JP2020143428A - Bearing device reinforcement method and bearing device - Google Patents

Abstract

To provide a bearing device reinforcement method capable of preventing or suppressing damage to a side block.SOLUTION: A through hole 11 which protrudes upward from a lower shoe part 3 of a bearing device 1 is formed in a side block 5 and the lower shoe part 3. A hole 12 is formed in a foundation 9. A bearing reinforcement method includes: a step S1 of removing an anchor bolt embedded in the hole 12 through the through hole 11; a step S3 for forming a spiral groove SG1 on an inner peripheral surface 13a of a hole 13 formed in the lower shoe part 3 of the through holes 11; and a step S5 for embedding an anchor bolt 7 including a screw part 7a in the hole 12 with the screw part 7a screwed into the spiral groove SG1. In step S5, a compressive stress CP1 in the direction along the through hole 11 is applied to the side block 5.SELECTED DRAWING: Figure 2

Description

The present invention relates to a method for reinforcing a bearing device that supports a bearing body fixed to a bridge girder and a bearing device.

A bearing device provided for a structure such as a bridge or an elevated structure having a lower structure consisting of a base such as a pier and an upper structure consisting of a bridge girder, and a bearing fixed to the bridge girder, that is, a bearing device that supports the upper structure on the lower structure. A bearing device that supports the bearing body is used. Such a bearing device has a lower shoe portion fixed to the lower structure by anchor bolts and an upper shoe portion fixed to the upper structure by welding or bolts or the like. The upper shoe portion has a plate-like shape including an upper surface composed of a flat surface and a lower surface composed of a flat surface, and the lower shoe portion is composed of a convex curved surface having a semi-cylindrical shape extending along the width direction of the bridge girder. Including the top surface. The lower surface of the upper shoe portion made of a flat surface makes line contact with the upper surface of the lower shoe portion made of a convex curved surface. Such bearing devices are also referred to as line bearings.

Japanese Patent Application Laid-Open No. 60-250106 (Patent Document 1) includes a lower shoe having a convex curved surface on the upper surface fixed to the lower structure and a plate-shaped upper shoe fixed to the upper structure, and has an upper and lower structure. A technique for arranging an intermediate shoe between the upper and lower shoes of an existing line bearing, which is configured to allow the relative displacement between the shoes by the line contact between the convex curved surface of the lower shoe and the upper shoe, is disclosed.

Japanese Unexamined Patent Publication No. 60-250106

As such a bearing device, there is one having a side block protruding from the upper surface of the lower shoe portion. The side block restricts the upper shoe from moving to one side in the width direction of the bridge girder. Steel is used for the side block and the lower shoe. In a bearing device having such a side block made of steel and a lower shoe portion, when an earthquake occurs, a large stress in the width direction of the bridge girder is applied to the side block from the upper shoe portion or the like, so that the side block is formed. May be damaged. If the side block is damaged, the bridge girder may shift in the width direction, so-called girder deviation, and the bridge girder may fall from the pier.

However, although movement restriction work or bridge collapse prevention work is carried out as a seismic reinforcement method for the bearing device, an effective method for seismic reinforcement of the entire bearing device having a side block made of steel and a lower shoe has been proposed. Not.

Further, the above-mentioned problem of damage to the side block is not limited to the case where a large stress in the width direction of the bridge girder is applied to the side block due to an earthquake, and an impact other than the earthquake is generated on the side block. This is a common problem even when a large stress is applied.

The present invention has been made to solve the above-mentioned problems of the prior art, and is used in a side block in a method of reinforcing a bearing device for reinforcing a bearing device that supports a bearing body fixed to a bridge girder. It is an object of the present invention to provide a method for reinforcing a bearing device capable of preventing or suppressing damage to a side block even when a large stress in the width direction of a bridge girder is applied.

A brief outline of the typical inventions disclosed in the present application is as follows.

A method of reinforcing a bearing device as one aspect of the present invention is a method of reinforcing a bearing device that reinforces a bearing device that supports a bearing body fixed to a bridge girder. The bearing device is fixed to the base, is provided under the bearing body, and is the first of the bearing main body portion that supports the bearing body and the bearing main body portion in the width direction of the bridge girder than the bearing body portion. It has a protruding portion that protrudes upward from the first portion arranged on the side and is provided integrally with the bearing main body portion. Through holes are formed in the projecting portion and the bearing body to reach the base through the projecting portion and the bearing body, and holes communicating with the through holes are formed in the base. , The first anchor bolt that penetrates the through hole is embedded in the hole and fixed to the base. The method of reinforcing the support device is as follows: a step (a) of removing the first anchor bolt from the hole and the through hole, and a first hole formed in the support main body of the through hole after the step (a). After the steps (b) and (b) of forming a spiral groove on the first inner peripheral surface, a second anchor bolt containing a screw portion screwable into the spiral groove is inserted into the through hole and into the through hole. It has a step (c) of fixing the protruding portion and the support main body portion to the base by embedding the inserted second anchor bolt in the hole portion in a state where the screw portion is screwed into the spiral groove. In the step (c), the threaded portion is screwed into the spiral groove to apply compressive stress in the direction along the through hole to the protruding portion.

Further, as another aspect, when the lower end surface of the protruding portion is the first lower end surface and the lower end surface of the second hole portion formed in the protruding portion of the through holes is the second lower end surface, the first portion On the upper surface, the first height position of the first side portion of the first lower end surface opposite to the first side in the width direction is the second side portion of the first lower end surface on the first side in the width direction. The third height position of the third side portion of the second lower end surface that is located above the second height position and is opposite to the first side in the width direction is the second lower end surface. It may be inclined so as to be arranged above the fourth height position of the fourth side portion on the first side in the width direction. In the step (b), even if a spiral groove is formed on the first inner peripheral surface of the first hole portion and the second inner peripheral surface of the second portion of the second hole portion adjacent to the first hole portion. Good. The fifth height position of the upper end of the second portion may be equal to or lower than the first height position and may be equal to or higher than the third height position.

