Bearing reaction force adjustment method and bearing reaction force adjustment system

Abstract

To provide a bearing reaction force adjustment method and bearing reaction force adjustment system for restoring the balance of reaction force in each bearing in a bridge in which the balance of reaction force in each bearing is unbalanced.SOLUTION: After lifting all the multiple jacks 12, jacking up each jack-up part 104A of an upper structure 101, and transferring the load received by the multiple bearings 106 to the multiple jacks 12, adjust the vertical movement amount of each jack 12 so that the values of the reaction forces of each jack 12 measured by the multiple reaction force measuring means 12A respectively become the predetermined reaction force values, and adjust the height position of each jack-up part 104A of the upper structure 101 where each jack 12 jacks up, and the height position of each jack-up part 104A of the superstructure 101 after the adjustment is measured by the corresponding displacement meter 16, and the height of each corresponding bearing 106 is adjusted based on the measurement result.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a support reaction force adjustment method and a support reaction force adjustment system. [Background technology]

[0002] In a bridge, a plurality of bearings are usually installed between the superstructure and the substructure, and the load is transmitted from the superstructure to the substructure via the bearings.

[0003] Even if the entire bridge was supported by each bearing with balanced reaction forces when it was first constructed, over time the balance of reaction forces at each bearing may become disrupted, causing some bearings to be subjected to an overload greater than anticipated in the design, while other bearings may not be subjected to the load anticipated in the design. If this situation is left unchecked, the bearings may be damaged by overload or lift, which could result in serious damage.

[0004] Patent Document 1 describes a rubber bearing equipped with a pressure sensor and a load detection function, but does not describe how to respond if the balance of reaction forces in each bearing is disrupted. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Application Laid-Open No. 2009-156284 Summary of the Invention [Problem to be solved by the invention]

[0006] The present invention has been made in consideration of the above points, and its objective is to provide a support reaction force adjustment method and support reaction force adjustment system that restores the balance of reaction forces at each support in a bridge where the balance of reaction forces at each support has been disrupted. [Means for solving the problem]

[0007] The present invention has been made to solve the above-mentioned problems, and provides a support reaction force adjustment method and support reaction force adjustment system as described below.

[0008] That is, the bearing reaction force adjustment method according to the present invention is a bearing reaction force adjustment method for adjusting reaction forces generated in a plurality of bearings that support the superstructure of a bridge, and (1) a jack placement process in which jacks for jacking up the superstructure are placed near all of the plurality of supports aligned in a direction perpendicular to the bridge axis; (2) a ground-breaking jack-up process in which all the jacks placed in the jack placement process are raised, each jack-up portion of the superstructure is jacked up, and the load borne by the support is transferred to the jack; (3) a jack reaction force detection process for detecting a reaction force of each jack generated by the load transferred in the ground breaking jack-up process; (4) a reaction force balance adjustment process in which each of the jacks is moved vertically so that the reaction force values ​​of each of the jacks detected in the jack reaction force detection process become predetermined reaction force values, thereby adjusting the height positions of each of the jacked-up portions of the upper structure that are jacked up by each of the jacks; (5) a support height adjustment process for adjusting the height of each of the plurality of supports to a height corresponding to the height position of each corresponding jack-up portion adjusted in the reaction force balance adjustment process; (6) a jack-down process in which, after the support height adjustment process, all of the jacks are lowered to jack down the superstructure and release the reaction forces of all of the jacks; The method for adjusting a bearing reaction force is characterized by having the following.

[0009] Here, the jacked-up portion of the superstructure refers to a portion that receives a vertical force directly from the jack (a portion that is in direct contact with the jack) or a portion that receives a vertical force indirectly from the jack via another member (a portion that is in direct contact with the other member). The same applies to other descriptions in this application.

[0010] In the ground breaking jacking up step, each jack up portion of the superstructure may be jacked up by the same amount using a uniform jack up amount.

[0011] The height of each support after its height has been adjusted in the support height adjustment process may be set so that the distance between the upper surface of each support after its height has been adjusted in the support height adjustment process and the lower surface of the corresponding jack-up portion of the upper structure adjusted in the reaction force balance adjustment process is the same for all supports.

[0012] Here, the distance between the "upper surface of each support" and the "lower surface of the corresponding jack-up portion" refers to the distance between a plane including the "upper surface of each support" and a plane including the "lower surface of the corresponding jack-up portion."

