JP2023124361A - Jack-up device with movement restriction function and bearing replacing method - Google Patents

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

The present invention is a jack-up device with a movement limiting function that jacks up an upper structure such as a bridge girder and limits the movement of the upper structure during jacking up when replacing an existing bridge bearing with a new one. The present invention relates to a bearing replacement method for replacing an existing bridge bearing with a new bearing.

Conventionally, when replacing bridge bearings, brackets are attached to the lower structure to expand the space of the lower structure of the piers and abutments, and the upper structure such as the bridge girder is jacked up to remove the stress acting on the existing bearings. , has been replaced with new bearings.

On the other hand, when replacing bridge bearings, it is necessary to take measures to withstand seismic horizontal forces (e.g. level 1 seismic force) even when the bearings are removed. Instead of replacing all of them at once, it is handled by removing every other one in a staggered manner. However, there is a problem in that it takes more than double the time to remove the bearings, requiring a number of construction days.

For example, in Patent Document 1, in 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, on the side surface 12 or the lower surface 13 of the existing concrete girder 1, A groove 15 is provided in a state in which the internal reinforcing bar 14 of the existing concrete girder 1 is not hung, and the projection 22 in the engaging fitting 24 having the projection 22 fitted in the groove 15 is fitted into the groove 15. discloses a method of updating an existing bearing device in which the engaging metal fittings 24 are provided on the existing concrete girder 1 and the existing concrete girder 1 is supported by the new bearing device 21 via the engaging metal fittings 24 (Patent Document 1, paragraphs [0013] to [0023] of the specification, and FIGS. 1 to 5 of the drawings, etc.).

However, the method for updating an existing bearing device described in Patent Document 1 does not take into account countermeasures in the event that seismic horizontal force acts when the bearings are removed. There was no other way but to take measures such as removing it, and it was not possible to solve the problem of requiring a number of construction days.

Further, Patent Document 2 discloses a temporary structure consisting of a flat jack 1 and a temporary bearing 11 for supporting an upper layer in place of the existing seismic isolation device when replacing the existing seismic isolation device with a new seismic isolation device. Disclosed is a method for replacing a seismic isolation device that provides a support device and can suppress vibrations of a structure due to an earthquake even when an earthquake occurs during replacement of the seismic isolation device (Patent Document 2, Patent Claims claim 1, paragraphs [0040] to [0055] of the specification, FIGS. 1 to 6 of the drawings, etc.).

However, in the method for replacing a seismic isolation device described in Patent Document 2, it is necessary to install temporary support devices consisting of flat jacks 1 and temporary bearings 11 on both front, back, left, and right sides of one seismic isolation device. There was a problem that a large space was required around the existing bearings of the substructure, and it was difficult to secure the space. In addition, the method for exchanging the seismic isolation device described in Patent Document 2 requires a special flat jack 1 and a temporary support 11 separately, and there is also the problem that the cost increases.

JP 2009-19493 A JP 2017-57636 A

Therefore, the present invention has been devised in view of the above problems, and its object is to provide a movement restriction function that can resist even an earthquake when the bearing is removed by jacking it up. To provide a jack-up device with an attachment and a bearing replacement method using the same.

The jack-up device with movement limiting function according to claim 1 comprises a jack device supported by a lower structure of a bridge to lift the upper structure, and a lower member supported by either the lower structure or the upper structure. and an upper member supported by the other, the lower member having a flat plate-shaped lower plate portion, the lower plate portion having screw holes drilled in the jack device and screws. A plurality of counterbore holes capable of accommodating the bolt heads of mating bolts are formed, and the upper member includes a plate-like upper plate portion and a jack erected on the upper plate portion to surround the jack device while being spaced apart from the jack device. and a surrounding portion, wherein the lower member and the jack device are bolted through the counterbore, and the jack device and the jack surrounding portion are fitted to each other to prevent the upper portion from occurring during an earthquake. It is characterized by limiting horizontal movement of the structure.

According to a second aspect of the invention, there is provided a jackup device with a movement limiting function, wherein a slit is formed in the jack surrounding portion in the jackup device with the movement limiting function according to the first aspect.

According to claim 3, there is provided a jack-up device with a movement-restricting function according to claim 1 or 2, wherein the inside of the portion surrounded by the jack-surrounding portion of the upper plate portion has a , which are fitted with slips that reduce friction.

According to claim 4, there is provided a jackup device with a movement limiting function according to any one of claims 1 to 3, wherein the upper plate portion attached to the upper structure and the upper structure A height adjusting filler corresponding to the gradient of the lower surface of the upper structure is interposed between the upper structures.

