the displacement limiting device is operated so as to be about 1/4 of the beam length SE (see FIG. 1).

FIG. 10 shows the operation of the bridge-preventing device combined with the displacement limiting device of the present invention in terms of the relationship between the design seismic force (tf) and the relative displacement (cm) of the bridge girder 3.
In the figure, kh is the design horizontal seismic intensity used for the seismic intensity method, Rd
Is dead load reaction force (tf), SE is the beam length (cm),
SF is the designed maximum displacement (cm) of the bridge prevention structure.

As shown in FIG. 11, the structure of the displacement limiting device 7 in the displacement limiting device 1 with the displacement limiting device is four holes (diameter 30) in the circumferential direction in a cylindrical steel pipe.
mm) 15 are provided at equal intervals, a type A (a) in which the seismic force is relieved by buckling of the hole, and a plurality of bolts 16 are arranged in several steps on the circumference of a cylindrical steel pipe. , The bolt 1
Type B (b), which resists stepwise with a shear strength of 6, and Type C (where a wedge 17 is disposed on the inner surface of a cylindrical steel pipe and a seismic force is audited by a hoop force against the penetration force of the wedge 17) C) was compared.

[0029] each type A, B, the relationship between the result of the load and displacement at C shown in FIG. 12. In the type A, buckling occurs at the position where the hole 15 is provided, and 56% of the maximum load.
Displacement increases from a moderate load. In type B, the shear strength corresponds to the calculated value in proportion to the number of bolts 16,
Little displacement at break. In the type C, the load is almost constant even if the displacement increases, and it is suitable for use in the displacement limiting device 7 of the present invention.

As described above, the displacement limiting device 1 of the present invention functions as a displacement limiting device at the time of a normal temperature change or an earthquake, and functions as a bridge limiting device at the time of an unexpected large earthquake. That is, the two functions are combined.

[0031]

As described above, the bridge-preventing device combined with the displacement limiting device according to the present invention has a connecting member of a predetermined length, and stoppers are provided at both ends of the connecting member, so that the bridge girder can be moved from the abutment. A device for preventing a bridge from falling from a pier, wherein the displacement limiting device engages with the connecting member and is plastically deformed by displacement of the connecting member, and restricts horizontal displacement of the bridge girder by the plastic deformation. The displacement limiting device is provided interposed between the stoppers ,
A metal cylinder loosely fitted to the member, and a stopper side of the cylinder;
At the time of displacement of the bridge girder
A wedge plate for increasing the diameter of the cylindrical body, and the wedge
Hold press interposed between plate and stopper
Between the wedge plate and the hold plate.
A bullet interposed between the plates to maintain the space between the plates during normal operation
Since it is made of a natural body, it is possible to prevent the bridge girder from falling from the abutment etc. in the event of a large earthquake, and to limit the movement of the bridge girder in the direction of the bridge axis in the event of an earthquake by a displacement limiting device. The combined use type fall prevention device has an excellent effect that the structure is simple, the construction is easy, and the cost is reduced. In addition, it becomes a fall prevention device combined with a displacement limiting device in response to a request from a road bridge specification book.

The displacement limiting device is provided with a metal cylindrical member loosely fitted to the connecting member, and a wedge provided on the stopper side of the cylindrical member so as to be inserted into the connecting member to increase the diameter of the cylindrical member when the bridge girder is displaced. Plate, a hold plate interposed between the wedge plate and the stopper, and an elastic body interposed between the wedge plate and the hold plate and maintaining a space between the two plates in a normal state. It has an excellent effect of being simple and easy to construct.

In the displacement limiting device, the wedge plate is pushed into the required position from the opening on the stopper side of the cylindrical body, and a part of the cylindrical body is attached to the bridge girder in a state where the diameter of the cylindrical body is expanded and preloaded. Therefore, the yield point is high at a small displacement, and thereafter, the plastic deformation is made almost flat, which is an excellent effect that the seismic energy can be sufficiently absorbed.

In the wedge plate, a tapered portion for expanding the diameter of the cylindrical body is provided on the outer peripheral surface, and the angle of the tapered portion is
Since the angle is set to 2 ° to 20 °, the cylindrical body can be expanded naturally and plastically deformed.

The elastic body and the hold plate are assembled with bolts on the wedge plate of the preloaded cylinder, and after the cylinder is attached to the bridge girder, the bolts are removed and attached.
The present invention has an excellent effect that it is compact and convenient for transportation, and is easy to attach to the connecting cable.

[Brief description of the drawings]

FIG. 1 is a side view schematically showing a state of use of a structure of a displacement-preventing device-combined type bridge prevention device 1 according to the present invention.

FIG. 2 is a cross-sectional view showing a detailed structure of a displacement limiting device 7 in the displacement limiting device combined type bridge prevention device 1 according to the present invention.

