JP5389293B1 - Fixed structure - Google Patents

Abstract

An object of the present invention is to provide a fixing structure for attaching a seismic isolation device or a fallen bridge prevention structure to an abutment without using a resin anchor.
SOLUTION: A bearing plate 100 for attaching an anchor head 100a of a ground anchor 100 for supporting an abutment 3 to the abutment 3 and a plate member 310 for attaching one attachment portion 5b of a damper device 5 to the abutment 3. It is fixed.
Therefore, the bearing steel plate 400 serves as both a member for attaching the ground anchor 100 to the abutment 3 and a member for attaching the damper device 5 to the abutment 3, and the damper device 5 extends to move the abutment 3 toward the bridge girder 1. When a pulling force is applied, the force is stopped by the pulling force of the ground anchor 100, and as a result, a situation where the abutment 3 tilts can be avoided. Moreover, since the ground anchor 100 prevents the abutment 3 from overturning and sliding due to the level 2 earthquake motion, it is possible to more effectively realize the seismic reinforcement of the bridge.
[Selection] Figure 1

Description

  The present invention relates to a fixing structure for fixing a connecting device such as a seismic isolation device or a falling bridge prevention structure provided between an upper structure of a bridge and an abutment to the abutment.

  In general, the design criteria for road bridges are determined by the “Road Bridge Specification (hereinafter simply referred to as“ Specification ”)”. It is described in “Aseismic Design”. A road bridge designed based on the design criteria described in the “Earthquake Design” section of this specification will be within the scope of limited damage if an earthquake as envisaged in that document occurs. Can be used even after the convergence.

  The 2011 off the Pacific coast of Tohoku Earthquake, which occurred on March 11, 2011, is a large and strong earthquake that exceeds the seismic intensity (Meteorological Agency seismic intensity class) and the scale generally assumed so far. Damaged many buildings such as bridges. In addition, a large-scale tsunami occurred around the Pacific coast of Tohoku. As a result, the entire region of East Japan from the Tohoku region to the Kanto region was severely damaged by the earthquake and tsunami (Great East Japan Earthquake).

  In the specification, type I and type II ground motions are defined as Level 2 ground motions that cause massive damage. Type I ground motion assumes a large oceanic earthquake that occurs at the plate boundary. The Tohoku-Pacific Ocean Earthquake corresponds to this type I ground motion.

  In the specification, for type I earthquakes, for example, in reinforced concrete piers, it is stipulated that the degree of damage is such that cracks of a certain width occur, and sufficient safety against the ultimate state of the structure is provided. We are trying to secure it. As a result, the bridge can be used even after the earthquake.

  Now, this specification was revised in March 2012, following the occurrence of the Tohoku-Pacific Ocean Earthquake. According to the revised specifications, for example, the design seismic intensity for Type I ground motion (ie, ground motion due to the same type of earthquake as the Tohoku-Pacific Ocean Earthquake) among Level 2 ground motions has greatly increased.

  Specifically, for example, in the revised manual, the design seismic intensity of a bridge with a natural period of 1 second on Class I ground (such as rock) was revised to about 1.0. Here, in the pre-revision manual, the design seismic intensity of the bridge with a natural period of 1 second was 0.7. Therefore, in the post-revision manual, the design seismic intensity in the earthquake resistance standard is significantly larger than before the revision. ing.

  Therefore, for bridges that meet the earthquake resistance standards of the old specifications, and for bridges that have been seismically strengthened based on the old specifications, a significant strength (strength) is considered when considering the design seismic intensity of the revised specifications. Therefore, if an earthquake of the Tohoku-Pacific Ocean Earthquake occurs in the future, those bridges may be seriously damaged.

For such bridges with insufficient strength, it is possible to ensure the required strength by applying seismic reinforcement work corresponding to the design seismic intensity in the revised specifications. As one of the seismic reinforcement works, for example, a seismic isolation device or a structure for preventing a fallen bridge (prevention of a fallen bridge) between an upper structure (for example, a bridge girder) and a lower structure (for example, an abutment or a pier) of a bridge (bridge). System).
In the present invention, since the seismic isolation device and the falling bridge prevention structure connect the upper structure and the lower structure of the bridge by some means, they are collectively referred to as a connecting device.

