Jack-up device with movement limiting function and bearing replacement method

Abstract

To provide a jack-up device with movement restriction function and a bearing replacing method which can resist earthquake even in a state where a (bridge-) bearing is removed after jacking up.SOLUTION: A jack-up device 1 with movement restriction function comprises: a jack device J1 supported by a lower structure P1 of a bridge B1 and jacking up an upper structure BG; a lower member 2 supported by either one of the lower structure P1 or the upper structure BG; and an upper member 3 supported by the other. The lower member 2 has a plate-like lower plate part 20. The lower plate part 20 is formed with a plurality of counterbore holes 21 capable of each housing a bolt head of a bolt to be screwed into a screw hole bored in the jack device J1. The upper member 3 has a tabular upper plate part 30 and jack surrounding parts 31 that are erected on the upper plate part 30 so as to be spaced away from and surrounds the jack device J1. The lower member 2 and the jack device J1 are bolt-connected through the counterbore holes 21 and the jack device J1 is fitted to the jack surrounding parts 31 so that the upper structure BG is restricted from moving horizontally during earthquake.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a jack-up device with a movement limiting function that jacks up a superstructure such as a bridge girder and limits the movement of the superstructure during jack-up when replacing an existing bridge bearing with a new bearing, and a bearing replacement method using the same for replacing an existing bridge bearing with a new bearing. [Background technology]

[0002] Traditionally, when replacing bridge bearings, brackets are attached to the substructure to increase the space in the piers and abutments, and the superstructure, such as the bridge girders, is jacked up to remove the stress acting on the existing bearings, and then the existing bearings are replaced with new ones.

[0003] On the other hand, when replacing bridge bearings, measures must be taken to ensure that the bridge can resist horizontal seismic forces (for example, Level 1 earthquake forces) even when the bearings are removed, and currently this is addressed by removing every other bearing in a staggered pattern rather than replacing all adjacent bearings at once. However, this means that it takes more than twice the time to remove the bearings, which increases the number of days required for construction.

[0004] For example, Patent Document 1 discloses a method for updating an existing bearing device in which an existing bearing device on a substructure 4 is removed and a new bearing device is installed, in which grooves 15 are formed on the side surface 12 or underside 13 of the existing concrete girder 1 so as not to chip the internal reinforcing bars 14 of the existing concrete girder 1, and an engaging fitting 24 having a protrusion 22 that fits into said groove 15 is provided on the existing concrete girder 1 so that said protrusion 22 fits into said groove 15, and the existing concrete girder 1 is supported by a new bearing device 21 via said engaging fitting 24 (see claim 1 in the scope of claims of Patent Document 1, paragraphs

[0013] to

[0023] of the specification, and Figures 1 to 5 of the drawings, etc.).

[0005] However, the method of updating existing bearing devices described in Patent Document 1 does not take into consideration countermeasures in the unlikely event that horizontal earthquake forces act upon the bearings when they are removed, and as mentioned above, the only possible countermeasure is to remove every other bearing in a staggered pattern, which does not solve the problem of the number of days required for construction.

[0006] Furthermore, Patent Document 2 discloses a method for replacing a seismic isolation device, in which when replacing an existing seismic isolation device with a new one, a temporary support device consisting of a flat jack 1 and a temporary bearing 11 is provided to support the upper layer in place of the existing seismic isolation device, thereby making it possible to suppress vibrations of a structure caused by an earthquake even if an earthquake occurs during the replacement of the seismic isolation device (see claim 1 in the scope of claims of Patent Document 2, paragraphs

[0040] to

[0055] of the specification, Figures 1 to 6 of the drawings, etc.).

[0007] However, the method for replacing a seismic isolation device described in Patent Document 2 requires the installation of temporary support devices consisting of flat jacks 1 and temporary bearings 11 on both the front, back, left and right sides of each seismic isolation device, which requires a large amount of space around the existing bearings of the substructure, and there is the problem that it is difficult to secure this space.In addition, the method for replacing a seismic isolation device described in Patent Document 2 requires the separate installation of special flat jacks 1 and temporary bearings 11, which also poses the problem of increased costs. [Prior art documents] [Patent documents]

[0008] [Patent Document 1] Japanese Patent Application Laid-Open No. 2009-19493 [Patent Document 2] Japanese Patent Application Publication No. 2017-57636 Summary of the Invention [Problem to be solved by the invention]