Further, as another aspect, the method of reinforcing the bearing device widens the third portion of the second hole portion above the second portion after the step (a) and before the step (b). It may have a process.

As another aspect, the method for reinforcing the bearing device includes a step (e) of injecting an injection material made of mortar into a hole after the step (b) and before the step (c). May be good. In the step (c), after the step (e), the second anchor bolt is inserted into the second hole portion, and the second anchor bolt inserted into the second hole portion is inserted into the hole portion into which the injection material is injected. After the steps (c1) and (c1) in which the threaded portion is screwed into the spiral groove, the injection material is cured, and the second anchor bolt is embedded in the hole by the cured injection material to project. The step of fixing the portion and the support main body portion to the base (c2) may be included.

The bearing device as one aspect of the present invention is a bearing device that supports a bearing body fixed to a bridge girder. The bearing device is fixed to the base, is provided under the bearing body, and is the first of the bearing main body portion that supports the bearing body and the bearing main body portion in the width direction of the bridge girder with respect to the bearing body. It has a protruding portion that protrudes upward from the first portion arranged on the side and is provided integrally with the bearing main body portion. Through holes are formed in the protruding portion and the supporting main body to reach the base through the protruding portion and the supporting main body, and a hole communicating with the through hole is formed in the base. A spiral groove is formed on the first inner peripheral surface of the first hole portion formed in the above, and an anchor bolt including a screw portion screwable into the spiral groove is inserted into the through hole in the protruding portion and the support main body portion. Anchor bolts inserted into the through holes are fixed to the base by being embedded in the holes with the threaded portions screwed into the spiral groove. A compressive stress in the direction along the through hole is applied to the protruding portion by screwing the threaded portion into the spiral groove.

Further, as another aspect, when the lower end surface of the protruding portion is the first lower end surface and the lower end surface of the second hole portion formed in the protruding portion of the through holes is the second lower end surface, the first portion On the upper surface, the first height position of the first side portion of the first lower end surface opposite to the first side in the width direction is the second side portion of the first lower end surface on the first side in the width direction. The third height position of the third side portion of the second lower end surface that is located above the second height position and is opposite to the first side in the width direction is the second lower end surface. It may be inclined so as to be arranged above the fourth height position of the fourth side portion on the first side in the width direction. The spiral groove may be formed on the first inner peripheral surface of the first hole portion and the second inner peripheral surface of the second portion of the second hole portion adjacent to the first hole portion. The fifth height position of the upper end of the second portion may be equal to or lower than the first height position and may be equal to or higher than the third height position.

Further, as another aspect, the first inner diameter of the third portion above the second portion of the second hole portion may be larger than the second inner diameter of the first hole portion.

Further, as another aspect, in the protruding portion and the support main body portion, the anchor bolt is inserted into the second hole portion, and the anchor bolt inserted into the second hole portion is screwed into the spiral groove. Anchor bolts inserted into the holes and inserted into the holes may be fixed to the base by being embedded in the holes by an injection material made of hardened mortar.

By applying one aspect of the present invention, in the method of reinforcing the bearing device for reinforcing the bearing device that supports the bearing body fixed to the bridge girder, even when a large stress in the width direction of the bridge girder is applied to the side block. , It is possible to prevent or suppress damage to the side block.

It is a top view which shows the bearing apparatus of embodiment. It is sectional drawing which shows the bearing apparatus of embodiment. It is sectional drawing which shows the bearing apparatus of embodiment. It is sectional drawing which shows the bearing device before performing the reinforcement process of the bearing device of embodiment. It is a flow figure which shows a part of the reinforcement process of the bearing apparatus of embodiment. It is sectional drawing which shows the reinforcement process of the bearing apparatus of embodiment. It is sectional drawing which shows the reinforcement process of the bearing apparatus of embodiment. It is sectional drawing which shows the reinforcement process of the bearing apparatus of embodiment. It is sectional drawing which shows the reinforcement process of the bearing apparatus of embodiment. It is sectional drawing which shows the reinforcement process of the bearing apparatus of embodiment. It is sectional drawing which shows the reinforcement process of the bearing apparatus of embodiment.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.

It should be noted that the disclosure is merely an example, and those skilled in the art can easily conceive of appropriate changes while maintaining the gist of the invention are naturally included in the scope of the present invention. Further, in order to clarify the description, the drawings may schematically represent the width, thickness, shape, etc. of each part as compared with the embodiment, but this is just an example, and the interpretation of the present invention is used. It is not limited.

Further, in the present specification and each of the drawings, the same elements as those described above with respect to the above-described drawings may be designated by the same reference numerals, and detailed description thereof may be omitted as appropriate.

Further, in the drawings used in the embodiment, hatching (shading) may be omitted in order to make the drawings easier to see even if they are cross-sectional views. Further, even if it is a plan view, hatching may be added to make the drawing easier to see.

(Embodiment)
<Bearing device>
A bearing device according to an embodiment of the present invention will be described. The bearing device of the present embodiment is a bearing device that supports a bearing body fixed to a bridge girder, and is reinforced by a method of reinforcing the bearing device of the present embodiment, which will be described later.

In the following, a case where the bearing device is provided on the bridge will be described as an example. However, the bearing device of the present embodiment has a lower sill portion fixed to the lower structure and an upper sill fixed to the upper structure. It can be widely applied to a bearing device having a portion and, and is not limited to a bearing device provided on a bridge, but can also be applied to a bearing device provided on an elevated structure, for example.

FIG. 1 is a plan view showing a bearing device according to an embodiment. 2 and 3 are cross-sectional views showing the bearing device of the embodiment. FIG. 2 shows a cross-sectional view taken along the line AA of FIG. 1, and FIG. 3 shows a cross-sectional view taken along the line BB of FIG. In addition, in FIG. 1, the illustration of the base is omitted. Further, in FIGS. 1 and 3, the upper shoe portion and the structure above the upper shoe portion are not shown.

