JP6498436B2 - Fall bridge prevention device - Google Patents

Description

  The present invention is connected between a bridge pier and a bridge girder, and has a damper function that absorbs an impact generated when a vehicle passes or an earthquake occurs, prevents a displacement, and limits the allowable limit of the damper. The present invention relates to a falling bridge prevention device having a function of preventing a falling bridge when it exceeds the limit.

As shown in FIG. 12C, a slack is provided between the lower bracket 50 of the bridge pier 11 and the upper bracket 51 of the bridge girder 10 in order to prevent a fallen bridge due to earthquake motion, vehicle traffic, flooding, etc. By attaching the fall prevention device connected by the cable 52, the bridge girder 10 was prevented from being dropped by keeping the displacement of the cable 52 so that the slack of the cable 52 becomes a straight line.
A damper 12 as shown in FIGS. 12 (a) and 12 (b) was attached in order to absorb not only mere fallen bridges but also impacts and displacements (Patent Document 1).
According to this Patent Document 1, as shown in FIG. 12 (a) or (b), when the bridge girder 10 is mounted on the bridge pier 11 with a support shoe (not shown) interposed, 10, the damper 12 is interposed between the bridge pier 11 and the bridge girder 10 via brackets 50 and 51 in order to absorb the shock caused by various vibrations and reduce accidents, breakage, etc. as much as possible. It is attached.

Vibrations and shocks are generated in all directions such as a vertical direction, a horizontal direction, an oblique direction, a rotational direction, and a combined direction thereof. In particular, in the case of earthquake motion, the amount of fluctuation and the tensile load increase unexpectedly. Therefore, a vibration damping device that can quickly respond in any of these directions is desired, and a device that prevents the falling bridge while protecting the damper 12 is desired when the allowable limit of the damper 12 is exceeded.
In the case shown in FIG. 12A, when the damper 12 is mounted between the pier 11 side and the bridge girder 10 with the lower bracket 50 and the upper bracket 51, the upper bracket 51 is attached to the base plate 13a on the bridge girder 10 side. The rib plates 14a are integrally attached at predetermined intervals, the first support shaft 15a is vertically attached between the rib plates 14a, and the spherical bearing 17a is attached to the gusset plate 16a fixedly provided at one end of the damper 12. The first support shaft 15a is fitted to the spherical bearing 17a. Similarly, in the lower bracket 50 on the pier 11 side, two rib plates 14b are integrally attached to the base plate 13b at a predetermined interval, the first support shaft 15b is vertically attached between the rib plates 14b, and the damper 12 A spherical bearing 17b is attached to a gusset plate 16b fixedly provided at one end of the first support shaft 15b, and the first support shaft 15b is fitted to the spherical bearing 17b.
With such a configuration, not only in the plane perpendicular to the upper and lower first support shafts 15a and 15b but also in all directions within the range of the allowable alignment angle by the spherical surfaces of the spherical bearings 17a and 17b.

In FIG. 12 (b), instead of the spherical bearings 17a and 17b shown in FIG. 12 (a), upper and lower first support shafts 15a and 15b and second support shafts 18a orthogonal to each other at positions away from these. And 18b are shown. More specifically, the first support shaft 15a is vertically mounted between the rib plates 14a, the upper end portion of the gusset plate 20a is fixed to the bearing 19a fitted to the first support shaft 15a, and the gusset plate 20a is suspended. The first support shaft 15a and the second support shaft 18a are connected to each other at right angles to each other at a lower end portion thereof and a gusset plate 16a at one end portion of the damper 12. The pier 11 side has the same configuration.
With such a configuration, the in-plane orthogonal to the first support shafts 15a and 15b and the in-plane orthogonal to the second support shafts 18a and 18b can be combined to cope with all directions.

  Further, in Patent Document 2, when a damper is attached between a bridge pier and a bridge girder, a knock-off bolt that breaks when an unexpected external force is applied to the bolt for attaching the damper is used. It is described that the function is lost. In this patent document 2, it is described that a fallen bridge prevention composed of a cable, a chain or the like is used in combination for the case where the function of the damper is lost.

Japanese Patent Laying-Open No. 2005-299078. Unexamined-Japanese-Patent No. 2014-31670.

In the case of using the first support shaft 15 and the spherical bearing 17 shown in FIG. 12 (a), the spherical bearing 17 has a precise structure. Since the allowable alignment angle is set to about 5 to 6 degrees, the bearing 17 cannot cope with a large misalignment. When the pin diameter is increased, there are some which are about 10 degrees. However, when the pin diameter is increased and the rotation angle is increased, the spherical bearing 17 is also increased accordingly, and the brackets and the like receiving it are increased. If there is a limit to the mounting gap, such as between, it cannot be used.
In addition, since the allowable alignment angle is small and it is not possible to cope with a large misalignment, it is not possible to obtain an effect of preventing the falling bridge only by installing the damper 12. In order to prevent a fallen bridge with a damper alone, a high earthquake resistance is required, which is extremely expensive.

  In the example where the first support shaft 15 and the second support shaft 18 are attached with a distance as shown in FIG. 12B, the length from the bracket at one end of the damper 12 to the bracket at the other end of the damper 12 is long. Therefore, since it is structurally large, it can be used only for a large distance between the pier 11 and the bridge girder 10. Furthermore, since the load having the first support shaft 15 as a fulcrum and the load having the second support shaft 18 as a fulcrum are applied at a distance, there is a problem that the damper 12 cannot be smoothly damped. .

  In the example shown in Patent Document 2, in addition to the damper provided between the bridge pier and the bridge girder, this damper and a separate fall prevention device must be attached, and the bridge falls into a narrow gap between the bridge pier and the bridge girder. Since the installation of the prevention device is restricted and the damper is compatible with only one direction, it does not have a function that can cope with earthquake motion that cannot be predicted in which direction, and it does not have the function of preventing falling bridges. It was enough. For example, even if the technique of Document 1 and the technique of Document 2 are combined, the functions of the universal joints must be provided at both ends of the damper and at both ends of the falling bridge prevention device, resulting in a complicated structure. When installing multiple units in a narrow gap between the bridge pier and the bridge girder, there was a problem that installation was restricted.