[0009] The present invention was devised in consideration of the above-mentioned problems, and its purpose is to provide a jack-up device with a movement limiting function that can withstand earthquakes even when the device is jacked up and the bearings are being removed, and a bearing replacement method using the same. [Means for solving the problem]

[0010] The jack-up device with movement limiting function according to claim 1 is supported on the substructure of a bridge. The bridge a jacking device for lifting the superstructure; Can be installed upside down Either the lower structure or the upper structure Fixed to withstand level 1 earthquake horizontal forces a supported lower member; Can be installed upside down On the other hand Fixed so as to be able to resist the horizontal earthquake force and an upper member to be supported by the jack device, the lower member having a flat lower plate portion, and a plurality of countersunk holes formed in the lower plate portion capable of accommodating bolt heads that screw into screw holes drilled in the jack device, the upper member having a flat upper plate portion and a jack surrounding portion erected on the upper plate portion and surrounding the jack device at a distance, the upper plate portion is bolted to the upper structure or the lower structure or fixed with a vise; The lower member and the jack device are bolted together through the countersunk holes, and the jack device and the jack surrounding portion are fitted together. will be By To be able to withstand level 1 earthquake horizontal forces Horizontal movement of the superstructure during an earthquake but limit It has been It is characterized by:

[0011] A jack-up device with a movement limiting function according to a second aspect of the present invention is the jack-up device with a movement limiting function according to the first aspect of the present invention, characterized in that a slit is formed in the jack surrounding portion.

[0012] The jack-up device with movement limiting function described in claim 3 is the jack-up device with movement limiting function described in claim 1 or 2, characterized in that a sliding material that reduces friction is attached to the inside of the part of the upper plate portion surrounded by the jack surrounding portion.

[0013] The jack-up device with movement limiting function described in claim 4 is a jack-up device with movement limiting function described in any of claims 1 to 3, characterized in that a height-adjusting filler corresponding to the slope of the underside of the upper structure is interposed between the upper plate portion attached to the upper structure and the upper structure.

[0014] The bearing replacement method described in claim 5 is characterized by installing a jack-up device with a movement limiting function described in any one of claims 1 to 4, jacking up the superstructure of the bridge with a jack to replace the existing bearing with a new bearing, and then removing the jack-up device with a movement limiting function. [Effects of the Invention]

[0015] According to the inventions of claims 1 to 5, when replacing bridge supports, even if the bridge is subjected to seismic force, after the support has been jacked up and removed, the horizontal force can be resisted and the horizontal movement of the superstructure can be limited.

[0016] In particular, according to the invention of claim 2, since the slit is formed, it is easy to access the vicinity of the upper part of the jack device, and the work efficiency when jacking up the jack device J1 is improved.

[0017] In particular, according to the invention of claim 3, a sliding material that reduces friction is attached to the inside of the upper plate portion, so that it is possible to respond to the temperature expansion and contraction of the upper structure during jacking up.

[0018] In particular, according to the invention of claim 4, the height-adjusting filler is installed, so the other lower and upper members can be made common regardless of the gradient of the bridge superstructure, thereby achieving cost reduction of the jack-up device with movement limiting function. [Brief explanation of the drawings]

[0019] [Figure 1]FIG. 1 is a side view of a jack-up device with a movement limiting function according to an embodiment of the present invention, as viewed in a direction perpendicular to the bridge axis, with the jack-up device placed on a jack-up bracket. [Figure 2] FIG. 2 is a horizontal cross-sectional view taken along line AA of the jack-up device with movement limiting function shown in FIG. [Figure 3] FIG. 3 shows only the lower member of the jack-up device with movement restriction function, where (a) is a plan view, (b) is a vertical cross-sectional view along line BB, (c) is a top perspective view looking down from above, and (d) is a bottom perspective view obtained by inverting the top perspective view of FIG. 3(c). [Figure 4] FIG. 4 shows only the upper member of the jack-up device with movement limiting function, where (a) is a plan view, (b) is a vertical cross-sectional view taken along line CC, and (c) is a perspective view of the bottom with the top and bottom turned upside down. [Figure 5] FIG. 5 is a flowchart showing each work step of the bearing replacement method according to the embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0020] Hereinafter, a jack-up device with a movement limiting function and a bridge bearing replacement method using the same according to an embodiment of the present invention will be described in detail with reference to the drawings.