As shown in FIGS. 1 to 3, the bearing device 1 of the present embodiment includes a rib portion 2, a lower shoe portion 3 as a bearing main body portion, and an upper shoe portion 4 as a bearing body fixed to a bridge girder. It has a side block 5 as a protruding portion, a side block 6 as a protruding portion, and an anchor bolt 7.

The rib portion 2 projects downward from the lower shoe portion 3 and is provided integrally with the lower shoe portion 3. The rib portion 2 has a cross shape in a plan view, whereby the stress in the length direction of the bridge girder 8 and the strength in the width direction of the bridge girder 8 are applied to the lower shoe portion 3. Can be improved.

In the following, for convenience of explanation, the length direction of the bridge girder 8 may be referred to as the X-axis direction, the width direction of the bridge girder 8 may be referred to as the Y-axis direction, and the vertical direction, that is, the vertical direction may be referred to as the Z-axis direction.

The lower shoe portion 3 as the bearing main body portion is fixed to the pier, that is, the base 9. The lower shoe portion 3 is also referred to as a base plate.

The upper shoe portion 4 as a bearing body fixed to the bridge girder is provided on the lower shoe portion 3 and is fixed directly to the bridge girder 8 or via, for example, the connecting portion 10. Although detailed illustration is omitted, the upper shoe portion 4 has a plate-like shape including a lower surface 4a made of a flat surface and an upper surface made of a flat surface, and the lower shoe portion 3 has a width direction (Y axis) of the bridge girder 8. Includes a top surface 3a made of a convex curved surface having a semi-cylindrical shape extending along the direction). Since the lower surface 4a of the upper shoe portion 4 made of a flat surface is in line contact with the upper surface 3a of the lower shoe portion 3 made of a convex curved surface, the support device 1 is also referred to as a line bearing. By fixing the lower shoe portion 3 to the pier, that is, the base 9, and fixing the upper shoe portion 4 to the bridge girder 8, the relative between the base 9 and the bridge girder 8 such as expansion and contraction due to temperature change or creep of the bridge girder 8. Displacement is allowed, and bending of the bridge girder 8 due to loading or the like is allowed. The upper shoe portion 4 is also referred to as a sole plate.

The lower shoe portion 3 is formed on the upper surface of a portion PR13 of the lower shoe portion 3 provided below the upper shoe portion 4, and has a semi-cylindrical shape (kamaboko) extending along the width direction of the bridge girder 8. The upper surface portion 3b including the upper surface formed by the convex curved surface having the shape) may be included.

Alternatively, the bearing device 1 may not have the rib portion 2 and may not have the upper shoe portion 4. When the bearing device 1 does not have the upper shoe portion 4, the bearing device 1 supports a bearing body (for example, a connecting portion 10) composed of a lower portion such as a leg portion of the bridge girder 8. Further, the lower shoe portion 3 is fixed to the base 9, is provided under the supported body, and supports the supported body.

The side block 5 is arranged on one side (first side) of the lower shoe portion 3 as the bearing main body portion in the width direction (Y-axis direction) of the bridge girder 8 with respect to the upper shoe portion 4 as the bearing body. It protrudes upward from the portion PR11 and is provided integrally with the lower shoe portion 3. The side block 6 projects upward from the portion PR12 of the lower shoe portion 3 arranged on one side (first side) and the opposite side in the width direction (Y-axis direction) of the bridge girder from the upper shoe portion 4. Moreover, it is provided integrally with the lower shoe portion 3.

The side block 5 is arranged on one side (first side) in the width direction (Y-axis direction) of the bridge girder 8 with respect to the upper shoe portion 4, and the upper shoe portion 4 is moved to one side in the width direction of the bridge girder 8. Restrict movement. Further, the side block 6 is arranged on the side opposite to one side (first side) in the width direction (Y-axis direction) of the bridge girder 8 from the upper shoe portion 4, that is, on the other side, and the upper shoe portion 4 is the bridge girder. Restricts movement to the other side in the width direction of 8. Therefore, the side blocks 5 and 6 sandwich the upper shoe portion 4 from both sides in the width direction of the bridge girder 8. As a result, it is possible to prevent the bridge girder 8 from being displaced in the width direction, that is, laterally displaced.

Although not shown, the upper shoe portion 4 may include a sandwiching portion that sandwiches the side block 5 from both sides in the length direction (X-axis direction) of the bridge girder 8 in a plan view, and the side block 6 is included in a plan view. A sandwiching portion sandwiched from both sides in the length direction of the bridge girder 8 may be included.

The side blocks 5 and 6 and the lower shoe portion 3 are made of steel (carbon content 0.02 to 2.14% by weight) or cast iron (carbon content 2.14 to 6.67% by weight). Can be used. In such a carbon content range, the higher the carbon content, the higher the hardness but the lower the toughness.

The side block 5 and the lower shoe portion 3 are formed with a through hole 11 that penetrates the side block 5 and the lower shoe portion 3 and reaches the base 9. A hole portion 12 communicating with the through hole 11 is formed in the base 9.

In the bearing device 1 of the present embodiment, the spiral groove SG1 is formed on the inner peripheral surface 13a of the hole portion 13 formed in the lower shoe portion 3 of the through holes 11. In the side block 5 and the lower sill portion 3, an anchor bolt 7 including a screw portion 7a that can be screwed into the spiral groove SG1 is inserted into the through hole 11, and the anchor bolt 7 inserted into the through hole 11 has a screw portion 7a. It is fixed to the base 9 by being embedded in the hole 12 in a state of being screwed into the spiral groove SG1, that is, in a state of being screwed and embedded. Further, a compressive stress CP1 in the direction along the through hole 11 is applied to the side block 5 by screwing the screw portion 7a into the spiral groove SG1.