  The present invention can follow a large angle change in all directions, and can withstand a large load with a compact structure. If the allowable limit of the damper is exceeded, the falling bridge is protected while protecting the damper. It is an object of the present invention to provide a fallen bridge prevention device that can prevent the above.

  The fallen bridge preventing apparatus of the present invention is the fallen bridge preventing apparatus in which both ends of a damper 55 using a viscous material are connected between the bridge pier 11 and the bridge girder 10 with brackets 22 interposed therebetween. The damper 55 is configured such that the member fixed to the bracket 22 on the pier 11 side and the member fixed to the bracket 22 on the bridge girder 10 side reach the stroke limit of the tensile force set in the damper 55. It is characterized in that it is configured to function as a fallen bridge prevention member 63 by sometimes locking each other.

  The damper 55 fills the inside of the cylinder 56 with a viscous body 60 and has a piston 57 and a piston rod 58, and is fixed to either the bracket 22 on the bridge pier 11 side or the bracket 22 on the bridge girder 10 side. The member is composed of the piston rod 58, and the member fixed to the other is composed of the cylinder 56. When the stroke limit of the expansion / contraction amount set in the damper 55 is reached, the piston 57 of the piston rod 58 is moved to the cylinder. It is configured to be engaged with 56 cylinder inner wall end portions 69 so as to function as a falling bridge prevention member 63.

  The damper 55 fills the inside of the cylinder 56 with a viscous body 60 and has a piston 57 and a piston rod 58, and is fixed to either the bracket 22 on the bridge pier 11 side or the bracket 22 on the bridge girder 10 side. The member is composed of an outer cover 61 that protects the cylinder 56, and the member fixed to one of the other is composed of the cylinder 56 and a protective cylinder 74, and immediately before reaching the stroke limit of the expansion / contraction amount set in the damper 55, The front inward protruding portion 70 of the outer cover 61 is configured to be engaged with a cylinder outer step portion 71 at a connecting portion between the cylinder 56 and the protective cylinder portion 74 so as to function as a falling bridge preventing member 63. .

  The member fixed to one of the bracket 22 on the bridge pier 11 side and the bracket 22 on the bridge girder 10 side is composed of a steel rod 64 fixed to a fixing ring 65, and the member fixed to the other is the steel rod 64, and a stopper 67 at the tip of the steel rod 64 is locked to the stopper ring 66 immediately before reaching the stroke limit of the set expansion / contraction amount in the damper 55, and functions as a falling bridge prevention member 63. It is characterized by having constituted so.

  The member fixed to one of the bracket 22 on the bridge pier 11 side and the bracket 22 on the bridge girder 10 side is composed of an outer cover 61, and the member fixed to the other is loosely fitted inside the outer cover 61. The inner cover 62 is formed, and immediately before reaching the stroke limit of the amount of expansion and contraction set in the damper 55, the tip inner protrusion 70 of the outer cover 61 is locked to the tip outer protrusion 72 of the inner cover 62 and falls down. It is configured to function as the prevention member 63.

  A fixing ring 65 is fixed to one of the bracket 22 on the bridge pier 11 side and the bracket 22 on the bridge girder 10 side, and a stopper ring 66 is fixed to the other, and the tip of the PC cable 79 fixed to the fixing ring 65 is fixed. Is inserted into the stopper ring 66, and a PC cable slack prevention spring 78 is interposed between the stopper ring 66 and the grip cylinder 76 at the leading end of the PC cable 79. Immediately before reaching the stroke limit of the amount, the grip cylinder 76 at the tip of the PC cable 79 is engaged with the stopper ring 66 so as to function as the falling bridge prevention member 63.

  A fixing ring 65 is fixed to each of the bracket 22 on the bridge pier 11 side and the bracket 22 on the bridge girder 10 side, and a stopper ring 66 is fixed to the cylinder 56 located between these fixing rings 65, and each fixing ring is fixed. The end of the PC cable 79 fixed to 65 extends through the stopper ring 66 and extends to the other fixing ring 65 side. Between the both ends of the stopper ring 66 and the grip cylinder 76 at the extended end. PC cable slack prevention springs 78 are interposed, respectively, and the grip cylinder 76 at the tip of each PC cable 79 is engaged with the stopper ring 66 immediately before reaching the stroke limit of the expansion / contraction amount set in the damper 55. It is configured to stop and function as a fallen bridge prevention member 63

  A fixing ring 65 is fixed to one of the bracket 22 on the bridge pier 11 side and the bracket 22 on the bridge girder 10 side, and a stopper ring 66 is fixed to the other, and the tip of the PC cable 79 fixed to the fixing ring 65 is fixed. Is inserted into the stopper ring 66, and a PC cable slack prevention spring 78 is interposed between the stopper ring 66 and the grip cylinder 76 at the leading end of the PC cable 79. Immediately before reaching the stroke limit of the amount, the grip cylinder 76 at the tip of the PC cable 79 is engaged with the stopper ring 66 so as to function as the falling bridge prevention member 63.

  Fixing rings 65a and 65b are fixed to the bracket 22 on the bridge pier 11 side and the bracket 22 on the bridge girder 10 side, respectively, and a stopper ring 66 is fixed to the cylinder located between the fixing rings 65a and 65b. The ends of the PC cable 79 fixed to the fixing rings 65a and 65b extend through the stopper ring 66 to the other fixing ring 65a or 65b, respectively. A PC cable slack prevention spring 78 is interposed between each grip cylinder 76 and the grip cylinder 76 at the tip of each PC cable 79 immediately before reaching the stroke limit of the expansion / contraction amount set in the damper 55. Is locked to the stopper ring 66 as a falling bridge prevention member 63 Characterized by being configured to capacity.