[0021] <Jack-up device with movement restriction function> First, a jack-up device 1 with a movement limiting function according to an embodiment of the present invention (hereinafter simply referred to as the jack-up device 1) will be described with reference to Figures 1 to 4. Figure 1 is a side view of the jack-up device 1 with a movement limiting function according to an embodiment of the present invention placed on a jack-up bracket B2, viewed along a direction perpendicular to the bridge axis. Figure 2 is a horizontal cross-sectional view of the jack-up device 1 of Figure 1 taken along line AA. Figure 3 shows only the lower member of the jack-up device 1, with (a) being a plan view, (b) being a vertical cross-sectional view taken along line BB, and (c) being a perspective top view viewed from above. Figure 4 shows only the upper member of the jack-up device 1, with (a) being a plan view, (b) being a vertical cross-sectional view taken along line CC, and (c) being a perspective bottom view with the device turned upside down.

[0022] Here, the illustrated bridge B1 has a superstructure, a bridge girder BG made of steel girders, installed on top of a substructure, a pier P1, made of reinforced concrete, via bearings not shown.When replacing the existing bearing with a new bearing, the bridge is jacked up with a jack device J1 to remove stress from the existing bearing, and this will be explained as an example using a jack-up device 1 with a movement limiting function.

[0023] The jack-up bracket B2 is an additional bracket for mounting the jack device J1, which is supported by bolts attached to the side of the pier P1, which is the substructure of the bridge B1. The parallel overhead lines shown by the dashed dotted lines in Figure 2 indicate the bottom flange H1 of the steel girder, and the central overhead double circle shown by the dashed dotted lines in Figures 2 to 4 indicates the position where the jack device J1, which lifts the bridge girder BG, will be installed.

[0024] As shown in Figures 1 to 4, the jack-up device 1 comprises a lower member 2 attached to the upper surface of a jack-up bracket B2, and an upper member 3 attached to the underside of the lower flange H1 of a bridge girder BG, which is the superstructure, facing the lower member 2. This jack-up device 1 is a device that is attached to a jacking device J1 supported on a substructure, and is a movement limiting device that resists a level 1 earthquake that occurs during work to lift the superstructure, including the bridge girder BG of bridge B1, and replaces part of the function of the bridge B1's bearings, thereby limiting the horizontal and vertical movement of the bridge girder BG, which is the superstructure.

[0025] (Lower part) 2 and 3, the lower member 2 is mainly composed of a rectangular flat lower plate portion 20. The lower plate portion 20 has a plurality of countersunk holes 21 formed therein that can accommodate the bolt heads of bolts B3 that screw into screw holes (female threads) drilled in the bottom surface of the jack device J1 so that the bolt heads do not protrude from the bottom surface.

[0026] As shown in Figure 3(a), the lower plate portion 20 is a rectangular (oblong) steel plate of a predetermined thickness that can withstand collision loads, and as shown in Figures 3(a), 3(c), and 3(d), bolt holes 22 are drilled at the longitudinal ends for bolting to the jack-up bracket B2.

[0027] However, the lower member 2 may be configured to have no bolt holes 22, and the lower plate portion 20 and the upper plate of the jack-up bracket B2 may be clamped with a vice or the like to be fixed to the jack-up bracket B2.

[0028] 3(a) to 3(d), the countersunk holes 21 are provided at positions inward a predetermined distance from the outer periphery of the bottom surface of the jacking device J1, and eight of them are provided at equal intervals in the illustrated embodiment. These countersunk holes 21 fix the bottom surface of the jacking device J1 to the jack-up bracket B2 via the lower member 2, and have the function of transmitting horizontal stress and bending stress caused by seismic forces acting on the jacking device J1 to the pier P1, which is the substructure.

[0029] In this way, in the jack-up device 1, the jack device J1 is indirectly bolted (mechanically joined) to the pier P1, which is the lower structure, so that the risk of the jack device J1 tipping over due to horizontal forces during an earthquake while the jack device J1 is jacking up the upper structure is completely eliminated.

[0030] (Upper member) As shown in FIGS. 2 and 4, the upper member 3 has a plate-shaped upper plate portion 30 and a jack surrounding portion 31 standing on the upper plate portion 30.