The bearing replacement method according to claim 5 is a method of installing a jack-up device with a movement limiting function according to any one of claims 1 to 4, jacking up the superstructure of the bridge with a jack, and installing a new existing bearing. It is characterized in that the jack-up device with movement limiting function is removed after replacement with the bearing.

According to the inventions of claims 1 to 5, when replacing a bridge bearing, even if the bearing is jacked up and removed, even if an earthquake force is received, the horizontal force of the superstructure can be resisted and the horizontal direction of the superstructure movement can be restricted.

In particular, according to the second aspect of the invention, since the slit is formed, it is easy to access the vicinity of the upper part of the jack device, and the work efficiency in jacking up the jack device J1 is improved.

In particular, according to the third aspect of the invention, since the sliding material that reduces friction is attached to the inner side of the upper plate portion, it is possible to cope with temperature expansion and contraction of the upper structure during jacking up.

In particular, according to the fourth aspect of the invention, since the height adjusting filler is interposed, the lower member and the upper member can be shared regardless of the slope of the superstructure of the bridge. . Therefore, it is possible to reduce the cost of the jackup device with the movement limiting function.

FIG. 1 is a side view of a jackup device with a movement limiting function according to an embodiment of the present invention placed on a jackup bracket and viewed along a direction perpendicular to the bridge axis. FIG. 2 is a horizontal cross-sectional view of the jackup device with a movement limiting function of FIG. 1, taken along the line AA. FIG. 3 is a diagram showing only the lower member of the jackup device with a movement restriction function, (a) is a plan view, (b) is a vertical sectional view along the line BB, and (c) is a top view looking down from above. FIG. 3(d) is a perspective view, and FIG. 3(d) is a bottom perspective view obtained by reversing the top perspective view of FIG. 3(c). FIG. 4 is a diagram showing only the upper member of the jackup device with a movement restriction function, (a) is a plan view, (b) is a vertical cross-sectional view along the CC line, and (c) is an upside-down lower surface. It is a perspective view. FIG. 5 is a flow chart showing each work process of the bearing replacement method according to the embodiment of the present invention.

BEST MODE FOR CARRYING OUT THE INVENTION A jackup device with a movement restricting function and a bridge support replacement method using the jackup device according to an embodiment of the present invention will now be described in detail with reference to the drawings.

<Jack-up device with movement restriction function>
First, a jackup device 1 with a movement restriction function (hereinafter also simply referred to as jackup device 1) according to an embodiment of the present invention will be described with reference to FIGS. 1 to 4. FIG. FIG. 1 is a side view of a jack-up device 1 with a movement limiting function according to an embodiment of the present invention placed on a jack-up bracket B2 and viewed along a direction perpendicular to the bridge axis, and FIG. 2 is a side view of FIG. 1 is a horizontal cross-sectional view of the jackup device 1 taken along the line AA. FIG. 3 is a diagram showing only the lower member of the jackup device 1, (a) is a plan view, (b) is a vertical cross-sectional view along the line BB, and (c) is a perspective top view looking down from above. It is a diagram. FIG. 4 is a diagram showing only the upper member of the jackup device 1, (a) is a plan view, (b) is a vertical cross-sectional view along the CC line, and (c) is a bottom oblique view that is inverted upside down. It is a diagram.

Here, in the illustrated bridge B1, a bridge girder BG consisting of steel girders, which is an upper structure, is installed on a pier P1, which is a lower structure made of reinforced concrete, via a bearing (not shown). A case of using the jack-up device 1 with a movement limiting function to remove the stress of the existing bearing by jacking it up with the jack device J1 when replacing it with a new one will be described as an example.

Also, the jack-up bracket B2 is an additional bracket for mounting the jack device J1 supported by being bolted to the side surface of the pier P1, which is the lower structure of the bridge B1. 2 indicates the lower flange H1 of the steel girder, and the double circle of the central overhead line indicated by the one-dot chain line in FIGS. 2 to 4 indicates the bridge girder BG. It shows the position where the lifting jack device J1 is installed.

As shown in FIGS. 1 to 4, the jackup device 1 includes a lower member 2 attached to the upper surface of a jackup bracket B2 and a lower flange of a bridge girder BG which is an upper structure facing the lower member 2. an upper member 3 attached to the lower surface of H1. This jack-up device 1 is used by being attached to a jack device J1 supported by a lower structure. , is a movement-restricting device that resists a level 1 earthquake that occurs during work, replaces a part of the function of the bearing of the bridge B1, and restricts the horizontal and vertical movement of the bridge girder BG, which is the superstructure.

