JP2016008463A - Bearing installation method and bearing structure - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a bearing installation method and a bearing structure for solving conventional problems, specifically, facilitating height adjustment of an installed bearing, eliminating a concern on rusting of components used, and avoiding serious effect on the bearing even when mortar and other materials undergoes creeping.SOLUTION: A bearing installation method of the present invention includes at least a bearing installation step, a height adjustment step, an injection step and a bolt extraction step. In the bearing installation step, a bearing is installed by mounting a bottom end of a height adjustment bolt on a blockout part disposed at a position to install the bearing, on a lower foundation that supports the bearing. In the height adjustment step, the height adjustment bolt is rotated for adjusting a bearing installation height. In the injection step, a filler is injected into the blockout part. In the bolt extraction step, the height adjustment bolt is extracted after the filler reaches a prescribed strength.

Description

  The present invention is a technology related to a bearing, and more specifically, a technology related to a bearing installation method and a bearing structure in which the installation height can be easily adjusted and is less susceptible to the effects of creep such as filling mortar after installation. is there.

  The support is installed between the superstructure of the bridge and the substructure, and transmits the live load and dead load from the superstructure to the substructure, so to speak, it becomes the fulcrum of the superstructure. These bearings are broadly divided into fixed bearings that restrain horizontal movement and rotation of superstructures, and movable bearings that allow horizontal movement and rotation freely. It can be divided into pin bearings to be freed.

  Some bearings have a function of attenuating the vibration of superstructure during an earthquake, and such bearings are called seismic isolation bearings. For example, the seismic isolation rubber bearing uses the shear rigidity of rubber to lengthen the natural period of the superstructure, thereby damping the vibration of the superstructure.

  FIG. 7 is a cross-sectional view showing a state in which a general rubber bearing A is installed on an abutment. As shown in this figure, the rubber bearing A is mainly composed of an upper collar A1 and a lower collar A2, and a laminated body A3 disposed therebetween. Among these, the laminated body A3 is obtained by alternately laminating steel plates and rubber and vulcanizing and bonding them, and has a feature of exhibiting high rigidity in the vertical direction and flexibly deforming in the horizontal direction.

  As shown in FIG. 7, a space (hereinafter referred to as a “box removal part”) that is recessed more than the others is provided at a place where the rubber support A is installed. Further, the general rubber bearing A is provided with an anchor A4. Therefore, a space for anchor burying (hereinafter referred to as “anchor hole”) is also provided in the box opening portion. When the rubber support A is installed on the abutment, the box opening portion is filled with mortar, and the rubber support A is fixed on the abutment by hardening the mortar. That is, a space for filling the mortar is required below the rubber support A, and therefore the rubber support A is installed on a pedestal (for example, a steel liner B) disposed in the box opening portion. become.

  FIG. 8 is a model diagram showing a general procedure for installing the rubber bearing A on the abutment. As shown to (a) of this figure, the box opening part is provided in the predetermined position of the abutment. As a procedure, first, the steel liner B is disposed at a predetermined position of the box-cutting portion (FIG. 8B), and the rubber support A is installed on the steel liner B (FIG. 8C). Next, the mortar is filled in the box opening portion including the anchor hole (FIG. 8D), and the mortar is cured until it exhibits a predetermined strength. Waiting for the mortar to harden, the bridge girder C is fixed on the rubber bearing A (FIG. 8 (e)).

  By the way, as already described, the bearing mounts the superstructure, that is, the installation accuracy of the bearing is directly connected to the installation accuracy of the superstructure. For example, if the support is installed at a position lower than the planned height, the height of the superstructure placed on it will be lower than planned as well. Needless to say, the bridge is an important structure, and it should be installed as planned due to the safety after operation. Therefore, the installation work of the support is very careful.

  On the other hand, in order to fill the mortar, the rubber support A is installed on the steel liner B as shown in FIG. In this case, the manufacturing accuracy and installation accuracy of the steel liner B will affect the installation accuracy of the rubber bearing A, and consequently the installation accuracy of the superstructure. However, even after the steel liner B or the rubber bearing A is installed, it is not easy to adjust the height even if it is found that it differs from the planned installation height. When installed at a position lower than the planned height, measures such as laying a plate for height adjustment can be taken, but when installed at a position higher than the planned height, the steel liner B is made thinner. You have to adjust it. Further, in order to adjust the horizontal posture of the rubber bearing A, when a certain steel liner B is made higher and a certain steel liner B is made lower, it becomes more complicated.