[0031] As shown in Figure 4(a), the upper plate portion 30 is an octagonal (rectangular) steel plate of a predetermined thickness that can withstand collision loads, and has bolt holes 32 drilled at the end in the longitudinal direction (in the bridge axis direction in the illustrated case) for bolting to the lower flange H1 of the bridge girder BG, which is the superstructure.

[0032] However, the upper member 3 may be configured without the bolt holes 32, and the upper plate portion 30, the height-adjusting filler 4, and the lower flange H1 of the bridge girder BG may be clamped and fixed to the lower flange H1 using a vice or the like. This is because there is no need to drill bolt holes that would result in a cross-sectional defect in the lower flange H1, which is the superstructure of the bridge B1.

[0033] 2, the jack surrounding portion 31 is a cylindrical wall formed to surround the jack device J1, spaced a predetermined distance from the outer peripheral wall of the jack device J1, and has a horizontal cross-sectional arc-shaped portion cut off at certain distances in places. In other words, the jack surrounding portion 31 has slits 33 formed in the cylindrical wall for accessing the jack device J1. The jack surrounding portion 31 of this embodiment has a total of four slits 33 formed to facilitate access to the jack device J1.

[0034] In this way, four large slits 33 are formed in the jack surrounding portion 31, making it easier to access the area near the top of the jack device J1 (around the ram portion J1b), improving work efficiency when jacking up the jack device J1.

[0035] Although the jack surrounding portion 31 has been described as having a cylindrical (arc-shaped) horizontal cross section, the jack surrounding portion 31 may be a cylindrical portion having a similar horizontal cross section that fits with the jack device J1 at a predetermined distance. For example, the jack surrounding portion 31 may be a rectangular cylindrical portion.

[0036] (Sliding material) As shown in Figures 4(a) and 4(c), a sliding member 5 that reduces friction between the upper plate member 30 of the upper member 3 and the jack device J1 is attached to the underside of the upper plate member 30 and the shaded area inside the jack surrounding member 31. The sliding member 5 in this embodiment is a plate made of fluororesin (polytetrafluoroethylene). The sliding member 5 has the function of reducing friction between the upper member 3 and the jack device J1, thereby preventing the jack device J1 from tipping over due to expansion and contraction caused by temperature changes in the bridge girder BG during the bridge B1 bearing replacement work in a jacked-up state.

[0037] (Height adjustment filler) The lower member 2 is bolted directly to the top surface of the jack-up bracket B2, and the upper member 3 is bolted to the underside of the bridge girder BG, which is the superstructure, i.e., to the lower flange H1 via a height-adjusting filler 4 that corresponds to the gradient of the lower flange H1. Therefore, in a jack-up device 1 that can be used on bridges with different gradients, the lower member 2 and upper member 3 can be installed horizontally in common regardless of the gradient of the bridge girder BG, improving safety and reducing the cost of the jack-up device 1 with movement restriction function.

[0038] However, the jack-up device 1 can also be turned upside down so that the upper member 3 is attached to the upper surface of the jack-up bracket B2 and the lower member 2 is attached to the lower surface of the lower flange H1.

[0039] According to the jack-up device 1 with movement limiting function according to the embodiment of the present invention described above, the jack surrounding portion 31 of the upper member 3 is spaced apart from the jack device J1 and is formed to surround the jack device J1. Therefore, when replacing bridge bearings, the jack-up device 1 can resist the horizontal force and limit the horizontal movement of the superstructure even if a level 1 earthquake occurs after the bridge has been jacked up with the jack device J1 and the bearing has been removed.

[0040] Furthermore, according to the jack-up device 1, four large slits 33 are formed in the jack surrounding portion 31 of the upper member 3, making it easier to access the top of the jack device J1, thereby improving work efficiency when jacking up the jack device J1.

[0041] Furthermore, according to the jack-up device 1, sliding materials 5 that reduce friction are attached to the underside of the upper plate portion 30 and inside the jack surrounding portion 31, so that it is possible to respond to the temperature expansion and contraction of the upper structure during jack-up.

[0042] Furthermore, according to the jack-up device 1, a height-adjusting filler 4 according to the gradient of the lower flange H1 is interposed between the upper member 3 and the lower flange H1, so that the jack-up device 1 with movement-limiting function can be adapted to bridges with various gradients, thereby achieving cost reduction.