The invention according to claim 1 is the falling bridge prevention device in which both ends of the damper using the viscous material are interposed between the bridge pier and the bridge girder, respectively, and the bracket is rotatable. The damper has a member fixed to the bridge pier side bracket and a member fixed to the bridge girder side bracket ,
The damper fills the inside of the cylinder with a viscous material and has a piston and a piston rod,
The member fixed to one of the bracket on the bridge pier side and the bracket on the bridge girder side is composed of an outer cover that protects the piston rod and the cylinder, and the member fixed to the other is the cylinder and the protective cylinder portion The inner protrusion at the tip of the outer cover is locked to the cylinder outer step at the connecting portion of the cylinder and the protective cylinder portion immediately before reaching the stroke limit of the set expansion / contraction amount in the damper. Since it is configured to function as a member, when the stroke limit of the tensile force set by the damper is exceeded, the member fixed to the bracket on the bridge pier side and the member fixed to the bracket on the bridge girder side are locked together. Functions as a falling bridge prevention member. Therefore, when the impact exceeds the allowable limit of the damper, it is possible to prevent the falling bridge while protecting the damper. In addition, since the bracket is rotatable, it can follow changes in a large angle, and since it is a damper with a falling bridge prevention function, it has a compact structure and multiple units are installed in a narrow gap between the pier and the bridge girder And is not limited by the number of attachments. Furthermore, the piston rod and cylinder that make up the damper have a relatively small proof strength as a damper, and the outer cover has a high proof strength to prevent falling bridges, thus providing a function to prevent falling bridges at low cost and compactly. You can have it.

The invention according to claim 2 is the falling bridge prevention device in which both ends of the damper using the viscous material are interposed between the bridge pier and the bridge girder, respectively, and the bracket is rotatable. The damper has a member fixed to the bridge pier side bracket and a member fixed to the bridge girder side bracket ,
The member fixed to one of the bracket on the bridge pier side and the bracket on the bridge girder side consists of a steel bar fixed to a fixing ring,
The member fixed to the cylinder consists of a stopper ring penetrating the steel rod, and the stopper at the tip of the steel rod is locked to the stopper ring immediately before reaching the stroke limit of the set expansion / contraction amount in the damper to prevent the falling bridge. Since it is configured to function as a member, it is possible to provide a function for preventing a falling bridge in a compact manner simply by providing a steel rod on the outer periphery of a conventional damper.

The invention according to claim 3 is an anti-falling bridge apparatus in which both ends of a damper using a viscous material are connected between a bridge pier and a bridge girder, respectively, and the bracket is rotatable. The damper has a member fixed to the bridge pier side bracket and a member fixed to the bridge girder side bracket ,
The member fixed to one of the bracket on the bridge pier side and the bracket on the bridge girder side consists of an outer cover,
The member fixed to the other is an inner cover that is loosely fitted inside the outer cover, and the front inner protrusion of the outer cover immediately before reaching the stroke limit of the set expansion / contraction amount in the damper. Since it is configured so as to function as a falling bridge prevention member by being locked to the tip outer protrusion, it is possible to provide a falling bridge prevention function compactly simply by providing an outer cover and an inner cover on the outer periphery of a conventional damper.

The invention according to claim 4 is the falling bridge prevention device in which both ends of the damper using the viscous material are interposed between the bridge pier and the bridge girder, respectively, and the bracket is rotatable. The damper has a member fixed to the bridge pier side bracket and a member fixed to the bridge girder side bracket ,
The damper fills the inside of the cylinder with a viscous material and has a piston and a piston rod,
A fixing ring is fixed to one of the bracket on the bridge pier side and the bracket on the bridge girder side, a stopper ring is fixed to the cylinder, and the tip of the PC cable fixed to the fixing ring is passed through the stopper ring, and this stopper A PC cable slack prevention spring is interposed between the ring and the grip cylinder at the tip of the PC cable, and the grip cylinder at the tip of the PC cable immediately before reaching the stroke limit of the set expansion / contraction amount in the damper. Since the body is configured to be locked to the stopper ring and function as a fallen bridge prevention member, it can cope with any direction with a flexible PC cable, and has excellent responsiveness by eliminating the slack of the PC cable. Yes.

The invention according to claim 5 is the falling bridge prevention device in which both ends of the damper using the viscous material are interposed between the bridge pier and the bridge girder, respectively, and the bracket is rotatable. The damper has a member fixed to the bridge pier side bracket and a member fixed to the bridge girder side bracket ,
The damper fills the inside of the cylinder with a viscous material and has a piston and a piston rod,
A fixing ring is fixed to each of the bracket on the bridge pier side and the bracket on the bridge girder side, and a stopper ring is fixed to the cylinder located between the fixing rings, and the tip of the PC cable fixed to each fixing ring is attached. Each of the stopper rings extends through the stopper ring toward the other fixed ring, and a PC cable slack prevention spring is interposed between both sides of the stopper ring and the grip cylinder at the extended tip. The grip cylinder at the tip of each PC cable is locked to the stopper ring and functions as a falling bridge prevention member immediately before reaching the stroke limit of the set expansion / contraction amount in the damper. It won't be overwhelmed and can be prevented from destruction.

The invention according to claim 6 is an anti-falling bridge apparatus in which both ends of a damper using a viscous material are interposed between a bridge pier and a bridge girder, respectively, and the bracket is rotatable. The damper has a member fixed to the bridge pier side bracket and a member fixed to the bridge girder side bracket ,
The damper fills the inside of the cylinder with a viscous material and has a piston and a piston rod,
The fixing ring is fixed to the bracket on the bridge pier side and the bracket on the bridge girder side, and a stopper ring is fixed to the cylinder located between the fixing rings, and the tip of the steel rod fixed to each fixing ring is fixed. Each extending through the stopper ring to the other fixed ring side, and provided with a grip cylinder at the extended tip thereof, immediately before reaching the stroke limit of the set expansion / contraction amount in the damper. Since the grip cylinder at the tip of the steel bar is configured to be locked to the stopper ring and function as a falling bridge prevention member, the PC cable can be replaced with a steel bar.