FIG. 3 is a front view of a fixing plate 8a of a cylinder 8 in the displacement limiting device 7 of the displacement limiting device 1 with the displacement limiting device according to the present invention.

FIG. 4 is an explanatory view showing that the wedge plate 9 and the hold plate 11 are temporarily fixed with bolts 12 in the displacement limiting device 7 of the displacement limiting device 1 with the displacement limiting device according to the present invention.

FIG. 5 is a device for preventing a bridge from being dropped using a displacement limiting device according to the present invention;
It is explanatory drawing explaining the state which acts by a temperature change or a small-and-medium earthquake.

FIG. 6 is a view of a bridge-preventing device 1 with a displacement limiting device according to the present invention.
Is an explanatory diagram for explaining a state in which a large earthquake occurs.

FIG. 7 is an explanatory view showing a state in which the cylinder 8 is plastically deformed in the displacement limiting device 7;

FIG. 8 is a diagram showing a relationship between a load and a displacement in a cylindrical body in the displacement limiting device 7.

FIG. 9 is a view of a bridge-preventing device 1 with a displacement limiting device according to the present invention.
Is an explanatory diagram for explaining a state in which a large earthquake occurs.

FIG. 10 is a diagram showing a relationship between a design force and a displacement amount of the displacement limiting device combined type bridge prevention device 1 of the present invention.

FIG. 11 is a front view (a), (b), and (c) of a displacement limiting device 7 in the displacement limiting device 1 in combination with the displacement limiting device according to the present invention, which shows each example of a cylindrical body in a semi-cutaway manner. is there.

FIG. 12 is a diagram showing a relationship between a weight and a displacement curve obtained by testing each of the cylindrical bodies.

FIG. 13 is a front view showing the structure of a device for preventing a bridge from falling A according to a conventional example .

FIG. 14 is an explanatory view of a use state of a bridge prevention device A according to the conventional example.

FIG. 15 is an explanatory diagram of a use state of the bridge-fall prevention device A according to the conventional example.

FIG. 16 is an explanatory view of a use state of the bridge-fall prevention device A according to the conventional example.

[Explanation of symbols]

1 Displacement limiting device combined type bridge prevention device, 2 abutment, 2a
Parapet, 3 bridge girder, 3a cross girder, 4 connecting cable, 4a apartment, 4b screw groove, 4c guide pipe, 5, 6 nut, 7 displacement limiting device, 8 cylinder, 9 wedge plate, 9a taper, 9b recess, 10 Spring, 11 Hold plate, 11
a Through hole, 11b recess, 12 bolt, 13 cap.

──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Akira Hirayama 6-3-1 Nishi-Shinjuku, Shinjuku-ku, Tokyo Inside SEI Co., Ltd. (72) Inventor Hiroshi Kibe 6-3-1 Nishi-Shinjuku, Shinjuku-ku, Tokyo No. 72, inventor Yoshiya Moriya 6-3-1, Nishi-Shinjuku, Shinjuku-ku, Tokyo (56) References JP-A-11-315510 (JP, A) JP-A Heisei 10-131123 (JP, A) (58) Field surveyed (Int. Cl. ⁷ , DB name) E01D 19/04

Claims (4)

(57) [Claims] An apparatus for preventing a bridge girder from dropping from an abutment or a pier by providing a connecting member having a predetermined length and providing stoppers at both ends of the connecting member. The displacement of the connecting member is plastically deformed by the displacement of the connecting member, and a displacement limiting device for limiting horizontal displacement of the bridge girder by the plastic deformation is provided between the stoppers, and the displacement limiting device is loosely fitted to the connecting member. Metal cylinder
Is inserted into the connecting member on the stopper side of the cylindrical body.
Webs that expand the diameter of the cylinder when the bridge girder is displaced.
Between the wedge plate and the stopper
A hold plate interposed in the wedge play
Between the holding plate and the
A bridge-preventing device combined with a displacement limiting device , comprising an elastic body for maintaining a space between the bridges. 2. A wedge plug is formed through an opening on the stopper side of the cylindrical body.
The rate is pushed inside to the required position,
The bridge girder is partially expanded and preloaded.
The fall prevention device combined with a displacement limiting device according to claim 1, wherein the device is attached . 3. A wedge plate for expanding a diameter of a cylindrical body.
A taper portion is provided on the outer peripheral surface, and the angle of the tapered portion is 2 °.
The fall prevention device with displacement limiting device according to claim 1, wherein the angle is set to 20 to 20 degrees . 4. An elastic body and a hold plate are provided with a pre-load
Bolt on the wedge plate of the
After attaching the cylinder to the bridge girder,
3. The fall prevention device combined with a displacement limiting device according to claim 2, wherein the bolt is removed and attached .