Methods for reinforcing the main body of a column, reinforcing structure, and support structure

Abstract

To promptly reinforce existing concrete columnar structures that have a footing and a column body extending upward from the footing. [Solution] The method includes: a main reinforcement hole creation step of providing a plurality of main reinforcement holes 5a in the footing 5 arranged along the outer circumference of the column body 6; a first main reinforcement anchoring step of inserting a first main reinforcement 21 into each of the main reinforcement holes 5a and injecting a filler to anchor the first main reinforcement 21 to the footing 5; a support step of inserting at least one portion of the first main reinforcement 21 through the main reinforcement through-holes 22e of the corresponding fixing bracket 22, fixing the fixing bracket 22 to the side surface of the column body 6, and then attaching an engaging member 23 to the first main reinforcement 21 so as to engage with the fixing bracket 22 to construct a support structure 24 that supports the column body 6; and a first reinforcement step of pouring concrete around the outer circumference of the column body 6 so as to embed all the first main reinforcement 21, fixing bracket 22 and engaging member 23, thereby reinforcing at least the lower part of the column body 6.

Description

Technical Field

[0001] The present invention relates to a method for reinforcing a column body, a reinforcing structure, and a support structure in an existing concrete columnar structure having a footing and a column body extending upward from the footing.

Background Art

[0002] In some cases, a reinforced concrete columnar structure damaged due to an earthquake, salt damage, or the like is reinforced. Patent Document 1 describes an RC erection method for reinforcing a reinforced concrete pier extending upward from a footing. In the RC erection method, a reinforced concrete wall is provided on the outer periphery of the pier to thicken the pier.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] Before reinforcing a damaged pier by the RC erection method, a temporary support for supporting the load received by the pier to be reinforced is installed near the pier. However, it takes time to install the temporary support. In addition, the damaged pier gradually deteriorates until it is reinforced. For example, the pier may be damaged by an earthquake and then further damaged by aftershocks. Then, the damage becomes large before reinforcement, and the pier may collapse. Therefore, there is a need for a method for quickly reinforcing a pier and a reinforcing structure that can be quickly constructed.

[0005] In view of the above background, an object of the present invention is to enable quick reinforcement of a column body in an existing concrete columnar structure having a footing and a column body extending upward from the footing. [Means for solving the problem]

[0006] To solve the above problems, one aspect of the present invention provides a method for reinforcing a column body (6) in an existing concrete columnar structure (2) having a footing (5) and a column body (6) extending upward from the footing, comprising: a main reinforcement hole creation step (Figure 2) in which a plurality of main reinforcement holes (5a) are provided in the footing at intervals from each other along the outer circumference of the column body; a first main reinforcement anchoring step (Figure 3) in which a first main reinforcement (21) for reinforcing the column body is inserted into each of the main reinforcement holes and a filler is injected to anchor the first main reinforcement to the footing; and a main reinforcement through hole (22e A reinforcement method comprising: a support step (Figures 3 to 5) in which a support structure (24) for supporting the column body is constructed by preparing a plurality of fixing brackets (22) having ), inserting at least one portion of the first main reinforcement through the main reinforcement through hole of the corresponding fixing bracket, fixing the fixing bracket to the side surface of the column body, and then attaching an engaging member (23) to the first main reinforcement so as to engage with the fixing bracket; and a first reinforcement step (Figure 10) in which concrete is poured around the outer circumference of the column body so as to embed all of the first main reinforcement, the fixing brackets and the engaging member, thereby reinforcing at least the lower part of the column body.

[0007] According to this embodiment, the support structure is simple in configuration, allowing for rapid construction. Therefore, workers can construct the support structure and quickly reinforce the column body without installing temporary supports to support the load on the column body. Furthermore, since the first reinforcement step is performed without removing the support structure, the first reinforcement step can be performed quickly to reinforce the column body. Accordingly, the reinforcement method allows for rapid reinforcement of the column body in existing concrete columnar structures having a footing and a column body extending upward from the footing.

[0008] In the above embodiment, after the support step and before the first reinforcement step, a base reinforcement construction step (Figure 9) is included in which a plurality of first stirrups (31) extending in the circumferential direction of the column body are attached to a plurality of first main reinforcements to construct a base reinforcement (32), and in the first reinforcement step, concrete is poured around the outer circumference of the column body so that the plurality of first main reinforcements, the plurality of first stirrups, the fixing fittings and the engaging members are embedded.

[0009] According to this embodiment, since the multiple first stirrups are attached to the first main reinforcement after the support process, the first stirrups are not attached to the first main reinforcement when constructing the support structure during the support process. This allows the support structure to be constructed without interference from the first stirrups. Furthermore, the time required to attach the first stirrups before constructing the support structure is reduced. As a result, the support structure can be constructed more quickly compared to the case where the support process is carried out after the multiple first stirrups have been attached to the first main reinforcement.

[0010] In the above embodiment, after the support step, the base reinforcement may include an extension step (Figures 11 and 12) in which second main reinforcements (35) are joined to the upper ends of each of the first main reinforcements via joints (34), and a plurality of second stirrups (36) extending in the circumferential direction of the column body are attached to the second main reinforcements to extend the base reinforcement upward, and a second reinforcement step (Figure 13) in which concrete is poured around the outer circumference of the column body to reinforce the column body so that all of the second main reinforcements and second stirrups are embedded.

[0011] In this embodiment, the extension process, which includes the work of attaching the second main reinforcement to the upper end of the first main reinforcement, is performed after the support process. When constructing the support structure in the support process, the second main reinforcement is not attached to the first main reinforcement. This allows the support structure to be constructed without interference from the second main reinforcement. Furthermore, the time required to attach the second main reinforcement before constructing the support structure is eliminated. As a result, the support structure can be constructed more quickly compared to the case where the support process is performed after the second main reinforcement has been attached to the first main reinforcement.