In other words, in the side block 5 and the lower sill portion 3, the anchor bolt 7 including the screw portion 7a screwable into the spiral groove SG1 is inserted into the through hole 11, and the anchor bolt 7 inserted into the through hole 11 is screwed. The portion 7a is embedded in the hole portion 12 while being screwed into the spiral groove SG1, and is fixed to the base 9 in a state where the compressive stress CP1 in the direction along the through hole 11 is applied to the side block 5.

That is, the anchor bolt 7 is provided on one side of the threaded portion 7a in the length direction or on one side of the threaded portion 7a, and has an outer diameter larger than the inner diameter of the hole portion 15 (through hole 11). Includes a head (nut) 7b to have. Further, the anchor bolt 7 is inserted into the hole portion 15, that is, the through hole 11 with the head portion 7b arranged at the upper end, and the anchor bolt 7 inserted into the through hole 11 has a screw portion 7a with a spiral groove SG1. It is embedded in the hole 12 in a fastened (tightened) state. Further, the side block 5 is formed by the head portion 7b locked above the hole portion 15, that is, above the through hole 11, and the lower shoe portion 3 locked to the screw portion 7a via the spiral groove SG1. By being sandwiched and held from above and below, that is, by being sandwiched, the compressive stress CP1 in the direction along the hole portion 15, that is, the through hole 11 is applied to the side block 5.

As will be described in detail with reference to FIGS. 4 to 11 described later, the present inventors have found that most of the damage to the side block 5 when a large earthquake occurs breaks, for example, the lower end surface LE1 of the side block 5 described later. As a cross section, it was found that the side block 5 is a shear fracture that breaks diagonally. Therefore, by reinforcing the bearing device so as to have a structure similar to that of the bearing device 1 of the present embodiment, prestress can be introduced into the side block 5 and the side block 5 is prevented from being sheared. Or it can be suppressed.

The bearing device 1 of the present embodiment may have a holding block 14. The holding block 14 is arranged on the side block 5. At this time, the holding block 14 is formed with a through hole that penetrates the holding block 14 and reaches the side block 5, and a through hole formed in the holding block 14. May communicate with the through hole 11, and the anchor bolt 7 may penetrate the through hole and the through hole 11 formed in the holding block 14. The holding block 14 is a hook portion provided on the center side of the lower shoe portion 3 in the width direction (Y-axis direction) of the bridge girder 8, and is provided between the upper shoe portion 4 or the upper shoe portion 4 and the bridge girder 8. Press the member (not shown) downward.

The lower end surface of the side block 5 is referred to as the lower end surface LE1, and the lower end surface of the hole portion 15 formed in the side block 5 of the through holes 11 is referred to as the lower end surface LE2. At this time, on the upper surface of the partial PR11, the height position HP1 of the side portion LE11 opposite to one side (first side) in the width direction (Y-axis direction) of the bridge girder 8 of the lower end surface LE1 is the lower end surface. The width of the bridge girder 8 of the lower end surface LE2 is arranged above the height position HP2 of the side portion LE12 on one side (first side) of the LE1 in the width direction (Y-axis direction) of the bridge girder 8. The height position HP3 of the side portion LE21 opposite to one side (first side) in the direction (Y-axis direction) is one side (Y-axis direction) of the lower end surface LE2 in the width direction (Y-axis direction) of the bridge girder 8. The side portion LE22 on the first side) is inclined so as to be arranged above the height position HP4.

In such a case, preferably, the spiral groove SG1 is adjacent to the hole portion 13 of the hole portions 15 formed in the side block 5 from the inner peripheral surface 13a of the hole portion 13 formed in the lower shoe portion 3. It is continuously formed up to the inner peripheral surface 15a of the partial PR2, and is not formed on the inner peripheral surface of the portion of the hole 15 above the partial PR2. Further, in such a case, preferably, the height position HP5, which is the height position of the upper end of the spiral groove SG1, that is, the height position of the upper end of the partial PR2, is equal to or less than the height position HP1 and has a height. The position is HP3 or higher.

As will be described in detail with reference to FIGS. 4 to 11 described later, such a structure increases the compressive stress CP1 applied to the side block 5 to further reliably improve the shear strength of the side block 5, and lower It is possible to prevent compressive stress from being applied to the shoe portion 3.

Preferably, the inner diameter DA1 of the portion PR3 above the portion PR2 of the hole 15 is larger than the inner diameter DA2 of the hole 13, and the height position HP6 of the lower end of the portion PR3 is the height position HP5 or higher. , Height equal to or higher than HP5.

As will be described in detail with reference to FIGS. 4 to 11 described later, such a structure makes it possible to easily form the spiral groove SG1 on the inner peripheral surface 13a of the hole portion 13.

Preferably, the side block 5 and the lower mortar portion 3 have the anchor bolt 7 inserted into the hole portion 15, and the anchor bolt 7 inserted into the hole portion 15 has a hole while the screw portion 7a is screwed into the spiral groove SG1. Anchor bolts 7 inserted into the portion 12 and inserted into the hole portion 12 are fixed to the base 9 by being embedded in the hole portion 12 by an injection material 16 made of hardened mortar, that is, in an embedded state. .. As a result, the side block 5 and the lower shoe portion 3 can be easily fixed to the base 9.

<Reinforcement method of bearing device>
Next, a method of reinforcing the bearing device according to the present embodiment will be described. FIG. 4 is a cross-sectional view showing the bearing device before performing the reinforcing step of the bearing device of the embodiment. FIG. 5 is a flow chart showing a part of the reinforcing process of the bearing device of the embodiment. 6 to 11 are cross-sectional views showing a reinforcing process of the bearing device according to the embodiment. The cross-sectional views shown in FIGS. 4 and 6 to 11 are cross-sectional views taken along the line AA of FIG. 1 in the same manner as the cross-sectional views shown in FIG.