The invention according to claim 7 is the falling bridge prevention device in which both ends of the damper using the viscous material are interposed between the bridge pier and the bridge girder, respectively, and the bracket is rotatable. The damper has a member fixed to the bridge pier side bracket and a member fixed to the bridge girder side bracket ,
The damper fills the inside of the cylinder with a viscous material and has a piston and a piston rod,
A fixing ring is fixed to each of the bracket on the bridge pier side and the bracket on the bridge girder side, and a stopper ring is fixed to the cylinder between the fixing rings, and the steel rod fixed to one of the fixing rings The tip extends through the stopper ring to the other fixing ring side, the tip of the PC cable fixed to one of the other fixing rings extends through the stopper ring to the one fixing ring side, A PC cable slack prevention spring is interposed between the side surface of the stopper ring that penetrates the PC cable and the grip cylinder at the tip end of the PC cable, and reaches the stroke limit of the expansion / contraction amount set in the damper. Immediately before the steel pipe and / or the grip cylinder at the tip of the PC cable is locked to the stopper ring and the falling bridge prevention member Since it is configured to work in, one of the left and right PC cable can be replaced with a steel rod.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 shows a first embodiment of a fallen bridge prevention device according to the present invention, in which (a) is a cross-sectional view before functioning as a fallen bridge prevention, and (b) is a partial cross-sectional view when functioning as a fallen bridge prevention. Example 2 of the fallen bridge prevention apparatus by this invention is shown, (a) is sectional drawing before functioning as fallen bridge prevention, (b) is AA sectional view taken on the line. Example 3 of the fallen bridge prevention device by this invention is shown, (a) is sectional drawing before functioning as fallen bridge prevention, (b) is a BB sectional drawing. It is a partial cross section figure which shows Example 4 of the fallen bridge prevention apparatus by this invention. 5 shows a fifth embodiment of a fallen bridge prevention device according to the present invention, in which (a) is a sectional view before functioning as a fallen bridge prevention, and (b) is a sectional view taken along the line CC. FIG. 7 shows a sixth embodiment of the fallen bridge prevention device according to the present invention, in which (a) is a sectional view taken along line GG of (c) before functioning as fallen bridge prevention, and (b) is a sectional view taken along line CC; (C) is the EE sectional view taken on the line, (d) is the FF sectional view. It is sectional drawing seen from the plane of the bracket used for the damping device. It is front sectional drawing seen from the front of the bracket used for the damping device. It is a perspective view explaining the principle of the bracket used for the damping device. It is a front view which shows the state displaced from the A point of the bracket used for the damping device to the B point. It is a top view which shows the state displaced from the A point to the C point in FIG. (A) And (b) is sectional drawing which showed the example from which the conventional falling bridge prevention apparatus each differs, (c) is explanatory drawing of the conventional falling bridge prevention apparatus.

  The present invention relates to a falling bridge prevention apparatus in which both ends of a damper 55 using a viscous material are connected between a bridge pier 11 and a bridge girder 10 with brackets 22 interposed therebetween. The bracket 22 is like a universal clevis. Further, the damper 55 is rotatable in a two-dimensional or three-dimensional direction, and the damper 55 includes a member fixed to the bracket 22 on the pier 11 side and a member fixed to the bridge girder 10 side. When the stroke limit at which the pressure acts is reached, they are in contact with each other and function as the fallen bridge prevention member 63.

  The damper 55 fills the inside of the cylinder 56 with a viscous body 60 and has a piston 57 and a piston rod 58, and is fixed to either the bracket 22 on the bridge pier 11 side or the bracket 22 on the bridge girder 10 side. The member is composed of the piston rod 58, and the member fixed to the other is composed of the cylinder 56. When the stroke limit of the expansion / contraction amount set in the damper 55 is reached, the piston 57 of the piston rod 58 is moved to the cylinder. It is configured to function as a falling bridge prevention member 63 by being locked to 56 cylinder inner wall end portions 69.

  The damper 55 fills the inside of the cylinder 56 with a viscous body 60 and has a piston 57 and a piston rod 58, and is fixed to either the bracket 22 on the bridge pier 11 side or the bracket 22 on the bridge girder 10 side. The member is composed of an outer cover 61 that protects the cylinder 56, and the member fixed to one of the other is composed of the cylinder 56 and a protective cylinder 74, and immediately before reaching the stroke limit of the expansion / contraction amount set in the damper 55, The tip end inward protrusion 70 of the outer cover 61 is configured to be engaged with the cylinder outer step 71 of the connecting portion of the cylinder 56 and the protective cylinder portion 74 so as to function as the falling bridge prevention member 63.

  The member fixed to one of the bracket 22 on the bridge pier 11 side and the bracket 22 on the bridge girder 10 side is composed of a steel rod 64 fixed to a fixing ring 65, and the member fixed to the other is the steel rod 64, and a stopper 67 such as a nut at the tip of the steel rod 64 is engaged with the stopper ring 66 immediately before reaching the stroke limit of the set expansion / contraction amount in the damper 55, and the falling bridge prevention member It is configured to function as 63.

  The member fixed to one of the bracket 22 on the bridge pier 11 side and the bracket 22 on the bridge girder 10 side is composed of an outer cover 61, and the member fixed to the other is loosely fitted inside the outer cover 61. The inner cover 62 is formed, and immediately before reaching the stroke limit of the amount of expansion and contraction set in the damper 55, the tip inner protrusion 70 of the outer cover 61 is locked to the tip outer protrusion 72 of the inner cover 62 and falls down. The prevention member 63 is configured to function.

As shown in FIG. 12 (c), a bridge girder 10 is placed on a bridge pier (abutment) 11 with a support shoe interposed therebetween.
The fallen bridge prevention device according to the first embodiment of the present invention is shown in FIGS. 1A and 1B, and shows an example of a design load that gives the main body of the damper 55 a fallfall prevention function.
As shown in FIG. 1A, the bridge piers 11 and the bridge girder 10 are connected to both ends of the bridge prevention device according to the present invention, which mainly includes a damper 55, with brackets 22 interposed therebetween. The damper 55 is exemplified by a cylinder type filled with a viscous material such as oil. The cylinder 56 is filled with a viscous material 60 and a piston 57 is provided so as to be able to move forward and backward. One end of the piston rod 58 protrudes from one side of the cylinder 56 and is fixedly connected to the base plate 34 of one bracket 22 by screwing or the like. The other end of the piston rod 58 protrudes from the other side of the cylinder 56 and is provided so as to be able to advance and retreat inside a protective cylinder portion 74 that is integral with the cylinder 56 or fixed by screwing or the like. An outer cover 61 is fitted to the cylinder 56 so as to be able to advance and retract. The outer cover 61 is fixedly attached to the threaded portion 34 a of the base plate 34. The protective cylinder portion 74 that is integral with the cylinder 56 or fixed by screwing or the like is fixedly attached to the screw portion 34 a of the other base plate 34.