[0013] If the height of each support after its height has been adjusted in the support height adjustment process is set to a height such that the distance between the upper surface of each support after its height has been adjusted in the support height adjustment process and the lower surface of the corresponding jack-up portion of the upper structure adjusted in the reaction force balance adjustment process is the same, then the same distance may be the uniform jack-up amount in the ground-breaking jack-up process.

[0014] It is preferable that the relative difference in height position between the upper surfaces of adjacent supports in the direction perpendicular to the bridge axis after the heights have been adjusted in the support height adjustment process be equal to or less than a predetermined value.

[0015] It is preferable that the relative difference between the height position of the upper surface of the support after its height has been adjusted in the support height adjustment process and the height position of the upper surface of the support adjacent to the support in the bridge axis direction is less than a predetermined value.

[0016] Here, the term "adjacent bearings in the bridge axis direction" refers to bearings that are adjacent in the bridge axis direction on the top end of the same substructure. The same applies to other descriptions in this application.

[0017] It is preferable that the difference between the heights of the support before and after the height adjustment in the support height adjusting step is equal to or less than a predetermined value.

[0018] After the reaction force balance adjustment of each jack is completed in the reaction force balance adjustment step, each jack may be mechanically fixed.

[0019] The height adjustment of the plurality of bearings in the bearing height adjustment process may be performed by replacing at least one of the plurality of bearings with a new bearing having a height corresponding to the height position adjusted in the reaction force balance adjustment process of the corresponding jack-up portion.

[0020] The height adjustment of the multiple bearings in the bearing height adjustment process may be performed by replacing each bearing with a new bearing having a height corresponding to the height position adjusted in the reaction force balance adjustment process of the corresponding jack-up portion.

[0021] The support height adjustment process may be repeated for each set of support that is spaced a predetermined number of times apart in the direction perpendicular to the bridge axis, without overlapping times.

[0022] After the jacking down process following the completion of the support height adjustment process, the jacks located near all of the multiple supports whose heights have been adjusted may be raised, and each jacked-up portion of the superstructure may be jacked up again by the same amount using a uniform jack-up amount, so that the load carried by the multiple supports whose heights have been adjusted may be transferred to each of the jacks, and the reaction force distribution status of each jack after the load has been transferred may be reconfirmed.

[0023] The height position of each jack-up portion may be measured by a displacement meter installed near each jack between the top of the bridge's substructure and the underside of the bridge's superstructure.

[0024] The method for adjusting the bearing reaction force may be carried out while the bridge continues to be in service.

[0025] The bridge may include a steel main girder, and the jack-up portion may be the underside of the steel main girder.

[0026] The bearing reaction force adjustment system according to the present invention is a bearing reaction force adjustment system that adjusts the reaction forces generated in a plurality of bearings that support the superstructure of a bridge, and includes a plurality of jacks that are respectively arranged in the vicinity of all of the plurality of bearings that are lined up in a direction perpendicular to the bridge axis and that jack up the superstructure, a plurality of jack control means that respectively control the amount of vertical movement of the plurality of jacks, a plurality of reaction force measurement means that measure the reaction forces of the plurality of jacks, and a plurality of displacement meters that are respectively installed between the top of the substructure of the bridge and the underside of the superstructure of the bridge, in the vicinity of each of the jacks, and This is a support reaction force adjustment system characterized by jacking up each jack-up portion of the substructure and transferring the load carried by the multiple supports to the multiple jacks, then adjusting the amount of vertical movement of each jack so that the reaction force values ​​of each jack measured by the multiple reaction force measuring means become predetermined reaction force values, thereby adjusting the height position of each jack-up portion of the superstructure that is jacked up by each jack, measuring the height position of each jack-up portion of the superstructure after adjustment with the corresponding displacement meter, and adjusting the height of each corresponding support based on the measurement results.

[0027] It is preferable to confirm that the relative difference in height between the upper surfaces of adjacent supports in the direction perpendicular to the bridge axis after height adjustment is equal to or less than a predetermined value.

[0028] It is preferable to confirm that the relative difference between the height position of the upper surface of the bearing after height adjustment and the height position of the upper surface of the bearing adjacent to the bearing in the bridge axis direction is less than a predetermined value.

[0029] It is preferable to confirm that the relative difference in height between before and after the height adjustment of each support is equal to or less than a predetermined value.

[0030] The apparatus may further include a command device that issues a command to the jack control means, and the command device may be configured to issue a command to the jack control means by an electrical signal.

