JP2007270486A - Structure of spiral hoop for pile, and construction method for rc pile - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a structure of a spiral hoop for a pile, which improves the property of infilling concrete, by securing a long bar-arrangement interval required for the infilling of the concrete, while securing the amount of the arrangement of the necessary spiral hoop, and a construction method for an RC pile using the spiral hoop for the pile. <P>SOLUTION: The spiral hoops 2 for the pile are spirally arranged on the outer peripheries of a plurality of main reinforcements 1 in the axial direction of the main reinforcement 1. The spiral hoop 2 is formed in such a manner that a plurality of parts 2a, in which the plurality of hoops are wound in a superposed state, and a plurality of parts 2b, in which the single hoop is wound, are alternately arranged in the axial direction of the main reinforcement 1. The part 2a is formed by bundling the plurality of hoops in the state of making them superposed on the outer periphery of the main reinforcement 1. The part 2b is formed of the single hoop. The parts 2a and 2b are formed of a single round bar or deformed bar in such a shape as to spirally continue in the axial direction of the main reinforcement 1. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a structure of a spiral hoop for piles and a method for constructing an RC pile constructed using the spiral hoop for piles as a shear reinforcement, and is applied to a foundation pile having an RC structure, for example.

  In recent years, foundation piles of RC structure are often arranged with hoop bars spirally wound around the outer periphery of the main bars as shear reinforcement bars. The hoops arranged in a spiral shape (hereinafter referred to as “spiral type hoops”) not only act as shear reinforcements, but also have the function of preventing the main bars and concrete from getting caught due to excessive axial compression force. In RC piles such as foundation piles that mainly receive axial compression force, they are considered to be very effective shear reinforcements.

Conventionally, for example, as shown in FIGS. 3 and 4, this type of spiral hoop muscle 2 has been arranged at substantially equal intervals on the outer periphery of a plurality of main reinforcing bars 1 arranged at predetermined intervals. muscle mass has been determined by the spiral hoop 2 of diameter and Haisuji interval (pitch) P _1.

JP 2000-64630 A Japanese Patent Laid-Open No. 11-152745

However, since the reinforcement pitch P ₁ with reinforcing bar diameter of the spiral hoop 2 is thicker becomes narrower as reinforcement of the spiral hoop 2 is increased, it is difficult reinforcement work reinforcing bars, also concrete There was a problem that the filling property of No. 3 was remarkably lowered.

  The present invention has been made in order to solve the above-described problems, and can secure a wide spacing interval necessary for filling concrete while securing a necessary amount of spiral-type hoop reinforcement, and the main reinforcement and spiral. An object of the present invention is to provide a structure of a spiral type hoop reinforcement for piles that enables concrete to be surely placed to every corner of the mold hoop reinforcement, and a construction method for RC piles using the spiral type hoop reinforcement for piles. It is.

  The structure of the spiral hoop muscle for piles according to claim 1 is a structure of a spiral hoop muscle for piles in which hoop muscles are spirally wound around the outer periphery of a plurality of principal muscles and arranged in the axial direction of the principal muscles. Then, a plurality of overlapped winding portions formed by bundling a plurality of the hoop muscles on the hoop muscles and a single winding portion formed by a single hoop muscle are alternately formed in the axial direction of the main muscles. It is characterized by being made.

  In particular, the present invention secures a necessary amount of shear reinforcement in a plurality of overlapping winding portions formed by bundling a plurality of hoop muscles on the outer periphery of the main reinforcement, and also provides a plurality of overlapping winding portions and a plurality of overlapping winding portions. The space required for placing concrete in a single winding portion formed by a single hoop bar between the two is secured so as not to hinder concrete filling.

  In general, when the pile head semi-fixed method is used, the bending moment transmitted from the upper frame side to the pile head is greatly reduced, so the pile diameter itself can be reduced, but the shear force is not reduced, so the pile diameter can be reduced as it is. If it is made smaller, the cross-sectional area of the pile will be reduced and the shear strength of the pile will be insufficient. Therefore, it is necessary to closely arrange the shear reinforcement bars accordingly.

  In this case, it is desirable to closely arrange the shear reinforcement bars in a range of about 5D (D: pile diameter) from the pile head. However, by using the hoop bars of the present invention in such a portion, the concrete filling is performed. It is possible to arrange a necessary amount of shear reinforcement without causing any trouble.

