JP5147068B2 - Base plate construction method for attaching a seismic isolation device, and reinforcing bars for base plate installation used in the construction method - Google Patents

Description

  The present invention relates to a construction technique for a base plate for mounting a seismic isolation device and a reinforcement technique used for the construction.

Concerning construction to install seismic isolation devices in place, form foundation pillars for installing the seismic isolation devices for the structures for which the seismic isolation devices are to be installed, and through these foundation pillars Construction methods for installing seismic isolation devices are widely known. In this case, first, a hook-shaped reinforcing bar is installed at a predetermined position of the structure, and then an anchor bolt installed on one side of a base plate for attaching a seismic isolation device to the hook-shaped reinforcing bar or a jig plate instead of the base plate, etc. The anchor means is inserted and temporarily supported in that state, and then the concrete is cast to form the foundation pillar portion, and the seismic isolation device using the female screw formed in the anchor means embedded in the foundation pillar portion A construction technique for fastening and fixing the steel is also well known (Patent Document 1).
Japanese Patent Laid-Open No. 11-50694

By the way, the foundation pillar part for installing the seismic isolation device is suppressed so that the height is not so high, and the width is set to a relatively small width that is slightly larger than the flange plate on the seismic isolation device side. It is common. As described above, since the height of the foundation pillar portion is suppressed and the width cannot be made so large, it is difficult to secure sufficient fixing strength by anchor means such as anchor bolts, so it is extremely important to solve this It becomes. Moreover, it goes without saying that the ease of construction in that case is also an important factor. On the other hand, as a reinforcement technique for reinforcing the pull-out strength of the anchor bolt, a reinforcing bar composed of a U-shape is reinforced so as to straddle the cone-shaped fracture surface generated with the fixing plate provided on the anchor bolt as a vertex. The prior art is known (Patent Document 2). However, in the case of this prior art, since the construction method of arranging reinforcing bars around the anchor bolts by fixing the reinforcing bars to the lower end bars or the like, the seismic isolation device mounting target of the present invention is used. As a reinforcement technique for the foundation pillar for installing the base plate, there is a big problem in construction, and it is difficult to apply as it is. That is, when this conventional technique is applied as a reinforcing technique for the foundation pillar portion according to the present invention, and the reinforcing bars are fixed to the lower end bars or the like, a plurality of anchor bolts installed on one side of the base plate are placed at predetermined positions in the hook-shaped reinforcing bars. However, there is a technical problem that the two positioning operations, that is, the positioning of each anchor bolt itself and the relative positioning with the corresponding reinforcing bar, must be performed simultaneously and accurately. For this reason, if there is an error in the fixing position of the reinforcing bars installed near the periphery corresponding to the anchor bolts, the anchor bolts should be installed accurately at the intended position or between the reinforcing bars. Not only is it difficult to position the positional relationship in an appropriate state, but in some cases, the anchor bolt and the reinforcing bar interfere with each other, and there is a troublesome problem that the insertion work itself is hindered.
Japanese Utility Model Publication No. 4-112933

  In view of the above-described conventional technical situation, the present invention makes it easy to insert anchor bolts by inserting a plurality of anchor bolts installed on one side of a base plate for attaching a seismic isolation device to a predetermined position in a bar-shaped reinforcing bar. In addition, the anchor bolt can be accurately installed at the intended position, and the positional relationship between the reinforcing bars arranged in the vicinity of the anchor bolt can be maintained in an appropriate state, and the corner pillar portion can be maintained. It is an object of the present invention to provide an installation technology for a base plate for mounting a seismic isolation device that can secure sufficient fixing strength even if the height and width of the base plate are suppressed.

  In the present invention, in order to solve the above-described problem, a hook-shaped reinforcing bar that reinforces the foundation column for installing the base plate is assembled in advance, and a fixing plate installed on one side of the base plate is placed at a predetermined position in the hook-shaped reinforcing bar. Temporarily supporting the base plate by inserting a plurality of anchor bolts provided, and then using a reinforcing bar having a height lower than that of the foundation pillar portion in the vicinity of the periphery of each anchor bolt as a vertex. A construction method was adopted, in which the resulting cone-shaped fracture surface was laid across the top and bottom, and concrete was cast to form the foundation pillar. That is, in the present invention, in order to separate the positioning work of each anchor bolt to a predetermined position in the hook-shaped reinforcing bar and the relative positioning work of each anchor bolt and the reinforcing bars arranged in the vicinity thereof, The technical means of solving the technical difficulties associated with the prior art by shifting the reinforcing bar installation work back in time was adopted. In addition, as a reinforcing bar used in the base plate construction method for attaching the seismic isolation device, the height is lower than the foundation column for installing the base plate for attaching the seismic isolation device, and it is composed of one deformed reinforcing bar. A central bent portion having a substantially U-shape that is arranged along an anchor bolt installed on one side of the base plate at the central portion, and extending both ends of the central bent portion to extend the central bent portion Reinforcing bars formed in a state of extending in the horizontal direction from the full width of the are adopted. Furthermore, instead of the central bent portion having the substantially U-shape, a central bent portion having a loop shape is adopted, and the height is lower than the corner pillar portion for installing the base plate for mounting the seismic isolation device, and 1 It consists of a deformed reinforcing bar of a book, and has a central bent part consisting of a loop shape that is arranged along the anchor bolt installed on one side of the base plate at the central part, and both ends of the central bent part are extended. Reinforcing bars formed in a state of extending in the horizontal direction from the entire width of the central bent portion were employed. In addition, it is also possible to set the width | variety between the both-sides edge parts extended in the both ends of the said center bending part more than the pitch of the reinforcement bar which comprises a saddle-shaped reinforcement.