[0031] The command device may be configured to send the electrical signal individually to each of the jack control means, thereby enabling the raising and lowering movements of the jacks to be individually controlled. [Effects of the Invention]

[0032] According to the present invention, it is possible to provide a support reaction force adjustment method and a support reaction force adjustment system that restore the balance of reaction forces at each support in a bridge where the balance of reaction forces at each support has been disrupted. [Brief explanation of the drawings]

[0033] [Figure 1] A block diagram showing the schematic configuration of a support reaction force adjustment system 10 according to an embodiment of the present invention. [Figure 2] An enlarged side view showing a state in which a main girder 104, which is a superstructure 101 of a bridge 100, is being jacked up by a hydraulic jack 12, together with an existing bearing 106 and a new bearing 50. [Figure 3] A flowchart showing the flow of support reaction force adjustment by the support reaction force adjustment system 10 according to the embodiment of the present invention. [Figure 4] FIG. 10 is a diagram showing the results of adjusting the bearing reaction force when the bearing reaction force adjustment system 10 according to the embodiment of the present invention is applied to an actual bridge 200 (a diagram showing a comparison between the jack reaction force and the target design reaction force). DETAILED DESCRIPTION OF THE INVENTION

[0034] Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

[0035] (1) Configuration of the support reaction force adjustment system according to the embodiment of the present invention Figure 1 is a block diagram showing the general configuration of a support reaction force adjustment system 10 according to an embodiment of the present invention, and Figure 2 is an enlarged side view showing a schematic diagram of a main girder 104, which is the superstructure 101 of a bridge 100, being jacked up by a hydraulic jack 12, together with an existing support 106 and a new support 50.

[0036] A support reaction force adjustment system 10 according to an embodiment of the present invention comprises a hydraulic jack 12, a pressure gauge 12A, an electric pump 14, and a displacement gauge 16. An electrical signal is sent from a command device 18 to the electric pump 14 via a relay device 20, and based on the electrical signal, the electric pump 14 adjusts the amount of hydraulic oil sent to the hydraulic jack 12, thereby controlling the amount of lift and lowering of the hydraulic jack 12. Meanwhile, pressure measurement data of the hydraulic oil of the hydraulic jack 12 measured by the pressure gauge 12A and displacement measurement data of the underside of the main girder 104 measured by the displacement gauge 16 are sent as electrical signals to the command device 18 via the relay device 20.

[0037] The hydraulic jacks 12 are respectively placed near all of the multiple existing bearings 106 lined up in a direction perpendicular to the bridge axis. In the support reaction adjustment system 10 according to the embodiment of the present invention, as shown in Fig. 2, the hydraulic jacks 12 are placed on height adjustment platforms 102B attached to brackets 102A attached to the sides of the piers 102, and jack up the main girders 104, which are the superstructure 101 of the bridge 100, from below. If the hydraulic jacks 12 can be safely installed on the top of the piers 102, the hydraulic jacks 12 can be installed on the top of the piers 102 without attaching the brackets 102A to the sides of the piers 102.

[0038] The jacking-up amount (amount of lift and amount of lowering) of the hydraulic jack 12 is controlled by the amount of hydraulic oil sent to the hydraulic jack 12 by the electric pump 14 (see FIG. 1 ). As described above, an electric signal is sent from the command device 18 to the electric pump 14 via the relay device 20, and based on that electric signal, the electric pump 14 adjusts the amount of hydraulic oil sent to the hydraulic jack 12, thereby controlling the amount of lift and lowering of the hydraulic jack 12. The reaction force that the hydraulic jack 12 receives from the main girder 104, which is the object being jacked up, can be calculated from the pressure of the hydraulic oil of the hydraulic jack 12 measured by the pressure gauge 12A. Therefore, the pressure gauge 12A can be considered a reaction force measuring means that measures the reaction force acting on the hydraulic jack 12. The pressure measurement data measured by the pressure gauge 12A is output as an electric signal to the command device 18 via the relay device 20.

[0039] The electric pumps 14 are arranged near the hydraulic jacks 12, one for each hydraulic jack 12, and control the amount of hydraulic oil sent to the hydraulic jacks 12 based on an electric signal sent from the command device 18 via the relay device 20, thereby controlling the jack-up amount (amount of lift, amount of lowering) of the hydraulic jacks 12. Therefore, the electric pumps 14 can be said to be jack control means, and the electric signal sent from the command device 18 via the relay device 20 to the electric pumps 14 can be said to be a control signal for controlling the hydraulic jacks 12.