[0012] In the above embodiment, the first main reinforcement bar may have a threaded node, and the engaging member may be a nut (23) that screws onto the node.

[0013] According to this embodiment, the engaging member can be quickly attached to the first main reinforcement by screwing it with the first main reinforcement. This reduces the time required to construct the support structure. Furthermore, a general-purpose product that can be prepared without special processing can be used as the first main reinforcement. Using a general-purpose product as the first main reinforcement makes it easier to prepare for implementing the reinforcement method.

[0014] In the above embodiment, in the support step, it is preferable to first attach the engaging member to the first main reinforcement bar, which is located close to the damaged part of the column body.

[0015] According to this embodiment, the first main reinforcement, fixing brackets, and engaging members can be used to support the column body, prioritizing the area closest to the damaged part. Therefore, the extent of damage to the column body can be appropriately suppressed.

[0016] In the above embodiment, the present invention further includes an installation step (Figure 1) in which a measuring device (11) for detecting the inclination or relative position of the column body is installed before the main reinforcement hole creation step, and a monitoring step in which the detection results of the measuring device are continuously monitored over time from the start of the main reinforcement hole creation step until the reinforcement of the columnar structure is completed, wherein in the monitoring step, it is possible to determine whether the inclination or relative position of the column body is abnormal based on the detection results of the measuring device, and to provide notification when it is determined that the inclination or relative position is abnormal.

[0017] According to this configuration, notification is issued when the inclination or relative position of the column body is abnormal and is considered to be in a highly dangerous situation. When notification is issued, workers can stop the reinforcement work. This makes it possible to reinforce the column body more safely than if the monitoring process were not implemented.

[0018] Furthermore, in order to solve the above problems, another aspect of the present invention is a reinforcing structure (1) for a column body in an existing concrete columnar structure (2) having a footing (5) and a column body (6) extending upward from the footing, the reinforcing structure (1) comprising: a first main reinforcement (21) whose lower end is fixed to each of a plurality of main reinforcement holes (5a) provided in the footing and arranged at intervals from each other along the outer circumference of the column body; a fixing bracket (22) fixed to the side surface of the column body, with a corresponding main reinforcement through hole (22e) inserted through at least one of the first main reinforcement; an engaging member (23) attached to the first main reinforcement and engaged with the fixing bracket; and a first reinforcing concrete (33) constructed at least at the lower part of the outer circumference of the column body such that all of the first main reinforcement, the fixing bracket and the engaging member are embedded.

[0019] According to this embodiment, the support structure has a simple configuration, allowing it to be constructed quickly. Therefore, workers can construct the support structure and quickly reinforce the column body without having to install temporary supports to support the load on the column body. Furthermore, since the first reinforcing concrete can be constructed without removing the support structure, the first reinforcing concrete can be constructed quickly to reinforce the column body. Thus, the reinforcing structure makes it possible to quickly reinforce the column body in an existing concrete columnar structure having a footing and a column body extending upward from the footing.

[0020] In the above embodiment, it is preferable to further include second main reinforcement bars (35) joined to the upper ends of each of the first main reinforcement bars via joints (34), a plurality of second stirrups (36) attached to the second main reinforcement bars and extending in the circumferential direction of the column body, and a second reinforcing concrete (37) poured around the outer circumference of the column body so that all of the second main reinforcement bars and the plurality of second stirrups are embedded.

[0021] According to this embodiment, the column body can be reinforced even more firmly by the second reinforcing concrete.

[0022] In the above aspect, the fixing fitting includes a first plate portion (22a) fixed to the side surface of the column main body, a second plate portion (22b) rising from the edge of the first plate portion and extending in a direction intersecting the plate surface of the first plate portion, and a third plate portion (22c) extending in a direction orthogonal to the plate surfaces of the first plate portion and the second plate portion and coupled to the first plate portion and the second plate portion. The second plate portion may have the main reinforcement through-hole through which the first main reinforcement is inserted and engage with the engaging member.

[0023] According to this aspect, since the fixing fitting has a simple structure, the fixing fitting can be easily manufactured.

[0024] In the above aspect, the fixing fittings arranged at the first height (h1) and the fixing fittings arranged at the second height (h2) lower than the first height may be alternately arranged along the circumferential direction.

[0025] According to this aspect, since interference between adjacent fixing fittings is suppressed, it becomes easy to attach the fixing fittings to each of the plurality of first main reinforcements.

[0026] In the above aspect, the first main reinforcement to which the fixing fitting and the engaging member are attached and at least one first main reinforcement to which the fixing fitting and the engaging member are not attached may be alternately arranged along the circumferential direction.

[0027] According to this aspect, since the interval between the fixing fittings adjacent to each other in the circumferential direction can be made sufficiently large, it becomes easy to attach the fixing fitting 22 to each of the plurality of first main reinforcements.

[0028] In the above aspect, the first reinforced concrete may be provided only at the lower part of the column main body.

[0029] According to this aspect, since the reinforcement structure can be constructed promptly, the column main body can be reinforced more promptly.

[0030] Furthermore, in order to solve the above problems, another aspect of the present invention is a support structure (24) for a column body in an existing concrete columnar structure (2) having a footing (5) and a column body (6) extending upward from the footing, the support structure comprising: a first main reinforcement (21) whose lower end is fixed to each of a plurality of main reinforcement holes (5a) provided in the footing and arranged at intervals from each other along the outer circumference of the column body; a fixing bracket (22) fixed to the side surface of the column body, through which a corresponding main reinforcement through hole (22e) is inserted into at least one of the first main reinforcement; and an engaging member (23) attached to the first main reinforcement and engaged with the fixing bracket.

