JP6629604B2 - Bearing mounting method and holding device used for the method - Google Patents

Description

  The present invention relates to a bearing construction method and a holding device used for the method.

  BACKGROUND ART Conventionally, as a construction method for fixing a bearing supporting a structure to a cast-in-place concrete pile, for example, a construction method described in Patent Literature 1 is known. This construction method is performed in the following procedure. First, an excavation hole is formed by excavating the ground, and a main bar extending vertically is arranged in the excavation hole. At this time, an anchor bolt for fixing the bearing is integrated with the upper end of the main bar.

  Next, pre-cast concrete is poured into the excavation hole, and a pre-cast concrete portion is formed so that an extra concrete portion is formed on the upper side. Thereby, the lower part of the anchor bolt is fixed to the pre-cast concrete part. Thereafter, the excess concrete portion is peeled off, and post-cast concrete is cast on the upper side of the pre-cast concrete portion to form a post-cast concrete portion. Then, a support is installed on the upper side of the post-cast concrete part, and the lower part of the support is fixed to the upper end of the anchor bolt.

JP 2001-288744 A

  In the above construction method, the anchor bolt is integrated with the upper end of the main bar and then fixed to the pre-cast concrete portion. Therefore, before casting the pre-cast concrete, the anchor bolt is set at a position where the bearing is fixed. It needs to be positioned. However, it was very difficult to accurately locate the anchor bolts because the main reinforcement with the anchor bolts was placed in an unstable state in the excavation hole before placing the precast concrete. . For this reason, in the conventional construction method, there was a problem that the bearing could not be accurately fixed to the cast-in-place concrete pile.

  The present invention has been made in view of such circumstances, and an object of the present invention is to provide a bearing construction method capable of accurately fixing a bearing to a cast-in-place concrete pile, and a holding device used for the method. I do.

  The construction method of the bearing of the present invention is a construction method in which a support for supporting a structure is anchored by an anchor bolt to a cast-in-place concrete pile formed by forming a post-cast concrete part on the top of a pre-cast concrete part, In the state where the main reinforcement is arranged in the hole, a step of placing precast concrete in the excavation hole, forming the precast concrete portion so that a surplus portion is formed on the upper side, and removing the surplus portion Exposing an upper surface of the precast concrete portion, and holding the anchor bolt via a holding device in a state where the anchor bolt is positioned at a position where the support is fixed on the exposed upper surface of the precast concrete portion. In the state where the anchor bolts are held, by casting a post-cast concrete into the excavation hole to form the post-cast concrete portion, And a step of fixing the concrete portion out after the lower together with the holding device of the anchor bolt, and fixing the bearing to the top of the anchor bolt fixed to the concrete part out after the, the.

  According to the construction method of the bearing configured as described above, on the upper surface of the precast concrete portion exposed by removing the excess portion, the anchor bolt is positioned and held via the holding device, from this state The anchor bolt is fixed to the post-cast concrete portion by casting the post-cast concrete. Thereby, the anchor bolt can be positioned on the upper surface of the precast concrete portion which is stably arranged in the excavation hole. Therefore, the anchor bolts can be positioned with higher precision than in the case where the anchor bolts are integrated with the main bar as in the related art, so that the bearing can be accurately fixed to the cast-in-place concrete pile.

  The holding device of the present invention is a holding device used for the method of mounting the bearing, wherein the mount is disposed on the upper surface of the precast concrete portion which is exposed by removing the extra bank, and A support portion provided so as to be position adjustable in the direction, and placed on the support portion so as to be position adjustable in the horizontal direction, and capable of holding the anchor bolt in a state where at least one end in the longitudinal direction thereof projects upward. Holding section.

  According to the holding device configured as described above, the gantry is installed on the upper surface of the exposed precast concrete portion by removing the excess portion, and the support is vertically adjusted with respect to the gantry, By adjusting the position of the holding part holding the anchor bolt in the horizontal direction with respect to the support part, the anchor bolt can be positioned in the vertical and horizontal directions. Thereby, the anchor bolt can be positioned on the upper surface of the precast concrete portion which is stably arranged in the excavation hole. Therefore, the anchor bolts can be positioned with higher precision than in the case where the anchor bolts are integrated with the main bar as in the related art, so that the bearing can be accurately fixed to the cast-in-place concrete pile.

  ADVANTAGE OF THE INVENTION According to this invention, a bearing can be fixed to a cast-in-place concrete pile accurately.

