JPS6160926A - Reinforcing metal for joint between pile and foundation - Google Patents

Abstract

PURPOSE:To prevent breakage of a foundation part due to a horizontal force such as earthquake, by a method wherein the horizontal parts of L-shaped reinforcing bars are coupled by means of plural annular ring reinforcements to form a reinforcing metal, and the head part of a foundation pile is interposed in the ring reinforcement for concreting. CONSTITUTION:L-shaped reinforcing bars 1 each formed with a vertical part 1a and a horizontal part 1b, are coupled to horizontally-tripled ring reinforcements 2a, 2b, and 2c by welding to form a reinforcing metal 4. A ground projection part 5a of a foundation pile 5 is inserted in an annular body 2a of the reinforcing metal 4, reinforcing bars 6a, 7a, and 8a are arranged, and after forms are mounted, concrete is placed to complete foundation. This, even if a horizontal force due to earthquake is exerted on a joint between the foundation pile 5 and the foundation part, it makes the horizontal part 1b of the L-shaped reinforcing bar 1 share the horizontal force, resulting in prevention of breakage.

Description

[Detailed description of the invention] (1) Industrial application fields The present invention is a steel pipe pile (S pile) driven into the ground.

This invention 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 steel tube-wrapped concrete piles (SC piles), prestressed concrete piles (PC piles), and high-strength PC piles (PHC piles).

(2) Conventional technology As damage to foundation structures, especially damage to pile foundations, has been revealed through recent earthquake damage surveys, there is an increasing need for seismic design of foundation structures that are balanced with the superstructure.

However, in the conventional No. 1 (the reinforcement at the foundation joint where it connects to the foundation pile is 411 & from the cage reinforcement consisting of horizontal reinforcement and vertical reinforcement on the upper and side surfaces, and the main reinforcement on the lower surface, as shown in Fig. 8 and As shown in Figure 9, a plurality of main reinforcements (a) are arranged on each side of the foundation shaft (b), and these main reinforcements (a),
It is common that J/C&) serves to reinforce the joint (C).

(3) Problems to be Solved by the Invention According to the reinforcement using these main reinforcements (&)... (a), due to an earthquake, the horizontal edge reversing force CP is applied to the foundation pile (b) as shown in Figure 8. ), a part of the shear force due to that force acts intensively on the lower end of the foundation joint, and a part of the shear force is received by the main reinforcing bars (&)...(iL),
These main reinforcements (L)... (a) are arranged in a square shape around the 71i foundation pile (b), so they are easily deformed and do not serve as sufficient reinforcement, and the foundation joints (C) Since the inside of the pile is made only of concrete, the bending moment acting on the foundation pile (b) due to the horizontal repetitive force (P) acting on the foundation pile (b) described in 1.
According to the above! Cracks were generated around the penetration hole (d) of the foundation pile (b) in the U-joint (c), and thus the lA foundation joint (C) had the disadvantage of not having 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 connects the upper and lower annular bodies vertically by connecting a plurality of abbreviations each consisting of a vertical part and a horizontal part extending laterally from one end of the vertical part. It is characterized in that the inner and outer annular bodies are connected at the horizontal part.

(5) By burying the No. 1 reinforcing metal fittings in the foundation joint with the inner and outer annular bodies facing downward and covering the upper ends of the foundation piles, it is possible to prevent the foundation piles from being exposed to water caused by an earthquake (left and right in one direction). At the lower end of the foundation joint, which receives a portion of the shearing force caused by the repeated force, the inner and outer rings, which are hard to deform, are connected by the horizontal part of the connecting rod buried within the lower end. Part of the shearing force is concentratedly received by the body, and furthermore, in the entire base ta joint, there are vertical parts of a plurality of connecting rods buried in the vertical direction within the joint part, and upper and lower annular bodies connected by these vertical parts. As a result, the rest of the shearing force is distributed and received by the entire joint, and furthermore, a bending moment is applied to the foundation pile due to the horizontal left and right force, and the penetration hole of the 25i foundation pile at the joint is Even if a tensile force is applied to the peripheral portion, 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. tjS1 to 5.

(1) is a connection of L-shaped reinforcing bars consisting of a vertical part (1a) and a horizontal part (1b) extending laterally from one end, (2a
), (2b), and (2c) show an annular body consisting of three inner and outer ring muscles, (3) an upper and lower annular body consisting of spiral muscles, and! A The above-mentioned connections (1)...(1) are connected at equal intervals inside the spiral-shaped annular body (3) at the vertical part (la) by welding or other means, and these connections (
1)...The horizontal part (lb)...(lb) of (1) has the above-mentioned inner and outer 3ffi annular bodies (2a), (2b), (2C
) are joined by welding or other means to form reinforcing metal A (4).

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 the foundation work of the concrete building is carried out. That is.