In such a damper 55, the piston end 68 of the piston 57 and the cylinder inner wall end 69 of the cylinder 56 face each other, and when these piston end 68 and the cylinder inner wall end 69 are in close contact with each other, the damper Since 55 does not extend any more, the damper 55 and the brackets 22 at both ends function as the falling bridge prevention member 63. For this reason, the members constituting the damper 55 and the members constituting the brackets 22 at both ends need to have sufficient mechanical strength to withstand the tensile force generated between the pier 11 and the bridge girder 10 and to prevent the falling bridge. It is.
Also, one or more fall prevention devices including the damper 55 and the brackets 22 at both ends are installed between the pier 11 and the bridge girder 10 according to the scale.
More specifically, when the damper 55 functions for tension and compression, as shown in FIG. 1A, the piston 57 is positioned substantially at the center of the cylinder 56, but when the damper 55 functions only for tensile force, The left stroke s in the figure is positioned to be sufficiently larger than the right side. Further, for example, when the design resistance of the damper 55 as a damper is 100 kN (assuming that the safety factor s = 2.5, the actual proof strength is 250 kN), and the actual proof strength for preventing a falling bridge is 1300 kN. In addition, the design proof strength for preventing a fallen bridge is a specification of 520 (= 1300 / 2.5) kN. This means that it is desirable that the design strength of the members constituting the damper 55 to prevent the falling bridge is 520 kN or more, for example 600 kN, as the design resistance of the damper.

Details of the brackets 22 at both ends of the damper 55 will be described with reference to FIGS. The bracket 22 can be rotated in a three-dimensional direction, and is compact and robust. For example, when the design strength of the damper 55 is 100 kN and the strength of preventing a falling bridge is 1300 kN, the strength of the bracket 22 is preferably 1300 kN.
Two rib plates 35 are fixed to a base plate 34 fixedly provided at one end of the damper 55 in parallel with a space 36 corresponding to the thickness of the bracket body 23. Further, two rib plates 32 are fixed to a base plate 31 fixedly provided with a plurality of bolts or the like on the pier 11 side with a space 33 that can be fitted in the vertical direction of the bracket body 23. . The rib plate 32 is reinforced by a reinforcing plate 37.

The bracket main body 23 is a thick octagonal columnar body, and a first shaft hole 27 is formed through the center of the upper and lower surfaces of the bracket main body 23. A first shaft hole 27 a coaxial with the first shaft hole 27 is formed.
On the upper and lower end surfaces of the bracket body 23, a second shaft hole 28a for mounting the second shaft body 25 is formed halfway toward the position orthogonal to the first shaft hole 27, and the second shaft hole 28a. A second shaft hole 28 is formed in the rib plate 32 coaxially with the rib plate 32.

A first shaft body 24 is fitted into the first shaft hole 27 of the bracket body 23 with a slide bearing 26 interposed on the outer periphery in order to smoothly rotate. The rib plates 35 on both sides are fitted to each other, both end surfaces of the first shaft bodies 24 are made to coincide with the outer surfaces of the rib plates 35, and a presser plate 29 is secured to the end surfaces by the bolts 30.
The second shaft bodies 25 fitted in the second shaft holes 28 on both sides are respectively composed of three-stage shafts of a large diameter portion 25a, a medium diameter portion 25b, and a small diameter portion 25c. The second shaft hole 28 formed in the rib plate 32 is fitted through the slide bearing 26, the medium diameter portion 25b is fitted into the second shaft hole 28a of the bracket body 23, and the small diameter portion 25c is fitted to the bracket. It is fixed by screwing inside the main body 23. Both end surfaces of these large diameter portions 25a are made to coincide with the outer surface of the rib plate 32, and a presser plate 29 is secured to the end surface by a bolt 30.

The first shaft body 24 and the second shaft body 25 are fitted to the inner circumferences of the first shaft hole 27 and the second shaft hole 28 with a slip bearing 26 interposed therebetween. The slide bearing 26 has a high load ( For example, it is a non-lubricated sliding bearing that can be used at 137 MPa, can be used in a wide temperature range (-200 ° C. to + 260 ° C.), has a thin plate pressure (1.0 to 2.5 mm), and is compact, and has a coefficient of friction (μ = 0.04 to 0.20), which is less worn and can be operated for a long time.
By interposing this sliding bearing, the friction becomes low and the response to the displacement becomes smooth, and it is possible to surely respond to the earthquake motion that cannot be predicted when it occurs.

  In the bracket 22 configured as described above, as shown in FIG. 9, the first shaft body 24 is rotatable in the two-dimensional direction of the x axis, and the second shaft body 25 is rotated in the two-dimensional direction of the y axis. Since it is rotatable, it can rotate in a three-dimensional direction as a whole.

As shown in FIG. 1, the bracket 22 on one end side of the damper 55 is fixedly attached to the bridge pier 11, and the bracket 22 on the other end side of the damper 55 is fixedly attached to the bridge girder 10.
In this state, if the expansion and contraction action is exerted between the pier 11 and the bridge girder 10 due to the earthquake motion, the viscous body 60 in the cylinder 56 is forced from one chamber of the cylinder 56 to the other chamber through the gap 59. It is moved and functions as a damper by the resistance at that time, absorbing the shock.

  Here, as shown in FIG. 10, when the mutual positions of the pier 11 and the bridge girder 10 are displaced in the vertical direction from the point A to the point B, the bracket 22 is rotated at an angle by the rotation about the first shaft body 24. Follow in the range of α. This angle α is determined by the position where the rib plate 35 on the damper 55 side and the rib plate 32 on the pier 11 (or bridge girder 10) side contact, and in this example, is ± 15 degrees. This angle α can be further increased if the mechanical strength of the bracket 22 is taken into consideration.

