JPH0461134B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to the structure of a joint between a pile head and a concrete member such as a footing foundation.

[Conventional technology]

In the conventional pile head reinforcement structure, as shown in (a) Figs. 9 and 10, main reinforcements 11 are arranged around the head of the steel pipe pile 1 in the orthogonal X direction, Y direction, and diagonal direction. (b) Figure 11 and Figure 1.
As shown in Figure 2, there is one in which a reinforcing bar cage 3 is placed over the head of a steel pipe pile 1, welded on site, and main reinforcement is arranged in the same way as in (a) to transmit shear force, moment, etc.

Figures 13 to 15 show the construction procedure of (b) above, and the work is carried out in the following steps.

Driving steel pipe pile 1 into the ground 2.

Removal of soil within the pipe (10 in the figure indicates the earth removal section).

On-site welding of reinforcing bar cage 3 (numeral 4 in the figure indicates the on-site welding part).

Reinforcement in the footing (main reinforcement 11).

Placing concrete 5 for the footing.

[Problem that the invention seeks to solve]

However, the above-mentioned conventional technology has the following problems.

(1) Conventional joints between concrete members such as footings and steel pipe piles are nearly untreated, and the bending moment and shear force are resisted by the bearing pressure and shear of the concrete, resulting in poor load-bearing capacity.

(2) During an earthquake, a pulling force acts on the steel pipe pile, but in the structure (a) above, the pullout force is not transmitted to the steel pipe pile, and in the structure (b), the load is transferred between the reinforcing bar cage and the steel pipe pile. Since it is transmitted at the site welding part, there are problems with the strength and quality of that part.

(3) The main reinforcing bars in the footing are arranged in such a way as to avoid the steel pipe piles, and are arranged in the orthogonal X direction, Y direction, and diagonal direction, and there is also a connection with the steel pipe piles, making the construction complicated due to the overcrowded reinforcement. Become.

This invention was created in view of the above-mentioned problems of this invention, and aims to improve the strength, reliability, and workability of the joint between the pile head and concrete members, and to reduce the thickness of concrete members such as footings. There is.

[Means for solving problems]

In the joint between the pile head and the concrete member of this invention, a plurality of horizontal through holes are provided in the head of the steel pipe pile that is housed within the concrete member, and reinforcing bars are inserted into the through holes to penetrate the inside of the steel pipe pile. .

〔Example〕

Fig. 1 shows the basic structure of the present invention, in which a horizontal through hole 8 through which a reinforcing bar passes is provided in the pile head of a steel pipe pile 1, and a bending reinforcing bar 6 for transmitting bending moment is passed through the hole 8. Reinforcement is passed through the hole 8 and placed above and below the concrete 5 of the footing. Similarly, shear reinforcing bars 7 are passed through the through holes 8 so as to be sandwiched between these bending reinforcing bars 6, and placed in the center of the footing in the thickness direction of the concrete 5. In addition, since the through-hole 8 for reinforcing bars is inserted into the steel pipe pile 1, there is a risk that the strength of the steel pipe itself will decrease.
In this case, if necessary, this can be compensated for by inserting a reinforcing bar cage 9 into the steel pipe pile 1.
Further, as shown in FIGS. 4 and 5, the main reinforcing bars 11 of the footing and the bending reinforcing bars 6 of the pile head can be connected by a conventional method such as overlapping.
As a result, the bending moment and shear force of the pile head are smoothly transmitted to the footing via the inserted reinforcement bars (bending reinforcement 6, shear reinforcement 7), and the main reinforcement 11 can also be arranged in two directions, X and Y. Workability and reliability are improved.

The embodiment shown in FIGS. 2 and 3 is a case where the bending moment applied to the pile cap is relatively small, and only the shear reinforcing bars 7 are inserted into the through holes. The protruding length of the pile head from the ground 2 is short, and the reinforcing bars in the axial direction of the reinforcing bar cage 9 inserted into the steel pipe pile 1 are bent so as to spread upward.

The embodiment shown in FIGS. 4 and 5 corresponds to the embodiment shown in FIG. It intersects with 7.

6 to 8 show the construction procedure, and when compared with the conventional example described above, the procedure is as follows.

Driving steel pipe pile 1 into the ground 2.

Removal of soil within the pipe (earth removal section 10).

Drilling of the head of one steel pipe pile (through hole 8).

Insertion of reinforcing bar cage 9.

Inserting the bending reinforcement 6 and the shear reinforcement 7 into the through hole 8.

Reinforcement in the footing (main reinforcement 11).

Placing concrete 5 for the footing.

〔Effect of the invention〕

(1) At the joint between the pile head and the concrete member of this invention, multiple reinforcing bars are passed through the head of the steel pipe pile in the horizontal direction, and the bending and shearing of the pile is directly performed by these reinforcing bars, such as footings and other concrete members. It is strong and reliable, and can reduce the thickness of concrete footings in some cases.

(2) There is sufficient resistance to pull-out force due to the dowel effect of the reinforcing bars that penetrate the head of the steel pipe pile, and there are no quality problems with on-site welds in conventional structures.

(3) The reinforcing bars at the head of the steel pipe pile and the main reinforcing bars in the concrete members can be connected using conventional joining methods such as overlapping, and the main reinforcing bars can only be placed in two directions, the X and Y directions, improving workability. Reliability is also improved compared to overcrowded reinforcement with complicated connections.

[Brief explanation of drawings]

FIG. 1 is a perspective view showing the basic structure of this invention, FIGS. 2 and 4 are plan views showing reinforcement arrangement in an embodiment of this invention, and FIGS. 3 and 5 are respectively FIGS. FIG. 4 is a longitudinal sectional view of the embodiment, FIGS. 6 to 8 are longitudinal sectional views showing an example of the construction procedure, FIGS. 9 and 11 are plan views showing reinforcement arrangement in the conventional example, and FIG. 10 and 12 are longitudinal sectional views of the conventional examples shown in FIGS. 9 and 11, respectively, and FIGS. 13 to 15 are longitudinal sectional views showing the construction procedure in the conventional examples. 1... Steel pipe pile, 2... Ground, 3... Rebar cage, 4
... Field welded part, 5 ... Concrete, 6 ... Bending reinforcement, 7 ... Shear reinforcement, 8 ... Through hole,
9... Rebar cage, 10... Earth removal section, 11... Main reinforcing bar.

Claims (1)

[Claims] 1. A pile head and concrete member characterized in that a plurality of horizontal through-holes are provided in the head of a steel pipe pile that is housed within the concrete member, and reinforcing bars are inserted into the through-holes to penetrate the inside of the steel pipe pile. Joining part.