Movement limiting device for upper structure in bridge

Abstract

To simplify installation work of a movement limiting device to a lower structure and an upper structure without excessively increasing resistance force received by the upper structure when the upper structure is relatively moved to the lower structure in limiting relative movement of the upper structure to the lower structure in a width direction (a direction perpendicular to the bridge axis).SOLUTION: A movement restriction device 1 comprises a pair of brackets 2, 2 fixed to both side surfaces in the width direction of a lower structure 6 so as to be opposed to each other, secured toward the center side in the width direction, with upper sections 2B protruding toward the upper structure 7 side, and a tensile member 3 installed between the upper sections 2B, 2B of the pair of brackets 2, 2, the tensile member 3 bearing a tensile force when the upper structure 7 is moved relative to the lower structure 6; the upper sections 2B of the pair of brackets 2, 2 are lockable to both side surfaces of the upper structure 7 in the width direction toward the center side in the width direction.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to a movement restricting device for a superstructure in a bridge that restricts relative movement in the width direction (perpendicular to the bridge axis) of the superstructure with respect to the substructure.

Background Art

[0002] As a method for restricting relative movement in the width direction of a superstructure such as a bridge girder with respect to a substructure such as a bridge pier, while fixing a fixing member to the middle part in the width direction of the substructure, a method is provided in which a restraining member that can be locked in the width direction of the superstructure, for example, a cylindrical restraining member, is fixed to the superstructure so that the restraining member is locked to the fixing member during relative movement (see Patent Document 1).

[0003] In addition, there is also a method of fixing a pair of restraining members to both sides in the width direction of a bearing that supports the superstructure (see Patent Documents 2 to 5). The "width direction of the superstructure and the substructure" mainly refers to the direction perpendicular to the bridge axis, but in the case where the planar shape of the floor slab supported by the bridge girder (main girder) is not rectangular, for example, parallelogram-shaped, it may also refer to the short side direction of the floor slab.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Patent Document 2

Patent Document 3

Patent Document 4

Patent Document 5

Summary of the Invention

Problems to be Solved by the Invention

[0005] In Patent Document 1, since the fixing member is arranged at one location in a part of the width direction of the lower structure, and the restraining member is arranged in a part of the width direction of the upper structure corresponding to the fixing member, when the upper structure tries to move in the width direction with respect to the lower structure and the restraining member engages with the fixing member, the resistance force (reaction force) accompanying the inertial force generated in the upper structure that the restraining member receives from the fixing member may become excessive.

[0006] According to the methods of Patent Documents 2 to 5 in which the restraining members are fixed on both sides of the support, since the movement of the upper structure in the width direction is restricted at a plurality of locations of the supports arranged in the width direction, the resistance force received by the restraining members from the supports is dispersed among the plurality of supports, and it is possible to avoid some of the resistance forces from becoming excessive. On the other hand, since the number of installation of the movement restricting device composed of the combination of the fixing member and the restraining member increases, the number of operations for the lower structure and the upper structure increases, and the work efficiency is likely to decrease.

[0007] Also, in the methods of Patent Documents 2 to 5, when fixing the restraining member to the lower structure, it is necessary to embed the anchor bolt vertically in the concrete of the lower structure. However, unless a space longer than the length of the anchor bolt is secured between the lower structure and the upper structure, it is difficult to form a hole for embedding the anchor bolt, and thus the construction itself may become impossible.

[0008] The present invention proposes a movement restricting device for the upper structure of a bridge having a structure in which the resistance force received when the restraining member engages with the fixing member, that is, the reaction force generated in the upper structure when the upper structure moves relative to the lower structure, does not become excessive, and the installation work for the lower structure and the upper structure is simplified.

Means for Solving the Problems

[0009] The superstructure movement limiting device in the bridge according to the invention described in claim 1 is a device for limiting the relative movement in the width direction of the superstructure with respect to the substructure in a bridge where a bearing for supporting the superstructure is fixed on the substructure. A pair of brackets that are fixed facing each other on both side surfaces in the width direction of the substructure, locking toward the center side in the width direction, with the upper section projecting toward the superstructure side; and a tension member installed between the upper sections of this pair of brackets, which bears the tensile force during the relative movement of the superstructure. It is a constituent requirement that the upper sections of the pair of brackets can lock to both side surfaces in the width direction of the superstructure toward the center side in the width direction.

[0010] The "width direction of the superstructure" is mainly the direction perpendicular to the bridge axis as described above, but in the case where the planar shape of the floor slab is, for example, a parallelogram shape, it may also refer to the short side direction of the floor slab. The "both side surfaces in the width direction of the substructure" refers to the side surfaces outside the width direction of the substructure. The substructure is mainly a pier or an abutment.