[0031] According to this embodiment, the support structure is simple in configuration, allowing it to be constructed quickly. Therefore, workers can construct the support structure and quickly reinforce the column body without having to install temporary supports to support the load on the column body. [Effects of the Invention]

[0032] According to the above embodiment, an existing concrete columnar structure having a footing and a column body extending upward from the footing can be quickly reinforced. [Brief explanation of the drawing]

[0033] [Figure 1] Side view showing the schematic configuration of the bridge pier. [Figure 2] Side cross-section of a bridge pier under reinforcement. [Figure 3] Side cross-section of a bridge pier under reinforcement. [Figure 4] Side cross-section of a bridge pier under reinforcement. [Figure 5] Side cross-section of a bridge pier under reinforcement. [Figure 6] Perspective view of the fixing bracket [Figure 7] Plan view of a bridge pier showing the configuration of the support structure. [Figure 8] schematic front view of the support structure [Figure 9] Front view of the reinforcement structure under construction [Figure 10] Front view of the reinforcement structure under construction [Figure 11] Front view of the reinforcement structure under construction [Figure 12] Front view of the reinforcement structure under construction [Figure 13] Front view of the reinforcement structure under construction [Figure 14] Front view showing a modified reinforcement structure. [Modes for carrying out the invention]

[0034] Hereinafter, several embodiments and modifications of the present invention will be described in detail with reference to the drawings. The reinforcement structure 1 of the embodiment is a reinforcement structure for an existing concrete bridge pier 2 (columnar structure).

[0035] Figure 1 is a side view showing the schematic configuration of the pier 2. As shown in Figure 1, the pier 2 supports the bridge girder 4 from below via a bearing 3. The pier 2 has a footing 5 supported by the ground and a bridge truss body 6 (column body) extending upward from the footing 5. In this embodiment, the cross-section of the bridge truss body 6 is rectangular (see Figure 7). The cross-section of the bridge truss body 6 does not have to be rectangular. For example, the cross-section of the bridge truss body 6 may be circular, oval, or elliptical.

[0036] The reinforcement target of reinforcement structure 1 is the bridge truss body 6. Reinforcement structure 1 is a reinforced concrete wall that covers the outer perimeter of the bridge truss body 6. The reinforcement target of reinforcement structure 1 may be the column body of an existing concrete columnar structure having a footing and a column body extending upward from the footing. For example, the reinforcement target of reinforcement structure 1 may be the column of a building extending upward from the footing. Reinforcement structure 1 can be constructed using the reinforcement method described below. The reinforcement method is a type of RC jacketing method.

[0037] The reinforcement method involves constructing the reinforcement structure 1 while monitoring the condition of the bridge truss 6. The reinforcement method includes (A) an installation step and (B) a monitoring step for monitoring the condition of the bridge truss 6. The reinforcement method also includes (C) a main reinforcement hole creation step, (D) a first main reinforcement anchoring step, (E) a support step, (F) a base reinforcement construction step, (G) a first reinforcement step, (H) an extension step, and (I) a second reinforcement step. Details of these steps are described below.

[0038] (A) Installation process. The installation process involves installing a measuring device that detects the inclination or relative position of the bridge truss body 6. In this embodiment, an inclinometer 11 is used as the measuring device. The inclinometer 11 detects its own inclination (angle) in the vertical and horizontal directions as the inclination of the bridge truss body 6. As shown in Figure 1, the worker installs the inclinometer 11 on the side of the bridge truss body 6 and connects the inclinometer 11 to the control device 12. Note that the worker may change the position of the inclinometer 11 during the construction of the reinforcement structure 1 so that it does not interfere with the work.

[0039] Alternatively, instead of the inclinometer 11, a distance sensor may be used as the measuring device. Optical or ultrasonic distance sensors may be used. When a distance sensor is used as the measuring device, it may be installed on the upper surface of the bridge truss body 6 around the bearing 3, and a target marker may be installed on the bridge girder 4. The distance sensor measures the distance between itself and the target installed on the bridge girder 4 as the relative position of the bridge truss body 6. Therefore, the distance sensor detects the relative position of the part of the bridge truss body 6 where the distance sensor is installed relative to the part of the bridge girder 4 where the target is installed (the relative position of the bridge truss body 6 with respect to the bridge girder 4). The distance sensor and target may be installed so that the distance sensor measures the relative position in the bridge axis direction or the relative position perpendicular to the bridge axis.

[0040] As described later, the control device 12 is configured to determine whether the inclination of the bridge truss 6 is abnormal based on the inclination detected by the inclinometer 11, and to provide notification when it determines that the inclination is abnormal. An amplifier or speaker may be connected to the control device 12, and the control device 12 may provide notification by emitting sound from the speaker. A light-emitting device such as an LED may be connected to the control device 12, and the control device 12 may provide notification by illuminating the light-emitting device. In addition, the control device 12 may be connected to a computer network such as the Internet, and the control device 12 may provide notification by transmitting information that there is an abnormality in the inclination of the bridge truss 6 to a terminal connected to the computer network.

[0041] (B) Monitoring process. The monitoring process involves continuously monitoring the inclination detected by the inclinometer 11 over time, from the start of the (C) main reinforcement hole creation process until the reinforcement of pier 2 is completed (until the (I) second reinforcement process is completed). If a distance sensor is used instead of the inclinometer 11 as the measuring device, the relative position detected by the distance sensor is continuously monitored over time during the monitoring process.