As shown in FIG. 4, the bearing device 1 before performing the reinforcing step of the present embodiment includes a rib portion 2, a lower shoe portion 3 as a bearing main body portion, and an upper bearing body fixed to a bridge girder. It has a shoe portion 4, a side block 5, and a side block 6. Further, the bearing device 1 before performing the reinforcing step of the present embodiment has the shape of the through hole 11 and the point that the anchor bolt 107 is provided instead of the anchor bolt 7 (see FIG. 2). It has the same structure as the bearing device of the embodiment shown in the above, that is, the bearing device after the reinforcement step of the present embodiment is performed. Therefore, the description of the bearing device before performing the reinforcing step of the present embodiment will be omitted except for the parts related to the through hole 11 and the anchor bolt 7 (see FIG. 2).

In the bearing device 1 before the reinforcement step of the present embodiment, the side block 5 and the lower shoe portion 3 have the side block 5 and the same as the bearing device 1 after the reinforcement step of the present embodiment. A through hole 11 is formed that penetrates the lower shoe portion 3 and reaches the base. A hole portion 12 communicating with the through hole 11 is formed in the base 9.

On the other hand, in the bearing device 1 before performing the reinforcement step of the present embodiment, the spiral groove is not formed on the inner peripheral surface 13a of the hole portion 13 formed in the lower shoe portion 3 of the through holes 11. , Anchor bolt 107 does not include a threaded portion that can be screwed into the spiral groove. The anchor bolt 107 is inserted into the through hole 11, and the anchor bolt 107 inserted into the through hole 11 is embedded in the hole 12 by a mortar 116. That is, the side block 5 and the lower shoe portion 3 are fixed to the base 9 by embedding the anchor bolt 107 penetrating the through hole 11 in the hole portion 12, that is, in the embedded state.

In the bearing device 1 before performing the reinforcement step of the present embodiment, when an earthquake occurs, a large stress in the width direction (Y-axis direction) of the bridge girder 8 is applied to the side block 5 from the upper shoe portion 4 and the like. As a result, the side block 5 may be damaged. If the side block 5 is damaged, the bridge girder 8 is displaced in the width direction, that is, a so-called girder shift occurs, and the bridge girder 8 may fall from the base 9. Therefore, as shown below, the bearing device 1 is reinforced by performing the reinforcement step of the reinforcement method of the present embodiment.

First, as shown in FIG. 6, the existing anchor bolt 107 (see FIG. 4) is removed from the hole 12 and the through hole 11 (step S1 in FIG. 5). Various methods can be used as a method for removing the anchor bolt 107.

Next, as shown in FIG. 7, the hole portion 15 formed in the side block 5 of the through hole 11 is widened (step S2 in FIG. 5). In this step S2, the hole 15 is widened by using, for example, a core drill.

As will be described with reference to FIG. 8 described later, in step S3, preferably, not only the inner peripheral surface 13a of the hole portion 13 formed in the lower shoe portion 3 of the through hole 11 but also the through hole 11 A spiral groove SG1 is also formed on the inner peripheral surface 15a of the portion PR2 adjacent to the hole portion 13 of the hole portions 15 formed in the side block 5. In such a case, in step S2, the partial PR3 is preferably widened so that the inner diameter DA1 of the portion PR3 above the portion PR2 of the hole 15 is larger than the inner diameter DA2 of the hole 13. As a result, the inner diameter of the portion PR2 of the hole portion 15 adjacent to the hole portion 13 can be made equal to the inner diameter DA2 of the hole portion 13, and the shape accuracy of the formed spiral groove SG1 can be improved. The through hole formed in the holding block 14 may be widened so that the inner diameter thereof is equal to the inner diameter DA1.

Next, as shown in FIG. 8, a spiral groove SG1 is formed on the inner peripheral surface 13a of the hole portion 13 formed in the lower shoe portion 3 of the through hole 11 (step S3 in FIG. 5). In this step S3, for example, the spiral groove SG1 is formed by tapping the inner peripheral surface 13a of the hole 13.

As a result, as will be described with reference to FIGS. 11 and 2 described later, the anchor bolt 7 including the screw portion 7a is screwed into the spiral groove SG1 to side the compressive stress CP1 in the direction along the through hole 11. The side block 5 and the lower shoe portion 3 can be fixed to the base 9 while being applied to the block 5. Therefore, it is possible to prevent or suppress shear failure of the side block 5 at the boundary surface between the side block 5 and the lower shoe portion 3.

As described above, the lower end surface of the side block 5 is referred to as the lower end surface LE1, and the lower end surface of the hole portion 15 formed in the side block 5 of the through holes 11 is referred to as the lower end surface LE2. At this time, on the upper surface of the partial PR11, the height position HP1 of the side portion LE11 opposite to one side (first side) in the width direction (Y-axis direction) of the bridge girder 8 of the lower end surface LE1 is the lower end surface. The width of the bridge girder 8 of the lower end surface LE2 is arranged above the height position HP2 of the side portion LE12 on one side (first side) of the LE1 in the width direction (Y-axis direction) of the bridge girder 8. The height position HP3 of the side portion LE21 opposite to one side (first side) in the direction (Y-axis direction) is one side (Y-axis direction) of the lower end surface LE2 in the width direction (Y-axis direction) of the bridge girder 8. The side portion LE22 on the first side) is inclined so as to be arranged above the height position HP4.

In such a case, in step S3, preferably, a portion of the hole portion 15 formed in the side block 5 adjacent to the hole portion 13 from the inner peripheral surface 13a of the hole portion 13 formed in the lower shoe portion 3. The spiral groove SG1 is continuously formed up to the inner peripheral surface 15a of the PR2, and the spiral groove is not formed on the inner peripheral surface of the portion of the hole 15 above the partial PR2. As a result, the spiral groove SG1 can be formed on the entire inner peripheral surface 13a of the hole portion 13, and therefore, as will be described with reference to FIGS. 11 and 2 described later, the compressive stress CP1 applied to the side block 5 ( (See FIG. 11) can be increased so that compressive stress is not applied to the lower shoe portion 3.