(Lower member)
As shown in FIGS. 2 and 3, the lower member 2 is mainly composed of a rectangular lower plate portion 20. As shown in FIG. The lower plate portion 20 has a plurality of counterbore holes 21 that can accommodate the bolt heads of bolts B3 that are screwed into screw holes (female thread portions) drilled in the bottom surface of the jack device J1 so as not to protrude from the bottom surface. is formed.

As shown in FIG. 3A, the lower plate portion 20 is a rectangular (rectangular) steel plate having a predetermined thickness that can withstand a collision load. , and as shown in FIG. 3(d), bolt holes 22 for bolting to the jack-up bracket B2 are drilled at the ends in the longitudinal direction.

However, the lower member 2 can be fixed to the jack-up bracket B2 by omitting the bolt hole 22 and sandwiching the lower plate portion 20 and the upper plate of the jack-up bracket B2 with a vise or the like.

As shown in FIGS. 3A to 3D, the counterbore 21 is a counterbore provided at a position inside the outer peripheral edge of the bottom surface of the jack device J1 by a predetermined distance. 8 are provided at regular intervals. The counterbore 21 is formed by fixing the bottom surface of the jack device J1 to the jack-up bracket B2 via the lower member 2, and by removing the horizontal stress and bending stress caused by the seismic force acting on the jack device J1. It has the function of transmitting to the pier P1.

As described above, in the jack-up device 1, the jack device J1 is indirectly bolted (mechanically joined) to the bridge pier P1, which is the lower structure. It is possible to completely eliminate the possibility that the jack device J1 will overturn due to the horizontal force during an earthquake.

(Upper member)
As shown in FIGS. 2 and 4 , the upper member 3 has a plate-like upper plate portion 30 and a jack surrounding portion 31 erected on the upper plate portion 30 .

The upper plate portion 30, as shown in FIG. 4(a), is an octagonal (rectangular) steel plate having a predetermined thickness capable of withstanding a collision load, and the longitudinal direction (bridge axis direction in the illustrated case) end portion , bolt holes 32 are drilled for bolting to the lower flange H1 of the bridge girder BG, which is the superstructure.

However, even if the upper member 3 does not have the bolt hole 32, the upper plate portion 30, the height adjustment filler 4, and the lower flange H1 of the bridge girder BG are sandwiched by a vise or the like and fixed to the lower flange H1. I do not care. By doing so, it is not necessary to drill a bolt hole that causes a cross-sectional defect in the lower flange H1, which is the upper structure of the bridge B1.

Further, as shown in FIG. 2, the jack surrounding portion 31 is separated from the outer peripheral wall of the jack device J1 by a predetermined distance, and the cylindrical wall body formed so as to surround the jack device J1 is partially extended by a predetermined distance. It is a fragmented portion with an arc-shaped horizontal cross section. In other words, the jack surrounding portion 31 has a cylindrical wall formed with a slit 33 for accessing the jack device J1. A total of four slits 33 are formed in the jack surrounding portion 31 of the present embodiment to facilitate access to the jack device J1.

As described above, since four large slits 33 are formed in the jack surrounding portion 31, it is easy to access the vicinity of the upper portion of the jack device J1 (around the ram portion J1b), and the jack device J1 can be jacked up. Work efficiency is improved during work.

As the jack surrounding portion 31, a cylindrical (arc-shaped) horizontal cross section has been exemplified, but the jack surrounding portion 31 has a similar horizontal cross section that fits with the jack device J1 at a predetermined distance. can be a cylindrical portion. For example, the jack surrounding portion 31 can be a rectangular tubular portion.

(sliding material)
4(a) and 4(c), the upper plate portion 30 of the upper member 3 and A slip member 5 is attached to reduce friction with the jack device J1. The sliding member 5 according to this embodiment is a plate member made of fluororesin (polytetrafluoroethylene). The sliding material 5 reduces the friction between the upper member 3 and the jack device J1, and the jack device J1 is activated by expansion and contraction due to temperature changes of the bridge girder BG during the replacement work of the bearing of the bridge B1 in a jacked-up state. It has a feature that prevents it from tipping over.

(height adjustment filler)
The lower member 2 is directly bolted to the upper surface of the jack-up bracket B2, and the upper member 3 is attached to the lower surface of the bridge girder BG, which is the upper structure, through a height adjustment filler 4 according to the slope of the lower flange H1. are bolted to the lower flange H1. Therefore, in the jack-up device 1, which is also applicable to bridges with different slopes, the lower member 2 and the upper member 3 can be commonly installed horizontally regardless of the slope of the bridge girder BG, improving safety. At the same time, it is possible to reduce the cost of the jackup device 1 with movement restriction function.

