JP2520524B2 - Pile foundation footing construction method and pile foundation footing curved formwork - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a pile foundation footing construction method and a pile foundation footing curved portion mold, and in particular, by disposing a flexible mold made of a thin plate material in the curved portion,
TECHNICAL FIELD The present invention relates to a pile foundation footing construction method and a pile foundation footing curved portion formwork that can prevent deformation of a formwork by concrete in a fluid state and can realize simple formwork construction.

[0002]

2. Description of the Related Art Generally, a pile foundation structure is often used for the foundation of a large-scale building structure in consideration of the situation of the surrounding ground and the shape weight of the building. Then, the appropriate pile type, pile size, and layout are decided from each design and construction condition. In addition, the load of the upper structure is distributed and transmitted to each pile via footing, etc., but at this time, the underground beam structure that connects the pile heads is the main structural material, and a pile concrete is placed between these underground beams. Many slab structures are used. This underground beam structure has an advantage that the weight of the building can be reduced. By the way, when constructing an underground beam by connecting pile heads in this way, it is necessary to determine the dimensional structure thereof in consideration of an external force acting on the pile head. At this time, the pile head acting force varies depending on the fixing condition of the pile head, but in the fixed structure, the vertical supporting force V, the pile head bending moment M, and the horizontal shearing force H generally act on the pit foundation footing through the underground beam. The structure and dimensions of the pile foundation footing are determined according to the acting force. FIG. 5 is a perspective view showing an example of a foundation structure in which this type of pile foundation and each pile foundation are connected by an underground beam. Although only a part is shown in the figure, a rectangular parallelepiped-shaped pile foundation footing 20 having a substantially square planar shape is constructed so as to match the arrangement interval of the piles 21. Further, an underground girder G having a beam higher than the pile foundation footing 20 is connected so as to be integrated with the pile foundation footing 20. At this time, the beam width of the underground beam G is determined by the weight of the upper structure and the like, and is often larger than the footing height. Figure 6 shows pile foundation footing 2
The form 23 assembled so that 0 and the underground beam G part are integrally cast is shown. These formwork 23,
Chamfers 24, 24 ... Forming a concrete placing surface and receiving concrete lateral pressure, and end members 25, 25 for holding and fixing the crate 24 to prevent the shape of the form from being deformed.
…. A plywood generally called a control panel or a steel form called a metal foam is used for the weir board 24, and a square steel pipe or wood is used for the thick end material 25.
Each end thick member 25 is fixed to the weir plate 24 by foam ties 26, 26 ... At predetermined positions. Also,
The opposing weir plates 24 are fixedly held by the separator 27, and a predetermined structural finish dimension is secured.

[0003]

However, since the formwork of the pile foundation footing described above has a complicated shape and cannot be used as a standard length material such as metal foam, the control panel is processed to match the dimensions of the pile foundation footing. Each form must be manufactured, and it is complicated to integrally construct the underground beam and the pile foundation in a foundation where a large number of piles are placed.
Further, as shown in FIG. 7, since the weir plate constitutes a straight line, the concrete lateral pressure acts as an evenly distributed load on the weir plate, and a maximum bending moment is generated at approximately the central position of the weir plate. Maximum deflection of the plate. If the reinforcement with the thick timber is insufficient, the pressure of the concrete before hardening may cause the weir to stick outward, and the formwork may collapse. In addition, square footing with a combination of flat formwork required more concrete and rebar than design strength required.

[0004]

In order to achieve the above object, the pile foundation footing construction method according to the present invention is such that at least a part of the pile foundation footing is formed into an arc shape, and the circular shape is generated by the lateral pressure of concrete in a fluid state before hardening. A flexible form made of a thin plate material where the arc-shaped portion is strained and correctly matches the arc shape,
It is characterized in that it is arranged in a curved portion of a pile foundation footing to assemble a concrete pouring formwork, and concrete is placed in the formwork.

Further, the pile foundation footing curved portion mold according to the present invention has an arcuate portion, and the arcuate portion is tensioned by the lateral pressure of the concrete in a fluid state before hardening to be properly aligned with the arcuate shape. It is characterized in that it is made of a thin plate material and a band-shaped rib for connection is formed at an edge portion of the thin plate material.

[0006]

According to the pile foundation footing construction method of the present invention,
Since the flexible formwork that is tensioned by the lateral pressure of the concrete in the fluid state and correctly matches the arc shape is arranged in the curved part of the pile foundation footing, it is not necessary to construct a strong formwork in the curved part, Frame construction is greatly simplified. Also,
Since the flexible formwork arranged on the curved portion of the pile foundation footing is matched with the circular arc shape by the poured concrete lateral pressure, it is possible to prevent the inconvenience of the work due to the deformation and collapse of the formwork.

Further, in the formwork pile for the curved portion of the pile foundation footing used for constructing the pile foundation footing described above, a thin plate material is curved at a predetermined bending radius into an arc shape, and a band plate rib for connection is formed at an edge portion. Since it is formed, it is possible to form a strong mold with a simple structure and to easily and surely connect the adjacent molds.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the foundation construction method according to the present invention will be described below with reference to the accompanying drawings.