Next, as shown in FIG. 9, the injection material 16a is injected into the hole 12 (step S4 in FIG. 5). As the injection material 16a, a material made of mortar can be preferably used, but the material has fluidity at the time of injection and can be easily cured in the step S8 described later with reference to FIG. However, other curable injection material 16a such as resin can be used.

Next, as shown in FIGS. 10, 11 and 2, an anchor bolt 7 including a screw portion 7a screwable into the spiral groove SG1 is inserted into the through hole 11, and the anchor bolt 7 inserted into the through hole 11 is inserted. The side block 5 and the lower bolt 3 are fixed to the base 9 by embedding the screw portion 7a in the hole portion 12 in a state of being screwed into the spiral groove SG1. (Step S5 in FIG. 5). Further, in step S5, the compressive stress CP1 in the direction along the through hole 11 is applied to the side block 5 by screwing the screw portion 7a into the spiral groove SG1.

In step S5, first, as shown in FIG. 10, the anchor bolt 7 is inserted into the hole portion 15, and the anchor bolt 7 inserted into the hole portion 15 is screwed into the hole portion 12 into which the injection material 16a is injected. 7a is inserted into the spiral groove SG1 in a state of being screwed (step S6 in FIG. 5). As described above, the head as the anchor bolt 7 is provided on one side of the threaded portion 7a in the length direction or on one side of the threaded portion 7a and has an outer diameter larger than the inner diameter of the hole portion 15. Those including a part (nut) 7b can be used. In such a case, the anchor bolt 7 is inserted into the hole portion 15, that is, the through hole 11 with the head portion 7b arranged at the upper end. As shown in FIG. 10, as the anchor bolt 7, a screw groove is formed in all of the shaft portions of the anchor bolt 7 including the head portion 7b and the shaft portion, that is, all of the shaft portions are screw portions. Screw bolts can be used.

In step S5, next, as shown in FIG. 11, compressive stress CP1 in the direction along the through hole 11 is applied to the side block 5 (step S7 in FIG. 5). In this step S7, the screw portion 7a is fastened (tightened) to the spiral groove SG1, and the head portion 7b locked above the hole portion 15, that is, above the through hole 11, and the screw portion via the spiral groove SG1. By sandwiching and holding the side block 5 from above and below with the lower spiral portion 3 locked to 7a, that is, by sandwiching the side block 5, the compressive stress CP1 in the direction along the hole portion 15, that is, the through hole 11 is applied to the side block 5. Apply.

In step S5, the injection material 16a is then cured, and the anchor bolt 7 is embedded in the hole portion 12 by the cured injection material 16 to fix the side block 5 and the lower shoe portion 3 to the base 9. (Step S8 in FIG. 5). As a result, the side block 5 and the lower shoe portion 3 can be easily fixed to the base 9. Further, at this time, as shown in FIG. 2, the compressive stress CP1 in the direction along the through hole 11 is applied in a state where the screw portion 7a is screwed and fastened (tightened) with the spiral groove SG1. Anchor bolts 7 are embedded in the holes 12 while being applied to the side blocks 5.

As described above, in the bearing device 1 (see FIG. 4) before the reinforcement step of the present embodiment, when an earthquake occurs, the width direction (Y) of the bridge girder 8 from the upper shoe portion 4 or the like with respect to the side block 5. When a large stress (in the axial direction) is applied, the side block 5 may be damaged, the bridge girder 8 may be displaced, and the bridge girder 8 may fall from the base 9.

Further, the above-mentioned problem of damage to the side block 5 is not limited to the case where an earthquake occurs and a large stress in the width direction (Y-axis direction) of the bridge girder 8 is applied to the side block 5, and other than the earthquake. This is a common problem even when an impact is generated and a large stress is applied to the side block 5.

Here, the present inventors consider that among the bridges for railways, the side block 5 is damaged when a large earthquake such as the Hyogo-ken Nanbu Earthquake and the Tohoku-Pacific Ocean Earthquake occurs, and the side block after the damage. As a result of detailed analysis of the shape of 5, it was found that most of the damage to the side block 5 is, for example, shear fracture in which the side block 5 is obliquely broken with the lower end surface LE1 of the side block 5 as the fracture surface. ..

On the other hand, according to the method of reinforcing the bearing device of the present embodiment, after removing the existing anchor bolt 107, a spiral is formed on the inner peripheral surface 13a of the hole portion 13 formed in the lower shoe portion 3 of the through hole 11. After forming the groove SG1, the anchor bolt 7 including the screw portion 7a is newly installed.

In such a case, by tightening the head portion 7b of the anchor bolt 7, compressive stress in the direction along the through hole 11 can be applied to the side block 5, that is, prestress can be introduced into the side block 5. Therefore, even when the side block 5 receives shear stress from the upper shoe portion 4, a crack is generated between the side block 5 and the lower shoe portion 3 at the tensile edge of the side block 5, that is, the side block. It is possible to prevent or suppress shear failure of 5 and improve the shear strength of the side block 5.

Further, by forming the spiral groove SG1 on the inner peripheral surface 15a of the hole portion 15, the fracture surface of the side block 5 becomes a filling structure, and the shear strength of the side block 5 can be improved.

Further, when the lower shoe portion 3 is made of a material such as cast iron or steel such as cast steel, the anchor bolt 7 is preferably used as a material for the side block 5 and the lower shoe portion 3 such as steel. A material having a relatively high toughness, that is, a material having a low carbon content can be used. As a result, even if a crack occurs between the side block 5 and the lower shoe portion 3, it is possible to prevent or suppress the growth of the crack, and prevent or suppress the side block 5 from breaking. can do.

