Method of accurately positioning anchor bolt to foundation by swing-type anchor bolt

Abstract

To enable realization of accurate positioning of an anchor bolt to a foundation with a simple procedure using a member of an extremely simple structure without using a temporary reference construction. An anchor bolt 6 is accurately positioned and installed on leveling concrete 2 by fixedly installing a base seat 1a of a mounting member 1 so as to be aligned with a center mark for the anchor bolt positioned and indicated thereon, disposing the anchor bolt 6 upright on a hollow bolt 1b via a hinge member 4 and a turn buckle member 5, then casting concrete for a base portion and a rising portion of the foundation simultaneously, adjusting the anchor bolt 6 which is inclined at the hinge member 4 being bent due to the casting pressure into a vertical state while measuring with a plummet instrument before the concrete is hardened, and maintaining the anchor bolt 6 in the vertical state by a verticality holder until the concrete is hardened.

Description

TECHNICAL FIELD [0001] The present invention relates to a method of accurately positioning an anchor bolt to be embedded in foundation concrete of various building structures by a swing-type anchor bolt. BACKGROUND ART [0002] In foundations of various building structures, it is necessary to provide an anchor bolt for firmly connecting the foundation and building frame of an upper structure to be installed thereon at the time of construction. The anchor bolt is a member whose lower portion is to be embedded in the foundation in a state in which an upper portion thereof projected from an upper surface of the foundation, as is needless to say. [0003] In residential construction built by a conventional construction method, through holes for anchor bolts opening on bed-sills have been formed by measuring positions of the anchor bolts extending upright from a top end of the foundation individually, marking the positions on groundwork before installation, and drilling the marked positions ...

AI Technical Summary

Benefits of technology

[0049] According to the first, second, third, and fourth aspects of the present invention, accurate and quick positioning of the anchor bolt on the foundation is realized in a simple procedure using members of an extremely simple structure without using a temporary reference construction.

[0050] In addition by securing the verticality of the anchor bolt or the reference center shaft using the plummet instrument, the immovable center mark on the leveling concrete can be moved to the top end of the foundation with a high degree of accuracy.

Problems solved by technology

Therefore, installation of the bed-sill to the top end of the foundation is enabled only after such a troublesome work, and is a very inefficient work.

In prefabricated buildings or steel-frame buildings, superstructures are fabricated in a factory, and hence flexibility at the building site is extremely low.

Since this method must be completed within a relatively short time until concrete is hardened, the procedures are hurriedly performed, and hence measurement may be inaccurate.

In addition, with this method, the temporary reference construction which serves as a reference of measurement can be displaced with a slight external force, and hence there is a problem such that the reliability of the temporary reference construction which serves as a reference cannot be secured.

Furthermore, there is also a problem such that the temporary reference construction becomes an obstacle of various works.

Therefore, the problems described above are not solved at all.

However, it seems that required positioning accuracy of the anchor bolt cannot be achieved sufficiently in a practical sense.

The concrete form for building the foundation is, as long as it is the one currently used, not able to avoid slight displacement due to a high pressure exerted when casting concrete.

Therefore, in spite of increase of positioning accuracy in support of the anchor bolt supporting member itself, displacement occurs on the side of concrete form and, accordingly, displacement of the anchor bolt supporting member itself may be resulted.

Furthermore, the high pressure exerted when casting concrete is also exerted to the anchor bolt which is supported by the supporting member or the like.

Therefore, the supporting member cannot support the pressure, and hence slight displacement cannot be avoided unless it has a substantially solid structure.

Therefore, with the technique in which the anchor bolt is fixed to the concrete form via the supporting means as shown in Patent Documents 2 and 3, the positioning accuracy cannot be improved sufficiently.

However, in such a structure, the longer the anchor bolt becomes, the higher strength of the frame is required.

Therefore, the cross-section of the frame further increases, and the weight also increases correspondingly, whereby workability is deteriorated and hence increase in cost cannot be avoided.

However, such reinforcing steel is displaced easily and significantly when casting concrete.

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