Reinforcement (6&) of the foundation joint (6) is installed at the above ground protrusion (5a) of each base vertical pile (5), and these joints (6)...(6) are connected respectively. Do 21!
i Reinforcement of foundation cusp (7) (7a) and column (8) reinforcement (8a)
Here, the main It)i(9)...(9) are arranged on the lower surface of the foundation joint (6) as in the past.

Then, at each foundation joint (6), place the foundation pile (5
) on the protruding part (5a) of the reinforcing metal fitting (4) inside and outside 3Tf.
Insert the L annular bodies (2a), (2b), and (2c) so that they are on the bottom, and place these 1;
) are placed on the main reinforcements (9)...(9) of the base gi2 joint (6). Thereafter, the formwork is attached and concrete is poured, and after curing the concrete, the formwork is removed and the foundation part 11i of the concrete LM structure is completed as shown in Figure 4.

Thus, (when a force (P) in the direction of water 1 acts on the vertical pile (5) due to an earthquake as shown in the PS5 diagram).

The lower end of the foundation joint (6) receives a part of the shear force (F) from the foundation pile (5), but this part of the concentrated shear force (f)! ! Connection (1)...(1) horizontal part (1b)...(1)
The force in the horizontal direction is received by the three inner and outer annular bodies (2a) (2b) (2c) connected by b), and since these annular bodies (2a) (2b) (2c) are annular, Even if (F) acts repeatedly in any direction, front, back, left, or right within its horizontal plane, the annular body (2a) (2
b) (2C) does not deform, and the lower end of the base joint (6) maintains sufficient strength.

Also, the remaining shear force (F) is received by the A part of the foundation joint (6), but the remaining shear force (F) of 3A is received by the vertical part (l a) of the connection (1)...(1) ・=
Since (1a) extends to the basic joint (6) c>C part, it is transmitted to the C part by these vertical parts (1a)...(1a), and the spiral-shaped annular body (3)
Since it connects the basic joint (1111 of part A and part B of (i)), it is transmitted to part B by the body (3),
In this way, the remaining shear force (F) is basically distributed and received throughout the joint (6), and the horizontal force (P)
) acts repeatedly in the front, back, left and right directions, the basic joint (6)
provides sufficient strength as a whole.

In addition, the horizontal force (P) causes a bending moment (M) to act on the foundation pile (5), bending the vertical foundation pile 5), and the foundation pile at the pile-foundation joint (6) Even if a vertical tensile force (T) is generated on the circumferential surface of the biting hole (10) in (5), the tensile force (T) is absorbed by the connection (1)...(
It is received by the vertical part (1a)...(la) of 1),
The circumferential surface of the insertion hole (10) has no cracks and is tough.

One of the authors prepared a test specimen (D) of a conventional foundation joint with foundation piles joined and a test specimen (E) of the foundation joint of the present invention with foundation piles joined, and tested these test specimens CD) or (E). ) to the 6th
As shown in the figure, the test equipment includes a support (10) and a test bed (
11) Fixed via (l l), each Ti
An experiment was conducted in which a specified location of a vertical foundation pile was pressed laterally using a push-pull hydraulic jack (12), and the following results were obtained. (13) indicates a load cell. (D) and test specimen of the present invention (E)
There are six main reinforcements with a diameter of 16 mm, and
The reinforcing metal fittings (4) of the test specimen (E) of A Ming are connected (1)
The inner and outer annular bodies (
2a), (2b), and (2c) are ring stripes with a diameter of 16 m5, and the upper and lower annular bodies (3) are 13 mm in diameter and consist of six spiral strips. Furthermore, the location (F) where the foundation pile is suppressed by jacking (12) is! d at the intersection=2.5d position from the joint
is the diameter of the foundation pile.

As a result of the experiment, the maximum yield strength of the conventional test specimen (D) was approximately 20 tons, but that of the test specimen of the present invention (E) was approximately 30 tons.
74 that the yield strength became large. In addition, the displacement at the maximum proof stress, that is, the displacement (& amount () at point F of the foundation pile when it was able to maintain approximately the maximum proof stress) was approximately 20 mm in the conventional test specimen (D), but in the test specimen of the present invention. (E) is approximately 3
It can be seen that the toughness has improved significantly.

Nao i! Li connection (1)...Horizontal part of (1) (ib
)...(lb) connects the inside and outside j Also, the vertical part (1a)...(la) of the connection (1)...(1)
In the above embodiment, a spiral shape is shown as the upper and lower annular bodies connected by (1)...The vertical part (1a) of (1) connects a plurality of ring-shaped bodies.
...(1a) may be connected at appropriate intervals, and further, as shown in Figure 7, the vertical portions (1a)...(Ia) of (1)... The upper and lower annular bodies (3) are made to have a tapered slope, and the diameter becomes smaller as they go upward along this tapered slope.
The reinforcing metals A(4) may be stacked upon each other.