  In order to solve such a problem, Patent Document 1 proposes a method capable of adjusting the height even after the support is installed. Specifically, the height of the base plate for mounting the support is adjusted. A female screw is cut in the base plate, and a height adjusting bolt is inserted into the female screw, and this bolt is rotated. This makes it possible to move the base plate up and down.

Japanese Patent Laid-Open No. 06-002313

  As shown in FIG. 7, in order to fill the mortar below the rubber support A, the steel liner B as the pedestal is installed as described above, but by installing this steel liner B, There are problems that arise. Usually, the boxed portion for filling the mortar is not so deep, and therefore the installed steel liner B has a disadvantage that the mortar has a shallow fog and therefore easily rusts. If the steel liner B rusts, it will affect the support and superstructure placed on it, and the durability of the entire bridge may be deteriorated.

  Moreover, it is known that the hardened mortar will creep over time. That is, when the mortar creeps as shown in FIG. 7, the rubber bearing A is supported only by the steel liner B. As a result, the upper collar A1 supported by the points may bend and deform, and the steel liner B is forced to be overloaded. If the steel liner B is rusted, it may be impossible to withstand an excessive load.

  As described above, the conventional method of installing the steel liner B has a problem that it is difficult to adjust the height of the rubber bearing A after the installation, a problem that the steel liner B is easily rusted, and a problem that the mortar creeps. Have In addition, although patent document 1 can eliminate the problem of height adjustment, the problem that the height adjustment bolt used as the steel liner B tends to rust and the problem that the mortar creeps cannot be solved. .

  The object of the present invention is to solve the conventional problem, that is, the height of the support after installation is easy, there is no fear of rusting of the used member, and the support is supported even if mortar or the like creeps. It is to provide a bearing installation method and a bearing structure that do not greatly affect the bearing.

  The present invention has been made on the basis of an unprecedented idea that a bolt is used to adjust the installation height of the support and that the bolt is recovered after the height adjustment.

  The bearing installation method of the present invention is a bearing installation method comprising two or more bolt insertion holes and height adjustment bolts inserted through these bolt insertion holes, and at least a bearing installation process, a height adjustment process, and an injection process. The method includes a bolt removing process. In the support installation process, the support is installed by placing the lower end of the height adjustment bolt on the box opening provided at the position where the support is installed, of the lower foundation supporting the support. In the height adjustment step, the installation height of the support is adjusted by rotating the height adjustment bolt. In the injection step, the filler is injected into the box extraction portion, and in the bolt extraction step, the height adjusting bolt is extracted after waiting until the filler reaches a predetermined strength.

  The support installation method of the present invention may be a method in which the superstructure is installed on the support after the support installation process and the height adjustment process is performed in that state.

  The support installation method of the present invention can also be a method further comprising a support installation step of installing a bolt support. In the support installation process in this case, the lower end of the height adjusting bolt is placed on the bolt support. When the support has upper and lower rods arranged substantially in parallel in the vertical direction, and the boxing depth of the boxing part is larger than the gap arrangement interval (interval between upper and lower rods) In the support installation step, it is preferable to install a bolt support that is thicker than the dimensional difference between the boxing depth and the saddle arrangement interval.

  The support installation method of the present invention can be a method further comprising a mold installation step. This mold installation process is performed before the support installation process, and specifically, a bolt curing mold is installed. In the support installation process in this case, the height adjustment bolt is disposed in the bolt curing mold, and a bolt curing space is formed by the filler and the bolt curing mold that are injected in the subsequent injection process.

  The bearing structure of the present invention includes a bearing including a lower arm, a lower foundation that supports the bearing, a box opening provided at a position where the bearing is installed in the lower foundation, and a filler injected into the box opening is cured. This structure has a cured body. An anchor body having an axis in the vertical direction is fixed to the lower rod, and two or more bolt insertion holes are provided, and height adjustment bolts are inserted into these bolt insertion holes. In addition, an anchor body and a height adjustment bolt are stored in a box extraction part. The installation height of the support can be adjusted by rotating the height adjustment bolt after the support is installed in the box extraction part, and the height adjustment bolt can be extracted after the filler has reached the specified strength. is there. A filler is injected into the space after the height adjustment bolt is removed.

