JPH0445615B2 - - Google Patents

Description

[Detailed description of the invention] (1) Industrial application field The present invention is applicable to steel pipe piles driven into the ground (S piles), steel pipe wrapped concrete piles (SC piles), prestressed concrete piles (PC piles), This article relates to reinforcing metal fittings that are applied to foundation joints of reinforced concrete buildings that are connected to the upper ends of foundation piles such as high-strength PC piles (PHC piles).

(2) Conventional technology As recent seismic damage surveys have revealed damage to foundation structures, especially damage to pile foundations, there is an increasing need for seismic design of foundation structures that are balanced with the superstructure. . However, the reinforcement at the foundation joint that connects to the conventional foundation pile consists of the main reinforcement on the bottom surface of the cage reinforcing bar, which is made up of horizontal and vertical reinforcements on the top and side surfaces, and is shown in Figures 7 and 8. Generally, a plurality of main reinforcements a, . . .

(3) Problems to be solved by the invention According to the reinforcement using these main reinforcements a...a, when the foundation pile b is subjected to a repeated force P in the horizontal direction due to an earthquake as shown in Figure 7, the shear force due to that force is reduced. A part of the shearing force acts intensively on the lower end of the foundation joint, and a part of the shearing force is received by the main reinforcements a...a, but these main reinforcements a...a are arranged in a rectangular shape around the foundation pile b. Since the foundation pile c is easily deformed and does not serve as sufficient reinforcement, and the inside of the foundation joint c is made only of concrete, the foundation pile b described above is
Due to the bending moment M acting on the foundation pile b due to the horizontal repetitive force P acting on the foundation pile b, a crack is generated around the penetration hole d of the foundation pile b in the foundation joint c, and thus the foundation joint There was a drawback that c did not have sufficient yield strength and toughness.

It is an object of the present invention to eliminate such drawbacks and provide a reinforcing metal fitting that has sufficient strength and toughness and is easy to work.

(4) Means for Solving the Problems In order to achieve this object, the present invention provides a plurality of approximately
The present invention is characterized in that the horizontal parts of the connecting rods are made to protrude radially, and the vertical parts are connected to each other by reinforcing rods at a plurality of places, and the horizontal parts are connected to each other by the reinforcing rods.

(5) Effect By burying the reinforcing metal fitting of the present invention in the foundation joint with the horizontal part of the connecting rod facing downward and covering the upper end of the foundation pile, the foundation pile is repeatedly subjected to horizontal left and right forces due to earthquakes. At the lower end of the foundation joint, which receives a portion of the shearing force caused by the applied force, the shearing force is absorbed by a reinforcing rod that is hard to deform and connected with the horizontal part of the connecting rod buried in the lower end. Furthermore, in the entire foundation joint, the shear force is absorbed by the vertical parts of a plurality of connecting rods buried in the vertical direction within the joint, and the reinforcing rods connected at multiple points of these vertical parts. The remaining force is dispersed and received by the entire joint, and a bending moment acts on the foundation pile due to the horizontal left and right forces, and a tensile force is applied to the area around the insertion hole of the foundation pile at the joint. Even if this tensile force is applied, this tensile force is received by the vertical portion of the connecting rod, and thus the base joint has extremely high yield strength and toughness.

(6) Embodiment An embodiment of the present invention will be described with reference to FIGS. 1 to 3.

Reference numeral 1 denotes an L-shaped reinforcing bar connecting rod consisting of a vertical portion 1a and a horizontal portion 1b extending laterally from one end of the rod, and 2 a plurality of vertical reinforcements 2a, 2a and horizontal reinforcements 2b, 2b horizontally combined. A lattice-shaped reinforcing rod is formed by welding or other means at the intersections of the lattice-shaped reinforcing rods, and a hole 2c is formed in the center. A reinforcing rod consisting of a plurality of ring-shaped striations having , 1 horizontal part 1b,
The lattice-shaped reinforcing rods 2 were attached to 1b by welding or other means with their centers substantially aligned to form a reinforcing metal fitting.

Next, the construction of the reinforcing metal fittings 4 will be explained.
First, foundation piles 5 are driven into the ground at predetermined locations on the construction site using a pile driver, and then foundation work for the concrete building is carried out. That is, the reinforcement 6a of the foundation joint part 6 is placed at the underground protruding part 5a of each foundation pile 5, and the reinforcement 7a of the foundation beam 7 and the column 8 which connect these joint parts 6, 6 are respectively installed. Place reinforcement 8a.

Here, hand reinforcing bars 9, 9 are arranged on the lower surface of the foundation joint 6 as in the conventional manner. Then, at each foundation joint 6, the reinforcing metal fittings 4 are inserted into the protruding parts 5a of the foundation piles 5 so that the lattice-shaped reinforcing rods 2 are on the lower side, and the lattice-shaped reinforcing rods 2 are connected to the main bars 9 of the foundation joint 6, 9
Place it on. Thereafter, the formwork is attached and concrete is poured, and after the concrete has cured, the formwork is removed to obtain the foundation of the concrete building as shown in Figure 2.

Thus, when a horizontal force P acts on the foundation pile 5 due to an earthquake as shown in Figure 3, a part of the shear force F is concentrated on the lower end of the foundation joint 6 from the foundation pile 5, but this part The concentrated shear force f of the horizontal part 1b of the connecting rods 1, 1
1b, and even if the horizontal force F is repeatedly applied to these lattice-shaped reinforcing rods 2 in any direction, front, back, left, or right in the horizontal plane, the lattice-shaped reinforcing rods 2 will not deform. There is no such problem, and the strength of the lower end of the foundation joint 6 is maintained sufficiently.