  As shown in FIG. 11, assuming that the mutual positions of the pier 11 and the bridge girder 10 are moved in the horizontal direction from the point A to the point C, the bracket 22 is rotated around the second shaft body 25 in the range of the angle β. Follow in. This angle β is determined by the position at which the damper 55 contacts the base plate 31 and the rib plate 32 of the pier 11, and in this example, is ± 90 degrees.

The displacement of the bridge pier 11 and the bridge girder 10 is the vertical direction in FIG. 10 and the horizontal direction in FIG. 11, but in reality, the vertical direction and the horizontal direction are displaced simultaneously, so that it can follow a three-dimensional displacement. 10 may be the horizontal direction and FIG. 11 may be the vertical direction.
The bracket 22 is not limited to one that rotates in a three-dimensional direction, and may be one that rotates in a two-dimensional direction depending on the purpose of use.
If a relative displacement occurs between the bridge pier 11 and the bridge girder 10 and the amount of displacement is within an allowable limit of the damper 55 as a damper, the displacement is stopped within the range of the stroke s of the piston 57. However, when an unexpected huge earthquake motion occurs, the piston end 68 of the piston 57 is pressed against and locked to the cylinder inner wall end 69 of the cylinder 56. Since the end of the piston rod 58 is fixed to the bracket 22 on the side of the pier 11 and the end of the cylinder 56 is fixed to the bracket 22 on the side of the bridge girder 10, the constituent members of the damper 55 are configured to have a strength greater than the strength to prevent the falling bridge. Therefore, the bridge girder 10 functions as the falling bridge prevention member 63 and prevents the bridge girder 10 from dropping from the pier 11. Moreover, since the damper 55 connected between the brackets 22 at both ends functions as the falling bridge preventing member 63, it is not necessary to use a conventional cable or chain for preventing falling bridges, and a compact configuration can be achieved. A plurality of falling bridge prevention devices can be installed side by side between the pier 11 and the bridge girder 10.

In the first embodiment, the structural member of the damper 55 is provided with a strength to prevent the falling bridge, and the damper 55 functions as the falling bridge preventing member 63 in a state where the piston end portion 68 and the cylinder inner wall end portion 69 are locked.
On the other hand, in the second embodiment, as shown in FIG. 2, the length of the cylindrical outer cover 61 screwed and fixed to the screw portion 34 a of one base plate 34 is extended to the vicinity of the other bracket 22. The ring-shaped cylinder inner wall end 69 is fixedly attached to the inner side of the end of the outer cover 61 so as to face the cover inward projection 70 formed at the connecting portion of 56 and the protective cylinder 74, and the strength of preventing the falling bridge It is made to function as the falling bridge prevention member 63 by making it the structure which has sufficient. At this time, the distance d between the cover inner protrusion 70 and the cylinder inner wall end 69 is equal to the distance between the piston end 68 and the cylinder inner wall end 69 when no load (tensile force) is applied to the damper 55 in FIG. It is set to be smaller than the interval s.

In such a configuration, if the relative displacement occurs between the bridge pier 11 and the bridge girder 10 and the displacement amount is within the allowable limit of the damper 55 as the damper, the piston 57 stops within the range of the distance d. . However, when an unexpected large earthquake motion occurs, the cylinder inner wall end 69 of the outer cover 61 is moved into the cover before the piston end 68 of the piston 57 is locked to the cylinder inner wall end 69 of the cylinder 56. The outer cover 61 locked to the projecting portion 70 and connected to one base plate 34, the cylinder 56 connected to the other base plate 34, and the protective cylinder portion 74 function as the falling bridge prevention member 63. Prevents falling from the pier 11. At this time, the piston 57 is unloaded, and the function of the damper 55 as a damper is protected.
Similar to the first embodiment, the outer cover 61 connected between the brackets 22 at both ends, the cylinder 56, and the protective cylinder 74 function as a fall-bridge prevention member 63, so that a conventional fall-bridge prevention cable or chain is used. Can be made compact.

In the first embodiment and the second embodiment, the constituent member of the damper 55 is used as the falling bridge preventing member 63.
On the other hand, in Example 3, as shown in FIG. 3, an example in which a plurality of steel bars 64 are used on the outer periphery of the damper 55 is shown.
In FIG. 3, a fixing ring 65 is fixedly attached to the screw portion 34 a of one base plate 34, and a stopper ring 66 is fixedly attached to the stepped portions of the cylinder 56 and the protective cylinder portion 74 by screwing or the like. . Six steel rods 64 are inserted between the fixing ring 65 and the stopper ring 66 at regular intervals, for example, at intervals of 60 degrees. One end of a steel bar 64 is fixedly attached to the fixing ring 65 side with two nuts 67, and the stopper ring 66 side is loosely fitted in a through hole 73 so as to freely advance and retreat. A stopper 67 such as a nut is screwed onto the screw. The distance d between the stopper ring 66 and the stopper 67 when no load (tensile force) is applied to the damper 55 is set to be slightly shorter than the distance stroke s.

In such a configuration, relative displacement occurs between the bridge pier 11 and the bridge girder 10, and if the amount of displacement is within the allowable limit of the damper 55, the piston 57 stops within the range of the distance d. However, when an unexpected large earthquake motion occurs, the stopper 67 of the steel rod 64 is engaged with the stopper ring 66 before the piston end 68 of the piston 57 is engaged with the cylinder inner wall end 69 of the cylinder 56. The steel bar 64 between the fixed ring 65 connected to one base plate 34 and the stopper ring 66 connected to the other base plate 34 functions as a falling bridge prevention member 63, and the bridge girder 10 is a pier. Prevents falling from 11 At this time, the piston 57 is unloaded, and the function of the damper 55 as a damper is protected.
As in the first and second embodiments, the steel rod 64 integrated with the damper 55 connected between the brackets 22 at both ends functions as the falling bridge prevention member 63, so that a conventional cable and chain for preventing the falling bridge are used. There is no need to do this, and a compact configuration can be achieved.