It is a side view of the holding device used for the construction method of the bearing which concerns on one Embodiment of this invention. It is a sectional side view which shows the construction method of the bearing which concerns on one Embodiment of this invention, and has shown the process of forming a precast concrete part. It is a sectional side view which shows the process of exposing the upper surface of a pre-cast concrete part by removing a surplus part. It is a sectional side view which shows the process of mounting the gantry of a holding device on the upper surface of a precast concrete part. It is a sectional side view which shows the process which hold | maintains the anchor bolt in the holding plate of the holding device in the state located. It is a sectional side view which shows the process of installing a stirrup and a waste form. It is a sectional side view which shows the process of fixing the lower part of an anchor bolt to a post-cast concrete part with a holding device. It is a sectional side view showing a process of fixing a bearing to an anchor bolt.

Next, a preferred embodiment of the present invention will be described with reference to the accompanying drawings.
FIG. 1 is a side view of a holding device used in a method for constructing a bearing according to an embodiment of the present invention. This holding device 50 is for holding a plurality of anchor bolts B at predetermined positions on the upper surface 2a of the precast concrete portion 2 of the cast-in-place concrete pile 1 formed in a columnar shape, for example. The holding device 50 is mounted on the support 51 provided on the upper surface 2 a of the precast concrete portion 2, a plurality of support screws (support portions) 52 provided on the support 51, and mounted on the support screws 52. And a holding plate (holding portion) 53.

The gantry 51 is constituted by a plurality of legs 511 that are placed on the upper surface 2a of the precast concrete portion 2 at predetermined intervals in the circumferential direction.
Each leg portion 511 includes a base plate 511a, a frame 511b having a lower end surface fixed to the upper surface of the base plate 511a and extending upward, and a nut 511c fixed to an upper end portion of the frame 511b.

  The frame 511b of the present embodiment is made of, for example, an angle material. The length of the frame 511b in the up-down direction is set such that the frame 511b is higher than the main reinforcement 5 projecting from the upper surface 2a in a state where the base plate 511a is placed on the upper surface 2a of the precast concrete portion 2. ing.

  Each of the male screw portions 52b of the plurality of support screws 52 is fastened to the nut 511c of each leg portion 511 from above via a fixing nut 56. Thus, the head 52a of each support screw 52 protrudes above the upper end of the corresponding frame 511b. In this state, the height of the head 52a of each support screw 52 is adjusted vertically with respect to the leg 511 of the gantry 51 by adjusting the amount of tightening of the male screw 52b with respect to the nut 511c. be able to. Then, the support screws 52 after the position adjustment are prevented from rotating by the fixing nut 56.

  In this embodiment, the male screw portion 52b is fastened from above the nut 511c, but may be fastened from below the nut 511c. In this case, the height position of the tip surface of the male screw portion 52b of the support screw 52 may be adjusted, and the holding plate 53 may be placed on the tip surface. Further, in the present embodiment, the support screw is used as the support portion 52. However, as long as the support portion 52 is provided so as to be capable of adjusting the position in the vertical direction with respect to the gantry 51, the support portion 52 may be formed of a cutting bolt or another member. good.

  The holding plate 53 is formed of, for example, a flat plate member formed in a disk shape. A portion of the lower surface of the holding plate 53 near the center is placed on the upper surface of the head 52 a of the support screw 52 so as to be position-adjustable. ing. On the outer peripheral side of the holding plate 53, a plurality of through holes 53a penetrating in the thickness direction are formed at predetermined intervals in the circumferential direction. An anchor bolt B is inserted into each through hole 53a. A double nut 54 is fastened to one end of each anchor bolt B in the longitudinal direction with a washer 55 inserted. The lower surface of the double nut 54 contacts the upper surface of the holding plate 53 via the washer 55. Thus, the anchor bolt B is held by the holding plate 53 with the one end protruding above the holding plate 53. It is not always necessary to provide the washer 55 between the holding plate 53 and the double nut 54.

  With the above configuration, by adjusting the position of the head 52a of the support screw 52 in the vertical direction with respect to the leg 511 of the gantry 51, the anchor bolt B can be positioned in the vertical direction (Z-axis direction). Further, by adjusting the position of the holding plate 53 placed on the head 52a of the support screw 52 in the horizontal direction (X-axis direction and Y-axis direction), the anchor bolt B is positioned in the horizontal direction with respect to the gantry 51. can do.

  In this embodiment, a holding plate made of a flat plate member is used as the holding portion 53. However, the holding portion 53 is mounted on the support portion 52 so as to be position-adjustable in the horizontal direction, and the anchor bolt B is attached to at least one end in its longitudinal direction. May be constituted by other members as long as they can be held in a state of projecting upward.