  In addition, the multiple overlapping winding part may be formed by winding the hoop muscle around the main muscle at least twice, if necessary, more. Further, a plurality of overlapping winding portions and / or a single winding portion may be formed obliquely with respect to the main bar.

  Furthermore, if a plurality of overlapping winding portions are bundled by winding a binding material such as a wire, they are not separated and are easy to handle. Moreover, a plurality of overlapping winding portions and a single winding portion can be continuously formed in a spiral shape from one round steel or deformed reinforcing bar.

  The structure of the spiral hoop reinforcement for piles according to claim 2 is the structure of the spiral hoop reinforcement for piles according to claim 1, wherein the plurality of overlapping winding portions or the single winding portion are formed at right angles to the main reinforcement. It is characterized by.

  The structure of the spiral hoop reinforcement for piles according to claim 3 is the structure of the spiral hoop reinforcement for piles according to claim 1 or 2, wherein a plurality of overlapping winding portions are bound by a binding member. Is. A number wire can be used for the bundling member, and the number wires may be wound around the outer periphery of a plurality of overlapping winding portions in a coil shape, or may be wound at predetermined intervals.

  The RC pile construction method according to claim 4 is an RC pile construction method in which a plurality of main bars and spiral hoop bars are arranged, and a plurality of hoop bars formed by stacking and bundling a plurality of hoop bars. A pile-type hoop is formed on the outer periphery of the main bar, and the pile-type spiral type is formed by alternately forming the single-winding part formed by the lap winding part and the one hoop bar in the axial direction of the main bar. The hoop muscle is stretched in the axial direction of the main muscle.

  The present invention is an arrangement in which the spiral hoop muscle for pile described above can be easily arranged on the outer periphery of the main reinforcement, and in this case, in particular, if a plurality of overlapping winding portions are bundled with a binding material such as a number wire, When the spiral hoop muscle for piles is stretched in the axial direction of the main muscle, a plurality of overlapping winding portions are not stretched together with a single winding portion, and can be arranged at a predetermined interval.

  In particular, the present invention secures a necessary amount of shear reinforcement in a plurality of overlapping winding portions formed by stacking and bundling a plurality of hoop muscles on the outer periphery of the main reinforcing bar, so that a plurality of overlapping winding portions and a plurality of overlapping windings are secured. Since it is possible to secure a wide space necessary for placing concrete in a single winding portion formed by a single hoop bar between the portions, there is no problem in filling the concrete.

  In addition, if a plurality of overlapping winding portions are bundled by wrapping a binding material such as a wire, they are not separated, and the arrangement of the bars is easy and easy to handle.

  1 and 2 show RC structure piles, in particular, FIGS. 1 (a) and 1 (b) show RC structure piles constructed in a circular cross section, and FIGS. 2 (a) and 2 (b) show rectangular cross sections. Each constructed RC pile is shown.

  In these drawings, a plurality of main reinforcing bars 1 are arranged at predetermined intervals in a circular shape or a rectangular shape, and a pile-type spiral hoop muscle 2 is arranged on the outer periphery of the plurality of main reinforcing bars 1, and the main reinforcing bars 1 and spirals are arranged. Concrete 3 is placed around the mold hoop reinforcement 2.

  The spiral hoop muscle 2 for piles is continuously formed in a spiral shape in the axial direction of the main reinforcement 1 along the outer periphery of the main reinforcement 1. In addition, the spiral hoop muscle 2 has a plurality of overlapping winding portions 2 a formed by double wrapping around the outer periphery of the main muscle 1 and a single winding portion formed by winding once around the outer periphery of the main muscle 1. 2b and is formed continuously in the axial direction of the main muscle 1.

Further, the plurality of lap winding portion 2a and one wound portion 2b is formed alternately in the axial direction of the main reinforcement 1, a plurality of lap winding portions 2a, 2a are formed at predetermined intervals P ₂ intervals. Further, the multiple overlapping winding portions 2a are formed substantially perpendicular to the main bar 1 and are bundled by winding a binding wire such as a number wire. On the other hand, the single winding portion 2 b is formed obliquely with respect to the main bar 1.