In FIG. 1, reference numeral 1 denotes a formwork of an underground girder G. The formwork 1 is arranged in the longitudinal direction in accordance with a black marking on a waste concrete surface that has been placed in advance.
It is arranged at a predetermined interval in the vicinity of the pile head (not shown). Further, pile foundation forms 2 and 2 made of a thin steel plate are attached to the end of each form 1 of the underground beam G in a state of being curved in an arc shape. In this embodiment, the mold 2 has a thickness of 0.
Using a colored rustproof steel plate of 8 mm, it is curved so as to form a part of an arc with a diameter of 1.2 m, and the width is 10 cm at the end.
The connecting rib 2a is integrally formed so as to be folded back. This rib 2a is applied to the end of the formwork 1 of the underground beam, and further fixed to the end of the formwork 1 of the underground by nails 3, 3, ..., to form an integral formwork for foundation concrete. Assemble. By the way, as shown in FIG. 2, the piles 5 are arranged almost in the center of the pile foundation footing 4,
The pile head treatment of the pile 5 is performed based on the design specifications. Also,
Reinforcing reinforcing bars (not shown) are arranged at the joints between the pile-head-treated reinforcing bars and the reinforcing bars of the underground beam so that the acting force from the underground beam G can be reliably transmitted to the pile head.

In addition, in order to hold and fix the weir plate of the underground beam formwork 1, unshown thick timbers are arranged at a predetermined interval, but in the circular formwork part of the footing, the thick timbers are not arranged at all. Not not. Here, concrete is supplied into this form from a concrete supply device (not shown) such as a concrete pump, and the concrete is sequentially placed by a predetermined procedure. At this time, the lateral pressure of the concrete not yet solidified in the molds 1 and 2 acts uniformly in the circumferential direction as shown in FIG. Therefore, this concrete lateral pressure is converted into a tensile force in the circumferential direction without generating a bending moment on the dam. This circumferential tensile force is much smaller than the allowable tensile strength of the steel sheet, and the deformation of the mold 2 in the radial direction hardly occurs. Therefore, it can be seen that this circular formwork 2 portion does not require any reinforcing thickening material at all.

FIG. 3 shows an underground beam G using the circular formwork described above.
2 shows an example of integrally constructing the pile foundation footing 4 and the pile foundation footing 4. The upper beam of the circular formwork 2 is constructed by connecting formwork for another beam and performing a predetermined splicing process.

The circular mold 2 described above is formed by connecting molds which are previously formed in an arc shape, but the rib 2a is provided at the end.
It is also possible that the bent flat cuff is curved into a predetermined shape when the form is set so that the form becomes circular due to concrete lateral pressure. In such a case, a resin dam may be used. In any case, it can be easily diverted to other pile foundations.

FIG. 4 shows an example of assembling a mold in which an arc-shaped mold is combined with a flat plate-shaped mold as a modification of the above-described embodiment. The figure (a) is for constructing a columnar independent foundation footing, and the figure (b) is an example for constructing an oval footing for a plurality of piles. In this case, it is preferable to dispose a predetermined reinforcing edge thick material on the linear form part. FIG. 7C shows an example in which an arc-shaped mold is applied to the corners of a rectangular footing, and the arc-shaped mold can simplify the end of the mold.

[0014]

As is apparent from the above description, according to the present invention, a plurality of arc-shaped molds are fixed and held so that the pile head is located at the center position, and the edges of the arc-shaped molds are fixed. Since the formwork for basic concrete was assembled by connecting to the side ends of the adjacent formwork, and the basic concrete was placed in the formwork, it is possible to easily assemble the formwork for the pile foundation part and improve the efficiency. It can be well placed in concrete, and as a pile foundation form used for the above-mentioned foundation construction, a thin plate material is curved with a predetermined bending radius into an arc shape, and a band plate rib for connection is formed at the edge. As a result, it is possible to obtain an inexpensive and simple structure of the formwork, and it is possible to construct an arc-shaped footing that the design expects.

[Brief description of drawings]

FIG. 1 is an assembly conceptual diagram showing an aspect of an embodiment of a foundation building method according to the present invention.

FIG. 2 is an explanatory view of concrete lateral pressure distribution when constructing a foundation according to the present invention.

FIG. 3 is a perspective view showing a part of an underground beam constructed by the formwork of the present invention.

FIG. 4 is a plan view showing a modified example of the arc-shaped mold according to the present invention.

FIG. 5 is a perspective view showing a part of an underground beam constructed by a conventional formwork.

FIG. 6 is a schematic plan view showing an example of a conventional mold.

FIG. 7 is an explanatory diagram of concrete lateral pressure distribution when constructing a foundation using a conventional formwork.

[Explanation of symbols]

 1 Underground beam formwork 2 Formwork for pile foundation 4 Pile foundation Hoochig 5 Pile

 ─────────────────────────────────────────────────── ─── Continuation of the front page (56) References Japanese Patent Publication No. 46-17017 (JP, B1) Actual Publication No. 45-30527 (JP, Y1) Actual Publication No. 45-6177 (JP, Y1) Actual Publication 45- 20033 (JP, Y1)

Claims (2)

(57) [Claims] 1. A flexible form frame made of a thin plate material, at least a part of which is formed into an arc shape, and the arc shape portion is tensioned by the lateral pressure of the concrete in a fluid state before being hardened so that the arc shape is correctly aligned. A method for constructing a pile foundation footing, characterized in that it is arranged in a curved portion of a pile foundation footing to assemble a concrete pouring formwork, and concrete is placed in the formwork. 2. A thin plate material having an arcuate portion, the arcuate portion being tensioned by lateral pressure of the concrete in a fluid state before being hardened and being correctly aligned with the arcuate shape, and connected to an edge portion of the thin plate material. Form for footing curved part of pile foundation, characterized by forming strip-shaped ribs.