  Fig.3 (a) shows the construction example of the seismic reinforcement work when a damper device is installed as a seismic isolation device between the bridge girder and the abutment, and Fig.3 (b) shows between the bridge girder and the abutment. An example of seismic reinforcement work when a wire-type restraint system is installed as a fall-bridge prevention structure (fall-bridge prevention system) is shown. Fig. 3 (c) shows a damper in the seismic reinforcement work shown in Figs. 3 (a) and 3 (b). It is the figure which showed an example of the structure of the part which attaches an apparatus or a fall bridge prevention structure to an abutment. FIGS. 3A and 3B show a case where an abutment is applied as the lower structure of the bridge. In FIG. 3B, the same or corresponding parts as those in FIG. 3A are denoted by the same reference numerals.

  In the seismic reinforcement work shown in FIG. 3A, the bracket 2 is attached to the lower surface of the bridge girder 1 which is the upper structure of the bridge, the mounting plate 4 is attached to the side surface of the abutment 3 which is the lower structure of the bridge, One mounting portion 5 a and the other mounting portion 5 b of the damper device 5 are respectively attached to the mounting portion 2 a provided on the side surface facing 3 and the mounting portion 4 a provided on the mounting plate 4. Further, the end portion of the bridge girder 1 is supported by a movable support 6 provided in the girder hanging portion 3 a of the abutment 3.

  In the seismic reinforcement work shown in FIG. 3B, one end portion 7a of the wire 7 is attached to the attachment portion 4a of the attachment plate 4 provided on the side surface of the abutment 3, and the other end portion 7b of the wire 7 is These are attached to a reinforcing member 1 b provided at the lower part of the bridge girder 1 via a fixture 8. Further, the end portion of the bridge girder 1 is supported by a support 9 provided in the girder hanging portion 3 a of the abutment 3.

  In the seismic reinforcement work shown in FIGS. 3 (a) and 3 (b), a plurality of mounting structures BB for mounting the mounting plate 4 on the side surface of the abutment 3 are provided on the side surface of the abutment 3 as shown in FIG. 3 (c). The fixing holes 3c are drilled and a predetermined amount of adhesive GL is injected into the fixing holes 3c, and then anchor bolts BA are inserted into the respective fixing holes 3c. Thus, the attachment plate 4 is attached to the side surface of the abutment 3 by the plurality of anchor bolts BA. The nut BK provided at the head of the anchor bolt BA is for defining the insertion length of the anchor bolt BA into the fixing hole 3c.

  In this mounting structure BB, the volume increases as the adhesive GL injected into the fixing hole 3c gradually hardens, and a force pressing outward is applied to the surface of the fixing hole 3c, and the adhesive GL is fixed to the outer peripheral surface of the adhesive GL. Adhesive force acts between the surface of the hole 3c. Then, when the adhesive GL is completely solidified, the force with which the outer circumferential surface of the adhesive GL having the anchor bolt BA as a core presses the surface of the fixing hole 3c is sufficiently large, The anchor bolt BA is fixed to the fixing hole 3c by the adhesion force and the frictional force acting between the surface of the fixing hole 3c, whereby the attachment plate 4 is attached to the side surface of the abutment 3. Thus, the fixing structure in which the anchor bolt BA is fixed to the fixing hole 3c by the adhesive GL injected into the fixing hole 3c is generally called “resin anchor”.

  Thus, a standard construction example of the mounting structure BB using the resin anchor is shown in “Actual Collection of Seismic Strengthening Methods for Existing Bridges” (Non-Patent Document 1). In the construction example, the diameter P of the fixing hole 3c is set to a value obtained by adding 10 mm to the diameter dimension of the anchor bolt BA, and the length dimension L in the drilling direction of the fixing hole 3c is set to the anchor bolt BA. Is set to a value obtained by adding 10 mm to a length obtained by multiplying the size of the diameter by 15 times or more.

  In addition, the installation structure of seismic isolation devices, etc. to the abutment shown in this “Examples of Seismic Strengthening Methods for Existing Bridges” is a standard structure applied during the construction of seismic reinforcement work. As a mounting structure for seismic isolation devices, etc. on the abutment, this mounting structure is almost adopted except in special cases.

