JP2948098B2 - Core spacers for cast-in-place concrete piles - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a spacer for a core in a cast-in-place concrete pile that absorbs an error between a core such as a reinforcing bar cage and a steel pipe and a hole.

[0002]

2. Description of the Related Art In a method of forming a cast-in-place concrete pile by mechanical excavation, drilling of a drilled hole is performed by suspending a core material such as a reinforcing steel cage or a steel pipe, and forming a hole between a hole core and a pile core. The coincidence is performed while checking from two horizontal directions. However, it is difficult to completely eliminate the error between the hole center and the pile center in both the case where the casing (stand pipe) is used and the case where it is not used. An error of several tens mm to 100 mm occurs, and this error remains in the completed pile.

On the other hand, in Japanese Utility Model Publication No. 5-16276, the applicant has proposed an error absorbing spacer in which two groove-shaped spacers are combined in the radial direction of the core material. In this method, the position of the adjustment spacer is adjusted by a bolt with respect to the fixed spacer to be joined to the core material. However, since the adjustment spacer is composed of three parts, the number of parts is large and the cost is high. Further, since the adjustment spacer has a long band shape in one direction, the direction in the adjustment state is specified, and the adjustment of the bolt screw portion is performed in units of one pitch or half pitch, and does not work until fine adjustment.

[0004] This invention is an extension of the above invention,
An object of the present invention is to propose an error absorbing spacer capable of finely adjusting the manufacturing cost and reducing the manufacturing cost.

[0005]

According to the present invention, there is provided a fixed spacer which is joined to a core material and has a cutout formed in a part thereof, and two fixed spacers which are inserted into the cutouts of the fixed spacer and sandwich the fixed spacer around the cutout. The error absorption spacer is composed of two parts of the adjustment bolts screwed with the nuts, and the number of parts is reduced by eliminating the adjustment spacers in Japanese Utility Model No. 5-16276. Enable.

[0006] The tip of the adjustment bolt on the casing side or the hole wall side abuts against the inner peripheral surface or the hole wall of the casing, and the distance between the core material peripheral surface and the casing inner peripheral surface, or between the core material peripheral surface and the hole wall. To secure the distance.

The amount of protrusion of the adjusting bolt from the fixing spacer is adjusted in accordance with the length of the adjusting bolt screwed into the nut screwed to the adjusting bolt, and the direction of the adjusting bolt with respect to the fixing spacer is not specified. Fine adjustment is possible by making adjustment within one pitch of the section.

[0008]

DESCRIPTION OF THE PREFERRED EMBODIMENTS A core spacer 1 according to the present invention is joined to a core member 5 as shown in FIGS. 1 to 4 and a fixed spacer 2 having a cutout 24 formed in a part thereof, and a cutout of the fixed spacer 2. 24, two nuts 8, which sandwich the fixed spacer 2,
An adjusting bolt 4 is screwed onto the adjusting bolt 4, and the amount of protrusion of the adjusting bolt 4 from the fixed spacer 2 is adjusted according to the length of screwing of the adjusting bolt 4 to the nuts 8, 8.

As shown in FIGS. 4 and 5, the core spacer 1 is mounted on the outer peripheral surface of the core member 5 at the position of the casing 6 or near the position of the pile head, and the cover thickness between the peripheral surface of the core member 5 and the hole wall. Is used to absorb the error between the hole center and the pile center while securing the core material 5 at the regular pile position.

FIGS. 4 to 6 show the case of excavation using the casing 6, but the core spacer 1 of the present invention is also used for excavation without using the casing 6, in which case the adjustment is performed. The tip of the bolt 4 will strike the hole wall. The case where the casing 6 is not used is a case where at least the casing 6 is not inserted at the time of inserting the core material 5 into the drilled hole. In addition to the earth drilling method, the reverse circulation drilling method, and the like, the cast-in-place concrete pile is continuous. Including the underground diaphragm wall method.

The fixed spacer 2 has a hat shape from flanges 21 and 21 joined to the outer peripheral surface of the core member 5 and a connection piece 22 parallel to the flange 21 and connected to the adjustment bolt 4. At the core material 5.