[0042] The bridge girder 4 expands and contracts in response to temperature changes such as changes in ambient temperature. The bridge truss body 6 is displaced in response to the expansion and contraction of the bridge girder 4. The damaged bridge truss body 6 will gradually become more damaged until it is reinforced. When the damage to the bridge truss body 6 becomes extensive, it may be displaced more than it would be under normal conditions and may collapse. Therefore, in the monitoring process, the control device 12 continuously monitors the inclination detected by the inclinometer 11 over time, from the start of the (C) main reinforcement hole creation process until the reinforcement of the bridge pier 2 is completed ((I) until the second reinforcement process is completed). In monitoring, the control device 12 determines whether the inclination of the bridge truss body 6 is abnormal based on the inclination (angle) detected by the inclinometer 11, and if it determines that the inclination is abnormal, it continuously provides notification as described above over time.

[0043] Various methods may be used for the determination method of the control device 12. For example, the minimum and maximum values ​​of the inclination (angle) of the bridge truss 6 are measured using the inclinometer 11 at a predetermined time (for example, one day). Then, the worker sets an angle range in which the bridge truss 6 is considered to be normal (hereinafter referred to as the "normal range"). The normal range may be a theoretical value. In monitoring, the control device 12 obtains the angle from the inclinometer 11 and determines whether the obtained angle is within the normal range. If the angle is within the normal range, the inclination of the bridge truss 6 can be considered to be normal. If the control device 12 determines that the angle is within the normal range, it determines that the inclination of the bridge truss 6 is normal. On the other hand, if the angle is not within the normal range (if the angle detected by the inclinometer 11 is less than the lower limit of the normal range or greater than the upper limit of the normal range), the inclination of the bridge truss 6 can be considered to be abnormal. If the control device 12 determines that the angle is not within the normal range, it determines that there is an abnormality in the inclination of the bridge truss 6 and issues a notification.

[0044] Furthermore, for example, the worker calculates the average value of the inclination (angle) of the bridge truss 6 measured by the inclinometer 11 over a predetermined period of time (e.g., one day). During monitoring, the control device 12 obtains the angle from the inclinometer 11 and determines whether the absolute value of the difference between the obtained angle and the average value (average value - angle) is greater than or equal to a predetermined threshold. If the control device 12 determines that the absolute value of the difference between the angle and the average value (average value - angle) is less than the threshold (not greater than or equal to the threshold), it determines that there is no abnormality in the inclination of the bridge truss 6. On the other hand, if the control device 12 determines that the absolute value of the difference between the angle and the average value (average value - angle) is greater than or equal to the threshold, it determines that there is an abnormality in the inclination of the bridge truss 6 and issues a notification.

[0045] Furthermore, if a distance sensor is used instead of the inclinometer 11, the determination may be made as follows. For example, the worker measures the minimum and maximum relative position of the bridge truss body 6 (the relative position of the bridge truss body 6 with respect to the bridge girder 4) using the distance sensor at a predetermined time (e.g., one day). The worker then sets a range of relative positions within which the bridge truss body 6 is considered to be normal (hereinafter referred to as the "normal distance range"). The normal distance range may be a theoretical value. During monitoring, the control device 12 obtains the relative position from the distance sensor and determines whether the relative position is within the normal distance range. If the relative position is within the normal distance range, the bridge truss body 6 can be considered to have no abnormalities in its relative position. If the control device 12 determines that the relative position is within the normal distance range, it determines that the bridge truss body 6 has no abnormalities in its relative position. On the other hand, if the relative position is not within the normal distance range (if the relative position detected by the distance sensor is less than the lower limit of the normal distance range or greater than the upper limit of the normal distance range), the bridge truss body 6 can be considered to have an abnormality in its relative position. If the control device 12 determines that the relative position is not within the normal distance range, it determines that there is an abnormality in the relative position of the bridge truss 6 and issues a notification.

[0046] Thus, in this reinforcement method, notification is issued if the inclination or relative position of the bridge truss 6 is abnormal and is considered to be in a highly dangerous situation. When notification is issued, workers can stop the reinforcement work. This makes it possible to reinforce the bridge truss 6 more safely than if the monitoring process were not implemented.

[0047] (C) Main reinforcement hole creation process. As shown in Figure 2, the main reinforcement hole creation process is the process of creating multiple main reinforcement holes 5a in the footing 5. The worker drills holes at multiple predetermined locations on the footing 5 (multiple positions spaced apart from each other along the outer circumference of the bridge truss 6) to create multiple main reinforcement holes 5a. As a result, the multiple main reinforcement holes 5a are arranged spaced apart from each other along the outer circumference of the bridge truss 6. Before or after the main reinforcement hole creation process, the worker may create irregularities on the surface of the footing 5 and the bridge truss 6 by blasting or chipping. As a result, the first reinforcing concrete 33 (see Figure 10) and the second reinforcing concrete 37 (see Figure 13), which will be described later, will adhere more closely to and integrate with the footing 5 and the bridge truss 6.

[0048] (D) First main reinforcement anchoring process. As shown in Figure 2, the first main reinforcement anchoring process is the process of inserting the first main reinforcement 21 into each of the main reinforcement holes 5a and anchoring the first main reinforcement 21. The worker inserts the first main reinforcement 21 to reinforce the bridge truss body 6 into each of the main reinforcement holes 5a and injects a filler to anchor the first main reinforcement 21 to the footing 5. For the filler, it is preferable to use a resin such as epoxy resin or mortar (especially non-shrink mortar). The first main reinforcement 21 has threaded nodes. This ensures that the first main reinforcement 21 is firmly anchored to the footing 5.

