Joint structure of precast concrete boards, foundation structure, and construction method of foundation structure

Abstract

To provide a joint structure of a precast concrete slab capable of improving the working efficiency of foundation work by connecting the precast concrete slab by a simple structure.SOLUTION: A joint structure of a precast concrete plate includes plate-like precast concrete plates 10 arranged so that corner parts of end faces 11 are in contact with each other in a substantially L-shape in a plan view, and joint metal fittings 20 connecting the end faces 11 of the precast concrete plates 10 to each other. An insert metal fitting 16 is embedded in the end face 11 of the precast concrete board 10, and the joint metal fitting 20 is attached to the insert metal fitting 16.SELECTED DRAWING: Figure 4

Description

[Technical Field]

[0001] The present invention relates to a joint structure for precast concrete plates that form the sides of a foundation, a foundation structure using these precast concrete plates, and a method for constructing this foundation structure. [Background technology]

[0002] BACKGROUND ART Conventionally, foundations have been constructed using precast concrete plates (see Patent Documents 1 and 2). Patent Document 1 shows a foundation structure constructed by installing a PC continuous footing in a root excavation area. A recess is formed on one end of the PC continuous footing and a protrusion is formed on the other end, and adjacent PC continuous footings are joined by fitting the protrusion of one PC continuous footing into the recess of the other PC continuous footing. Patent Document 2 discloses a method of constructing a foundation beam by arranging PC plate bodies opposite each other and pouring concrete between these PC plate bodies. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 7-82755 [Patent Document 2] Japanese Patent Application Publication No. 8-41899 Summary of the Invention [Problem to be solved by the invention]

[0004] An object of the present invention is to provide a precast concrete plate joint structure, a foundation structure, and a method for constructing a foundation structure that can connect precast concrete plates with a simple structure and improve the work efficiency of foundation construction. [Means for solving the problem]

[0005] The joint structure for precast concrete plates of the first invention is a joint structure for precast concrete plates (e.g., precast concrete plate 10 described below) that form the side of a foundation (e.g., foundation 3 described below), and is characterized in that it comprises plate-shaped precast concrete plates arranged in an approximately L-shape in plan view so that the corners of their end faces (e.g., end face 11 described below) touch each other, and joint hardware (e.g., joint hardware 20 described below) that connects the end faces of the precast concrete plates, and that fixing hardware (e.g., insert hardware 16 described below) is embedded in the end faces of the precast concrete plates, and the joint hardware is attached to the fixing hardware.

[0006] According to this invention, precast concrete plates are arranged in a substantially L-shape, and the end faces of these precast concrete plates are connected to each other with metal joints. Precast concrete plates cannot stand on their own, but by arranging them in an approximately L-shape and connecting them with metal joints, the precast concrete plates can stand on their own without being supported by support materials, improving the work efficiency of foundation construction. Furthermore, fixing metal fittings are embedded in the end faces of the precast concrete plates, and the end faces of the precast concrete plates with these fixing metal fittings embedded therein are connected with connecting metal fittings, so that the precast concrete plates can be connected with a simple structure at low cost.

[0007] The foundation structure of the second invention is a foundation structure (for example, foundation structure 1 described below) using the above-mentioned precast concrete plates, characterized in that it comprises a plurality of the precast concrete plates arranged in a frame shape, connecting metal fittings connecting the end faces of the precast concrete plates, and a concrete foundation body (for example, foundation body 30 described below) constructed inside and surrounded by the plurality of precast concrete plates.

[0008] According to this invention, a foundation structure is realized by arranging multiple precast concrete plates in a frame shape and pouring concrete inside the frame to construct the foundation body. By using precast concrete plates as both the formwork and the structure of the foundation, the necessary cover thickness for the foundation can be ensured with the precast concrete plates, making the foundation body smaller and easier to construct. In addition, by connecting adjacent precast concrete plates with metal joints, the precast concrete plates can stand on their own without being supported by support materials, improving the work efficiency of foundation construction.