The bearing installation method and the bearing structure of the present invention have the following effects.
(1) Even if it turns out that it differs from the planned installation height after installing a support, height adjustment can be easily performed only by rotating a height adjustment bolt.
(2) Since metal members such as height adjusting bolts and conventionally used steel liners are not left, the risk of durability deterioration due to rusting is reduced.
(3) Even if the filler material undergoes creep deformation, the height adjustment bolt is removed, so that the bearing follows the creep deformation. Therefore, there is a risk of change in the installation position (horizontal position) of the bearing and deformation of the bearing. There is no.

The side view which shows an example of the support used by this invention. The flowchart which shows the flow of the main processes of this invention. The step figure which shows the flow of the main processes of this invention. The model figure which shows the state which installed the volt | bolt support body according to these dimensions while showing the dimension of a heel space | interval and a boxing depth. The model figure which shows a mode that a void pipe | tube is installed in a boxed upper surface as a curing formwork, and a support is installed in that state. The flowchart which shows the flow of the main processes in the case of adjusting the height of a support after superstructure installation. Sectional drawing which shows the state which installed the general rubber bearing on the abutment. The model figure which shows the general procedure at the time of installing a rubber bearing on an abutment.

  An example of a bearing installation method and a bearing structure according to the present invention will be described with reference to the drawings.

1. Bearing First, an example of a bearing 100 used in the present invention will be described with reference to FIG. As shown in this figure, the bearing 100 includes an upper rod 101 horizontally disposed at the upper portion and a lower rod 102 disposed horizontally at the lower portion. A laminate 103 in which steel plates and rubber are alternately laminated and vulcanized and bonded is disposed between the upper rod 101 and the lower rod 102, and an anchor 104 having a vertical axis as an axis is fixed to the lower rod 102. ing. The upper collar 101 and the lower collar 102 have a rectangular or circular shape when viewed in a plan view, and the laminated body 103 having a slightly smaller area than that has a rectangular or circular shape when viewed in a plan view. Also, a plurality of anchors 104 are often fixed to one support 100, and four anchors 104 are provided in FIG. In addition, the structure which consists of the upper collar 101, the lower collar 102, the laminated body 103, and the anchor 104 is the same as that of the conventional rubber bearing, ie, the rubber bearing currently distribute | circulated on the market can be utilized for this application.

  A plurality of height adjusting bolts 105 are attached to the support 100 used in the present invention. As will be described later, since the height adjustment bolt 105 temporarily supports the support 100, a plurality of (preferably three or more) height adjustment bolts 105 may be attached to one support 100. . Four height adjusting bolts 105 are attached to the support 100 of FIG.

  The height adjusting bolt 105 is inserted into a bolt insertion hole provided in the lower collar 102. The bolt insertion hole is threaded and can be moved in the vertical direction relative to the lower rod 102 by rotating the height adjusting bolt 105. Alternatively, the height adjustment bolt 105 can be rotated using a nut without cutting a screw in the bolt insertion hole provided in the lower rod 102. In this case, a nut (not shown) that fits the size of the height adjustment bolt 105 is welded to the upper surface of the lower rod 102 and the upper surface of the bolt insertion hole, and the height adjustment bolt 105 is inserted into this nut to raise the height. Make adjustments. Since the height adjustment bolt 105 is removed after the support 100 is installed, the total length of the height adjustment bolt 105 is the distance H1 between the upper collar 101 and the lower collar 102 (that is, the height of the laminated body 103). It needs to be shorter.

2. Next, the installation method of the support will be described with reference to FIGS. 2 and 3. FIG. 2 is a flowchart showing the main process flow of the present invention, and FIG. 3 is a step diagram thereof. As shown in the flowchart of FIG. 2, first, a lower foundation such as an abutment or a pier is constructed (Step 10). At this time, as shown in FIG. 3A, a box opening portion 200 having a surface (box upper surface 201) that is one step lower than the top end surface of the lower foundation is formed at a position where the support 100 is installed. The box opening portion 200 is also provided with an anchor hole 202 for embedding the anchor 104.