[0043] <Bearing replacement method> Next, a bearing replacement method according to an embodiment of the present invention will be described with reference to Figures 1 to 4 and 5. The description will be given by taking as an example a case where bearing renewal work is carried out to replace the existing bearing of the bridge B1 with a new bearing using the jack-up device 1 with movement restriction function described above. Figure 5 is a flowchart showing each work step of the bearing replacement method according to an embodiment of the present invention.

[0044] (Reinforcement material installation process) First, as shown in FIG. 5, in the bearing replacement method according to the embodiment of the present invention, a reinforcing material installation step for reinforcing the bridge girder BG is carried out as necessary as advance preparation.

[0045] Specifically, in this process, reinforcing ribs are joined to the web of the bridge girder BG, which is a steel girder, using high-strength bolts or welding, etc. to reinforce it so that it does not buckle when jacked up by the jack device J1.

[0046] (Bracket installation process) Next, as shown in Figure 5, in the bearing replacement method according to this embodiment, a bracket installation process is carried out to install a temporary bracket next to the substructure of the bridge B1 in order to secure space for installing the jack device J1.

[0047] Specifically, in this process, the aforementioned jack-up bracket B2 is bolted and attached to the side of the pier P1, which is the substructure, using post-installed anchors or the like (see also Figure 1).

[0048] (Jack-up device installation process) Next, as shown in Figure 5, in the support replacement method according to this embodiment, a jack-up device installation process is carried out in which the aforementioned jack-up device 1 with movement limiting function is installed on the jack-up bracket B2 installed in the front bracket installation process.

[0049] 1 and 2, in this process, bolts are inserted into the bolt holes 22 of the lower plate portion 20, and the lower member 2 is bolted onto the jack-up bracket B2. Then, directly above the lower member 2, bolts are inserted into the bolt holes 32 of the upper plate portion 30, and the upper member 3 is joined to the lower flange H1 of the bridge girder BG.

[0050] At this time, as shown in Figure 2, the jack device J1 and the jack surrounding part 31 are fitted together with a predetermined distance between them, and when the bridge girder BG, which is the superstructure, moves horizontally, the jack device J1 and the jack surrounding part 31 come into contact and fit together, thereby restricting horizontal and vertical movement during an earthquake.

[0051] In addition, as shown in Figure 1, the aforementioned height adjustment filler 4, which corresponds to the gradient of the lower flange H1 of the bridge girder BG, is interposed between the lower flange H1 and the upper member 3, and the upper member 3 is bolted to the lower flange H1 so that it is horizontal.

[0052] (Jacking up process) Next, as shown in Figure 5, in the bearing replacement method according to this embodiment, the aforementioned jacking device J1 is installed on the jacking device 1 with movement limiting function that was installed in the previous jacking device installation process, and the jacking is performed to remove stress on the existing bearing.

[0053] Specifically, as shown in Figure 2, in this process, the jacking device J1 is installed on the lower plate portion 20 of the jacking device 1 with movement limiting function, at a predetermined position indicated by the dot-dash circle within the jack surrounding portion 21 (see also Figure 1).The jacking device J1 is then operated to extend the ram portion J1b ​​of the jack, jacking up and lifting the upper plate portion 30 and bridge girder BG, thereby removing stress on the existing bearings.

[0054] (Existing bearing removal process) Next, as shown in FIG. 5, in the bearing replacement method according to this embodiment, an existing bearing removal step is carried out to remove the existing bearing from which stress has been removed in the previous step.

[0055] Specifically, in this existing bearing removal process, the shoe seat mortar and sole plate that secure the existing bearing to the pier P1 are chipped off, the anchors that were fixed to the pier P1 are cut, and bolts that were connected to the bridge girder BG, etc. are removed, and the existing bearing is removed.

[0056] (New bearing installation process) Next, as shown in FIG. 5, in the bearing replacement method according to this embodiment, a new bearing installation step is carried out to install a new bearing.

[0057] Specifically, a new sole plate and shoe seat mortar are installed, and a new bearing that meets current earthquake resistance standards is installed. In the bearing replacement method according to this embodiment, a new bracket is installed and the new bearing is bolted to the bracket. However, it is also possible to drill holes in the pier P1 to install new anchor bolts and then bolt the new bearing to the anchor bolts.