[0011] The "pair of brackets that lock toward the center side in the width direction of the substructure" means that, as shown in FIGS. 1 and 2, a pair of brackets 2, 2 located on both sides in the width direction of the substructure 6 are arranged in a state of being locked toward the center side in the width direction of the substructure 6. "Locking toward the center side in the width direction of the substructure 6" means that the bracket 2 on the side receiving the tensile force from the tension member 3 installed between the opposing brackets 2, 2 is locked to the substructure 6 toward the center side in the width direction, and the tensile force of the tension member 3 is transmitted to the substructure 6 as a compressive force (bearing pressure) in the width direction on the side surface of the substructure 6.

[0012] By the bracket 2 being locked toward the center side on the side surface of the substructure 6, together with the tension member 3 being installed between the opposing brackets 2, 2, the brackets 2, 2 transmit the tensile force of the tension member 3 as a compressive force (bearing pressure) in the width direction to the side surface of the substructure 6 when the tension member 3 bears the tensile force. The tension member 3 may be installed horizontally as shown in FIG. 5-(b), but since the heights of both side surfaces in the width direction of the superstructure 7 are not necessarily equal as shown in FIG. 1, the tension member 3 is not necessarily installed horizontally.

[0013] The "pair of brackets that are fixed facing each other with the upper section protruding toward the upper structure side" means that in a state where the upper section 2B shown in Fig. 4-(a), which is a partial section on the upper structure 7 side of the bracket 2, protrudes toward the upper structure 7 side, the lower section 2A, which is the section near the lower structure 6 of both brackets 2, 2, is fixed to the side surface of the lower structure 6. The bracket 2 mainly bears the inertial force from the upper structure 7 as a bearing pressure. The upper section 2B is basically not joined to the upper structure 7, but it may be joined. The lower section 2A refers to the section (part) that is in contact with the lower structure 6 within the entire length of the bracket 2.

[0014] The upper section 2B of the bracket 2 protruding toward the upper structure 7 side is in a state where it can be locked toward the center in the width direction on the side surface in the width direction of the upper structure 7. The "state where it can be locked" means that there are cases where the upper section 2B of the bracket 2 is in complete contact with the side surface of the upper structure 7 and cases where there is a slight clearance between the upper section 2B and the side surface of the upper structure 7. When the bracket 2 is in contact with the upper structure 7, the side surface of the upper structure 7 is locked to the bracket 2 simultaneously with the relative movement of the upper structure 7. When there is a clearance, the side surface of the upper structure 7 is locked to the bracket 2 when there is a relative movement amount exceeding the clearance.

[0015] When the upper section 2B of the bracket 2 is locked toward the center in the width direction on the side surface of the upper structure 7, when the upper structure 7 attempts to move relatively in the width direction due to earthquake motion or the like, the upper section 2B of the bracket 2 bears the force (inertial force) from the upper structure 7. At this time, the other opposing bracket 2 bears the reaction force and transmits it as a tensile force to the tension member 3 connected to the bracket 2 that bears the inertial force. The tensile force is transmitted as a bearing pressure from the other end of the tension member 3 to the bracket 2 on that side, toward the center in the width direction of the lower structure 6, and is directly transmitted to the lower structure 6.

[0016] By fixing the bracket 2 to the side surface in the width direction of the lower structure 6 in the lower section 2A, when fixing the bracket 2 to the lower structure 6, there is no need to insert the anchor bolt 4 vertically into the lower structure 6 from the upper surface side of the lower structure 6. Therefore, it is not necessary to secure a space between the lower structure 6 and the upper structure 7 that is longer than the length of the anchor bolt 4.

[0017] As shown in FIG. 1, an anchor bolt 4 for fixing the bearing 8 to the lower structure 6 may be vertically embedded near the installation position of the bearing 8 of the lower structure 6. In this regard, when fixing the bracket 2 to the lower structure 6, it is fixed to the side surface in the width direction, which is the position where the bearing 8 is removed and the surface layer portion of the lower structure 6 up to the tip of the anchor bolt 4 for fixing the bearing 8 is removed. This is also reasonable for avoiding interference with the anchor bolt 4 for the bearing 8.

[0018] From this point, the bracket 2 has a length greater than the length of the anchor bolt 4 that fixes the bearing 8 to the lower structure 6 as shown in FIGS. 1 and 2, and is fixed to the lower structure 6 by the anchor bolt 4 inserted horizontally or the like at a position below the tip position of the anchor bolt 4. The "surface layer portion of the lower structure 6" can also be described as the upper layer portion above the group of a plurality of anchor bolts 4 that fix the bracket 2 to the lower structure 6.