  When the box opening portion 200 is formed on the lower foundation, the support 100 is installed at a predetermined position (Step 30). At this time, the support 100 is installed by placing the height adjusting bolt 105 on the boxed upper surface 201. That is, at this point, the support 100 is supported by a plurality of (in this case, four) height adjustment bolts 105.

  Normally, the lower foundation has a concrete structure, that is, the height adjusting bolt 105 is placed on the concrete. The height adjusting bolt 105 receives the weight of the bearing 100, and as a result, a considerable bearing stress acts on the concrete, but it may be damaged depending on the allowable stress level of the concrete. In this case, a bolt support 300 such as a synthetic resin plate, a steel plate, or a high strength mortar may be installed at a position where the height adjustment bolt 105 is placed. By transmitting its own weight to the support 300 having a relatively large area, the stress generated in the concrete can be reduced. Further, the surface of the synthetic resin plate, the steel plate, or the high strength mortar is smoother than that of concrete, which is convenient when the height adjusting bolt 105 is rotated later.

  The bolt support 300 may be installed so that the height adjusting bolt 105 can be removed. FIG. 4 is a model diagram showing the dimensions of the heel spacing H1 and the boxing depth H2, and the state in which the bolt support 300 according to these dimensions is installed. Here, the boxing depth H <b> 2 is a height difference between the top end surface of the lower foundation and the boxed upper surface 201. As shown in FIG. 4, when the boxing depth H2 is larger than the heel spacing H1 (H2> H1), in order to arrange the lower heel 102 above (or at the same height) the top end surface of the lower foundation. The height adjusting bolt 105 must be longer than the heel spacing H1. As a result, it becomes difficult to remove the height adjusting bolt 105 after the support 100 is installed. Therefore, a bolt support 300 having a thickness t (that is, t> H2−H1) larger than the dimensional difference between the boxing depth H2 and the flange interval H1 is installed. Thereby, the height adjusting bolt 105 can be made shorter than the flange interval H1, and can be easily extracted after the support 100 is installed.

  When the height adjustment bolt 105 is placed on the box top surface 201 or the bolt support 300 and the installation of the support 100 (Step 30) is completed, the installation height of the support 100 is inspected. At this time, when the height of the actually installed support 100 is different from the planned installation height, the height is adjusted until the planned height is reached (Step 40). Further, even when the installation posture of the support 100 is inclined, the height is partially adjusted so as to be in a horizontal posture. The height adjustment at this time is performed by rotating the height adjustment bolt 105. In other words, when the installation height of the support 100 is desired to be higher than the current level, the height adjustment bolt 105 is rotated so as to extend below the lower rod 102, and the installation height of the support 100 is desired to be lower than the current level. Rotate the reverse.

  When it is confirmed that the height adjustment bolt 105 is installed at the planned height and in a horizontal posture, the filler 400 is injected into the box-opening portion 200 as shown in FIG. Step 50). As the filler 400, mortar that has been frequently used in the past can be used, but not limited thereto, concrete can be used, and synthetic resin or the like can also be used.

  After injecting the filler 400, curing is performed until the filler 400 has a predetermined strength (Step 60). The predetermined strength mentioned here is not necessarily limited to the strength (final strength) that is exhibited when the filler 400 is completely cured, but may be a strength that allows the weight of the support 100 to be applied.

  When the filler 400 is cured to a predetermined strength, the height adjusting bolt 105 is pulled out as shown in FIG. 3 (d) (Step 70). At this time, if the filler 400 is not completely cured (a predetermined strength state), the height adjusting bolt 105 can be rotated relatively easily. It is preferable to apply a release agent to the height adjustment bolt 105 in advance before filling the filler 400, because it can be rotated more easily.