[0009] The method for constructing a foundation structure of the third invention is a method for constructing the above-mentioned foundation structure, characterized in that it includes the steps of constructing basal concrete (e.g., basal concrete 61 described below) on ground (e.g., ground 2 described below) (e.g., step S1 described below), placing the plurality of precast concrete plates on the basal concrete and connecting the end faces of the precast concrete plates with the connecting metal fittings (e.g., step S2 described below), and pouring concrete inside the area surrounded by the plurality of precast concrete plates to construct the foundation body (e.g., step S3 described below).

[0010] According to this invention, a foundation structure is realized by arranging multiple precast concrete plates in a frame shape and pouring concrete inside the frame to build the foundation body. This allows the foundation structure to be constructed efficiently. [Effects of the Invention]

[0011] According to the present invention, it is possible to provide a precast concrete plate joint structure, a foundation structure, and a method for constructing a foundation structure that can connect precast concrete plates using a simple structure and improve the work efficiency of foundation construction. [Brief explanation of the drawings]

[0012] [Figure 1] FIG. 2 is a plan view of a base structure according to an embodiment of the present invention. [Figure 2] 2 is a cross-sectional view of the basic structure of FIG. 1 along the line AA. [Figure 3] 3 is a view of the basic structure of FIG. 2 taken along the arrow CC. [Figure 4] FIG. 2 is an enlarged view of the portion of the basic structure of FIG. 1 surrounded by the dashed line B. [Figure 5] FIG. 5 is a view of the basic structure of FIG. 4 taken along the arrow DD. [Figure 6] 1 is a flowchart of a procedure for constructing a basic structure. [Figure 7] This is an explanatory diagram of the construction procedure for the foundation structure (Part 1, precast concrete slabs installed on basal concrete). [Figure 8] This is an explanatory diagram of the construction procedure for the foundation structure (part 2, with pillar members erected on the foundation). [Figure 9] FIG. 10 is a vertical cross-sectional view of a foundation structure according to a modified example of the present invention. [Figure 10] FIG. 10 is a cross-sectional view of a precast concrete plate of the foundation structure according to the modified example. DETAILED DESCRIPTION OF THE INVENTION

[0013] The present invention relates to a joint structure for precast concrete plates with embedded fixing hardware (insert hardware), a foundation structure in which precast concrete plates are arranged in a frame shape and a concrete foundation body is provided inside it, and a method for constructing such a foundation structure. Hereinafter, an embodiment of the present invention will be described with reference to the drawings. Fig. 1 is a plan view of a base structure 1 according to one embodiment of the present invention, and Fig. 2 is a cross-sectional view of the base structure 1 taken along line AA in Fig. 1. The foundation structure 1 comprises improved ground 2, a reinforced concrete foundation 3 that is rectangular in plan view and constructed on the ground 2, steel-framed column members 4 erected on the foundation 3, and a reinforced concrete foundation slab 5 constructed on the foundation 3. The foundation 3 comprises four precast concrete plates 10 arranged in a rectangular frame shape when viewed from above, connecting metal fittings 20 connecting the end faces 11 of the precast concrete plates 10, and a concrete foundation body 30 constructed inside the area surrounded by the four precast concrete plates 10.

[0014] Fig. 3 is a view taken along the line CC of the basic structure 1 in Fig. 2. Fig. 4 is an enlarged view of a portion of the basic structure 1 enclosed by the dashed line B in Fig. 1. Fig. 5 is a view taken along the line DD of the basic structure 1 in Fig. 4. The precast concrete plate 10 comprises a plate-shaped concrete body 12, vertical reinforcement 13 and horizontal reinforcement 14 arranged in a grid pattern inside the concrete body 12, a channel steel 15 covering both end faces of the concrete body 12, and three insert metal fittings 16 as anchoring metal fittings arranged in a row above and below the channel steel 15. The bottom surface of the channel steel 15 forms the end surface 11 of the precast concrete plate 10. In addition, a through hole 17 is formed in the part of the channel steel 15 where the insert metal fitting 16 is provided, and a bolt 25 (described later) can be screwed into the insert metal fitting 16 through the through hole 17 of the channel steel 15. The horizontal end portions of the horizontal reinforcement 14 are bent, and the vertical reinforcement located at both horizontal ends is arranged in contact with the insert metal fittings 16.