[0019] The "tension member installed between the upper sections of a pair of brackets and bearing the tensile force during relative movement of the upper structure" means that the tension member 3 is installed between the upper sections 2B, 2B of the pair of brackets 2, 2 arranged and fixed on both sides in the width direction of the lower structure 6 in a state capable of bearing the tensile force when the upper structure 7 attempts to move relatively or when it has moved relatively. The "state capable of bearing the tensile force" means a state in which the tensile force can be transmitted from the pair of brackets 2, 2 to the tension member 3, for example, a state in which the tension member 3 is connected to the brackets 2, 2 without slack.

[0020] For the tension member 3 itself, cables such as reinforcing bars, steel bars, PC steel materials, chains, and wire ropes that can bear the tensile force (tension) are used. High-strength cables are used to reduce the cross-sectional area of the tension member 3 and achieve weight reduction, and cables coated with polyethylene or the like are used to enhance corrosion resistance. The tension member 3 is connected to the bracket 2 such that the tensile force of the tension member 3 can be transmitted to the bracket 2.

[0021] When the superstructure 7 attempts to move relative to the substructure 6 in either side of the width direction, as shown in Fig. 5-(b), a force (inertial force) P directed outward in the width direction acts on the upper section 2B of the bracket 2 located on that side from the superstructure 7, and a tensile force acts on the tension member 3 from the opposing bracket 2 that bears the reaction force of the bracket 2.

[0022] The tensile force of the tension member 3 is transmitted as a compressive force in the width direction to the substructure 6 through the upper side portion (section) of the lower section 2A of the bracket 2 from the end of the tension member 3 fixed to the bracket 2 located on the opposite side of the side where the superstructure 7 attempts to move. A tensile force acts on the lower side portion (section) through which the anchor bolt 4 of the lower section 2A passes, but this tensile force is borne by the anchor bolt 4 and transmitted from the anchor bolt 4 to the substructure 6.

[0023] Among the pair of brackets 2, 2 arranged on both sides in the width direction of the substructure 6, the load (inertial force) P from the superstructure 7 is transmitted to the side surface of the substructure 6 from the upper section 2B of one of the brackets 2 located on the side where the superstructure 7 attempts to move in the width direction through the tension member 3 and the other bracket 2, so that the entire substructure 6 resists the load from the superstructure 7. Therefore, the reaction force does not concentrate on a part of the substructure 6, and the excessive increase in the reaction force is avoided.

[0024] When the superstructure 7 attempts to move relative to the substructure 6, the force (inertial force) acting on either one of the brackets 2 will act in the same direction on the side surfaces in the width direction of the substructure 6 via the tension member 3 installed between the pair of brackets 2, 2 and the other bracket 2, and can receive a reaction force from the side surfaces of the substructure 6. Therefore, excessive stress will not be generated in either bracket 2.

[0025] The movement restricting device 1 is composed of a pair of brackets 2, 2 arranged on both sides in the width direction of the substructure 6 and three elements (parts) of the tension member 3 installed between the pair of brackets 2, 2. Thus, there is no need to arrange a combination of a restraint member and a fixing member for each support 8 as in the prior art, and the configuration of the movement restricting device 1 is simplified.

[0026] In order not to generate an eccentric moment in the bracket 2 due to the inertial force from the superstructure 7 and the reaction force (tensile force) of the tension member 3 when the superstructure 7 attempts to move, it is reasonable that the acting position of the force on the bracket 2 and the tension member 3 are located on the same line in the cross-section when the superstructure 7 and the substructure 6 are viewed in the bridge axis direction.

[0027] However, if the acting position of the force from the superstructure 7 and the installation position of the tension member 3 are at the same position (height), the eccentric distance between the position where the tensile force borne by the tension member 3 is transmitted from the bracket 2 to the substructure 6 will increase, resulting in the disadvantage that the eccentric moment acting below the upper section of the bracket 2 will increase.

[0028] Therefore, by installing the tension member 3 at a position below (within the height range) the height of the support 8 intervening between the substructure 6 and the superstructure 7 (Claim 2), the tension member 3 can be installed at an intermediate position between the position of the load from the superstructure 7 acting on the upper section 2B of the bracket 2 and the acting position of the reaction force of the tensile force transmitted from the bracket 2 to the substructure 6. As a result, it becomes possible to suppress the eccentric moment generated between the load generated between the superstructure 7 and the upper section 2B of the bracket 2 and the tensile force of the tension member 3, and between the tensile force of the tension member 3 and the main body section of the bracket 2.