However, the jackup device 1 can be turned upside down so that the upper member 3 is attached to the upper surface of the jackup bracket B2 and the lower member 2 is attached to the lower surface of the lower flange H1.

According to the jack-up device 1 with a movement limiting function according to the embodiment of the present invention described above, the jack surrounding portion 31 of the upper member 3 is separated from the jack device J1 and formed so as to surround the jack device J1. . For this reason, the jack-up device 1 can resist the horizontal force of a level 1 earthquake in a state where the bearings have been removed by jacking up the jacking device J1 in the replacement of the bridge bearings, and the upper structure can restrict the horizontal movement of

Moreover, according to the jack-up device 1, since the four large slits 33 are formed in the jack surrounding portion 31 of the upper member 3, it is easy to access the upper part of the jack device J1, and the jack of the jack device J1 can be easily accessed. Work efficiency is improved during up work.

Furthermore, according to the jack-up device 1, since the sliding material 5 that reduces friction is attached to the lower surface of the upper plate portion 30 and the inner side of the jack surrounding portion 31, the temperature expansion and contraction of the upper structure during jacking up. can respond.

Moreover, according to the jack-up device 1, since the height adjustment filler 4 corresponding to the slope of the lower flange H1 is interposed between the upper member 3 and the lower flange H1, the jack-up device with movement limiting function 1 can be diverted to bridges with various slopes, and cost reduction can be achieved.

<How to replace bearings>
Next, a bearing replacement method according to an embodiment of the present invention will be described with reference to FIGS. 1 to 4 and 5. FIG. A case where the above-mentioned jack-up device 1 with movement restriction function is used to perform bearing renewal work for replacing the existing bearings of the above-mentioned bridge B1 with new bearings will be described as an example. FIG. 5 is a flow chart showing each work process of the bearing replacement method according to the embodiment of the present invention.

(Reinforcing material installation process)
First, as shown in FIG. 5, in the bearing replacement method according to the embodiment of the present invention, as a preliminary preparation, a reinforcing member attaching step is performed to reinforce the bridge girder BG as necessary.

Specifically, in this step, reinforcing ribs are joined to the web of the bridge girder BG, which is a steel girder, by high-strength bolting or welding, and are reinforced so as not to buckle when jacked up by the jack device J1.

(Bracket installation process)
Next, as shown in FIG. 5, in the bearing replacement method according to the present embodiment, a temporary bracket is installed beside the lower structure of the bridge B1 in order to secure a space for installing the jack device J1. Carry out the bracket installation process.

Specifically, in this step, the above-described jack-up bracket B2 is bolted and fixed to the side surface of the pier P1, which is the lower structure, using a post-installed anchor or the like (see also FIG. 1).

(Jackup device installation process)
Next, as shown in FIG. 5, in the bearing replacement method according to the present embodiment, the jack-up device 1 with the movement limiting function is installed on the jack-up bracket B2 installed in the front bracket installation step. Carry out the equipment installation process.

Specifically, in this step, as shown in FIGS. 1 and 2, bolts are inserted through the bolt holes 22 of the lower plate portion 20 described above, and the lower member 2 is bolted onto the jack-up bracket B2. do. Then, bolts are inserted through the bolt holes 32 of the upper plate portion 30 at positions directly above the lower member 2 to join the upper member 3 to the lower flange H1 of the bridge girder BG.

At this time, as shown in FIG. 2, the jack device J1 and the jack surrounding portion 31 are engaged with each other with a predetermined gap therebetween, and when the bridge girder BG, which is the upper structure, moves horizontally, the jack device J1 and the jack surrounding portion 31 are engaged with each other. Install so that they fit abuttingly and limit horizontal and vertical movement during an earthquake.

In addition, as shown in FIG. 1, by interposing the above-mentioned height adjustment filler 4 corresponding to the slope of the lower flange H1 of the bridge girder BG between the lower flange H1 and the upper member 3, the upper member 3 can be made horizontal. It is bolted to the lower flange H1 so that

(Jacking up process)
Next, as shown in FIG. 5, in the bearing replacement method according to the present embodiment, the above-described jack device J1 is installed in the jack-up device 1 with a movement restriction function installed in the previous jack-up device installation process, and the jack-up is performed. Then, a jack-up process is carried out to remove the stress applied to the existing bearings.

Specifically, as shown in FIG. 2, in this step, a predetermined position indicated by a dashed-dotted circle on the lower plate portion 20 of the jack-up device 1 with a movement restriction function and within the jack surrounding portion 21 , a jack device J1 is installed (see also FIG. 1). After that, the jack device J1 is operated to extend the ram portion J1b of the jack, jack up the upper plate portion 30 and the bridge girder BG, and lift the stress applied to the existing bearings.