[0015] The joint hardware 20 comprises a plate-shaped first joint portion 21, a plate-shaped second joint portion 22 arranged approximately perpendicular to the first joint portion 21, and a stiffener 23 arranged across the first joint portion 21 and the second joint portion 22. The first joint portion 21 and the second joint portion 22 are integrally formed from angle iron. The first joint portion 21 and the second joint portion 22 are provided with through holes 24 at predetermined positions. The stiffeners 23 are provided on both sides of the through holes 24 of the first joint portion 21 and the second joint portion 22, sandwiching them vertically.

[0016] Adjacent precast concrete plates 10 are positioned so that the corners of their end faces 11 abut. The first joint portion 21 of the connecting hardware 20 is positioned on the end face 11 of one of the precast concrete plates 10, and the second joint portion 22 is positioned on the end face 11 of the other precast concrete plate 10. In this state, a bolt 25 is inserted through the through hole 24 of the connecting hardware 20 and the through hole 17 of the precast concrete plate 10, and screwed into the insert hardware 16, thereby connecting the end faces 11 of the precast concrete plates 10 via the connecting hardware 20.

[0017] Returning to FIG. 2, the foundation body 30 includes a concrete body 31 , foundation reinforcing bars 32 embedded in the concrete body 31 , and anchor bolts 33 embedded in the concrete body 31 . The column member 4 comprises a steel pipe 40 and a base plate 41 provided at the lower end of the steel pipe 40 and having a through hole 42. The column member 4 is joined to the foundation body 30 by inserting the anchor bolt 33 of the foundation body 30 into the through hole 42 of the base plate 41 of the column member 4 and tightening the nut 34. The foundation slab 5 comprises a concrete body 50 and slab reinforcing bars 51 embedded in the concrete body 50.

[0018] The procedure for constructing the above-described basic structure 1 will be described below with reference to the flowchart of FIG. In step S1, as shown in Fig. 7, basing concrete 61 is laid on the ground 2. That is, the ground 2 is improved and excavated down to the bedding surface 60. Next, concrete is poured on the bedding surface 60 to lay the basing concrete 61.

[0019] In step S2, as shown in Figure 7, precast concrete panels 10 are placed on basal concrete 61. Specifically, four precast concrete panels 10 are placed on basal concrete 61 in a rectangular frame shape in plan view, and the end faces 11 of these precast concrete panels 10 are connected to each other with connecting metal fittings 20. In step S3, as shown in Fig. 8, a foundation body 30 is constructed inside the precast concrete plate 10 to complete the foundation 3. Specifically, foundation rebars 32 are arranged inside the precast concrete plate 10, anchor bolts 33 are installed, and concrete is poured using the precast concrete plate 10 as a wall formwork to construct a concrete body 31. The soil outside the precast concrete plate 10 is then backfilled.

[0020] In step S4, as shown in Fig. 8, the pillar member 4 is erected on the foundation 3. That is, a mortar body (not shown) is provided on the foundation 3. Next, the pillar member 4 is lifted up and lowered onto the mortar body, and the anchor bolt 33 of the foundation 3 is inserted into the through hole 42 of the base plate 41 of the pillar member 4. Then, the nut 34 is tightened onto the anchor bolt 33. In step S5, a foundation slab 5 is constructed on the foundation 3. That is, slab reinforcing bars 51 are arranged, and concrete is poured to construct a concrete body 50.