[0029] Here, compare the tensile force that the anchor bolt 4 should bear when a tension member 3 that bears a tensile force is installed between a pair of opposing brackets 2, 2, with the tensile force that the anchor bolt 4 should bear when the tension member 3 is not installed. As shown in Fig. 5-(a), brackets 2, 2 are locked to both side surfaces in the width direction of the superstructure 7, and calculate the tensile force of the anchor bolt 4 when the bracket 2 is fixed to the substructure 6 with a plurality of anchor bolts 4 in the lower section (lower section 2A) closer to the bottom.

[0030] Assume that an inertial force P acts from the superstructure 7 on the bracket 2 when the superstructure 7 attempts to move relative to each other in the width direction. Let the distance from the lower end of the bracket 2 to the acting position of the inertial force P be h1, the distance from the lower end of the bracket 2 to the center (centroid) of the tensile forces of all the anchor bolts 4 be h5, and the sum (resultant force) of the tensile forces of all the anchor bolts 4 be A2. Then, from the balance of the moment M1 around the lower end of the bracket 2, M1 = P×h1 = A2×h5, so A2 = P×h1 / h5...(1).

[0031] On the other hand, as shown in Fig. 5-(b), calculate the sum (resultant force) A1 of the tensile forces of all the anchor bolts 4 when a tension member 3 is installed between the sections closer to the superstructure 7 of the opposing brackets 2, 2 (between the upper sections 2B, 2B). Let the tensile force borne by the tension member 3 be T, the distance from the lower end of the bracket 2 to the center of the tension member 3 be h2, the distance from the center of the tension member 3 to the upper surface of the substructure 6 be h3, and the distance from the upper surface of the substructure 6 to the center (centroid) of the tensile forces of all the anchor bolts 4 be h4. Then, from M1 = P×h1 = T×h2, T = P×h1 / h2.

[0032] As a result of the tensile force T of the tension member 3 acting on the upper section 2B of the right bracket 2, a moment M2 around the upper surface of the substructure 6 acts on the upper section 2B. Since the moment M2 balances with the sum (resultant force) A1 of the tensile forces of the plurality of anchor bolts 4, M2 = T×h3 = A1×h4. The sum A1 of the tensile forces of all the anchor bolts 4 is A1 = T×h3 / h4 = P×h1 / h2×h3 / h4 = P×h1×h3 / (h2×h4)...(2).

[0033] From (1) above, P can be expressed as P = A2 × h5 / h1. On the other hand, if P in (2) in the case with the tension member 3 is replaced with A2 × h5 / h1, then A1 = P × h1 × h3 / (h2 × h4) = A2 × h5 / h1 × h1 × h3 / (h2 × h4) = A2 × h5 × h3 / (h2 × h4)......(3).

[0034] From (3) above, the ratio of A1 to A2, A1 / A2, is A1 / A2 = h5 × h3 / (h2 × h4). Here, assuming h2 = 2.5m, h3 = 0.2m, h4 = 1.65m, and h5 = 0.65m from Figure 5, then A1 / A2 = 0.65 × 0.2 / (2.5 × 1.65) = 0.0315.

[0035] This indicates that the total tension A1 of all the anchor bolts 4 in the case with the tension member 3 (Figure 5-(b)) is reduced to about 3% or more of the total tension A2 of all the anchor bolts 4 in the case without the tension member 3 (Figure 5-(a)). In other words, in the case of Figure 5-(b) (with the tension member 3), it shows that it is sufficient to use about 3% or more of the number of anchor bolts 4 in the case of (a) (without the tension member 3), or the diameter of the anchor bolts 4 can be reduced accordingly.

[0036] The structure and form of the superstructure (main girder) 7 are not limited. However, when the superstructure 7 is in a form where two or more box girders (girder parts 71) are arranged in parallel as shown in Figures 1 and 2, if the adjacent girder parts 71, 71 are not interconnected, each girder part 71 of the superstructure 7 tends to move independently in the width direction. Therefore, it may be necessary to install the movement restriction device 1 for restricting the movement in the width direction for each girder part 71 unit.

[0037] Therefore, when the upper structure 7 is composed of a plurality of girder portions 71 arranged in parallel in the width direction of the upper structure 7, by disposing the intermediate bracket 5 that locks to the outside in the width direction of the upper structure 7 between the side surfaces of the adjacent girder portions 71, 71 (Claim 3), the integrity of the plurality of (multiple) girder portions (box girders) 71 can be ensured, and it becomes possible to restrict the movement in the width direction as one upper structure 7 composed of the plurality of girder portions 71. However, even when the upper structure 7 is composed of a plurality of girder portions 71, it is not always necessary to dispose the intermediate bracket 5 between the side surfaces of the adjacent girder portions 71, 71.