(7) Effects of the Invention As described above, according to the reinforcing metal fitting of the present invention, the upper and lower annular bodies can be connected at the vertical part by connecting a plurality of abbreviated shapes consisting of a vertical part and a horizontal part extending laterally from one end of the vertical part. Since the annular bodies are connected at the horizontal part, the reinforcing metal fitting of the present invention is buried in the foundation joint part with the inner and outer annular bodies facing downward and placed over the upper end of the foundation pile, thereby providing earthquake protection to the foundation pile. At the lower end of the foundation joint, which receives a portion of the shearing force caused by repeated horizontal left and right forces, the inner and outer parts connected by the horizontal part of the connection buried within the lower end are A portion of the shearing force is concentratedly received by the annular body that is difficult to deform, and furthermore, in the entire foundation joint, the vertical parts of the plurality of connections buried in the vertical direction within the joint part and the upper and lower parts connected by these vertical parts are j;
The rest of the shearing force is distributed and received by the entire joint, and the left and right forces in the horizontal direction cause a bending moment to act on the foundation pile, causing the joint to ! ! i
Even if a tensile force is applied to the periphery of the foundation pile vertical pile insertion hole, this tensile force is received by the vertical part of the connection, and thus 7!
The foundation joint has extremely high strength and toughness, is easy to construct, is inexpensive to use as a structural cylinder 11, and is easy to transport.

[Brief explanation of the drawing]

Fig. 1 is a front view of one embodiment of the reinforcing metal fitting of the present invention, Fig. 2 is a plan view thereof, Fig. 1'+3 is a bottom view thereof, Fig. 4 is a sectional view of the reinforcing metal fitting in use, and Fig. 5 is an explanatory diagram showing the state of force action in its usage state, FIG. 6 is a front view showing the experimental state, and FIG. 7 is a sectional view of another embodiment. ti4B(8)
is a cross-sectional view of the foundation joint where conventional foundation piles are joined, and Figure 9 is a cross-sectional view along the line IX-IXX.
(la)...Vertical part. (lb)...Horizontal part, (2a), (2b), (2c)...Inner and outer annular bodies. (3)... Upper and lower annular bodies, (4)... Reinforcement metal fittings Patent applicant: Japan Construction Planning, Sumitomo Metal Industries, Ltd. Thiem Giken Co., Ltd. Figure 6 D (E) Figure 7 el Figure 8 Figure 9 Procedural amendments stamped in 1982! -September/F-1 Case Display 1984 Patent Application! 1183996 No. 2 Name of the invention Reinforcing metal fittings for pile foundation joints 3 Relationship with the case of the person making the amendment Patent applicant address 2-38 vJ Hori, Higashi-ku, Osaka-shi, Osaka Name
8 Kensetsu Co., Ltd. 4 Agent 103 Address 16-8-5 Nihonbashi Kodenma-cho, Chuo-ku, Tokyo Column 6 Detailed explanation of the invention in the specification subject to amendment 6 Contents of amendment (1) Specification page 10, No. 3 The "displacement amount ()" in the row is corrected to "displacement amount (δ)". (2) Correct the "approximately 30 mmJ" in the 5th line of page 10 of the same book to "approximately 50 mmJ." Indication 1983 Patent Application No. 183996 2 Name of the invention Pile foundation joint J [drawing 1j strong metal fittings 3 Person making the amendment zb Relationship with the matter Patent applicant address 38 Yokom 2-chome, Higashi-ku, Osaka-shi, Osaka Prefecture Name
0 Kensetsu Co., Ltd. 4 Agent 103 Address 16-8-5-1 Nihonbashi Kodenma-cho, Chuo-ku, Tokyo
11i Positive object 1j Detailed explanation column of the invention in the subscript and brief explanation of the drawings in the same book 6 Contents of amendment (1) Akira Ai [Jm page 3 tfS line 17, page 5 line 6, same jlf 310 Line J￥ 12th line B, page 7, line 3, same page, line 16, 8] Mi, line 3, M
9M7310th line, ilO page 7th line, rfj1 page 1st
1st line 1, same page, page 15 to line 16, same page, line 18, page 11, line 8, page 11, line 7, page 11, line 20 to page 12, line 1 100, page 7, line 7 and page 13, line 2
(2) Correct the insertion of ``R Conjunction'' in line 6 to ``Connection Rod''.

Claims (1)

[Scope of Claims] Upper and lower annular bodies are connected at the vertical part, and inner and outer annular bodies are connected at the horizontal part by a plurality of approximately L-shaped connecting rods each consisting of a vertical part and a horizontal part extending laterally from one end of the vertical part. Reinforcing metal fittings for pile foundation joints.