(Existing bearing removal process)
Next, as shown in FIG. 5, in the bearing replacement method according to the present embodiment, an existing bearing removing step is performed to remove the existing bearing from which the stress has been removed in the previous step.

Specifically, in this existing bearing removal process, the mortar and sole plate that secure the existing bearing to the pier P1 are scraped off, the anchors fixed to the pier P1 are cut, and the bridge girder BG, etc. Remove the existing bearing by removing the bolts etc. that were connected to it.

(New bearing installation process)
Next, as shown in FIG. 5, in the bearing replacement method according to the present embodiment, a new bearing installation process for installing a new bearing is performed.

Specifically, a new sole plate and Kutsuza mortar will be constructed, and a new bearing that meets the current seismic standards will be installed. In addition, in the bearing replacement method according to the present embodiment, a new bracket is installed and the new bearing is bolted to the bracket. However, a new anchor bolt may be installed by drilling a hole in the bridge pier P1, and the new bearing may be bolted to the anchor bolt.

(Jack-down process)
Next, as shown in FIG. 5, in the bearing replacement method according to the present embodiment, after the high-strength bolts are fully tightened and necessary on-site welding is performed, the jack device J1 is operated to lift the ram portion J1b of the jack. It will be shortened, and a jack-down process will be carried out in which the load of the upper structure is borne by the new bearings installed in the previous process.

(Jackup device removal process)
Next, as shown in FIG. 5, in the bearing replacement method according to the present embodiment, the bolts or the like that have joined the jackup device 1 installed in the previous jackup device installation process are removed and removed. carry out the process. This completes the bearing renewal work for replacing the existing bearings of the bridge B1 with new bearings.

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 when the existing bearings are removed by jacking up the jack-up device 1 with movement restriction function. Therefore, the adjacent bearings cannot be renewed at the same time, and the adjacent bearings can be renewed at the same time unlike the conventional bearing replacement method in which the renewal work is performed in a staggered manner. Therefore, the construction period for bearing replacement work can be significantly shortened.

Further, according to the bearing replacement method according to the present embodiment, as described in Background Art, unlike the conventional bearing replacement method such as the seismic isolation device replacement method described in Patent Document 2, It is no longer necessary to install a temporary device such as a temporary support device that is separate from the jack device. Therefore, according to the bearing replacement method according to the present embodiment, it is not necessary to secure a large space around the narrow bearing, and the bearing can be easily updated.

The jack-up device 1 with a movement restriction function according to the embodiment of the present invention and the bearing replacement method using the same have been described in detail above. It merely shows one embodiment that is embodied for the purpose. Therefore, the technical scope of the present invention should not be construed to be limited by these.

1: Jack-up device with movement limiting function 2: Lower member 20: Lower plate portion 21: Counterbore 22: Bolt hole 3: Upper member 30: Upper plate portion 31: Jack surrounding portion 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 (lower structure)
B2: Jack-up bracket (extension bracket)
J1: Jack device J1a: Jack body J1b: Ram part B3: Bolt

Claims (5)

A jack device that is supported by the lower structure of the bridge and lifts the upper structure, a lower member that is supported by either the lower structure or the upper structure, and an upper member that is supported by the other;
The lower member has a flat lower plate portion, and the lower plate portion has a plurality of seats capable of accommodating bolt heads of bolts that are screwed into screw holes drilled in the jack device. A pit is formed,
The upper member has a plate-like upper plate portion and a jack surrounding portion that is erected on the upper plate portion and surrounds the jack device while being spaced from the jack device,
The lower member and the jack device are bolted through the counterbore, and the jack device and the jack surrounding portion are fitted to restrict horizontal movement of the upper structure during an earthquake. A jack-up device with a movement restriction function, characterized by: The jackup device with a movement limiting function according to claim 1, wherein a slit is formed in the jack surrounding portion. 3. The jack-up device with a movement limiting function according to claim 1, wherein a sliding material for reducing friction is attached to the inner side of the portion of the upper plate portion surrounded by the jack surrounding portion. . 4. A height adjusting filler according to the gradient of the lower surface of the upper structure is interposed between the upper plate portion attached to the upper structure and the upper structure. The jackup device with a movement restriction function according to any one of 1. A bearing replacement method for replacing an existing bridge bearing with a new bearing,
After installing the jack-up device with movement limiting function according to any one of claims 1 to 4, jacking up the superstructure of the bridge with a jack and replacing the existing bearing with a new bearing, the jack with movement limiting function A bearing replacement method characterized by removing the up device.

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