[0038] Even when there is no intermediate bracket 5 between the side surfaces of the adjacent girder portions 71, 71, for example, if the girder portion 71 located at either end in the width direction of the upper structure 7 attempts to move outward in the width direction, the inertial force is transmitted from that girder portion 71 to the bracket 2 that locks to that girder portion 71, transmitted through the tension member 3 to the bracket 2 on the opposite side, and then transmitted to the lower structure 6.

[0039] In Claim 3, the intermediate bracket 5 straddles between the opposing side surfaces of the adjacent girder portions 71, 71 in the width direction. When one of the two girder portions 71, 71 attempts to move in the direction opposite to the other, a part of the inertial force of one of the girder portions 71 is transmitted to the other girder portion 71, integrating the two girder portions 71, 71.

[0040] As a result, the other girder portion 71 that has received the inertial force from one of the girder portions 71 transmits the inertial force to the bracket 2 that locks to its side surface. At the same time, the one girder portion 71 that attempts to move also transmits a part of the inertial force to the intermediate bracket 5 that locks to its side surface, and transmits it to the lower structure 6 through the intermediate bracket 5.

[0041] In this case, when the intermediate bracket 5 interposed between the side surfaces of the adjacent digit portions 71, 71 is locked toward the outside in the width direction of the upper structure 7, if any one of the digit portions 71 arranged in parallel in the width direction of the upper structure 7 attempts to move toward the other digit portion 71 ahead of the other digit portion 71, a part of the inertial force is transmitted from the other digit portion 71 to the bracket 2 that locks to that digit portion 71, and at the same time, a part of the inertial force in the same direction is also transmitted to the lower structure 6 through the intermediate bracket 5. Therefore, the inertial force is dispersed and transmitted to a plurality of digit portions 71.

[0042] When one of the two digit portions 71, 71 attempts to move to the outside in the width direction of the upper structure 7, the inertial force is transmitted from that digit portion 71 to the bracket 2 that is locked to the side surface of that digit portion 71, and is transmitted to the side surface on the other side of the lower structure 6 through the bracket 2 facing that bracket 2 and the tension member 3.

[0043] In particular, if the intermediate bracket 5 is fixed (anchored) to the lower structure 6 (Claim 4), when any digit portion 71 that is locked to the side surface by the intermediate bracket 5 attempts to move toward the intermediate bracket 5, a part of the inertial force from that digit portion 71 is transmitted to the intermediate bracket 5 and then transmitted from the intermediate bracket 5 to the lower structure 6. At the same time, a part of the inertial force of the digit portion 71 that also attempts to move is transmitted through the intermediate bracket 5 to the adjacent digit portion 71, and is transmitted to the bracket 2 on the opposite side through the bracket 2 that is locked to the side surface of that digit portion 71 and the tension member 3, and is transmitted from that bracket 2 to the lower structure 6.

[0044] In this case, the inertial force of each digit portion 71 is dispersed and transmitted from all the digit portions 71 constituting the upper structure 7 to the lower structure 6 through the intermediate bracket 5 and the bracket 2. Therefore, unlike the case where the intermediate bracket 5 is not fixed to the lower structure 6, there is an advantage that the burden on the tension member 3 is reduced because the inertial force corresponding to the mass of the entire upper structure 7 composed of a plurality of digit portions 71 is not applied as a tensile force to the tension member 3 between the brackets 2, 2.

Advantages of the Invention

[0045] Locking to the center side in the width direction on both side surfaces in the width direction of the lower structure, with the upper section protruding toward the upper structure side, and being fixed facing each other in a state where they can be locked to the center side in the width direction on both side surfaces in the width direction of the upper structure, a pair of brackets, and a tension member that is installed between the upper sections of the pair of brackets and bears the tensile force are used as components of the movement restriction device. Therefore, it is not necessary to arrange a combination of a restraint member and a fixing member for each support as in the prior art, and the movement restriction device can be simplified.

[0046] When the upper structure attempts to move relative to each other, the force (inertial force) acting on either one of the brackets acts in the same direction on the side surfaces in the width direction of the lower structure via the tension member between the pair of brackets and the other bracket, and since it can receive a reaction force from the side surface of the lower structure, excessive stress is not generated in either bracket. Also, since the entire lower structure resists the force from the upper structure, the reaction force does not concentrate on a part of the lower structure, and the situation where the reaction force becomes excessive is avoided.