“Case Collection of Seismic Reinforcement Methods for Existing Bridges”, Ocean Bridge / Bridge Research Committee, April 2005

  When earthquake motion occurs and the bridge shakes, forces in various directions act on the bridge girder 1, and as a result, vibrations in the direction of the bridge axis act on the bridge girder 1. In the seismic isolation device shown in FIG. 3A, the vibration energy in the bridge axis direction is expanded and contracted when the expansion / contraction mechanism of the damper device 5 expands and contracts in the direction along the axial direction (bridge axis direction). Consumed by the mechanism.

  As a result, the swing of the bridge girder 1 in the direction of the bridge axis is suppressed to a small extent, and there is no situation where the bridge girder 1 drops off from the movable support 6 or the girder hanging portion 3a of the abutment 3, and as a result, the seismic motion is removed. It is also possible to use a bridge.

  In addition, in the falling bridge prevention structure shown in FIG. 3B, the movement of the bridge girder 1 is restrained by the wire 7. Thereby, even when the support 9 is destroyed by the earthquake motion, the bridge girder 1 can be prevented from falling off the portion 3a with the girder so that the bridge can be quickly restored after the earthquake motion is removed. .

  On the other hand, the mounting plate 4 that fixes the damper device 5 and the wire 7 to the abutment 3 is attached to the side surface of the abutment 3 with a plurality of anchor bolts BA as described above. When the earthquake motion occurs as described above and the vibration in the bridge axis direction acts, the axial force, that is, the anchor bolt BA is fixed to the anchor bolt BA fixing the mounting plate 4 to the abutment 3. A force in the direction of taking in and out of the hole 3c acts. In addition, when the damper device 5 is used, a force acting when the damper device 5 expands and contracts in the bridge axis direction is also applied.

  Here, the hardened adhesive GL injected into the fixing hole 3c has sufficient adhesion strength and acts between the outer peripheral surface of the adhesive GL lump with the anchor bolt BA as a core and the surface of the fixing hole 3c. When the adhesion force and the frictional force are sufficiently large, level 2 earthquake motion occurs, and even if a large force acts in the direction in which the anchor bolt BA is moved in and out of the fixing hole 3c, the anchor bolt BA is fixed to the fixing hole 3c. The mounting plate 4 is kept fixed to the abutment 3.

  However, when the adhesive strength of the adhesive GL injected into the fixing hole 3c deteriorates due to aging or the like, and its adhesion strength decreases, the mass of the adhesive GL having the anchor bolt BA as a core is reduced. Adhesive force and frictional force acting between the outer peripheral surface and the surface of the fixing hole 3c are also reduced.

  Therefore, when a level 2 earthquake motion occurs and a large force acts in the direction of inserting / removing the anchor bolt BA into / from the fixing hole 3c, a large force acts in the direction of pulling out the anchor bolt BA from the fixing hole 3c. There is a possibility that the BA will come out of the fixing hole 3c. In this case, the damper device 5 and the wire 7 are not fixed to the abutment 3, so that the seismic isolation device and the falling bridge prevention structure (including the falling bridge prevention system) were originally installed. There is a possibility of causing a problem that the performance cannot be exhibited.

  In particular, when the damper device 5 is used, for example, even if the bearing is not destroyed by the level 2 earthquake motion, when the damper device 5 extends in the axial direction, a force acts in the direction in which the abutment 3 is pulled down. A greater force acts in the direction in which the anchor bolt BA is pulled out from the fixing hole 3c, and thus the probability described above is increased.

  In addition, as an example of the malfunction related to the fixing structure using such a resin anchor, there is a “lion tunnel ceiling board fall accident” that occurred on December 2, 2012. As one of the causes of this accident, “a structure that supports the load on the ceiling panel only with an adhesive (that is, a structure having a fixed structure using a resin anchor)” has been suggested. Some say that over time, the adhesive has deteriorated, so that the structure can no longer withstand the load and the ceiling panel has fallen. "

  As described above, the mounting structure BB that fixes the mounting plate 4 to the abutment 3 also uses a resin anchor. Therefore, when a level 2 earthquake motion occurs around a long time after the construction of the seismic reinforcement work, the adhesive GL that has been injected into the fixing hole 3c and hardened at that time may be deteriorated. It can be considered that there is a possibility that the anchor bolt BA may come out of the fixing hole 3c, as in the case of the “lion tunnel ceiling board drop accident”.