  FIG. 2 to FIG. 8 are explanatory views showing a method of constructing a bearing according to an embodiment of the present invention. In this construction method, as shown in FIG. 8, a support 20 for supporting a structure is anchored to a cast-in-place concrete pile 1 formed by forming a post-cast concrete part 3 on an upper side of a pre-cast concrete part 2 with an anchor bolt B. This is the construction method to be performed. Hereinafter, this construction method will be described with reference to FIGS.

  First, as shown in FIG. 2, in a state where the main reinforcement 5 extending in the up-down direction is arranged in the excavation hole 10, first-cast concrete is poured into the excavation hole 10 so that the extra embossed portion 4 is formed on the upper side. A precast concrete section 2 is formed. At this time, the height H1 of the construction top (upper surface 2a) of the precast concrete part 2 is a length from the height H2 of the design top of the cast-in-place concrete pile 1 in which the anchor bolt B is embedded in the post-cast concrete part 3. The height shall be less than L.

  Next, as shown in FIG. 3, after excavating the ground G around the extra height portion 4, the extra height portion 4 is stripped off and removed. As a result, the upper surface 2a of the precast concrete portion 2 is exposed. Thereafter, the holding device 50 is set on the exposed upper surface 2a of the precast concrete portion 2.

  Specifically, first, as shown in FIG. 4, a plurality of legs 511 of the gantry 51 are placed inside the main reinforcement 5 on the upper surface 2 a of the precast concrete portion 2, and a nut 511 c of each leg 511 is placed. The height of the upper surface of the head portion 52a of the support screw 52 is adjusted by adjusting the amount of tightening of the male screw portion 52b fastened (see FIG. 1). In the present embodiment, the height H3 of the upper surface of the head 52a is adjusted to be the height obtained by subtracting the thickness t of the holding plate 53 from the height H2 of the design top end.

  Next, as shown in FIG. 5, the anchor bolt B is inserted into each through hole 53 a of the holding plate 53 in a state in which the central portion of the lower surface of the holding plate 53 is placed on the upper surface of the head 52 a of each support screw 52. The anchor bolts B are held on the holding plate 53 by the double nuts 54. Then, the holding plate 53 holding the anchor bolts B is horizontally adjusted with respect to the gantry 51 (the head 52a of the support screw 52). Thus, the anchor bolt B can be positioned at a position where the bearing 20 is fixed. When the horizontal position adjustment of the holding plate 53 is completed, the holding plate 53 is temporarily fixed to the head 52a of the support screw 52 by welding.

  Next, as shown in FIG. 6, after a plurality (three in this case) of a plurality of annular stirrups 6 are arranged at predetermined intervals in the up-down direction on a plurality of main streaks 5 projecting from the upper surface 2a, the first strike is performed. A cylindrical mold 7 is assembled on the outer periphery of the upper end of the concrete part 2. At this time, the height of the upper end surface of the discarding formwork 7 is set to the same height as the height H2 of the design top end.

  In the present embodiment, the gantry 51 (including the holding of the anchor bolt B), the strap 6, and the disposal form 7 are installed in this order on the upper side of the precast concrete portion 2, but the installation order is as follows. It is changed appropriately according to the situation at the site. For example, when the area of the upper surface 2a of the precast concrete portion 2 is large, the disposal form 7, the band 6, and the gantry 51 may be installed in this order.

  Next, as shown in FIG. 7, post-cast concrete is poured into the waste form 7 to form the post-cast concrete portion 3. At that time, the height of the construction top (upper surface 3a) of the post-cast concrete portion 3 is the same as the height H2 of the design top. As a result, the gantry 51, the support screw 52, the holding plate 53, the lower part of the anchor bolt B, the main bar 5 and the band bar 6 protruding from the upper surface 2 a are buried and killed by the post-cast concrete portion 3. Therefore, the anchor bolt B is fixed to the post-cast concrete portion 3 while being positioned by the holding device 50.

  Next, once the double nut 54 and the washer 55 are removed from the anchor bolt B, as shown in FIG. 8, the upper part of the anchor bolt B is made to penetrate in the thickness direction of the mounting plate 21 of the support 20, and the mounting plate 21 is It is placed on the upper surface 3a of the cast concrete part 3. Then, the mounting plate 21 is fixed to the upper part of the anchor bolt B by the double nut 54 and the washer 55. Thereby, the bearing 20 can be fixed to the anchor bolt B.