[0058] (Jacking down process) Next, as shown in Figure 5, in the bearing replacement method according to this embodiment, after the high-strength bolts are fully tightened and any necessary on-site welding is performed, the jacking device J1 is activated to shorten the ram portion J1b ​​of the jack, and a jacking-down process is carried out in which the load of the superstructure is borne by the new bearing installed in the previous process.

[0059] (Jack-up device removal process) Next, as shown in Figure 5, in the bearing replacement method according to this embodiment, a jack-up device removal process is carried out in which bolts and other fastening elements that joined the jack-up device 1 installed in the previous jack-up device installation process are removed. This completes the bearing renewal work of replacing the existing bearings of bridge B1 with new bearings.

[0060] According to the bearing replacement method according to the embodiment of the present invention described above, it is possible to withstand a level 1 earthquake even after jacking up with the jack-up device 1 with movement limiting function and removing the existing bearings. Therefore, unlike conventional bearing replacement methods in which adjacent bearings could not be replaced simultaneously and replacement work was performed in a staggered pattern, it is now possible to replace adjacent bearings simultaneously. This makes it possible to significantly shorten the construction period for bearing replacement work.

[0061] Furthermore, as described in the Background Art, the bearing replacement method according to this embodiment does not require the installation of time-consuming temporary equipment such as a jack device and a separate temporary support device, unlike conventional bearing replacement methods such as the seismic isolation device replacement method described in Patent Document 2. Therefore, the bearing replacement method according to this embodiment does not require the securing of a large amount of space around the narrow bearing, making it easy to perform the bearing renewal work.

[0062] The jack-up device 1 with movement limiting function and the bearing replacement method using the same according to the embodiment of the present invention have been described in detail above, but the above-mentioned and illustrated embodiments are merely specific examples of the present invention. Therefore, the technical scope of the present invention should not be interpreted as being limited by these embodiments. [Explanation of symbols]

[0063] 1: Jack-up device with movement restriction function 2: Lower part 20: Lower plate part 21: Seat-dug hole 22: Bolt hole 3: Upper member 30: Upper plate part 31: Jack enclosure 32: Bolt hole 33: Slit 4: Height adjustment filler 5:Sliding material B1: Bridge BG: Bridge girder (superstructure) H1: Lower flange (upper structure) P1: Pier (substructure) B2: Jack-up bracket (extension bracket) J1: Jack device J1a: Jack body J1b: Ram section B3: Bolt

Claims

1. The system comprises: a jack device supported on a substructure of a bridge to lift a superstructure of the bridge; a lower member that can be installed upside down and fixed to either the substructure or the superstructure so as to be able to resist a level 1 earthquake horizontal force; and an upper member that can be installed upside down and fixed to the other so as to be able to resist the earthquake horizontal force, The lower member has a flat lower plate portion, and a plurality of countersunk holes are formed in the lower plate portion, the countersunk holes being capable of accommodating bolt heads that screw into threaded holes drilled in the jack device; The upper member has a plate-shaped upper plate portion and a jack surrounding portion that is erected on the upper plate portion and surrounds the jack device at a distance, and is fixed to the upper structure or the lower structure via the upper plate portion by bolts or with a vise, The lower member and the jack device are bolted together through the countersunk holes, and the jack device and the jack surrounding part are fitted together to limit the horizontal movement of the upper structure during an earthquake so that it can resist the horizontal force of a level 1 earthquake. A jack-up device with a movement limiting function.

2. A slit is formed in the jack surrounding portion.

2. The jack-up device with movement limiting function according to claim 1,

3. A sliding member for reducing friction is attached to the inside of the portion of the upper plate surrounded by the jack surrounding portion.

3. The jack-up device with movement limiting function according to claim 1 or 2,

4. A height adjustment filler is interposed between the upper plate portion attached to the upper structure and the upper structure, the height adjustment filler being in accordance with the gradient of the underside of the upper structure.

4. A jack-up device with a movement limiting function according to claim 1, wherein:

5. A bearing replacement method for replacing an existing bridge bearing with a new bearing, A jack-up device with a movement limiting function according to any one of claims 1 to 4 is installed, the superstructure of the bridge is jacked up with a jack, the existing bearings are replaced with new bearings, and then the jack-up device with a movement limiting function is removed. A bearing replacement method characterized by the above.

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