[0047] Furthermore, since the brackets are fixed to the side surfaces in the width direction of the upper structure, when fixing the brackets to the lower structure, it is not necessary to insert anchor bolts from the upper surface side of the lower structure into the lower structure, and it is not necessary to secure a space between the lower structure and the upper structure that is longer than the length of the anchor bolts.

Brief Description of the Drawings

[0048]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Embodiment for Carrying out the Invention

[0049] Figs. 1 to 3 show an installation example of a movement restricting device 1 for restricting the relative movement of the superstructure 7 in the width direction (perpendicular to the bridge axis) with respect to the substructure 6 in a bridge where a support 8 for supporting the superstructure 7 is fixed on the substructure 6. The drawings show an example where the superstructure (main girder) 7 is a box girder bridge in which two or more girder parts (box girders) 71 are arranged in parallel. In this example, each girder part 71 is supported by the substructure 6 via one or a plurality of supports 8 arranged in parallel in the width direction.

[0050] The movement restricting device 1 includes a pair of brackets 2, 2 that are fixed to both side surfaces in the width direction of the substructure 6 in the lower section 2A in a state of being locked to the center side in the width direction and facing each other, and a tension member 3 that is installed between the upper sections 2B, 2B of the pair of brackets 2, 2 and bears the tensile force when the superstructure 7 moves relatively. The brackets 2 are mainly made of steel, but this is not necessarily required.

[0051] The lower section 2A shown in Fig. 4-(a) where the bracket 2 is locked to the substructure 6 is joined to the substructure 6 mainly by anchor bolts 4 or the like in a state of being in direct or indirect contact with the side surface of the substructure 6. The section of the upper section 2B shown in Fig. 4-(a) that projects toward the superstructure 7 projects toward the superstructure 7 side, and when the superstructure 7 attempts to move relatively in the width direction with respect to the substructure 6, the side surface of the superstructure 7 is in a state where it can be locked to the upper section 2B of the bracket 2. The upper section 2B of the bracket 2 locks to the side surface of the superstructure 7 immediately when the superstructure 7 attempts to move relatively or after a certain amount of relative movement.

[0052] The supports 8 for supporting the superstructure 7 on the substructure 6 are arranged at least at two positions in the width direction of the superstructure 7, fixed to the superstructure 7 (girder part 71) on the upper plate 81 as shown in FIG. 1, and fixed to the substructure 6 on the lower plate 82. When the superstructure 7 is composed of a plurality of (a plurality of) girder parts 71, they are arranged at least at two positions in the width direction of each girder part 71.

[0053] In this regard, it is difficult to arrange the anchor bolts 4 for fixing the bracket 2 to the substructure 6 at the installation location of the support 8 on the substructure 6 and its periphery. For this reason, in the drawing, as shown in FIG. 2, on the plane, except for the installation location of the support 8 and its periphery, the bracket 2 is fixed to the substructure 6 by the anchor bolts 4 that penetrate the lower part of the lower section 2A of the bracket 2 and are inserted horizontally into the substructure 6.

[0054] When the superstructure 7 attempts to move relative to the substructure 6 in the width direction or has moved relatively, one bracket 2 located on that side receives the inertial force from the superstructure 7 as a bearing pressure in the upper section 2B where it locks to the side surface of the superstructure 7. The inertial force received by one bracket 2 is transmitted as a bearing pressure to the substructure 6 from the upper part of the lower section 2A of the opposing bracket 2 through the tension member 3 installed between the upper sections 2B of the opposing brackets 2, 2. The tension member 3 is installed in the space between the upper surface of the substructure 6 and the lower surface of the superstructure 7. The tensile force acting on the lower part of the lower section 2A of the other bracket 2 is borne by the anchor bolt 4 passing through that part.

[0055] It should be noted that in order to reduce the eccentricity distance between the acting position of the inertial force from the superstructure 7 on one bracket 2 and the installation position of the tension member 3, and to reduce the eccentricity distance between the installation position of the tension member 3 and the transmission position of the inertial force from the other bracket 2 to the substructure 6, it is appropriate for the tension member 3 to be installed at a position (height range) below the height of the support 8 intervening between the substructure 6 and the superstructure 7.

[0056] Figure 4 shows a manufacturing example of the bracket 2 arranged on the right side in Figure 1. The bracket 2 has a base plate 21 that is joined by overlapping directly or indirectly with the side surface of the lower structure 6 at least in the lower section 2A, and a locked portion 22 that overlaps directly or indirectly with the side surface of the upper structure 7 in the upper section 2B and can be locked to the center side in the width direction. "Indirectly" means that an adjustment material or the like is interposed between the bracket 2 and the lower structure 6, and between the bracket 2 and the upper structure 7. The locked portion 22 has a flat surface or a curved surface corresponding to the shape of the side surface in the width direction of the upper structure 7 so as to receive the inertial force from the upper structure 7 (girder portion 71) as a bearing pressure.