In the first, second, and third embodiments, the load is directly applied to the constituent members of the damper 55.
On the other hand, in Example 4, as shown in FIG. 4, a load is applied between the outer cover 61 attached to one base plate 34 and the inner cover 62 attached to the other base plate 34. In the example, components such as a cylinder 56 and a piston rod 58 constituting the damper 55 are not subjected to a load when a falling bridge is prevented. More specifically, the inner cover 62 is screwed and fixed to the threaded portion 34 b of the other base plate 34, and a cylinder outer stepped portion 71 is provided outside the distal end portion of the inner cover 62. Further, the outer cover 61 having a size covering the inner cover 62 is screwed and fixed to the screw portion 34 a of one base plate 34, and a cylinder inner wall end portion 69 is provided inside the front end portion of the outer cover 61. Then, they are fitted together so as to be able to advance and retract. The interval d between the cylinder inner wall end 69 and the cylinder outer step 71 when no load (tensile force) is applied to the damper 55 is set to be slightly shorter than the interval stroke s.

In such a configuration, relative displacement occurs between the bridge pier 11 and the bridge girder 10, and if the amount of displacement is within the allowable limit of the damper 55, the piston 57 stops within the range of the distance d. However, when an unexpected large earthquake motion occurs, the cylinder inner wall end 69 of the outer cover 61 is moved to the inner cover before the piston end 68 of the piston 57 is locked to the cylinder inner wall end 69 of the cylinder 56. 62, the outer cover 61 connected to the one base plate 34 and the inner cover 62 connected to the other base plate 34 function as the falling bridge prevention member 63. Prevents falling from the pier 11. At this time, the piston 57 is unloaded, and the function of the damper 55 as a damper is protected.
As in the first, second, and third embodiments, the outer cover 61 and the inner cover 62 integrated with the damper 55 connected between the brackets 22 at both ends function as the falling bridge preventing member 63, thereby preventing the falling bridge as in the prior art. This eliminates the need for cables and chains, and allows a compact configuration.

  In the first, second, third, and fourth embodiments, the damper 55 is mainly composed of the cylinder 56, the piston 57, and the piston rod 58, and the cylinder 56 is filled with the viscous material 50. 3 and 4 function as a drop-off prevention member when the member fixed to the bridge pier side bracket and the member fixed to the bridge girder side bracket reach the stroke limit of the tensile force set in the damper 55. If it does, it is not limited to the cylinder type. In addition to oil, colloidal liquid, rubber-based viscous material, fluid, and the like can be used as the viscous material.

In Example 3 shown in FIG. 3, an example in which a plurality of steel rods 64 are used on the outer periphery of the damper 55 as the falling bridge prevention member 63 is shown, but the present invention is not limited to this, and in Example 5, As shown in FIG. 5, a PC cable 79 may be used instead of the steel bar 64. When the PC cable 79 is used, one end is fixed with a crimping grip 75, and the other end is fixed with a grip cylinder 76 with a conical wedge body 77 divided into two or three parts. It is desirable to urge the body 76 and the stopper ring 66 with a spring 78 to prevent the PC cable 79 from loosening.
The distance d between the stopper ring 66 and the grip cylinder 76 when no load (tensile force) is applied to the damper 55 is set to be slightly shorter than the piston stroke s.

In the embodiment shown in FIGS. 3 and 5, when the bridge 67 is prevented, the nut 67 or the grip cylinder 76 is in close contact with the stopper ring 66 and the steel rod 64 or the PC cable 79 is loaded. There is no load on the middle left half. However, a load is applied to the right half side of the cylinder 56 in the figure. Therefore, as shown in FIG. 6, in addition to the fixing ring 65a at the left end of the damper 55, a fixing ring 65b is fixed to the cylinder 55 at the right end of the damper 55 by screwing or the like. Then, together when installing the PC cable 79a between the left end of the fixing ring 65a and the center of the stopper ring 66, also between the right end fixing ring 65b and the center of the stopper ring 66 attached to PC cable 79b.
With such a configuration, when a bridge is prevented, when one grip cylinder 76a is in close contact with the stopper ring 66 and a load is applied to the PC cable 79a on the left side in the figure, the stopper ring 66 is simultaneously connected to the other ring. The grip cylinder 76b is in close contact with the PC cable 79b on the right side in the figure, and no load is applied directly from the left end to the right end of the cylinder 56 in the figure. Therefore, destruction of the damper 55 can be prevented.
In the above embodiment, four PC cables 79a and four right PC cables 79b are alternately arranged at equal intervals in the drawing, but the present invention is not limited to this.
In FIG. 6, the left PC cable 79a and the right PC cable 79b in the drawing can be steel bars or either one can be a steel bar. In the case of the steel bars, it is possible to omit the I 78 if for loosening prevention.

  DESCRIPTION OF SYMBOLS 10 ... Bridge girder, 11 ... Bridge pier, 12 ... Damper, 13 ... Base plate, 14 ... Rib plate, 15 ... 1st support shaft, 16 ... Gusset plate, 17 ... Spherical bearing, 18 ... 2nd support shaft, 19 ... Bearing, 20 Gusset plate, 21 ... damper, 22 ... bracket, 23 ... bracket body, 24 ... first shaft body, 25 ... second shaft body, 26 ... plain bearing, 27 ... first shaft hole, 28 ... second shaft hole, 29 ... Presser plate, 30 ... Bolt, 31 ... Base plate, 32 ... Rib plate, 33 ... Space, 34 ... Base plate, 35 ... Rib plate, 36 ... Space, 37 ... Reinforcement plate, 50 ... Lower bracket, 51 ... Upper Bracket, 52 ... cable, 55 ... damper, 56 ... cylinder, 57 ... piston, 58 ... piston rod, 59 ... gap, 60 ... viscous body, 61 ... outer cover, 62 ... inner cover, 63 ... falling bridge prevention member, DESCRIPTION OF SYMBOLS 4 ... Steel rod, 65 ... Fixing ring, 66 ... Stopper ring, 67 ... Nut (stopper), 68 ... Piston end part, 69 ... Cylinder inner wall end part, 70 ... Outer cover inward protrusion part, 71 ... Cylinder outer step , 72 ... inner cover outer protrusion, 73 ... through hole, 74 ... protective cylinder part, 75 ... crimping grip, 76 ... grip cylinder, 77 ... wedge body, 78 ... spring, 79 ... PC cable.