  This invention is made | formed in view of this situation, and it aims at providing the fixing structure which attaches a seismic isolation apparatus and a fall-bridge prevention structure to an abutment, without using a resin anchor.

The present invention is a fixing structure for fixing a connecting device provided between a superstructure of a bridge and an abutment to the abutment, and a ground anchor that supports the abutment, and an attachment for fixing the connecting device to the abutment A fixing structure in which the attachment portion is fixed to a fixing portion for fixing the anchor head of the ground anchor to the abutment.
In addition, the supporting portion is configured to support the supporting plate at an angle orthogonal to a supporting plate and a supporting plate that fixes the anchor head, and an extension direction of the ground anchor. It is characterized by comprising a bearing mounting member having an angled mounting portion to be attached to a steel plate.
Further, the connecting device is characterized in that it is at least one of a seismic isolation device and a falling bridge prevention structure.

  As described above, according to the present invention, the fixing device that fixes the ground anchor that supports the abutment to the abutment is attached to the attachment portion that attaches the connecting device to the abutment. Can be fixed to the abutment. Details of the effect will be described later.

FIG. 1 is a schematic configuration diagram illustrating a fixing structure according to an embodiment of the present invention. FIG. 2A is a schematic front view for explaining the main part of the fixing structure according to one embodiment of the present invention, and FIG. 2B is the main part of the fixing structure according to one embodiment of the present invention. It is a schematic plan view for demonstrating a part. Fig.3 (a) shows the construction example of the seismic reinforcement work when a damper device is installed as a seismic isolation device between the bridge girder and the abutment, and Fig.3 (b) shows between the bridge girder and the abutment. An example of seismic reinforcement work when a wire-type restraint system is installed as a fall-bridge prevention structure (fall-bridge prevention system) is shown. Fig. 3 (c) shows a damper in the seismic reinforcement work shown in Figs. 3 (a) and 3 (b). It is the figure which showed an example of the structure of the part which attaches an apparatus or a fall bridge prevention structure to an abutment.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings.
〔Example〕
FIG. 1 is a schematic configuration diagram illustrating a fixing structure according to one embodiment of the present invention, and FIG. 2A is a schematic front view for explaining a main part of the fixing structure according to one embodiment of the present invention. FIG. 4B is a schematic plan view for explaining the main part of the fixing structure according to one embodiment of the present invention. In FIG. 1 and FIGS. 2 (a) and 2 (b), the same parts as those in FIG. 3 (a) and corresponding parts are denoted by the same reference numerals.

  In this figure, in this embodiment, a seismic isolation device using a damper device 5 is provided as a connecting device provided between a bridge girder 1 which is an upper structure of a bridge and an abutment 3 which is a lower structure of the bridge. Is supported by a movable bearing 6 provided in a girder hanging portion 3a of the abutment 3. The present embodiment describes a case where the seismic reinforcement work for the bridge is performed using a seismic isolation device.

  On the left and right sides of the damper device 5 (see FIGS. 2A and 2B), a ground anchor (also referred to as an “earth anchor”) 100 that supports the abutment 3 in order to prevent the abutment 3 from falling in the direction of the bridge girder. , 200, a mounting portion 300 for mounting the mounting portion 5b on the abutment side of the damper device 5 to the abutment 3, and a fixing portion for fixing the anchor heads 100a, 200a of the ground anchors 100, 200 to the abutment 3, respectively. 100b and 200b are respectively attached to a bearing steel plate 400 made of a thick steel plate.

  The attachment part 300 is composed of a substantially square plate member 310 made of steel, and fixing plates 300a and 300b that are attached so as to stand upright on the surface of the plate member 310 and sandwich and fix the attachment part 5b of the damper device 5 from both sides. The fixing plates 300a and 300b are formed with mounting holes (not shown) through which the engaging pins 320 to be inserted into the engaging holes (not shown) of the mounting portion 5b are inserted. With this engagement pin 320, the mounting portion 5b of the damper device 5 is fixed to the plate material 310 via the fixing plates 300a and 300b. Here, since the plate member 310 is attached to the bearing steel plate 400, the mounting portion 5 b on the abutment side of the damper device 5 is attached to the bearing plate steel plate 400 via the fixing plates 300 a and 300 b and the plate member 310. Fixed.