  In addition, the multiple overlap winding part 2a and the single winding part 2b of the spiral type hoop reinforcement 2 for piles which consist of round steel or a deformed reinforcing bar are continuously formed in the axial direction of the main reinforcement 1 from one hoop reinforcement. .

The pile-shaped spiral hoop reinforcement 2 is formed in this way, so that the necessary amount of shear reinforcement is mainly secured in the plurality of overlapping winding portions 2a, and one winding between the plurality of overlapping winding portions 2a, 2a. interval required striking設時concrete (gap) P ₂ is secured widely in the portion 2b. Therefore, when placing the concrete 3, the concrete 3 can be reliably placed around the main reinforcement 1 and the spiral hoop reinforcement 2 for piles.

That is, the conventional spiral hoop 2, whereas in increasing the Haisuji amount as is apparent from FIGS. 3 and 4, it is necessary to narrow the Haisuji interval P _1, in the present invention Since the number of windings of the plurality of overlapping winding portions 2a can be increased to increase the amount of bar arrangement, it is not necessary to narrow the interval between the plurality of overlapping winding portions 2a, 2a. For this reason, the plurality of overlapping winding portions 2a , it is possible to secure a wide required spacing concrete hitting設時(gap) P ₂ between 2a.

  Next, a description will be given of a method for constructing an RC structure foundation pile using the spiral hoop reinforcement 2 for a pile as a shear reinforcement. First, a pile spiral is attached to the outer periphery of a plurality of main reinforcements 1 arranged at predetermined intervals. The hoop muscle 2 is attached in a state in which the plurality of overlapping winding portions 2a and the single winding portion 2b of the spiral spiral hoop muscle 2 are overlapped with each other, and one end side of the pile spiral hoop muscle 2 is fixed.

  Next, the other end side of the pile-type spiral hoop muscle 2 is pulled in the axial direction of the main muscle 1, and the whole is stretched in the axial direction of the main muscle 1, and is arranged in a spiral shape in the axial direction of the main muscle 1.

At that time, the one wound portion 2b of the gap P ₂ between a plurality of lap winding portions 2a and 2a can be freely set according to the length stretching the pile for spiral hoop 2.

  The present invention can secure the necessary amount of spiral hoop reinforcement, and can ensure a wide space between the reinforcements necessary for filling the concrete. Can be cast.

The pile of the RC structure of this invention constructed | assembled in the circular cross section is shown, (a) is the one part longitudinal cross-sectional view, (b) is a cross-sectional view. The pile of RC structure of this invention constructed | assembled in the rectangular cross section is shown, (a) is the partial longitudinal cross-sectional view, (b) is a cross-sectional view. The pile of the conventional RC structure constructed | assembled by the circular cross section is shown, (a) is the one part longitudinal cross-sectional view, (b) is a cross-sectional view. The pile of the conventional RC structure constructed | assembled by the rectangular cross section is shown, (a) is the one part longitudinal cross-sectional view, (b) is a cross-sectional view.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Main reinforcement 2 Spiral type hoop reinforcement 2a for piles Multiple overlapping part 2b Single winding part 3 Concrete

Claims (4)

  A structure of a spiral hoop muscle for a pile in which hoop muscles are spirally wound around the outer periphery of a plurality of principal muscles and arranged in the axial direction of the principal muscles, and a plurality of the hoop muscles are stacked and bundled on the hoop muscles A pile-shaped spiral hoop muscle, wherein a plurality of overlapped winding portions formed by this and a single winding portion formed by one hoop muscle are alternately formed in the axial direction of the main reinforcement. Construction.   The structure of a spiral hoop bar for piles according to claim 1, wherein the plurality of overlapping winding parts or the single winding part is formed at a right angle or a substantially right angle with respect to the main bar.   The structure of the spiral type hoop muscle for piles according to claim 1 or 2, wherein a plurality of overlapping winding portions are bound by a binding member.   An RC pile construction method in which a plurality of main bars and spiral hoop bars are arranged, and is formed by a plurality of overlapping wound portions formed by bundling a plurality of hoop bars and a single hoop bar. Attaching a spiral hoop muscle for piles in which the single wound portion formed alternately in the axial direction of the main muscle is attached to the outer periphery of the main muscle, and extending the spiral hoop muscle for pile in the axial direction of the main muscle An RC pile construction method that is characteristic.

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