According to the present invention, the following effects can be obtained.
(1) In the present invention, since the reinforcing bar installation work time is shifted backward, when inserting a plurality of anchor bolts installed on one side of the base plate into predetermined positions in the hook-shaped reinforcing bars, the anchor bolts are inserted. Since the reinforcing bars arranged in the vicinity of the stool are not yet installed, the insertion work is very easy.
(2) Further, in the insertion operation, the installation position of the anchor bolt is not constrained by the surrounding reinforcing bars as in the prior art. Therefore, the anchor bolt and the base plate can be accurately installed at a predetermined position. Is possible.
(3) Further, after temporarily supporting the anchor bolt at an accurate position, reinforcing bars are arranged near the periphery of each anchor bolt, so that the positional relationship between the anchor bolt and the reinforcing bar is maintained in an appropriate state. Is easy.
(4) Moreover, since both ends of the central bent portion constituting the reinforcing bar are extended and formed so as to extend in the horizontal direction from the entire width of the central bent portion, the height of the reinforcing bar is low. However, since the fixing force in the pull-out direction can be greatly increased, even if the height and width of the foundation pillar are suppressed, the central bent portion and the protruding portions at both ends thereof are combined to ensure sufficient fixing strength. Is possible.

  The present invention can be widely applied to any seismic isolation device installed via a base plate regardless of the specific form of the seismic isolation device. When assembling the saddle-shaped reinforcing bars, the reinforcing bars may be started up in a state where the reinforcing bars are placed in advance inside the saddle-shaped reinforcing bars, or the saddle-shaped reinforcing bars assembled when the reinforcing bars are arranged are configured. You may make it insert in an inside later through the opening part between the gluteal muscles. In particular, in order to increase the reinforcing strength, when setting the width between the two end portions extending at both ends of the central bent portion to be equal to or greater than the pitch of the reinforcing bar constituting the reinforcing bar, When assembling, a construction form is preferred in which the reinforcing bars are started up in a state where the reinforcing bars are previously placed inside.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. 1 to 6 exemplify a construction procedure according to the present invention, and FIGS. 1 and 2 show a cross-sectional view and a plan view showing a state in which saddle-shaped reinforcing bars are assembled and installed. 3 is a front view illustrating the base plate, FIG. 4 is a plan view thereof, and FIG. 5 is a plan view illustrating a modification of the base plate. FIG. 6 is a cross-sectional view showing a state in which an anchor bolt installed on a base plate is inserted into the hook-shaped reinforcing bar. In the construction procedure according to the present invention, first, as shown in FIG. 1 and FIG. 2, the hooked reinforcing bar 2 is assembled and installed at a predetermined position on the structure 1 as an installation target by the same technique as in the past. In this case, it is needless to say that the specific configuration related to the hooked reinforcing bar 2 such as the height of the hooked reinforcing bar 2 and the pitch between the hooked reinforcing bars 3 constituting the hooked reinforcing bar 2 can be appropriately set according to circumstances. Absent.

  Next, as illustrated in FIG. 3 and FIG. 4, a plurality of, for example, octagonal base plates 4 made of a steel plate are installed on one side of the base plate 4 so as to correspond to insertion holes for fixing bolts formed in the flange plate on the seismic isolation device side. The anchor bolt 5 is shifted to an inserting operation of the anchor bolt 5 to be inserted into a predetermined position through the opening 6 formed between the reinforcing bars 3 of the saddle-shaped reinforcing bar 2. In the case of the base plate 4 of this embodiment, as shown in the drawing, the position corresponding to the insertion hole for the fixing bolt formed in the flange plate on the seismic isolation device side, that is, the position corresponding to the anchor bolt 5. Insertion holes 7 are formed in each of the bolts, and fixing bolts are screwed into the female screws formed on the anchor bolts 5 through the insertion holes 7 to fix the flange plate on the seismic isolation device side. It is configured to install a seismic device. In addition, a fixing unit is provided below each anchor bolt 5 by holding the fixing plate 8 from above and below with a nut. In this case, it is needless to say that specific configurations such as the length and detailed structure of the anchor bolt 5 and the size and mounting method of the fixing plate 8 and the mounting position can be appropriately set according to circumstances. Furthermore, in the present embodiment, the case where an octagonal shape is adopted as the base plate 4 is shown, but it is needless to say that other shapes can be selected depending on the case. Further, as shown in FIG. 5, it is possible to provide an opening 9 in the center of the base plate 4.