As described above, the lower end surface of the side block 5 is referred to as the lower end surface LE1, and the lower end surface of the hole portion 15 formed in the side block 5 of the through holes 11 is referred to as the lower end surface LE2. At this time, on the upper surface of the partial PR11, the height position HP1 of the side portion LE11 opposite to one side (first side) in the width direction (Y-axis direction) of the bridge girder 8 of the lower end surface LE1 is the lower end surface. The width of the bridge girder 8 of the lower end surface LE2 is arranged above the height position HP2 of the side portion LE12 on one side (first side) of the LE1 in the width direction (Y-axis direction) of the bridge girder 8. The height position HP3 of the side portion LE21 opposite to one side (first side) in the direction (Y-axis direction) is one side (Y-axis direction) of the lower end surface LE2 in the width direction (Y-axis direction) of the bridge girder 8. The side portion LE22 on the first side) is inclined so as to be arranged above the height position HP4.

In other words, the boundary surface between the side block 5 and the partial PR11, that is, the lower shoe portion 3, is the boundary surface BS1 (see FIG. 8), and the boundary surface between the hole portion 15 and the hole portion 13 is the boundary surface BS2 (see FIG. 8). To do. At this time, the upper surface of the partial PR11 is the height position of the side portion BS11 (see FIG. 8) of the boundary surface BS1 on the side opposite to one side (first side) in the width direction (Y-axis direction) of the bridge girder 8. HP1 is arranged above the height position HP2 of the side portion BS12 (see FIG. 8) on one side (first side) of the boundary surface BS1 in the width direction (Y-axis direction) of the bridge girder 8. , The height position HP3 of the side portion BS21 (see FIG. 8) on one side (first side) and the opposite side in the width direction (Y-axis direction) of the bridge girder 8 of the boundary surface BS2 is the boundary surface BS2. The bridge girder 8 is inclined so as to be arranged above the height position HP4 of the side portion BS22 (see FIG. 8) on one side (first side) in the width direction (Y-axis direction).

As described above, the lower shoe portion 3 is formed on the upper surface of the portion PR13 of the lower shoe portion 3 provided below the upper shoe portion 4, and is formed in the width direction (Y-axis direction) of the bridge girder 8. An upper surface portion 3b including an upper surface formed of a convex curved surface having a semi-cylindrical shape extending along the line may be included. In such a case, the height position HP1 means the height position of the portion PR14 (see FIG. 3) having the highest height position in the side portion LE11.

In such a case, as described with reference to FIG. 8 described above, preferably, the spiral groove SG1 is formed on the side block 5 from the inner peripheral surface 13a of the hole portion 13 formed in the lower shoe portion 3. The hole portion 15 is continuously formed up to the inner peripheral surface 15a of the portion PR2 adjacent to the hole portion 13. As a result, the spiral groove SG1 is formed on the entire inner peripheral surface of the hole portion 13, so that the head of the anchor bolt 7 is compared with the case where the spiral groove SG1 is not formed on a part of the upper side of the inner peripheral surface of the hole portion 13. By tightening 7b, the compressive stress CP1 applied to the side block 5 can be surely increased, and the shear strength of the side block 5 can be surely improved. Since the spiral groove SG1 is formed on the entire inner peripheral surface of the hole portion 13, it is possible to prevent compressive stress from being applied to the lower shoe portion 3.

Further, with such a structure, the fracture surface of the side block 5 becomes a filling structure more reliably, and the shear strength of the side block 5 can be reliably improved.

Further, preferably, the height position HP5, which is the height position of the upper end of the spiral groove SG1, that is, the height position of the upper end of the partial PR2, is equal to or lower than the height position HP1 and equal to or higher than the height position HP3. ..

The height position HP1 is a side portion LE11 on one side (first side) and the opposite side in the width direction (Y-axis direction) of the bridge girder 8 of the lower end surface LE1, that is, the side block 5 and the lower shoe portion 3. This is the height position of the part where the cracks occur. Therefore, when the height position HP5 is equal to or less than the height position HP1, the portion of the side block 5 near the height position HP1, that is, the side portion LE11, is compared with the case where the height position HP5 exceeds the height position HP1. Compressive stress can be reliably applied to the portions where the height positions are almost the same. Therefore, the shear strength of the side block 5 can be reliably improved.

When the height position HP5 is equal to or higher than the height position HP3, as described above, the spiral groove SG1 is formed on the entire inner peripheral surface of the hole portion 13, so that the height position HP5 is less than the height position HP3. The compressive stress CP1 applied to the side block 5 can be surely increased as compared with the case where the spiral groove is not formed in a part of the upper side of the inner peripheral surface of the hole portion 13.

Preferably, the inner diameter DA1 of the portion PR3 above the portion PR2 of the hole 15 is larger than the inner diameter DA2 of the hole 13, and the height position HP6 of the lower end of the portion PR3 is the height position HP5 or higher. , Height equal to or higher than HP5.

With such a structure, after removing the existing anchor bolt 107 (see FIG. 4) and widening the hole portion 15, a spiral groove SG1 or a tap groove is formed on the inner peripheral surface 13a of the hole portion 13. , The spiral groove SG1 can be easily formed on the inner peripheral surface 13a of the hole portion 13.

Although the invention made by the present inventor has been specifically described above based on the embodiment thereof, the present invention is not limited to the embodiment and can be variously modified without departing from the gist thereof. Needless to say.

Within the scope of the idea of the present invention, those skilled in the art can come up with various modified examples and modified examples, and it is understood that these modified examples and modified examples also belong to the scope of the present invention.

For example, a person skilled in the art appropriately adds, deletes, or changes the design of each of the above-described embodiments, or adds, omits, or changes the conditions of the process of the present invention. As long as it has a gist, it is included in the scope of the present invention.

The present invention is effective when applied to a method for reinforcing a bearing device that supports a bearing body fixed to a bridge girder and a bearing device.