[0040] The displacement meters 16 are arranged on the tops of the piers 102 and in the vicinity of all of the hydraulic jacks 12, and are installed between the tops of the piers 102 of the bridge 100 and the undersides of the main girders 104 of the bridge 100. The displacement meters 16 measure the amount of displacement in the distance between the tops of the piers 102 of the bridge 100 and the undersides of the main girders 104 of the bridge 100, and output the displacement measurement data as an electrical signal to the command device 18 via the relay device 20. The tops of the piers 102 are fixed points, and the displacement meters 16 are installed at the tops of the piers 102, which are fixed points, so the displacement meters 16 can accurately measure the amount of displacement in the distance between the tops of the piers 102 and the undersides of the main girders 104. If the amount of displacement in the distance between the top of the pier 102 and the underside of the main girder 104 can be accurately measured, the amount of displacement of the main girder 104 caused by the up and down movement of the hydraulic jack 12 can be accurately measured.

[0041] On the other hand, for example, if a support beam (not shown) is placed above adjacent brackets 102A so as to span between adjacent brackets 102A in the direction perpendicular to the bridge axis, and a hydraulic jack 12 is placed on the support beam, if the bracket 102A is not located directly below it, there is a risk that the support beam will deflect when jacked up by the hydraulic jack 12, and there is a possibility that the amount of vertical movement of the hydraulic jack 12 itself will not match the amount of actual vertical movement of the main girder 104. Even in such a case, by placing a displacement meter 16 at the top of the pier 102, which is a fixed point, it is possible to accurately measure the amount of displacement in the distance between the top of the pier 102 and the underside of the main girder 104, and therefore the amount of displacement of the main girder 104 due to the vertical movement of the hydraulic jack 12 can be accurately measured.

[0042] Although the portion of the underside of the main girder 104 that is the object of measurement by the displacement meter 16 (the portion with which the displacement meter 16 comes into contact) is a small area at one point, if it can be confirmed that there is no abnormality near the portion of the underside of the main girder 104 that receives a direct vertical force from the hydraulic jack 12 (the jacked-up portion 104A), the amount of displacement of the portion of the underside of the main girder 104 that is the object of measurement by the displacement meter 16 (the portion with which the displacement meter 16 comes into contact) can be regarded as the amount of displacement of the surrounding area of ​​the underside of the main girder 104 (the area including the jacked-up portion 104A and the area with which the support comes into contact).

[0043] (2) Operation of the support reaction force adjustment system according to the embodiment of the present invention We will explain how each component of the bearing reaction adjustment system 10 according to the embodiment of the present invention should be operated to achieve bearing reaction adjustment of the bridge 100, and clarify the significance and interrelationship of each component of the bearing reaction adjustment system 10. Furthermore, by explaining the operation of the bearing reaction adjustment system 10 according to the embodiment of the present invention, we will also explain an embodiment of the bearing reaction adjustment method according to the present invention.

[0044] Fig. 3 is a flowchart showing the flow of support reaction force adjustment by the support reaction force adjusting system 10 according to an embodiment of the present invention, and the flow of support reaction force adjustment by the support reaction force adjusting system 10 will be described with reference to Fig. 3. As shown in Fig. 1, an electric signal for controlling the up and down movement of the hydraulic jack 12 is sent from the command device 18 to the electric pump 14 via the relay device 20, and also, pressure measurement data of the hydraulic oil of the hydraulic jack 12 measured by the pressure gauge 12A and displacement measurement data of the underside of the main girder 104 measured by the displacement gauge 16 are sent to the command device 18 via the relay device 20, but these will not be described in the following explanation of steps S1 to S7.

[0045] (Step S1) Jack placement process First, the hydraulic jacks 12 are placed near all of the existing bearings 106 (jack placement process (step S1)). As shown in Fig. 2, the hydraulic jacks 12 may be placed on brackets 102A attached to the side of the pier 102, but if the hydraulic jacks 12 can be safely installed on the top of the pier 102, the hydraulic jacks 12 may be installed on the top of the pier 102 without attaching the brackets 102A to the side of the pier 102.

[0046] After placing the hydraulic jacks 12 near all of the existing bearings 106, it is advisable to introduce a reaction force of about 10 tf into each hydraulic jack 12 in advance to suppress vibration displacement due to live load.

[0047] (Step S2) Ground jacking process All hydraulic jacks 12 placed in the jack placement process (step S1) are raised, and the underside of the jack-up portion 104A of the main girder 104 is jacked up by the same amount using a uniform jack-up amount, and the load that was being borne by the existing bearings 106 is transferred to the hydraulic jacks 12 (ground-breaking jack-up process (step S2)). In this ground-breaking jack-up process (step S2), the hydraulic jacks 12 placed near all of the existing bearings 106 are raised simultaneously in stages by about 0.3 mm each time, while checking the introduction reaction force to the hydraulic jacks 12 based on the pressure measurement data measured by the pressure gauge 12A. At this time, it is confirmed at each stage that there are no abnormalities in the main girders 104 or expansion devices near the hydraulic jacks 12. As the hydraulic jacks 12 are raised, the load that was being borne by the existing bearings 106 is gradually transferred to the hydraulic jacks 12. If the jack reaction force does not increase but remains constant, it indicates that the load has been completely transferred to the hydraulic jack 12, and the ground jacking is complete.