  The fixing portion 100b supports the supporting plate (supporting plate portion) 110 for fixing the head 100a of the ground anchor 100 and the supporting plate 110 in parallel with a surface orthogonal to the extending direction of the ground anchor 100. It is comprised from a pair of angled board | plate materials (angled attachment part) 111,112 for attaching to the pressed steel plate 400. FIG.

  Similarly, the fixing part 200b holds the supporting plate 210 for fixing the head 200a of the anchor 200, and the supporting plate 210 in parallel to the surface orthogonal to the extending direction of the anchor 200 to the supporting plate steel plate 400. It consists of a pair of angled plate members 211 and 212 for mounting.

  Further, the supporting steel plate 400 is provided with stiffening materials 410 and 420 for preventing the supporting steel plate 400 from being deformed by a force acting on the plate material 310 when a tensile force is applied through the damper device 5. ing. In addition, as shown in FIG.1 and FIG.2 (b), the cushioning material (filler material; stuffing material) 450 is provided between the bearing steel plate 400 and the abutment 3 for corrosion prevention etc. of the bearing steel plate 400. It is desirable. As a material of the cushion material 450, for example, an appropriate material such as carbon fiber which does not penetrate moisture and has excellent weather resistance can be used.

  The ground anchor 100 is provided in the hole HH that penetrates the abutment 3 and the ground KA on the back of the abutment 3 and reaches the ground KB made of a material harder than the ground KA. An anchor body 130 is provided at the tip of the ground anchor 100 and is fixed to the ground KB. Further, a tendon 140 as a pulling portion extends from the anchor body 130 and is fixed to the bearing plate 110 by the anchor head portion 100a. The tendon 140 is a portion that transmits the tensile force from the anchor head 100a to the anchor body 130. The anchor head 100a has a fixing tool (not shown) for fixing the end of the tendon 140 to the bearing plate 110. ) Is provided.

  Here, the anchor body 130 is a portion that directly transmits the tensile force of the ground anchor 100 to the ground KB, and the ground KB to be installed is preferably a solid material such as a rock as described above. The anchor body 130 is often formed by injecting a grout such as cement into the drilling hole HH. As the tendon 140, a PC steel wire, a PC steel wire, a multiple PC steel wire, and a continuous wire are used. A fiber reinforcement or the like is used. Usually, the tendon 140 is covered with a sheath material (not shown) for anticorrosion, and the anchor head 100a is often filled with a rust inhibitor or the like for anticorrosion.

  The hole HH is formed by drilling with a hole drilling machine from the mounting position of the damper device 5 on the abutment 3 to the hard ground KB, and the size of the depression angle is the height of the opening of the hole HH in the abutment 3. The distance from the opening to the fixing position of the anchor body 130 in the ground KB is determined. The angled plate members 111, 112, 211, and 212 have a trapezoidal planar shape having a hypotenuse with an inclination angle parallel to a direction orthogonal to the extending direction of the hole HH. The planar shape of the angled plate members 111, 112, 211, and 212 may be a triangle or a polygon having a hypotenuse similar to the trapezoid described above.

  Further, the bearing steel plate 400, the stiffeners 410 and 420, the plate member 310, the support plates 310a and 310b, the angled plate members 111, 112, 211, and 212, and the bearing plates 110 and 210 are each made of an appropriate material and have an appropriate thickness. These steel plates can be attached and fixed with each other by welding using an appropriate method. Thereby, attachment and fixation of these steel plates become strong.

  Thus, in the present embodiment, one mounting portion 5b of the damper device 5 is attached to the bearing steel plate 400 for mounting the anchor heads 100a, 200a of the ground anchors 100, 200 for supporting the abutment 3 to the abutment 3. Is fixed to a plate 310 for attaching to the abutment 3.