  FIG. 6 shows a state in which the anchor bolt 5 installed on one side of the base plate 4 is inserted into the hook-shaped reinforcing bar 2 assembled and installed at a predetermined position of the structure 1 to be installed. The anchor bolts 5 are inserted by inserting the anchor bolts 5 through the openings 6 formed between the reinforcing bars 3 on the upper surface of the saddle-shaped reinforcing bar 2, and in this state, the base plate 4 is inserted into the reinforcing bar 2. By temporarily supporting the base plate 4 at a predetermined position using a horizontal support member (not shown) installed between the support frames (not shown) installed on both sides, and adjusting and fixing the height and horizontal state of the base plate 4 Done. In this case, it goes without saying that the distance between the structure 1 and the fixing plate 8 provided on the anchor bolt 5 can be appropriately set depending on the case.

  As described above, when the temporary support operation for temporarily supporting the base plate 4 in a state where the anchor bolts 5 are inserted into the predetermined positions with respect to the bar-shaped reinforcing bars 2 assembled and installed at the predetermined positions of the structure 1 is completed. Next, reinforcing bars are installed near the periphery of each anchor bolt 5. FIG. 7 is a partially enlarged view showing a state in which reinforcing bars are arranged near the periphery of the anchor bolt 5, and FIG. 8 is a plan view. As shown in the figure, the reinforcing bar 10 according to the present embodiment is lower in height than the corner pillar part formed between the structure 1 and the base plate 4 and is composed of one deformed reinforcing bar, in the center part. A central bent portion 10a having a substantially U-shape arranged along the anchor bolt 5 is provided, and both end portions of the central bent portion 10a are extended to extend in the horizontal direction from the entire width of the central bent portion 10a. This is characterized in that the overhang portions 10b and 10c are formed. When reinforcing bars 10 are arranged, for example, as shown in FIG. 8, the reinforcing bars 10 are arranged symmetrically near both sides of the anchor bolt 5, and the reinforcing bars 10 are connected to the bar-shaped reinforcing bars 2 by a wire or the like. It is done by fixing to. At that time, the bent portion of the central bent portion 10a of each reinforcing bar 10 is supported with respect to the reinforcing bar 3 and the overhanging parts 10b and c on both sides are supported via a reinforcing bar or the like passed to the reinforcing bar 3. By this, it is possible to arrange the bars in the desired state. Thus, since the overhang | projection parts 10b and c of both sides can be utilized as a fixing | fixed part with respect to the saddle-shaped reinforcing bar 2, more exact support is possible. What is particularly important in the reinforcing bar placement work is that at least the central bent portion 10a is arranged so as to straddle the cone-shaped fracture surface generated with the fixing plate 8 provided on the anchor bolt 5 as the apex. It is to reinforce against the fracture from the cone-shaped fracture surface, and to ensure the fixing strength by the fixing plate 8 accurately. In the case of the reinforcing bar 10 according to the present embodiment, as described above, both ends of the central bent portion 10a are extended so as to protrude in the horizontal direction from the entire width of the central bent portion 10a. , C are formed, the resistance force in the pulling direction of the central bent portion 10a is greatly increased. Therefore, the height of the reinforcing bar 10 is set higher than that of the foundation pillar portion formed between the structure 1 and the base plate 4. Despite being kept low, it is possible to accurately secure the fixing strength of the fixing plate 8. Furthermore, according to the reinforcing bar 10 according to the present embodiment, since both end portions of the overhang portions 10b and c are folded back in the opposite direction, the resistance force in the pulling direction of the central bent portion 10a can be further increased. Is possible. Incidentally, the circle 11 shown in FIG. 8 shows the cone-shaped fracture surface of the part in contact with the base plate 4.

  Thus, when the reinforcing bar arrangement work for arranging the reinforcing bar 10 near the periphery of each anchor bolt installed on one side of the base plate 4 is completed, the mold is next formed around the bar-shaped reinforcing bar 2 and the like. A frame will be applied and concrete will be placed inside. By placing the concrete, a corner pillar portion is formed between the structure 1 and the base plate 4, and the work is completed by removing the formwork.