  As described above, according to the mounting method of the bearing according to the present embodiment, the anchor bolt B is held via the holding device 50 in a state where the anchor bolt B is positioned on the upper surface 2a of the precast concrete portion 2 which is exposed by removing the extra embossed portion 4. The anchor bolt B is fixed to the post-cast concrete portion 3 by casting post-cast concrete from this state. Thereby, the anchor bolt B can be positioned on the upper surface 2a of the precast concrete portion 2 which is stably arranged in the excavation hole 10. Therefore, the anchor bolts B can be positioned with higher precision than in the case where the anchor bolts are integrated with the main reinforcement as in the related art, so that the bearing 20 can be accurately fixed to the cast-in-place concrete pile 1. .

  Further, according to the holding device 50, the gantry 51 is installed on the upper surface 2 a of the precast concrete portion 2 which is exposed by removing the excess portion 4, and the support screw 52 is vertically adjusted with respect to the gantry 51. At the same time, by adjusting the position of the holding plate 53 holding the anchor bolt B in the horizontal direction with respect to the support screw 52, the anchor bolt B can be positioned in the vertical and horizontal directions. Thereby, the anchor bolt B can be positioned on the upper surface 2a of the precast concrete portion 2 which is stably arranged in the excavation hole 10. Therefore, the anchor bolts B can be positioned with higher precision than in the case where the anchor bolts are integrated with the main reinforcement as in the related art, so that the bearing 20 can be accurately fixed to the cast-in-place concrete pile 1. .

  It should be understood that the embodiments disclosed this time are illustrative in all aspects and not restrictive. The scope of the present invention is defined by the terms of the claims, rather than the description above, and is intended to include any modifications within the scope and meaning equivalent to the terms of the claims.

DESCRIPTION OF SYMBOLS 1 Cast-in-place concrete pile 2 Pre-cast concrete part 2a Top surface 3 Post-cast concrete part 4 Extention part 5 Main reinforcement 10 Drilling hole 20 Bearing 50 Holder 51 Base 52 Support screw (support part)
53 Holding plate (holding part)
B anchor bolt

Claims (2)

A cast-in-place concrete pile formed by forming a post-cast concrete part on the upper side of a pre-cast concrete part, a construction method in which a support for supporting a structure is anchored by an anchor bolt,
In the state where the main reinforcement is arranged in the excavation hole, a step of casting pre-cast concrete into the excavation hole, and forming the pre-cast concrete portion so as to have an excess portion on the upper side,
Removing the excess portion, exposing the top surface of the precast concrete portion,
A step of installing a gantry on the upper surface of the exposed precast concrete portion ,
Along with adjusting the position of the support provided on the gantry in the up-down direction with respect to the gantry, the holding part is held with respect to the support in a state where the anchor bolt is held on the holding part placed on the support. a step horizontally by adjusting the position, the anchor bolts, that female positioning to a position for fixing the bearing Te,
In a state where the anchor bolt is positioned, by casting a post-cast concrete into the excavation hole to form the post-cast concrete portion, the lower part of the anchor bolt is fixed together with the gantry, the support portion, and the holding portion. Fixing the post-cast concrete part,
Fixing the bearing on top of the anchor bolt fixed to the post-cast concrete portion;
Construction method of bearing including. In a construction method in which a support for supporting a structure is anchored with anchor bolts on a cast-in-place concrete pile formed by forming a post-cast concrete part on the upper side of a pre-cast concrete part,
In the state where the main reinforcement is arranged in the excavation hole, a step of casting pre-cast concrete into the excavation hole, and forming the pre-cast concrete portion so as to have an excess portion on the upper side,
Removing the excess portion, exposing the top surface of the precast concrete portion,
Holding the anchor bolt via a holding device in a state where the anchor bolt is positioned at a position where the bearing is fixed on the exposed upper surface of the precast concrete portion;
With the anchor bolt held, a post-cast concrete is cast into the excavation hole to form the post-cast concrete portion, thereby fixing the lower portion of the anchor bolt to the post-cast concrete portion together with the holding device. The process of
Fixing the bearing on the upper part of the anchor bolt fixed to the post-cast concrete part, and a holding device used in a method of constructing the bearing,
A gantry installed on the upper surface of the precast concrete portion exposed by removing the excess portion,
A support portion provided so as to be vertically adjustable with respect to the gantry,
A holding portion that is placed on the support portion so as to be position-adjustable in the horizontal direction, and that can hold the anchor bolt in a state where at least one end portion in the longitudinal direction projects upward.
A holding device comprising:

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