[0021] According to this embodiment, the following effects are obtained. (1) Precast concrete plates 10 were arranged in a roughly L-shape, and the end faces 11 of these precast concrete plates 10 were connected to each other with connecting metal fittings 20. Although the precast concrete plates 10 cannot stand on their own, by arranging the precast concrete plates 10 in a roughly L-shape and connecting these precast concrete plates 10 with connecting metal fittings 20, the precast concrete plates 10 can stand on their own without being supported by support materials, thereby improving the work efficiency of foundation construction. Furthermore, insert metal fittings 16 are embedded in the end faces 11 of the precast concrete plates 10, and the end faces 11 of the precast concrete plates 10 with the insert metal fittings 16 embedded therein are connected with joint metal fittings 20, so that the precast concrete plates 10 can be connected with a simple structure at low cost.

[0022] (2) The foundation structure 1 was realized by arranging four precast concrete plates 10 in a frame shape and pouring concrete inside the area surrounded by these precast concrete plates 10 to construct the foundation body 30. In this way, by using the precast concrete plates 10 as both the formwork and the structure for the foundation structure 1, the precast concrete plates 10 can ensure the necessary cover thickness for the foundation structure 1, making it possible to reduce the size of the foundation body 30 and to easily construct the foundation structure 1.

[0023] The present invention is not limited to the above-described embodiment, and modifications and improvements within the scope of achieving the object of the present invention are included in the present invention. For example, as shown in Figures 9 and 10, truss reinforcement 18 extending diagonally like a truss structure may be embedded in a precast concrete plate 10 to form a precast concrete plate 10A, and the truss reinforcement 18 may be used to integrate the precast concrete plate 10A with the foundation body 30. In the above embodiment, the insert metal 16 is used as the fixing metal, but this is not limiting and an anchor bolt or a rod-shaped body such as a nail or a screw may also be used. In addition, in the above-described embodiment, the joint metal 20 is composed of the first joint portion 21, the second joint portion 22, and the stiffener 23, but this is not limited to this, and the joint metal may be composed of only the first joint portion and the second joint portion. Furthermore, in the above-described embodiment, the column members 4 are made of steel pipes 40, but this is not limiting, and the column members 4 may be made of reinforced concrete. In the above-described embodiment, the precast concrete slabs 10 are buried to serve as formwork and structural members, but this is not limiting, and the precast concrete slabs 10 may be used solely as formwork materials for the foundation structure 1. In this case, after the foundation body 30 is constructed, the precast concrete slabs 10 can be removed and reused. [Explanation of symbols]

[0024] 1, 1A... Foundation structure 2... Ground 3... Foundation 4... Column member 5... Foundation slab 10, 10A... Precast concrete plate 11... End surface 12... Concrete body 13...Vertical reinforcement 14...Horizontal reinforcement 15...Channel steel 16...Insert metal fittings (fixing metal fittings) 17...Through hole 20... Joint metal fitting 21... First joint portion 22... Second joint portion 23...Stiffener 24...Through hole 25...Bolt 30... Foundation body 31... Concrete body 32... Foundation rebar 33...Anchor bolt 34...Nut 40...steel pipe 41...base plate 42...through hole 50...Concrete body 51...Slab reinforcing bars 60...Floor surface 61...Waste concrete

Claims

1. A joint structure of precast concrete plates that form the sides of the foundation, a plate-shaped precast concrete plate arranged so that corners of the end faces are in contact with each other in a substantially L-shape in plan view; and a metal joint that connects the end faces of the precast concrete plates together, An anchoring metal fitting is embedded in the end face of the precast concrete plate, A joint structure for precast concrete plates, characterized in that the joint hardware is attached to the fixing hardware.

2. A foundation structure using the precast concrete plate according to claim 1, A plurality of the precast concrete plates arranged in a frame shape; a metal joint that connects the end faces of the precast concrete plates; A foundation structure characterized by comprising: a concrete foundation body constructed inside and surrounded by the plurality of precast concrete plates.

3. 3. A method for constructing a substructure according to claim 2, comprising: A step of constructing a concrete foundation on the ground; a step of placing the plurality of precast concrete plates on the basal concrete and connecting the end faces of the precast concrete plates with the metal joints; and a step of constructing the foundation body by pouring concrete inside the area surrounded by the plurality of precast concrete plates.

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