[0049] (E) Support process. As shown in Figures 3 to 5, the support process is the process of constructing a support structure 24 that supports the bridge truss body 6 by assembling fixing fittings 22 and nuts 23 (engaging members), etc., to some of the first main reinforcement bars 21 that are anchored to the footing 5.

[0050] As shown in Figure 6, the fixing bracket 22 comprises a first plate portion 22a fixed to the side surface of the bridge truss 6, a second plate portion 22b through which the first main reinforcement 21 is inserted, and two third plate portions 22c that reinforce the fixing bracket 22. The first plate portion 22a has four anchor through-holes 22d that penetrate in the thickness direction. The second plate portion 22b rises from the edge of the first plate portion 22a and extends in a direction intersecting the plate surface of the first plate portion 22a. The second plate portion 22b has a main reinforcement through-hole 22e in the center of the plate surface that penetrates in the thickness direction. The inner diameter of the main reinforcement through-hole 22e is larger than the outer diameter of the first main reinforcement 21 and smaller than the outer diameter of the nut 23. The third plate portion 22c extends in a direction perpendicular to the plate surfaces of the first plate portion 22a and the second plate portion 22b and is connected to the first plate portion 22a and the second plate portion 22b. Thus, because the fixing bracket 22 has a simple structure, it can be easily manufactured.

[0051] The nut 23 is screwed onto the threaded section of the first main reinforcement bar 21. In this way, the nut 23 can be quickly attached to the first main reinforcement bar 21 by screwing it onto the first main reinforcement bar 21. This reduces the time required to construct the support structure 24. In addition, a general-purpose product that can be prepared without special processing can be used as the first main reinforcement bar 21. By using a general-purpose product as the first main reinforcement bar 21, the preparation for implementing the reinforcement method (preparation for constructing the reinforcement structure 1) becomes easier.

[0052] In the support process, the worker first prepares multiple fixing brackets 22. Next, the worker constructs the support structure 24 by performing the following tasks (i) to (iv). (i) As shown in Figure 3, the worker drills holes at corresponding positions on the side of the bridge truss 6 to create anchor holes 6a. (ii) As shown in Figure 3, the worker inserts the first main reinforcement 21 through the main reinforcement through hole 22e (see Figure 6) of the corresponding fixing bracket 22. (iii) As shown in Figure 3, the worker fixes the fixing bracket 22 to the side of the bridge truss 6 using anchor bolts 25. At this point, the worker injects filler into the anchor hole 6a and inserts the tip of the anchor bolt 25 into the anchor through hole 22d and anchor hole 6a of the fixing bracket 22. For the filler, it is preferable to use a resin such as epoxy resin or mortar (especially non-shrink mortar). (iv) As shown in Figures 4 and 5, the nut 23 is attached to the first main reinforcement bar 21 so that the nut 23 engages with the second plate portion 22b of the fixing bracket 22. The first main reinforcement bar 21 may be tensioned in the following way: The worker attaches the nut 23 to the first main reinforcement bar 21, attaches a jack to the upper end of the first main reinforcement bar 21 (above the nut 23), and pulls the upper end of the first main reinforcement bar 21 upward to tension the first main reinforcement bar 21. Then the worker engages the nut 23 with the second plate portion 22b of the fixing bracket 22, and then removes the jack. As a result, the first main reinforcement bar 21 is kept tensioned by the nut 23 engaged with the fixing bracket 22. The inner diameter of the main reinforcement bar through hole 22e is larger than the outer diameter of the first main reinforcement bar 21 and smaller than the outer diameter of the nut 23. As a result, in (ii), the fixing bracket 22 through which the first main reinforcement 21 is inserted can slide up and down relative to the first main reinforcement 21. In addition, the second plate portion 22b of the fixing bracket 22 engages with the nut 23.

[0053] In the support process, the worker performs the above steps (i) to (iv) on the first main reinforcement bar 21 located close to the damaged area of ​​the bridge truss 6, and then attaches the nut 23 first. This allows the area of ​​the bridge truss 6 closest to the damaged area to be supported by the first main reinforcement bar 21, fixing bracket 22, and nut 23 as a priority. Therefore, the extent of damage to the bridge truss 6 can be appropriately suppressed.

[0054] Generally, concrete is strong in compression but weak in tension. Conversely, reinforcing steel is weak in compression but strong in tension. When the upper part of the bridge truss 6 receives a force in the bridge axis direction from the bridge girder 4 via the bearing 3, a moment is generated centered on the lower part of the bridge truss 6. This moment generates a tensile force in the bridge truss 6. For example, in Figure 1, when the upper part of the bridge truss 6 receives a force to the right from the bridge girder 4 via the bearing 3, a moment is generated in the bridge truss 6 centered on the right end of the lower part of the bridge truss 6. Due to this moment, the left side of the lower part of the bridge truss 6 experiences an upward tensile force. Since the bridge truss 6 is made of concrete, it may be damaged by the tensile force.