[0048] (Step S3) Jack reaction force detection process After the ground-breaking jack-up process (step S2) is completed, the reaction force of each hydraulic jack 12 is detected (jack reaction force detection process (step S3)). The reaction force of each hydraulic jack 12 is calculated from the pressure of the hydraulic oil of the hydraulic jack 12 measured by the pressure gauge 12A provided for each hydraulic jack 12.

[0049] (Step S4) Reaction force balance adjustment process Based on the reaction force of each hydraulic jack 12 detected in the jack reaction force detection process (step S3), the vertical movement amount of each hydraulic jack 12 is adjusted so that the reaction force of each hydraulic jack 12 approaches the target value (target design reaction force), and the height position of the underside of the main girder 104 that each hydraulic jack 12 jacks up is adjusted to balance the reaction force of each hydraulic jack 12 (reaction force balance adjustment process (step S4)).

[0050] Specifically, each hydraulic jack 12 is adjusted individually by moving it up and down to bring the reaction force balance closer to the target value. The reaction force balance is adjusted basically by jacking down areas that are overloaded and jacking up areas that are underloaded. It is also advisable to make adjustments while checking that the relative difference between the undersides of adjacent main girders 104 does not exceed a specified value (for example, 3 mm).

[0051] (Step S5) Support height adjustment process After the reaction force balance adjustment in the reaction force balance adjustment step (step S4) is completed, each hydraulic jack 12 is mechanically fixed and the hydraulic pressure is released, and the bearing height is adjusted while maintaining the adjusted height of each hydraulic jack 12 (bearing height adjustment step (step S5)). The target bearing height is adjusted so that the distance between the top surface of each bearing and the underside of the main girder 104 in the state after the reaction force balance adjustment is complete is the same for all bearings. More specifically, the target bearing height can be determined by subtracting the uniform jack-up amount (simultaneous jack-up amount) of the underside of the main girder 104 in the ground-breaking jack-up step (step S2) from the height position of the underside of the main girder 104 in the state after the reaction force balance adjustment is complete (the height position from the top end of the pier 102 on which the corresponding displacement meter is installed).

[0052] Regarding the adjustment of bearing height, a case in which an existing bearing 106 is replaced with a new bearing 50 will be described with reference to Figure 2. In Figure 2, Ha is the height of the existing bearing 106, Hb is the height of the new bearing 50, H0 is the distance between the underside of the main girder 104 and the top of the pier 102 after completion of the reaction force balance adjustment in the reaction force balance adjustment process (step S4), H1 is the uniform jack-up amount (simultaneous jack-up amount) of the underside of the main girder 104 in the ground-breaking jack-up process (step S2), and H2 is the adjustment amount (reaction force balance adjustment amount) of the jack-up amount of the underside of the main girder 104 in the reaction force balance adjustment process (step S4). Note that Figure 2 shows the case where the reaction force balance adjustment amount H2 is positive, that is, the case in which the hydraulic jack 12 is raised and adjusted in the reaction force balance adjustment process (step S4).

[0053] As shown in Figure 2, the height Hb of the newly installed support 50 can be set to the height Ha of the existing support 106 plus the reaction force balance adjustment amount H2. In other words, the height can be set to the distance H0 between the underside of the main girder 104 and the top of the pier 102 after the reaction force balance adjustment is completed minus the simultaneous jack-up amount H1.

[0054] Specifically, the bearing height may be adjusted, for example, by attaching a height adjustment plate to the underside of the existing bearing 106. Alternatively, as described above, the bearing height may be adjusted by replacing the existing bearing 106 with a new bearing 50 that has been adjusted to the appropriate height. The replacement with new bearings 50 that have been adjusted to the appropriate height may involve replacing all of the multiple existing bearings 106 with the new bearings 50, or alternatively, only some of the multiple existing bearings 106 may be replaced with new bearings 50, and the height of the remaining existing bearings 106 may be adjusted using, for example, a height adjustment plate.