1 Bearing device 2 Rib part 3 Lower mortar part 3a Upper surface 3b Upper surface part 4 Upper mortar part 4a Lower surface 5, 6 Side block 7, 107 Anchor bolt 7a Screw part 7b Head 8 Bridge girder 9 Base 10 Connection part 11 Through hole 12 Hole part 13, 15 Holes 13a, 15a Inner peripheral surface 14 Pressing block 16, 16a Injection material 116 Mortar BS1, BS2 Boundary surface BS11, BS12, BS21, BS22 Side part CP1 Compressive stress DA1, DA2 Inner diameter HP1 to HP6 Height position LE1, LE2 Lower end surface LE11, LE12, LE21, LE22 Side part PR11, PR12, PR13, PR14, PR2, PR3 Part SG1 Spiral groove

Claims (8)

In the method of reinforcing the bearing device that supports the bearing body fixed to the bridge girder,
The bearing device is
A bearing body that is fixed to the base, is provided under the bearing, and supports the bearing.
Of the bearing main body, a protruding portion that protrudes upward from the first portion arranged on the first side in the width direction of the bridge girder with respect to the supported body and is provided integrally with the bearing main body. ,
Have,
Through holes are formed in the projecting portion and the bearing body portion to penetrate the projecting portion and the bearing body portion and reach the base.
A hole portion communicating with the through hole is formed in the base.
The protruding portion and the bearing main body portion are fixed to the base by embedding a first anchor bolt penetrating the through hole in the hole portion.
The method of reinforcing the bearing device is
(A) A step of removing the first anchor bolt from the hole and the through hole.
(B) After the step (a), a step of forming a spiral groove on the first inner peripheral surface of the first hole formed in the bearing main body among the through holes.
(C) After the step (b), a second anchor bolt including a screw portion screwable into the spiral groove is inserted into the through hole, and the second anchor bolt inserted into the through hole is inserted into the through hole. A step of fixing the protruding portion and the support main body portion to the base by embedding the screw portion in the hole portion in a state of being screwed into the spiral groove.
Have,
In the step (c), a method for reinforcing a bearing device in which a compressive stress in a direction along the through hole is applied to the protruding portion by screwing the screw portion into the spiral groove. In the method for reinforcing the bearing device according to claim 1,
When the lower end surface of the protruding portion is the first lower end surface and the lower end surface of the second hole portion formed in the protruding portion of the through holes is the second lower end surface.
On the upper surface of the first portion, the first height position of the first side portion of the first lower end surface opposite to the first side in the width direction is the width direction of the first lower end surface. The third side portion of the second lower end surface of the second lower end surface opposite to the first side in the width direction is arranged above the second height position of the second side portion of the first side. The third height position of the second lower end surface is inclined so as to be arranged above the fourth height position of the fourth side portion of the first side in the width direction of the second lower end surface.
In the step (b), the spiral is formed on the first inner peripheral surface of the first hole portion and the second inner peripheral surface of the second portion of the second hole portion adjacent to the first hole portion. Form a groove,
A method for reinforcing a bearing device, wherein the fifth height position of the upper end of the second portion is equal to or lower than the first height position and equal to or higher than the third height position. In the method for reinforcing the bearing device according to claim 2,
(D) After the step (a) and before the step (b), a step of widening the third portion of the second hole portion above the second portion.
A method of reinforcing a bearing device. In the method for reinforcing the bearing device according to claim 2 or 3,
(E) A step of injecting an injection material made of mortar into the hole after the step (b) and before the step (c).
Have,
The step (c) is
(C1) After the step (e), the second anchor bolt is inserted into the second hole, and the second anchor bolt inserted into the second hole is injected with the injection material. A step of inserting the screw portion into the hole portion while being screwed into the spiral groove.
(C2) After the step (c1), the injection material is cured, and the second anchor bolt is embedded in the hole portion by the cured injection material, whereby the protrusion portion and the support main body portion are used as the base. The process of fixing,
How to reinforce bearing devices, including. In a bearing device that supports a bearing body fixed to a bridge girder
A bearing main body that is fixed to the base, is provided under the bearing, and supports the bearing.
Of the bearing main body, a protruding portion that protrudes upward from the first portion arranged on the first side in the width direction of the bridge girder with respect to the supported body and is provided integrally with the bearing main body. ,
Have,
Through holes are formed in the projecting portion and the bearing body portion to penetrate the projecting portion and the bearing body portion and reach the base.
A hole portion communicating with the through hole is formed in the base.
A spiral groove is formed on the first inner peripheral surface of the first hole formed in the bearing main body of the through hole.
Anchor bolts including a screw portion that can be screwed into the spiral groove are inserted into the through hole in the protruding portion and the support main body portion, and the anchor bolt inserted into the through hole has the screw portion that spirals. By being embedded in the hole while being screwed into the groove, it is fixed to the base.
A bearing device in which a compressive stress is applied to the protruding portion in a direction along the through hole by screwing the threaded portion into the spiral groove. In the bearing device according to claim 5,
When the lower end surface of the protruding portion is the first lower end surface and the lower end surface of the second hole portion formed in the protruding portion of the through holes is the second lower end surface.
On the upper surface of the first portion, the first height position of the first side portion of the first lower end surface opposite to the first side in the width direction is the width direction of the first lower end surface. The third side portion of the second lower end surface of the second lower end surface opposite to the first side in the width direction is arranged above the second height position of the second side portion of the first side. The third height position of the second lower end surface is inclined so as to be arranged above the fourth height position of the fourth side portion of the first side in the width direction of the second lower end surface.
The spiral groove is formed on the first inner peripheral surface of the first hole portion and the second inner peripheral surface of the second portion of the second hole portion adjacent to the first hole portion.
A bearing device in which the fifth height position of the upper end of the second portion is equal to or lower than the first height position and equal to or higher than the third height position. In the bearing device according to claim 6,
A bearing device in which the first inner diameter of the third portion of the second hole portion above the second hole portion is larger than the second inner diameter of the first hole portion. In the bearing device according to claim 6 or 7.
In the protruding portion and the support main body portion, the anchor bolt is inserted into the second hole portion, and the anchor bolt inserted into the second hole portion is screwed into the spiral groove. An anchor bolt that is inserted into the hole and is fixed to the base by being embedded in the hole with an injection material made of hardened mortar.

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