[0055] As shown in Figure 5, in the support structure 24, the upper surface of the second plate portion 22b of the fixing bracket 22 fixed to the side of the bridge truss body 6 is engaged with a nut 23 attached to the first main reinforcement 21 anchored to the footing 5. When the damaged area of ​​the bridge truss body 6 is pulled upward, the fixing bracket 22 fixed to the side of the bridge truss body 6 is pulled upward, and the first main reinforcement 21 is pulled upward via the nut 23 engaged with the fixing bracket 22. Since the first main reinforcement 21 is strong in tension, it can reliably resist the upward pulling force. The first main reinforcement 21 exerts a downward force on the fixing bracket 22 via the nut 23, and the side of the bridge truss body 6 receives a downward force from the fixing bracket 22. In this way, a downward force acts from the first main reinforcement 21 on the bridge truss body 6 when it is pulled upward. As a result, the support structure 24 can support the bridge truss body 6 so that it does not tilt. Furthermore, as described above, in (iv) of the support process (E), if the first main reinforcement 21 is in a tensioned state, the tension of the first main reinforcement 21 prevents it from being pulled upward by the fixing bracket 22. As a result, the upward movement of the fixing bracket 22 is suppressed, and the upward movement of the side surface of the bridge truss 6 is further suppressed. Consequently, the support structure 24 can support the bridge truss 6 more firmly to prevent it from tilting.

[0056] Figure 7 is a plan view of the pier 2 showing the configuration of the support structure 24. Figure 8 is a schematic front view of the support structure 24. In Figure 7, the first main reinforcement bars 21 to which the fixing brackets 22 and nuts 23 are attached (hereinafter referred to as "support first main reinforcement bars") are indicated by black circles, and the first main reinforcement bars 21 to which the fixing brackets 22 and nuts 23 are not attached (hereinafter referred to as "fixed first main reinforcement bars") are indicated by white circles. As shown in Figure 7, in the support structure 24, the support first main reinforcement bars (black circles in Figure 7) and the fixed first main reinforcement bars (white circles in Figure 7) are arranged alternately along the circumferential direction. This makes it possible to sufficiently increase the spacing between adjacent fixing brackets 22 in the circumferential direction, making it easy to attach the fixing brackets 22 to each of the multiple first main reinforcement bars 21 during the support process. There is no limit to the number of fixed first main reinforcement bars (white circles in Figure 7) between two adjacent support first main reinforcement bars (black circles in Figure 7) (it may be 0 or 2 or more).

[0057] Furthermore, the first main reinforcement bars 21 are anchored to the footing 5 and are not located at a high position. Therefore, the support structure 24 can be constructed without building scaffolding. This allows the support structure 24 to be constructed quickly and the bridge truss 6 to be reinforced.

[0058] As shown in Figure 8, in the support structure 24, fixing brackets 22 positioned at a first height h1 and fixing brackets 22 positioned at a second height h2, which is lower than the first height h1, are arranged alternately along the circumferential direction. This suppresses interference between adjacent fixing brackets 22, making it easier to attach the fixing brackets 22 to each of the multiple first main reinforcement bars 21.

[0059] (F) Base reinforcement construction process. As shown in Figure 9, the base reinforcement construction process is the process of constructing the base reinforcement 32 by attaching multiple first stirrups 31 to multiple first main reinforcements 21. The worker attaches multiple first stirrups 31 extending in the circumferential direction of the bridge body 6 to multiple first main reinforcements 21 (support structure 24) to construct the base reinforcement 32 (in this process, the support structure 24 with multiple first stirrups 31 attached).

[0060] (G) First reinforcement step. As shown in Figure 10, the first reinforcement step is the step of pouring concrete around the outer perimeter of the bridge truss 6 so that a portion of the base reinforcement 32 is embedded. The workers set up the formwork. Next, the workers pour concrete around the outer perimeter of the bridge truss 6 so that all of the first main reinforcement bars 21, first stirrups 31, fixing brackets 22 and nuts 23 of the base reinforcement bars 32 are embedded, thereby constructing the first reinforcing concrete 33 that reinforces at least the lower part of the bridge truss 6.

[0061] As such, the structure of the support structure 24 is simple, and therefore it can be constructed quickly. For this reason, workers can construct the support structure 24 and quickly reinforce the bridge truss 6 without having to install temporary supports to support the load on the bridge truss 6. Thus, the support structure 24 makes it possible to quickly reinforce the bridge truss 6. In addition, since the (G) first reinforcement step is carried out without removing the support structure 24, the (G) first reinforcement step can be carried out quickly and the bridge truss 6 can be reinforced. Thus, the reinforcement method can quickly reinforce the column body of an existing concrete bridge pier 2 having a footing and a bridge truss 6 extending upward from the footing.

[0062] Furthermore, by embedding multiple first stirrups 31 in the concrete poured around the outer perimeter of the bridge truss body 6, the bridge truss body 6 can be reinforced more firmly. Also, since the multiple first stirrups 31 are attached to the first main reinforcement 21 after the (E) support process, the first stirrups 31 are not attached to the first main reinforcement 21 when constructing the support structure 24 in the (E) support process. As a result, the support structure 24 can be constructed without interference from the first stirrups 31. Moreover, there is no time required to attach the first stirrups 31 before constructing the support structure 24. As a result, the support structure 24 can be constructed more quickly compared to the case where the (E) support process is carried out after the multiple first stirrups 31 have been attached to the first main reinforcement 21.

[0063] (H) Extension process. As shown in Figures 11 and 12, the extension process is the process of extending the base reinforcement 32 upward. Workers construct scaffolding from the lower to the upper part of the outer circumference of the bridge truss body 6. Then, as shown in Figure 11, workers join the second main reinforcement 35 to each upper end of the first main reinforcement 21 via mechanical joints 34 (joints). Workers may extend the first main reinforcement 21 by joining multiple second main reinforcement 35 to one first main reinforcement 21. Mechanical joints 34 are, for example, sleeves or couplers. Sleeves and couplers are formed in a cylindrical shape and have an inner hole extending in the axial direction, and can join the first main reinforcement 21 and the second main reinforcement 35 inserted into the inner hole in a state where they are arranged coaxially with each other. Mechanical joints 34 can also join two second main reinforcement 35 in a state where they are arranged coaxially with each other. Pressure welding joints may also be used instead of mechanical joints 34. In other words, the worker may join the second main reinforcement bars 35 to the upper ends of each of the first main reinforcement bars 21 via compression joints.