[0057] The configuration of the bracket 2 is arbitrary as long as it has the above-described lower section 2A and upper section 2B. However, since the side surfaces of the lower structure 6 and the upper structure 7 are not necessarily continuous surfaces, in the drawing, the locked portion 22 is integrated with the base plate 21 while intersecting the base plate 21 at an arbitrary angle. In this example, adjustment plates 23, 23 arranged in parallel in the width direction of the base plate 21 are integrated with the surface side of the base plate 21, that is, the side opposite to the side surface of the lower structure 6, by welding or the like, and a locked portion 22 having a shape corresponding to the shape and angle of the side surface of the upper structure 7 is integrated between the parallel adjustment plates 23, 23 by welding or the like.

[0058] In any part of the lower section 2A of the base plate 21 that overlaps the side surface of the lower structure 6, as shown in Figure 4-(d), an insertion hole 21b through which an anchor bolt 4 that is inserted horizontally or the like into the lower structure 6 and joins the base plate 21 to the lower structure 6 is formed. In the drawing, for the reason of avoiding interference with the anchor bolt 4 of the above-described support 8, insertion holes 21b for four anchor bolts 4 are formed in parallel in the width direction in the section closer to the bottom of the base plate 21 in the height direction.

[0059] As shown in FIG. 1, the tension member 3 is connected and fixed to the upper section 2B of the base plate 21 that projects from the upper surface of the lower structure 6 toward the upper structure 7. In this regard, the tension member 3 is connected and fixed to the portion of the base plate 21 that projects toward the upper structure 7 (upper section 2B), or to the fixing plates 24 that are integrated on the opposite side of the base plate 21 of the adjusting plates 23, 23. The fixing plates 24 are joined to both of them by welding or the like across between the parallel adjusting plates 23, 23. Rib plates 25 for supplementary stiffening are joined to the necessary portions of the base plate 21 and the adjusting plates 23. In the example shown in FIG. 1, corresponding to the fact that the tension member 3 is installed inclined with respect to the horizontal, in FIG. 4, the surface of the fixing plate 24 is inclined with respect to the vertical plane.

[0060] As shown in FIGS. 4-(a) to (c), rib plates 25, 25 that form a vertical plane are also joined across between the ends of the parallel adjusting plates 23, 23 on the side of the fixing plate 24 and the rib plates 25 located on the opposite side of the opposing sides of the adjusting plates 23, 23. On the side of the rib plates 25, 25 toward the fixing plate 24, auxiliary plates 26 that share the tensile force of the tension member 3 borne by the fixing plate 24 together with the fixing plate 24, or for positioning the fixing plate 24, are joined. Insertion holes 26a through which the tension member 3 is inserted are formed at positions corresponding to the insertion holes 24a of the fixing plate 24 of the auxiliary plates 26.

[0061] When using the fixing plate 24, insertion holes 21a are formed at the insertion positions of the tension member 3 on the base plate 21. Insertion holes 24a through which the tension member 3 is inserted are also formed in the fixing plate 24. At the end of the fixing side of the tension member 3, an end fixing portion 31 such as a sleeve with external threads cut on the surface is integrally connected as shown in FIG. 1, and the end of the end fixing portion 31 passes through the insertion hole 24a of the fixing plate 24. A fixing tool 32 such as a nut that screws onto the outer periphery of the end fixing portion 31 is screwed and tightened or the like to the portion of the end fixing portion 31 that projects to the surface side after passing through the fixing plate 24, so that the end fixing portion 31 is fixed to the fixing plate 24.

[0062] The tensile force of the tension member 3 borne by the fixing plate 24 is transmitted from the fixing plate 24 through the adjusting plates 23, 23 on both sides to the base plate 21, and is transmitted and borne as a bearing pressure to the lower structure 6.

[0063] As shown in FIGS. 1 and 2, when the upper structure 7 is a box girder bridge in which a plurality of girder portions 71 are arranged in parallel, an intermediate bracket 5 for ensuring the integrity of the plurality of girder portions 71 is arranged in a state of being locked to the outside in the width direction of the upper structure 7 between the side surfaces of the adjacent girder portions 71, 71. The intermediate bracket 5 may only be placed on the upper surface of the lower structure 6, but in order to give the intermediate bracket 5 the role of restricting or restraining the relative movement in the width direction of the upper structure 7 with respect to the lower structure 6, it is fixed to the lower structure 6. The intermediate bracket 5 is also mainly made of steel, but this is not necessarily required.