[0055] Furthermore, if the relative difference in height between the top surfaces of adjacent bearings in the direction perpendicular to the bridge axis exceeds a specified value (for example, 3 mm), excessive stress may be generated in the cross beams and cross beam structures that connect the main girders 104 in the direction perpendicular to the bridge axis, so it is best to prevent the relative difference in height between the top surfaces of adjacent bearings in the direction perpendicular to the bridge axis from exceeding a specified value (for example, 3 mm). This specified value (for example, 3 mm) can be determined appropriately for each bridge in question, taking into account the environmental conditions, design conditions, etc., so as to ensure safety.

[0056] Furthermore, if the relative difference in height position of the top surfaces of adjacent bearings in the bridge axis direction (bearings adjacent in the bridge axis direction on the top end of the pier 102) exceeds a specified value (for example, 3 mm), there is a risk of damage to the expansion joint or a large difference in level with the road surface of the adjacent bridge, so it is advisable to prevent the relative difference in height position of the top surfaces of adjacent bearings in the direction perpendicular to the bridge axis from exceeding a specified value (for example, 3 mm). This specified value (for example, 3 mm) can be determined appropriately for each bridge in question so as to ensure safety in accordance with the environmental conditions, design conditions, etc.

[0057] Furthermore, it is preferable that the difference between the height of the bearing after its height has been adjusted in the bearing height adjustment process (step S5) and the height of the existing bearing 106 after the ground-breaking jack-up process (step S2) before the height has been adjusted be a predetermined value (for example, 1 mm) or less. This is because if the height of the bearing after adjustment differs too greatly from the height of the existing bearing 106, unforeseen problems may occur. This predetermined value (for example, 1 mm) may be determined appropriately for each bridge in question, taking into account the environmental conditions, design conditions, etc., so as to ensure safety.

[0058] Furthermore, in the bearing height adjustment process of step S5, it is advisable to adjust the bearing height so that more than a certain percentage of the bearings are not adjusted at the same time, to prevent the bridge from collapsing due to an external force such as a major earthquake while the bearing height is being adjusted. Therefore, for example, it is advisable to repeatedly adjust the bearing height for each set of bearings, skipping a predetermined number of positions in the direction perpendicular to the bridge axis, so that the adjustments do not overlap. More specifically, for example, it is possible to number the bearings lined up in the direction perpendicular to the bridge axis in order from one direction, dividing them into sets of even-numbered bearings and sets of odd-numbered bearings, and then repeatedly adjust the bearing height for these two sets separately so that the adjustments do not overlap.

[0059] (Step S6) Jacking down process After the support height adjustment process (step S5) is completed, all hydraulic jacks 12 are lowered to jack down the main girder 104, and the reaction forces of all hydraulic jacks 12 are unloaded (jacking down process (step S6)). When jacking down the main girder 104, the jacking is carried out while checking that the reaction force balance after adjustment in the reaction force balance adjustment process (step S4) is maintained. The jacking is carried out in stages of about 0.3 mm each time, and it is checked that the reaction forces of each hydraulic jack 12 are unloaded evenly.

[0060] (Step S7) Reaction force distribution confirmation process After the jacking down process (step S6) is completed, all hydraulic jacks 12 are raised again to uniformly jack up the main girders 104, transferring the entire load to the jacks, and it is again confirmed whether the reaction force is being distributed appropriately to each jack (reaction force distribution confirmation process (step S7)). This reaction force distribution confirmation process (step S7) is the same as the process combining steps S1 to S3. If a bias in the introduced reaction force is confirmed in this reaction force distribution confirmation process (step S7), the process returns to the reaction force balance adjustment process (step S4), where the reaction force balance is adjusted again, and the support height is adjusted (step S5) to correct the reaction force balance. Steps S4 to S7 are repeated until it can be confirmed again that the reaction force is being distributed appropriately to each hydraulic jack 12.

[0061] The operation of the bearing reaction force adjusting system 10 according to the embodiment of the present invention (an embodiment of the bearing reaction force adjusting method according to the present invention) has been described above, but the amount of jacking up of the main girder 104 in each of steps S1 to S7 is small, and normally does not affect vehicles passing over the bridge 100. Therefore, it is possible to carry out the bearing reaction force adjusting method according to the present invention while continuing to use the bridge 100 without closing it to traffic.

[0062] (3) Example of bearing reaction force adjustment using the bearing reaction force adjustment system according to the embodiment of the present invention An example will be described in which the support reaction adjustment system 10 according to the embodiment of the present invention is applied to an actual bridge 200 and support reaction adjustment is performed. Figure 4 shows the results, comparing the jack reaction force with the target design reaction force.