Claims (7)

In a falling bridge prevention device in which both ends of a damper using a viscous body are connected between a bridge pier and a bridge girder with brackets, the bracket is rotatable, and the damper is on the pier side. A member fixed to the bracket, and a member fixed to the bracket on the bridge girder side ,
The damper fills the inside of the cylinder with a viscous material and has a piston and a piston rod,
The member fixed to one of the bracket on the bridge pier side and the bracket on the bridge girder side is composed of an outer cover that protects the piston rod and the cylinder, and the member fixed to the other is the cylinder and the protective cylinder portion The inner protrusion at the tip of the outer cover is locked to the cylinder outer step at the connecting portion of the cylinder and the protective cylinder portion immediately before reaching the stroke limit of the set expansion / contraction amount in the damper. A fallen bridge prevention device configured to function as a member. In a falling bridge prevention device in which both ends of a damper using a viscous body are connected between a bridge pier and a bridge girder with brackets, the bracket is rotatable, and the damper is on the pier side. A member fixed to the bracket, and a member fixed to the bracket on the bridge girder side ,
The member fixed to one of the bracket on the bridge pier side and the bracket on the bridge girder side consists of a steel bar fixed to a fixing ring,
The member fixed to the cylinder consists of a stopper ring penetrating the steel rod, and the stopper at the tip of the steel rod is locked to the stopper ring immediately before reaching the stroke limit of the set expansion / contraction amount in the damper to prevent the falling bridge. A fallen bridge prevention device configured to function as a member. In a falling bridge prevention device in which both ends of a damper using a viscous body are connected between a bridge pier and a bridge girder with brackets, the bracket is rotatable, and the damper is on the pier side. A member fixed to the bracket, and a member fixed to the bracket on the bridge girder side ,
The member fixed to one of the bracket on the bridge pier side and the bracket on the bridge girder side consists of an outer cover,
The member fixed to the other is an inner cover that is loosely fitted inside the outer cover, and the front inner protrusion of the outer cover immediately before reaching the stroke limit of the set expansion / contraction amount in the damper. An apparatus for preventing a fallen bridge, which is configured to function as a fallen bridge prevention member by being locked to a tip outward projection. In a falling bridge prevention device in which both ends of a damper using a viscous body are connected between a bridge pier and a bridge girder with brackets, the bracket is rotatable, and the damper is on the pier side. A member fixed to the bracket, and a member fixed to the bracket on the bridge girder side ,
The damper fills the inside of the cylinder with a viscous material and has a piston and a piston rod,
A fixing ring is fixed to one of the bracket on the bridge pier side and the bracket on the bridge girder side, a stopper ring is fixed to the cylinder, and the tip of the PC cable fixed to the fixing ring is passed through the stopper ring, and this stopper A PC cable slack prevention spring is interposed between the ring and the grip cylinder at the tip of the PC cable, and the grip cylinder at the tip of the PC cable immediately before reaching the stroke limit of the set expansion / contraction amount in the damper. A falling bridge prevention device characterized in that a body is engaged with the stopper ring and functions as a falling bridge prevention member. In a falling bridge prevention device in which both ends of a damper using a viscous body are connected between a bridge pier and a bridge girder with brackets, the bracket is rotatable, and the damper is on the pier side. A member fixed to the bracket, and a member fixed to the bracket on the bridge girder side ,
The damper fills the inside of the cylinder with a viscous material and has a piston and a piston rod,
A fixing ring is fixed to each of the bracket on the bridge pier side and the bracket on the bridge girder side, and a stopper ring is fixed to the cylinder located between the fixing rings, and the tip of the PC cable fixed to each fixing ring is attached. Each of the stopper rings extends through the stopper ring toward the other fixed ring, and a PC cable slack prevention spring is interposed between both sides of the stopper ring and the grip cylinder at the extended tip. The grip cylinder at the tip of each PC cable is locked to the stopper ring and functions as a fallen bridge prevention member immediately before reaching the stroke limit of the set expansion / contraction amount in the damper. Fall bridge prevention device. In a falling bridge prevention device in which both ends of a damper using a viscous body are connected between a bridge pier and a bridge girder with brackets, the bracket is rotatable, and the damper is on the pier side. A member fixed to the bracket, and a member fixed to the bracket on the bridge girder side ,
The damper fills the inside of the cylinder with a viscous material and has a piston and a piston rod,
The fixing ring is fixed to the bracket on the bridge pier side and the bracket on the bridge girder side, and a stopper ring is fixed to the cylinder located between the fixing rings, and the tip of the steel rod fixed to each fixing ring is fixed. Each extending through the stopper ring to the other fixed ring side, and provided with a grip cylinder at the extended tip thereof, immediately before reaching the stroke limit of the set expansion / contraction amount in the damper. A falling bridge prevention device characterized in that a grip cylinder at the tip of a steel bar is engaged with the stopper ring and functions as a falling bridge prevention member. In a falling bridge prevention device in which both ends of a damper using a viscous body are connected between a bridge pier and a bridge girder with brackets, the bracket is rotatable, and the damper is on the pier side. A member fixed to the bracket, and a member fixed to the bracket on the bridge girder side ,
The damper fills the inside of the cylinder with a viscous material and has a piston and a piston rod,
A fixing ring is fixed to each of the bracket on the bridge pier side and the bracket on the bridge girder side, and a stopper ring is fixed to the cylinder between the fixing rings, and the steel rod fixed to one of the fixing rings The tip extends through the stopper ring to the other fixing ring side, the tip of the PC cable fixed to one of the other fixing rings extends through the stopper ring to the one fixing ring side, A PC cable slack prevention spring is interposed between the side surface of the stopper ring that penetrates the PC cable and the grip cylinder at the tip end of the PC cable, and reaches the stroke limit of the expansion / contraction amount set in the damper. Immediately before the steel pipe and / or the grip cylinder at the tip of the PC cable is locked to the stopper ring and the falling bridge prevention member Girder prevention apparatus characterized by being configured to function with.

Images