FIG. 1 shows a case in which the adjusting bolt 4 is composed of a shaft portion with a male thread and a head 41. In this case, the head 41, which is the tip of the casing 6 or the hole wall side, is It hits the inner peripheral surface or the hole wall. The adjustment bolt 4 includes a bolt having only a shaft portion without a head 41, and is not shown. Instead of the head 41, a plate in which a plate is welded to the tip of the bolt on the hole wall side or only a shaft portion without a head is used. In some cases, the bolt wall side may be bent.

In the case where the shaft is bent, the bent portion comes into contact with the casing 6 or the hole wall. The adjusting bolt 3 having the bent shaft portion may be connected to an intermediate piece 23 between the flange 21 and the connecting piece 22 of the fixed spacer 2 as shown in FIG.

The adjusting bolt 4 is provided with a notch 24 of the fixed spacer 2.
Are connected to the fixed spacer 2 by tightening the two nuts 8 and 8 screwed into the shaft portion at a distance from the shaft portion. 1 and 2 show a case where the notch 24 is formed in the connecting piece 22, and FIG. 3 shows a case where the notch 24 is formed in the intermediate piece 23.
In the case of FIG. 3, the shaft of the adjustment bolt 4 is bent, and the head 41 side faces the casing 6 side.

As shown in FIGS. 4 and 5, the core spacer 1 is uniformly fixed in the circumferential direction of the core 5 at the insertion position of the casing 6 corresponding to the pile head position or at the pile head position. By adjusting the amount of protrusion of 4 from the fixed spacer 2, an error between the pile center and the hole center is absorbed as shown in FIG.

In FIG. 6, when the chain line is the pile formation position and the center is the pile center, if an error occurs in the hole center as shown by the solid line, the adjustment bolt on the side where the hole center is eccentric with respect to the pile center is shown. 4 is projected toward the casing 6 or the hole wall side, and the adjustment bolt 4 on the opposite side is screwed into the core member 5 side to absorb an error in the eccentric direction, and the center of the core member 5 coincides with the center of the pile. Insertion of the core material 5 is performed in this state.

[0017]

According to the present invention, a fixed spacer joined to a core material and partially formed with a notch, and two nuts inserted into the notch of the fixed spacer and sandwiching the fixed spacer around the notch are screwed together. Since the error absorbing spacer is composed of two parts of the bolt and the adjusting spacer in Japanese Utility Model Publication No. 5-16276 is absent, the number of parts can be reduced and the manufacturing cost can be reduced.

Also, the amount of protrusion of the adjusting bolt from the fixing spacer is adjusted according to the length of the adjusting bolt screwed into the nut screwed thereto, and the direction of the adjusting bolt with respect to the fixing spacer is not specified. Since the adjustment can be performed within one pitch of the screw portion, fine adjustment is possible.

[Brief description of the drawings]

FIG. 1 is a perspective view showing a core material spacer.

FIG. 2 is an elevational view showing a use state of a core spacer.

FIG. 3 is an elevational view showing a core material spacer when a notch is formed in an intermediate piece of a fixed spacer.

FIG. 4 is an elevational view showing a state in which a core material spacer is attached to a core material.

FIG. 5 is a plan view of FIG. 4;

FIG. 6 is a plan view showing a use state of the core spacer when there is an error between the pile center and the hole center.

[Explanation of symbols]

1 ... spacer for core material, 2 ... fixed spacer, 21 ... flange, 22 ... connection piece, 23 ... intermediate piece, 24 ... notch,
4 ... adjustment bolt, 41 ... head, 5 ... core material, 6 ... casing, 8 ... nut.

Claims (3)

(57) [Claims] Claims: 1. An outer peripheral surface of a core material near a casing position or a pile head position, which absorbs an error between a hole core and a pile core while securing a cover thickness between the core material peripheral surface and a hole wall, A spacer for inserting the core material into the regular pile position, a fixed spacer that is joined to the core material and partially formed with a notch, and a fixed spacer that is inserted into the notch of the fixed spacer and is around the notch Are screwed together, and the tip of the casing side or the hole wall side is the inner peripheral surface of the casing,
Alternatively, a spacer for a core material in a cast-in-place concrete pile including an adjustment bolt abutting against a hole wall. 2. The core spacer for a cast-in-place concrete pile according to claim 1, wherein a tip of the adjustment bolt on the casing side or the hole wall side is bent with respect to the axis. 3. The spacer for a core in a cast-in-place concrete pile according to claim 1, wherein a plate is integrated with a tip of the adjusting bolt on a casing side or a hole wall side.