[0063] The superstructure 202 of the application section of bridge 200 is a simple four-main plate girder, and the substructure is a steel pier. As shown in Figure 4, the reaction forces before adjustment in all main girders 204 deviated significantly from the target values. If the existing bearings had continued to be used with this reaction force balance, it is thought that they might have been damaged by overload or uplift. The overall reaction force balance was adjusted by raising and lowering the jacks individually within a range of 0.2 mm to 0.3 mm. After multiple adjustments, it was successfully achieved as close as possible to the target design reaction force. It was also confirmed that the final relative differences between the girders in the direction perpendicular to the bridge axis and in the bridge axis direction were within 3 mm.

[0064] Furthermore, the bearing reaction force adjustment carried out on the bridge 200 as described above was carried out without closing the bridge to traffic and while the bridge 200 continued to be in service, and no problems arose.

[0065] (4) Supplementary information In the above explanation of the embodiments and examples, the target bridges have been steel bridges (bridges in which the main components that make up the superstructure are made of steel) and the object to be jacked up has been the steel main girder, but the bridges to which the bearing reaction force adjustment method and bearing reaction force adjustment system of the present invention can be applied are not limited to steel bridges, and can also be applied to concrete bridges (bridges in which the main components that make up the superstructure are made of concrete). [Explanation of symbols]

[0066] 10...Support reaction force adjustment system 12...Hydraulic jack 12A...Pressure gauge 14...Electric pump 16...Displacement meter 18…Command device 20...Relay device 50...Newly constructed bearing 100, 200...Bridge 101, 202...superstructure 102...Bridge pier 102A...Bracket 102B...Height adjustable stand 104, 204…Main digit 104A...Jack-up part 106...Existing bearing Ha: Height of existing bearing 106 Hb…Height of new bearing 50 H0: Distance between the bottom surface of the main girder 104 and the top of the pier 102 after reaction force balance adjustment is completed H1...Simultaneous jacking amount H2…Reaction force balance adjustment amount

Claims

1. A support reaction force adjustment method for adjusting reaction forces generated in a plurality of supports supporting a bridge superstructure, comprising: (1) a jack placement process in which jacks for jacking up the superstructure are placed near all of the plurality of supports aligned in a direction perpendicular to the bridge axis; (2) a ground-breaking jack-up process in which all the jacks placed in the jack placement process are raised, each jack-up portion of the superstructure is jacked up, and the load borne by the support is transferred to the jack; (3) a jack reaction force detection process for detecting a reaction force of each jack generated by the load transferred in the ground breaking jack-up process; (4) a reaction force balance adjustment process in which each of the jacks is moved vertically so that the reaction force values ​​of each of the jacks detected in the jack reaction force detection process become predetermined reaction force values, thereby adjusting the height positions of each of the jacked-up portions of the upper structure that are jacked up by each of the jacks; (5) a support height adjustment step of adjusting the height of each of the plurality of supports to a height corresponding to the height position of each corresponding jack-up portion adjusted in the reaction force balance adjustment step; (6) a jack-down process in which, after the support height adjustment process, all of the jacks are lowered to jack down the superstructure and release the reaction forces of all of the jacks; A method for adjusting a support reaction force, comprising:

2. 2. The method for adjusting a support reaction force according to claim 1, wherein in the ground-breaking jacking-up step, each jack-up portion of the superstructure is jacked up by the same amount with a uniform jack-up amount.

3. A support reaction force adjustment method as described in claim 1 or 2, characterized in that the height of each support after its height has been adjusted in the support height adjustment process is set to a height such that the distance between the upper surface of each support after its height has been adjusted in the support height adjustment process and the lower surface of the corresponding jack-up portion of the superstructure adjusted in the reaction force balance adjustment process is the same for all supports.

4. The height of each support after the height has been adjusted in the support height adjustment process is set to a height such that the distances between the upper surface of each support after the height has been adjusted in the support height adjustment process and the lower surface of the corresponding jack-up portion of the superstructure adjusted in the reaction force balance adjustment process are all the same, 3. The method for adjusting a support reaction force according to claim 2, wherein the same distance is the uniform jack-up amount in the ground-breaking jack-up process.

5. A support reaction force adjustment method described in any one of claims 1 to 4, characterized in that the relative difference in height positions of the upper surfaces of adjacent supports perpendicular to the bridge axis after the height has been adjusted in the support height adjustment process is less than a predetermined value.