In addition, the remaining shear force F is received by the A part of the foundation joint 6, but the remaining shear force F is because the vertical parts 1a, 1a of the connecting rods 1, 1 extend to the C part of the foundation joint 6. The information is transmitted to the C part by these vertical parts 1a, 1a, and since the ring-shaped reinforcing rod 3 connects the A part and B part of the foundation joint part 6, the information is transmitted to the B part by the reinforcing rod 3. Thus, the remaining shear force F is distributed and received by the entire foundation joint 6, and even if the horizontal force P acts repeatedly in the front, back, left, and right directions, the foundation joint 6 as a whole has sufficient strength. Has strength.

Further, a bending moment M acts on the foundation pile 5 due to the horizontal force P, and the foundation pile 5 is bent,
Even if a vertical tensile force T is generated on the circumferential surface of the insertion hole 10 of the foundation pile 5 of the pile foundation joint 6, the tensile force T is applied to the vertical portions 1a, 1a of the connecting rods 1, 1.
The circumferential surface of the bite hole 10 is tough and free from cracks.

In the above embodiment, the reinforcing rod 3 is formed of a ring-shaped strip, but it may be spiral-shaped.

FIG. 4 shows a second embodiment of the present invention,
A spiral reinforcing rod 12a is fixed to the horizontal parts 1b, 1b of the connecting rods 1, 1 by welding or the like, and a reinforcing rod 12b is fixed to the reinforcing rod 1a at these horizontal parts 1b, 1b by welding or the like. Therefore, the same effects as in the first embodiment can be obtained.

FIG. 5 shows a third embodiment of the present invention, in which a plurality of square reinforcing rods 22a, 22b, 22c are sequentially inscribed at an angle of 45 degrees to the horizontal portions 1b, 1b of the connecting rods 1, 1. Since it is fixedly formed by welding or the like, the same effect as the first embodiment can be obtained.

In addition, in these second and third embodiments, the first
Similar to the embodiment, the reinforcing rod 3 may be formed in a spiral shape.

FIG. 6 shows a fourth embodiment of the present invention, in which the vertical portions 1a, 1a of the connecting rod 1 are tapered and the reinforcing rod 2 is replaced by a single screw-shaped reinforcing rod 3.
2, the reinforcing metal fittings 4 can be stacked on top of each other during transportation, and the same effects as those of the first embodiment can be obtained.

(7) Effects of the Invention As described above, according to the auxiliary fitting of the present invention, a plurality of approximately L-shaped connecting rods each consisting of a vertical portion and a horizontal portion extending laterally from one end of the rod are connected by making the horizontal portion protrude radially and connecting the vertical portion. Since a plurality of locations and horizontal parts are connected to each other by reinforcing rods, the reinforcing metal fittings of the present invention can be buried in the foundation joint by covering the upper ends of the foundation piles with the horizontal parts of the connecting rods facing downward. , even if horizontal left and right forces are repeatedly applied to the foundation pile due to earthquakes, at the lower end of the foundation joint, which receives a portion of the shearing force due to that force, the horizontal position of the connecting rod buried within the lower end A portion of the shearing force is concentratedly received by the reinforcing rods that are hard to deform and connected at the joint, and furthermore, in the entire foundation joint, the vertical parts of the plurality of connecting rods buried vertically within the joint and the vertical parts of these vertical parts are The rest of the shearing force is distributed and received by the reinforcing rods connected at multiple points across the joint, and furthermore, the left and right forces in the horizontal direction act on the foundation pile to bending moment, which causes the bending moment to be applied to the joint at the joint. Even if a tensile force is applied to the area around the penetration hole of the foundation pile, this tensile force is received by the vertical part of the connecting rod, and thus the foundation joint has extremely high strength and toughness, making construction easier. It is easy to use, has a simple structure, can be obtained at low cost, and is easy to transport.

[Brief explanation of the drawing]

FIG. 1 is a perspective view of a first embodiment of the reinforcing metal fitting of the present invention, FIG. 2 is a sectional view of the reinforcing metal fitting in use, and FIG. 3 is an explanatory view showing the state of force applied in the use condition.
Figures 4, 5 and 6 are perspective views of second, third and fourth embodiments of the reinforcing metal fittings of the present invention, respectively, and Figure 7 is a sectional view of a foundation joint where conventional foundation piles are joined. ,
FIG. 8 is a cross-sectional view taken along the line. 1...Connecting rod, 1a...Vertical part, 1b...Horizontal part, 2
...Reinforcement rod, 3...Reinforcement rod, 12a...Reinforcement rod, 22a
...Reinforcement rod, 22b...Reinforcement rod, 22c...Reinforcement rod, 3
2...Reinforcement rod, 4...Reinforcement metal fittings.

Claims (1)

[Claims] 1. A plurality of approximately L-shaped connecting rods each consisting of a vertical portion and a horizontal portion extending laterally from one end of the vertical portion are connected to each other by reinforcing rods at multiple locations of the vertical portion with the horizontal portions protruding radially. , a reinforcing metal fitting for a pile foundation joint, which is formed by connecting the horizontal parts with each other by a reinforcing rod.