  Therefore, the bearing steel plate 400 serves as both a member for attaching the ground anchors 100 and 200 to the abutment 3 and a member for attaching the damper device 5 to the abutment 3, and the damper device 5 extends to attach the abutment 3 to the bridge girder 1. When a force pulling in the direction is applied, the force is stopped by the pulling force of the ground anchors 100 and 200, and as a result, a situation in which the abutment 3 tilts can be avoided.

  Here, the situation in which the damper device 5 greatly expands and contracts occurs, for example, when an earthquake motion such as the above-described level 2 earthquake motion occurs. Therefore, according to the present embodiment, when the level 2 earthquake motion occurs. Due to the behavior of the damper device 5, it is possible to prevent problems such as the use of the bridge becoming unusable due to the attachment portion 300 that attaches the damper device 5 to the abutment 3 being detached from the abutment.

  That is, in this embodiment, the damper device 5 can be appropriately attached to the abutment 3 without using a resin anchor. Therefore, even if a level 2 earthquake motion occurs after a long period of time from the time of construction, the structure where the damper device 5 is attached to the abutment 3 is damaged and the bridge cannot be used. There is no problem that occurs.

  In addition, as is well known, the ground anchors 100 and 200 prevent the abutment 3 from falling or sliding when an earthquake occurs. Therefore, by providing the fixing structure of the present embodiment, the earthquake resistance reinforcement of the bridge is more effective. Can be done.

  By the way, in the above-described embodiment, the case where the damper device 5 is used as the connecting device provided between the bridge superstructure and the abutment during the seismic reinforcement work for the bridge has been described. Even when a seismic device is provided, the present invention can be similarly applied. In addition, the present invention can be applied not only to seismic isolation devices but also to bridges in which the above-described bridge-falling prevention structure is installed during the seismic reinforcement work for bridges.

  In the above-described embodiments, the angled plate members 111, 112, 211, and 212 are used as the angled attachment portions. However, as the angled attachment portions, for example, the cross-sectional shape is an angled plate material. In order to support an anchor head such as a concrete block having a shape similar to the planar shape of 111, 112, 211, and 212, an angle adjusting member, and the like so as to be parallel to a plane perpendicular to the extending direction of the ground anchors 100 and 200 In addition, an appropriate member or the like that is usually used can be used.

  Moreover, the bearing mounting member which consists of a bearing plate part and an angled mounting part can also be comprised with one member. For example, when the both ends of the steel plate are molded at an angle corresponding to the angled attachment portion, the both end portions are bent, and the both end portions are fixed to the bearing steel plate 400, the central plane serving as the bearing plate portion is a ground anchor. It is good to make it parallel to the surface orthogonal to the extending direction of 100,200.

  In addition, the configurations and modifications of the embodiments described above can be applied in appropriate combinations within a consistent range. For example, the present invention can be applied in the same manner to a bridge provided with both a seismic isolation device and a falling-bridge prevention structure during the seismic reinforcement work for the bridge.

  The present invention can be applied to any type of connecting device as long as the connecting device provided between the superstructure of the bridge and the abutment is fixed to the abutment.

1 Bridge Girder 3 Abutment 5 Damper Device 100,200 Ground Anchor (Earth Anchor)
100a, 200a Anchor head 100b, 200b Fixing portion 110, 210 Bearing plate 111, 112, 211, 212 Angled plate member 300 Mounting portion 310 Plate member 400 Bearing plate steel plate 410, 420 Stiffener

Claims (3)

A fixing structure for fixing a connecting device provided between the upper structure of the bridge and the abutment to the abutment,
A ground anchor that supports the abutment,
An attachment portion for fixing the connecting device to the abutment,
The fixing structure characterized by fixing the said attaching part to the fixing | fixed part for fixing the anchor head of the said ground anchor to the said abutment. The fixing part is
A bearing steel plate made of a thick steel plate;
A bearing member having a bearing plate for fixing the anchor head, and an angled attachment for attaching the bearing plate to the bearing steel plate at an angle orthogonal to the extending direction of the ground anchor;
The fixing structure according to claim 1, comprising:   The fixing structure according to claim 1, wherein the connecting device is at least one of a seismic isolation device and a falling bridge prevention structure.