  FIG. 9 is a partially enlarged view showing a state in which the reinforcing bar is arranged near the periphery of the anchor bolt 5 using another embodiment, and FIG. 10 is a plan view. As shown in the drawing, the reinforcing bar 12 according to the present embodiment is lower in height than the corner pillar part formed between the structure 1 and the base plate 4 and is composed of one deformed reinforcing bar, in the center part. A projecting portion having a loop-shaped central bent portion 12a laid along the anchor bolt 5 and extending both ends of the central bent portion 12a in a horizontal direction from the entire width of the central bent portion 12a. 12b and c are characteristic. Also in this embodiment, for example, as shown in FIG. 10, each reinforcing bar 12 is fixed to the bar-shaped reinforcing bar 2 by a wire or the like in a state of being symmetrically disposed near both sides of the anchor bolt 5. In that case, the same bar arrangement work as in the above embodiment is performed. Further, also in the reinforcement work of the reinforcing bars 12, it is particularly important that at least the central bent portion 12a straddles the cone-shaped fracture surface generated with the fixing plate 8 provided on the anchor bolt 5 as the apex. In other words, the fixing strength of the fixing plate 8 is accurately secured. And also in the case of the reinforcing bar 12 according to the present embodiment, as described above, both ends of the central bent portion 12a are extended so as to protrude in the horizontal direction from the entire width of the central bent portion 12a. , C is formed, the resistance force in the pulling direction of the central bent portion 12a is greatly increased, and therefore the height of the reinforcing bar 12 is set higher than that of the foundation column portion formed between the structure 1 and the base plate 4. This is the same as in the case of the above-described embodiment in that it is possible to accurately secure the fixing strength of the fixing plate 8 despite being kept low. In addition, as shown in FIG. 11, it is also possible to arrange the reinforcing bars 12 by turning them upside down.

It is sectional drawing which showed the assembly installation state of the hook-shaped reinforcement. It is the top view which showed the same state. It is the front view which illustrated the base plate. It is the top view which showed the base plate. It is the top view which illustrated the modification of the base plate. It is sectional drawing which showed the insertion state with respect to the hook-shaped reinforcement of the anchor bolt installed in the baseplate. It is the elements on larger scale which showed the reinforcing bar arrangement state. It is the top view which showed the same state. It is the elements on larger scale which showed the bar arrangement state of the other Example regarding a reinforcing bar. It is the top view which showed the same state. It is the elements on larger scale which showed the other bar arrangement state regarding a reinforcing bar.

Explanation of symbols

  1: Structure, 2: Reinforcing bar, 3: Reinforcing bar, 4: Base plate, 5: Anchor bolt, 6: Opening, 7: Insertion hole, 8: Fixing plate, 9: Opening, 10: Reinforcing bar 10a: Central bent portion, 10b, c: Overhang portion, 11: Cone-shaped fracture surface, 12: Reinforcing bar, 12a: Central bent portion, 12b, c: Overhang portion

Claims (4)

  In the construction method for installing the base plate for mounting the seismic isolation device in a predetermined position, the bar-shaped reinforcing bars that reinforce the foundation pillar for installing the base plate are pre-assembled, and the predetermined positions in the bar-shaped reinforcing bars are A plurality of anchor bolts provided with fixing plates installed on one side of the base plate are inserted to temporarily support the base plate, and then a reinforcing bar having a height lower than that of the foundation pillar portion in the vicinity of each of the anchor bolts. A base plate for attaching a seismic isolation device, wherein the base column is formed by placing concrete in a state where the cone-shaped fracture surface generated using the fixing plate as a vertex is straddling the top and bottom. Method.   Reinforcing bars used in the base plate construction method for attaching a seismic isolation device according to claim 1, wherein the reinforcing bars are lower than the foundation pillar portion for installing the base plate for attaching the seismic isolation device, and 1 It consists of a deformed reinforcing bar of a book, and has a central bent part consisting of a substantially U shape that is arranged along an anchor bolt installed on one side of the base plate at the central part, and both ends of the central bent part are extended. A reinforcing bar for installing a base plate for attaching a seismic isolation device, wherein the reinforcing plate is formed in a state of extending horizontally from the entire width of the central bent portion.   Reinforcing bars used in the base plate construction method for attaching a seismic isolation device according to claim 1, wherein the reinforcing bars are lower than the foundation pillar portion for installing the base plate for attaching the seismic isolation device, and 1 It consists of a deformed reinforcing bar of a book, and has a central bent part consisting of a loop shape that is arranged along the anchor bolt installed on one side of the base plate at the central part, and both ends of the central bent part are extended. A reinforcing bar for installing a base plate for attaching a seismic isolation device, characterized in that it is formed in a state of extending in the horizontal direction from the entire width of the central bent portion.   The base plate for mounting a seismic isolation device according to claim 2 or 3, wherein a width between both end portions extending at both ends of the central bent portion is set to be equal to or greater than a pitch of the reinforcing bars constituting the reinforcing bar. Reinforcing bar for installation.

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