[0064] The intermediate bracket 5 has a mounting portion 51 that is directly or indirectly placed on the upper surface of the lower structure 6, and overhanging portions 52, 52 that project from both axial sides of the mounting portion 51 toward the girder portion side. At the tips of the overhanging portions 52 on the girder portion 71 side, locked portions 53, 53 that can be directly or indirectly locked to the opposing side surfaces of the adjacent girder portions 71, 71 are integrated. The locked portions 53 may be in contact with the side surface of the girder portion 71, or there may be a clearance between them and the side surface.

[0065] The mounting portion 51 is placed on the upper surface of the lower structure 6, while the girder portion 71 is supported by a support 8 installed on the lower structure 6. In this relationship, the locked portions 53, 53 that contact the side surface of the girder portion 71 are often located above the upper surface of the lower structure 6. In this relationship, in the drawing, the axis of the overhanging portion 52 is inclined with respect to the axis of the mounting portion 51, but it may be parallel depending on the height and installation level of the support 8, etc.

[0066] When the intermediate bracket 5 is fixed to the lower structure 6, the mounting portion 51 is composed of a base plate 51a placed on the upper surface of the lower structure 6 as shown in Fig. 1, and an axial portion 51b integrated on the base plate 51a and bearing the inertial forces from the adjacent girder portions 71, 71 as compressive forces. The base plate 51a is fixed to the lower structure 6 by anchor bolts 4 embedded vertically or otherwise in the lower structure 6. Square steel pipes, H-shaped steel, etc. are used for the axial portion 51b.

[0067] Insertion holes through which the anchor bolts 4 pass are formed in the base plate 51a. As shown in Figs. 1 and 2, since the anchor bolts 4 for fixing the base plate 51a to the lower structure 6 are arranged at positions where the supports 8 for supporting the girder portions 71 are removed, even if they are arranged in the surface layer portion of the lower structure 6 above the group of anchor bolts 4 for fixing the bracket 2 to the lower structure 6, there will be no interference with the anchor bolts for the supports 8.

[0068] In addition, since the tension member 3 of the movement restriction device 1 is installed in the space between the upper surface of the lower structure 6 and the lower surface of the upper structure 7 as described above, the intermediate bracket 5 is arranged at a position where there is no interference with the movement restriction device 1 (tension member 3) on the plane as shown in Fig. 2.

Explanation of Reference Numerals

[0069] 1……Movement restriction device, 2……Bracket, 2A……Lower section, 2B……Upper section, 21……Base plate, 21a……Insertion hole (for tension member), 21b……Insertion hole (for anchor bolt), 22……Engaged portion, 23……Adjusting plate, 24……Fixing plate, 24a……Insertion hole, 25……Rib plate, 26……Auxiliary plate, 26a……Insertion hole, 3……Tension member, 31……End fixing portion, 32……Fastener, 4……Anchor bolt, 5……Intermediate bracket, 51……Mounting portion, 51a……Base plate, 51b……Axial portion, 52……Overhanging portion, 53……Engaged portion, 6……Lower structure, 7……Upper structure, 71……Girder portion, 8……Support, 81……Upper plate, 82……Lower plate.

Claims

1. In a bridge in which a bearing for supporting an upper structure is fixed on a lower structure, it is a device for restricting relative movement of the upper structure in the width direction with respect to the lower structure, a pair of brackets that are fixed to both side surfaces in the width direction of the lower structure, locked toward the center in the width direction, and facing each other with an upper section projecting toward the upper structure side, and a tension member that is installed between the upper sections of the pair of brackets and bears a tensile force during the relative movement of the upper structure, wherein the upper sections of the pair of brackets are in a state of being able to be locked to both side surfaces in the width direction of the upper structure toward the center in the width direction. A device for restricting movement of an upper structure in a bridge.

2. The device for restricting movement of an upper structure in a bridge according to claim 1, wherein the tension member is installed at a position below the height of the bearing interposed between the lower structure and the upper structure.

3. The upper structure is composed of a plurality of girder portions arranged in parallel in the width direction of the upper structure, and an intermediate bracket that locks outward in the width direction of the upper structure is arranged between side surfaces of the adjacent girder portions. A device for restricting movement of an upper structure in a bridge according to claim 1 or claim 2.

4. The device for restricting movement of an upper structure in a bridge according to claim 3, wherein the intermediate bracket is fixed to the lower structure.

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