6. A support reaction force adjustment method described in any one of claims 1 to 5, characterized in that the relative difference between the height position of the upper surface of the support after the height has been adjusted in the support height adjustment process and the height position of the upper surface of the bearing adjacent to the support in the bridge axis direction is less than a predetermined value.

7. A support reaction force adjustment method as described in any one of claims 1 to 6, characterized in that the difference between the height of the support before and after the height is adjusted in the support height adjustment process is less than a predetermined value.

8. A support reaction force adjustment method as described in any one of claims 1 to 7, characterized in that after the balance adjustment of the reaction forces of each jack is completed in the reaction force balance adjustment process, each jack is mechanically fixed.

9. A bearing reaction force adjustment method described in any one of claims 1 to 8, characterized in that the height adjustment of the multiple bearings in the bearing height adjustment process is performed by replacing at least one of the multiple bearings with a new bearing having a height corresponding to the height position adjusted in the reaction force balance adjustment process of the corresponding jack-up portion.

10. A support reaction force adjustment method described in any one of claims 1 to 8, characterized in that the height adjustment of the multiple supports in the support height adjustment process is performed by replacing each support with a new support having a height corresponding to the height position adjusted in the reaction force balance adjustment process of the corresponding jack-up portion.

11. A support reaction force adjustment method described in any one of claims 1 to 10, characterized in that the support height adjustment process is repeated for each set of support among the plurality of support, skipping a predetermined number of sets in the direction perpendicular to the bridge axis, so as not to overlap in time.

12. A support reaction force adjustment method described in any one of claims 1 to 11, characterized in that after the jacking down process following the completion of the support height adjustment process, the jacks respectively positioned near all of the multiple supports whose heights have been adjusted are raised, and each jacked-up portion of the superstructure is again jacked up by the same amount using a uniform jack-up amount, thereby transferring the load carried by the multiple supports whose heights have been adjusted to each of the jacks, and reconfirming the reaction force distribution status of each of the jacks after the load has been transferred.

13. A support reaction force adjustment method described in any one of claims 1 to 12, characterized in that the height position of each jacked-up portion is measured by a displacement meter installed between the top of the bridge's substructure and the underside of the bridge's superstructure in the vicinity of each jack.

14. A method for adjusting a bearing reaction force according to any one of claims 1 to 13, characterized in that the method is carried out while the bridge continues to be in service.

15. A method for adjusting a support reaction force according to any one of claims 1 to 14, characterized in that the bridge has a steel main girder, and the jack-up portion is the underside of the steel main girder.

16. A support reaction force adjustment system that adjusts reaction forces generated in a plurality of supports that support a bridge superstructure, a plurality of jacks for jacking up the superstructure, each of which is disposed near each of the plurality of supports aligned in a direction perpendicular to the bridge axis; a plurality of jack control means for controlling the vertical movement amounts of the plurality of jacks, respectively; a plurality of reaction force measuring means for measuring the reaction forces of the plurality of jacks, respectively; a plurality of displacement meters respectively installed between the top end of the bridge substructure and the underside of the bridge superstructure near each of the jacks; and A support reaction force adjustment system characterized by raising all of the multiple jacks, jacking up each jacked-up portion of the superstructure, and transferring the loads carried by the multiple supports to the multiple jacks, adjusting the amount of vertical movement of each jack so that the reaction force values ​​of each jack measured by the multiple reaction force measuring means become predetermined reaction force values, thereby adjusting the height position of each jacked-up portion of the superstructure that is jacked up by each jack, measuring the height position of each jacked-up portion of the superstructure after the adjustment with the corresponding displacement meter, and adjusting the height of each corresponding support based on the measurement results.

17. The support reaction force adjustment system described in claim 16, characterized in that it is confirmed that the relative difference in height positions of the upper surfaces of adjacent supports in the direction perpendicular to the bridge axis after height adjustment is less than a predetermined value.

18. A support reaction force adjustment system as described in claim 16 or 17, characterized in that it is confirmed that the relative difference between the height position of the upper surface of the support after height adjustment and the height position of the upper surface of the support adjacent to the support in the bridge axis direction is less than a predetermined value.

19. A support reaction force adjustment system as described in any one of claims 16 to 18, characterized in that it is confirmed that the relative difference in height of each support before and after height adjustment is less than a predetermined value.

20. Further, a command device is provided for giving a command to the jack control means, 20. The support reaction force adjusting system according to claim 16, wherein the command device issues a command to the jack control means by an electric signal.

21. The support reaction force adjusting system according to claim 20, characterized in that the raising and lowering movements of the plurality of jacks can be individually controlled by sending the electrical signal from the command device to each of the plurality of jack control means.

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