[0064] As shown in Figure 12, the worker then attaches a plurality of second stirrups 36 extending in the circumferential direction of the bridge truss body 6 to the second main reinforcement 35. This extends the base reinforcement 32 upward. Note that (H) extension step may be performed before (G) first reinforcement step. Alternatively, the second main reinforcement 35 may be joined to the first main reinforcement 21 before (G) first reinforcement step.

[0065] As shown in Figures 8 and 11, in the support structure 24, relatively long first main reinforcement bars 21 and relatively short first main reinforcement bars 21 are arranged alternately along the circumferential direction. This makes it easy to extend the upper ends of each of the multiple first main reinforcement bars 21 by joining them with the second main reinforcement bars 35.

[0066] (I) Second reinforcement process. As shown in Figure 13, the second reinforcement process is the process of pouring concrete around the outer perimeter of the bridge truss 6 so that the extended base reinforcement bars 32 are embedded. The workers set up formwork and pour concrete around the outer perimeter of the bridge truss 6 so that all the first main reinforcement bars 21, second main reinforcement bars 35 and second stirrups 36 are embedded, thereby constructing the second reinforcing concrete 37 that reinforces the bridge truss 6. This constructs the reinforcement structure 1. The height of the upper end surface of the second reinforcing concrete 37 is the same as the height of the upper end surface of the bridge truss 6.

[0067] Thus, in the extension process, the base reinforcement 32 is extended upward, and in the second reinforcement process, concrete is poured around the outer perimeter of the bridge truss 6 so that the extended base reinforcement 32 is embedded, thereby constructing the second reinforcement concrete 37. The second reinforcement concrete 37 further strengthens the bridge truss 6. Furthermore, the extension process (H), which includes the work of attaching the second main reinforcement 35 to the upper end of the first main reinforcement 21, is carried out after the support process (E). When constructing the support structure 24 in the support process, the second main reinforcement 35 is not attached to the first main reinforcement 21. As a result, the support structure 24 can be constructed without interference from the second main reinforcement 35. Moreover, there is no time required to attach the first stirrups 31 before constructing the support structure 24. As a result, the support structure 24 can be constructed more quickly compared to when the support process (E) is carried out after attaching the second main reinforcement 35 to the first main reinforcement 21.

[0068] <Variation> As shown in Figure 14, the modified reinforcement structure 38 is a structure in which the second main reinforcement 35, the second stirrup 36, and the second reinforcing concrete 37 are omitted from the reinforcement structure 1. The reinforcement structure 38 is the first reinforcing concrete 33 in which the support structure 24 is embedded, and is provided only at the lower part of the bridge truss body 6. That is, the reinforcement structure 38 has the first main reinforcement 21 anchored in each of the multiple main reinforcement holes 5a provided in the footing 5, fixing brackets 22 fixed to the side surface of the bridge truss body 6, nuts 23 attached to the first main reinforcement 21 and engaged with the fixing brackets 22, and the first reinforcing concrete 33 constructed at the lower part of the outer circumference of the bridge truss body 6 so that all the first main reinforcement 21, fixing brackets 22, nuts 23, and first stirrup 31 are embedded.

[0069] The reinforcement structure 38 is constructed by (A) installation process to (G) first reinforcement process. As shown in Figure 14, in the reinforcement structure 38, all first main reinforcements 21 are at the same height. All first main reinforcements 21 are embedded in the first reinforcement concrete 33.

[0070] Because the support structure 24 has a simple configuration, it can be constructed quickly. Therefore, workers can construct the support structure 24 and quickly reinforce the bridge truss 6 without having to install temporary supports to support the load on the bridge truss 6. In addition, since the first reinforcing concrete 33 is constructed without removing the support structure 24, the first reinforcing concrete 33 can be constructed quickly and the bridge truss 6 can be reinforced. Accordingly, the reinforcing structure 38 makes it possible to quickly reinforce the bridge truss 6 in an existing concrete bridge pier 2 having a footing 5 and a bridge truss 6 extending upward from the footing 5. Furthermore, since the first reinforcing concrete 33 is provided only in the lower part of the bridge truss 6, the reinforcing structure 38 can be constructed quickly and the bridge truss 6 can be reinforced.

[0071] This concludes the description of specific embodiments, but the present invention is not limited to the above embodiments or modifications and can be broadly modified and implemented. For example, the first reinforcing concrete 33 and the second reinforcing concrete 37 may be provided in a plate shape facing only the damaged side of the bridge truss 6. In this case, the main reinforcement holes 5a, anchor holes 6a, first main reinforcement 21, fixing brackets 22, nuts 23, first stirrups 31, second main reinforcement 35, and second stirrups 36 are provided only in positions facing only the damaged side of the bridge truss 6 (positions where they are embedded in the first reinforcing concrete 33 and the second reinforcing concrete 37).