  Further, for the purpose of facilitating removal of the height adjustment bolt 105, the curing mold 500 can be installed in advance so that the height adjustment bolt 105 does not contact the filler 400 (Step 21). The curing mold 500 is preferably a cylindrical one, and can be exemplified by a void tube. FIG. 5 is a model diagram showing a state where a void tube is installed on the boxed upper surface 201 as the curing mold 500 and the support 100 is installed in that state. As shown in this figure, when the support 100 is installed, the height adjusting bolt 105 is disposed in the curing mold 500. Since the filler 400 is injected in a state in which the curing mold 500 is installed, the filler 400 does not flow into the curing mold 500, and as a result, a space surrounded by the filler 400 (hereinafter referred to as the filler 400). , "Bolt curing space") is formed. Since the height adjusting bolt 105 is disposed in the bolt curing space, the height adjusting bolt 105 is not affected by the filler 400 and can be easily extracted. After the bolt curing space is formed, it is desirable to remove the curing mold 500 (Step 71). After removing the height adjusting bolt 105, the bolt curing space is filled with mortar or the like. It is desirable. The mortar filling at this time may be performed using a bolt insertion hole.

  After extracting the height adjusting bolt 105, the filler 400 is continuously cured (FIG. 3 (e)), and an upper work such as a bridge girder is installed as shown in FIG. 3 (f) (Step 80). Depending on the situation at the site, as shown in FIG. 6, after the installation of the support (Step 30), the superstructure is installed as a subsequent process (Step 80), and the support is installed with the superstructure installed on the support. Height adjustment can also be performed (Step 40).

  The bearing installation method and the bearing structure of the present invention can be used for bridges of various uses such as road bridges, railway bridges, pipeline bridges, and can be used for bridges exceeding various types such as river bridges, overpass bridges, and overpass bridges. . It can also be used as a seismic isolation structure for buildings such as office buildings and factory facilities. Considering that the present invention improves the construction quality of bridges and provides a high-quality seismic isolation structure, it can be said that the invention can be used not only industrially but can also make a great social contribution.

DESCRIPTION OF SYMBOLS 100 Support 101 Upper collar 102 Lower collar 103 Laminated body 104 Anchor 105 Height adjustment bolt 200 Box extraction part 201 Box extraction upper surface 202 Anchor hole 300 Bolt support 400 Filling material 500 Curing form A Rubber support B Steel liner C Bridge girder

Claims (6)

In the support installation method that can adjust the installation height,
The support includes two or more bolt insertion holes, and a height adjustment bolt inserted into the bolt insertion hole,
Of the lower foundation supporting the bearing, a bearing installation step of installing the bearing by placing a lower end of the height adjustment bolt on a box opening provided at a position where the bearing is installed;
A height adjustment step of adjusting the installation height of the support by rotating the height adjustment bolt;
An injection step of injecting a filler into the box opening part;
A bolt extracting step of extracting the height adjusting bolt after the filler has reached a predetermined strength;
A bearing installation method characterized by comprising:   The bearing installation method according to claim 1, wherein after the bearing installation process, an upper work is installed on the bearing, and the height adjustment process is performed in a state where the upper work is installed. Before the support installation step, further comprising a support body installation step of installing a bolt support body,
The support installation method according to claim 1 or 2, wherein, in the support installation step, a lower end of the height adjusting bolt is placed on the bolt support. The support comprises an upper collar and a lower collar arranged substantially parallel in the vertical direction,
When the boxing depth of the boxing part is larger than the heel arrangement interval between the upper heel and the lower heel, it is thicker than the dimensional difference between the boxing depth and the heel arrangement interval in the support installation step. The bearing installation method according to claim 3, wherein the bolt support is installed. Before the support installation process, further comprising a mold installation process for installing a bolt curing mold,
A bolt curing space is formed by the filler injected in the injection step and the bolt curing mold,
The support installation method according to any one of claims 1 to 4, wherein, in the support installation step, the height adjusting bolt is disposed in the bolt curing mold. In the support structure that can adjust the installation height,
A bearing including a lower arm, a lower foundation supporting the bearing, a box opening provided at a position of the lower foundation where the bearing is installed, and a cured body in which the filler injected into the box opening is cured And comprising
An anchor body with the vertical direction as an axis is fixed to the lower arm,
Furthermore, the lower arm is provided with two or more bolt insertion holes, and includes a height adjustment bolt inserted into the bolt insertion hole,
The anchor body and the height adjustment bolt are housed in the box opening portion,
After installing the support in the box-opening part, the installation height of the support can be adjusted by rotating the height adjustment bolt,
After the filler has reached a predetermined strength, the height adjusting bolt can be extracted, and the filler is injected into the space after the height adjusting bolt is extracted.

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