[0072] In addition, the specific configuration, arrangement, quantity, and materials of each component and part, as well as the specific operations and order of each operation, can be modified as appropriate, as long as they do not depart from the spirit of the present invention. Furthermore, not all of the components shown in the above embodiments are essential, and can be selected as appropriate. [Explanation of symbols]

[0073] 1. 38: Reinforcement structure 2: Bridge piers (columnar structures) 5: Footing 5a: Main reinforcement hole 6: Bridge Column Body (Main Column) 11: Inclinometer (measuring device) 21:1st main reinforcement 22: Fixing hardware 22a: 1st plate part 22b: 2nd plate part 22c: 3rd plate part 22e: Main reinforcement through hole 23: Nut 24:Support structure 31: First tiger muscle 32: Base reinforcing bars 33: First Reinforced Concrete 34: Mechanical couplings (fittings) 35:Second main reinforcement 36: Second tiger muscle 37: Second Reinforced Concrete h1: First height h2: Second height

Claims

1. A method for reinforcing a column body in an existing concrete columnar structure having a footing and a column body extending upward from the footing, A main reinforcement hole creation step involves creating a plurality of main reinforcement holes in the footing, which are arranged at intervals from one another along the outer circumference of the column body, A first main reinforcement anchoring step involves inserting a first main reinforcement into each of the main reinforcement holes to reinforce the column body and injecting a filler to anchor the first main reinforcement to the footing, A support step is to prepare a plurality of fixing brackets having holes for passing through main reinforcement bars, insert at least one portion of the first main reinforcement bars through the holes for passing through the main reinforcement bars of the corresponding fixing brackets, fix the fixing brackets to the side surface of the column body, and then attach engaging members to the first main reinforcement bars so as to engage with the fixing brackets, thereby constructing a support structure that supports the column body. A reinforcement method comprising: a first reinforcement step of pouring concrete around the outer circumference of the column body so that all of the first main reinforcements, the fixing brackets and the engaging members are embedded, thereby reinforcing at least the lower part of the column body.

2. After the support step and before the first reinforcement step, the process includes a base reinforcement construction step in which a plurality of first stirrups extending in the circumferential direction of the column body are attached to a plurality of first main reinforcements to construct the base reinforcement, The reinforcement method according to claim 1, wherein in the first reinforcement step, concrete is poured around the outer circumference of the column body so that a plurality of first main reinforcements, a plurality of first stirrups, the fixing brackets and the engaging members are embedded.

3. After the support step, an extension step is performed in which the second main reinforcement is joined to the upper end of each of the first main reinforcement via a joint, and a plurality of second stirrups extending in the circumferential direction of the column body are attached to the second main reinforcement to extend the base reinforcement upward, The reinforcement method according to claim 2, comprising a second reinforcement step of reinforcing the column body by pouring concrete around the outer circumference of the column body so that all of the second main reinforcements and the second stirrups are embedded.

4. The reinforcement method according to claim 1, wherein the first main reinforcement has a threaded node, and the engaging member is a nut that screws onto the node.

5. The reinforcement method according to claim 1, wherein in the support step, the engaging member is first attached to the first main reinforcement bar located close to the damaged part of the column body.

6. Prior to the main reinforcement hole creation step, there is an installation step of installing a measuring device that detects the inclination or relative position of the column body, The process further includes a monitoring step of continuously monitoring the detection results of the measuring device over time, from the start of the main reinforcement hole creation step until the completion of the reinforcement of the columnar structure, The reinforcement method according to claim 1, wherein in the monitoring step, it is determined whether the inclination or relative position of the column body is abnormal based on the detection result of the measuring device, and when it is determined that the inclination or relative position is abnormal, a notification is given.

7. A reinforcing structure for a column body in an existing concrete columnar structure having a footing and a column body extending upward from the footing, A first main reinforcement bar, with its lower end fixed in each of the multiple main reinforcement holes provided in the footing and arranged at intervals from one another along the outer circumference of the column body, At least one of the first main reinforcements has a corresponding main reinforcement through-hole inserted through it, and a fixing bracket is fixed to the side surface of the column body, An engaging member attached to the first main reinforcement and engaged with the fixing bracket, A reinforcing structure comprising: a first reinforcing concrete constructed at least at the lower part of the outer circumference of the column body such that all of the first main reinforcements, the fixing fittings and the engaging members are embedded.

8. A second main reinforcement is joined to each of the upper ends of the first main reinforcement via a joint, Multiple second stirrups extending in the circumferential direction of the column body are attached to the second main reinforcement, The reinforcing structure according to claim 7, further comprising: a second reinforcing concrete poured around the outer circumference of the column body such that all of the second main reinforcements and a plurality of the second stirrups are embedded.

9. The aforementioned fixing bracket is A first plate portion fixed to the side surface of the column body, A second plate portion rises from the edge of the first plate portion and extends in a direction intersecting the surface of the first plate portion, It comprises a third plate portion extending in a direction perpendicular to the plate surfaces of the first plate portion and the second plate portion, and being joined to the first plate portion and the second plate portion, The reinforcing structure according to claim 7, wherein the second plate portion has a main reinforcement through-hole through which the first main reinforcement is inserted and engages with the engaging member.

10. The reinforcing structure according to claim 7, wherein the fixing brackets positioned at a first height and the fixing brackets positioned at a second height lower than the first height are arranged alternately along the circumferential direction.

11. The reinforcing structure according to claim 7, wherein the first main reinforcing bars to which the fixing bracket and the engaging member are attached and at least one of the first main reinforcing bars to which the fixing bracket and the engaging member are not attached are arranged alternately along the circumferential direction.

12. The reinforcing structure according to claim 7, wherein the first reinforcing concrete is provided only at the lower part of the column body.

13. A support structure for a column body in an existing concrete columnar structure having a footing and a column body extending upward from the footing, A first main reinforcement bar, with its lower end fixed in each of the multiple main reinforcement holes provided in the footing and arranged at intervals from one another along the outer circumference of the column body, At least one of the first main reinforcements has a corresponding main reinforcement through-hole inserted through it, and a fixing bracket is fixed to the side surface of the column body, A support structure having an engaging member attached to the first main reinforcement and engaged with the fixing bracket.

Images