JP3724933B2 - Joints of piles using SC piles and SC piles - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a pile joint using SC pile (steel-concrete composite pile) and a structure of SC pile.
[0002]
[Prior art]
Conventionally, the main ready-made piles that have been used are steel pipe piles, concrete piles, SC piles, etc., and there is also a great demand for joint piles with joints at predetermined intervals to increase the peripheral frictional force of concrete piles. .
[0003]
In addition, ready-made piles are used by adding on-site as needed, but not necessarily when adding ready-made piles of the same type. For example, as seen in Japanese Patent Publication No. 5-47685, A steel pipe pile added to the upper part is known.
[0004]
This was achieved by using steel pipe piles or SC piles with high bending strength in the upper ground where a relatively large horizontal strength is required, and by using joint piles with excellent peripheral surface bearing capacity in the lower ground. This is because a reasonable foundation pile structure is obtained.
[0005]
When adding such ready-made piles together, the most common method is a method in which end plates provided at the ends of the ready-made piles are butted together and joined by in-situ butt welding. FIG. 3 shows a joint portion when the SC pile 61 as the upper pile is joined to the upper portion of the concrete joint pile 11 as the lower pile by welding the end plates 14 and 64.
[0006]
[Problems to be solved by the invention]
However, the conventional bonding method has the following problems.
[0007]
(1) For butt welding, high-precision construction is required on site.
[0008]
(2) Welding is particularly necessary for small-diameter piles and takes time.
[0009]
(3) Increase in cost is inevitable due to a decrease in construction efficiency due to welding.
[0010]
The present invention is intended to solve the above-described problems in the prior art. When at least one of the piles to be joined is an SC pile, the workability at the site is excellent, and a special skill is not required. It is an object of the present invention to provide an economical pile joint and an SC pile used for the joint.
[0011]
[Means for Solving the Problems]
The pile joint using the SC pile according to claim 1 of the present application is that at least one of the two piles to be joined to each other is an SC pile, and the end of the steel pipe of the SC pile is used as it is from the end of the concrete. a fitting recess formed on the inner side of the projecting portion of the steel pipe by a predetermined length projecting, and is characterized in that formed by joining by fitting the end of the other pile.
[0012]
The basic structure of the SC pile having concrete inside the steel pipe is the same as that of the conventional SC pile, and can be manufactured by centrifugal molding or the like. Further, the fitting recess can be easily formed by, for example, stuffing during molding.
[0013]
The other pile to be joined is not particularly limited as long as the pile end can be fitted into the fitting recess of the SC pile, and may be a steel pipe pile or an SC pile in addition to a concrete pile including a node pile. However, when transmission of compressive stress in the axial direction is considered, a structure capable of transmission between concrete such as concrete piles or SC piles is desirable.
[0014]
Claim 2 is a case where one of the two piles joined together in claim 1 is an SC pile as an upper pile and the other is a node pile as a lower pile.
[0015]
In this case, as described above, in addition to being able to transmit the compressive stress in the axial direction between the concrete parts of the upper and lower piles, SC piles with high bending strength are used for the upper ground where a relatively large horizontal strength is required. By using joint piles with excellent peripheral surface support for the lower ground, a foundation pile structure that takes advantage of both advantages can be obtained.
[0016]
A third aspect is the case where the adhesive is applied to the inner surface of the fitting recess in the first or second aspect. As an adhesive, synthetic resin or mortar can be used to increase the joint strength and fill the gap between the inner surface of the steel pipe of the SC pile forming the fitting recess and the outer peripheral surface of the other pile to be joined. Can do.
[0017]
SC piles according to claim 4 of the present application is intended to be used at the junction of the pile, the SC piles consisting of concrete integral with the inner surface of the steel pipe and the steel pipe, the end portion of the steel pipe it by a predetermined length protrudes from the edge of the concrete, characterized in that the formation of the fitting recess for joining other pile on the inside of the projecting portion of the steel pipe.
[0018]
Embodiment
FIG. 1 (a) shows a cross-section of a joint when an SC pile 1 as an upper pile is added to an upper portion of a joint pile 11 as a lower pile as a representative form of the present invention. (b) shows the cross section of SC pile only.
[0019]
SC pile 1 consists of steel pipe 2 and concrete 3 inside thereof, and is manufactured by centrifugal molding or the like. The three concrete parts are usually hollow. In the SC pile 1 according to the present invention, as shown in FIG. 1 (b), the end portion of the steel pipe 2 protrudes from the end portion of the concrete 3, and the fitting recess 4 is formed inside the steel pipe protruding portion 2a. Is formed.
[0020]
Therefore, when adding to the upper part of the joint pile 11, it can join so that the fitting recessed part 4 may come to a lower end, and it covers the trunk | drum 12 of the upper end of the joint pile 11. FIG. This joining position is, for example, a position where the joined pile as a whole is not subject to so much bending in the ground, and mainly when axial compressive stress should be transmitted, or in the embedded pile etc. When you receive it, you just need to cover it. Further, if necessary, by applying mortar or synthetic resin adhesive 5 or the like to the inner surface of the fitting recess 4 of the SC pile 1 or the upper end portion of the joint pile 11, the integrity can be improved.
[0021]
In the example shown in the figure, the upper end of the joint pile 11 and the lower end of the concrete 3 portion of the SC pile 1 are in direct contact with each other at the joint, so that a compressive stress can be directly transmitted between the concrete. However, about the upper end of the joint pile 11, an end plate may be provided and stress may be transmitted through the end plate.
[0022]
Further, regarding the protruding length of the protruding portion 2 a of the steel pipe 2, when considering the stability of the joint, it is preferable that the protruding length is as long as possible, but at least a slight gap between the protruding portion 11 and the uppermost node portion 13. It is desirable to drill. That is, since there is a gap between the lower end of the projecting portion 2a and the node portion 13, stress concentration from the steel pipe 2 portion of the SC pile 1 to the node portion 13 is avoided, and smooth between concrete as described above. This is because stress can be transmitted.
[0023]
2 (a) to 2 (d) show various combinations of pile joints other than the above in the present invention.
[0024]
FIG. 2A shows the case where the lower pile is the SC pile 1 and the upper pile is the reinforced concrete pile 21, and the lower end of the reinforced concrete pile 21 is inserted into the fitting recess 4 located at the upper end of the SC pile 1. In this case, the SC pile having a high strength is provided on the lower pile, but the upside down may be reversed. The same applies to the following examples. An end plate may be provided on the end surface of the reinforced concrete 21.
[0025]
FIG. 2 (b) shows the case where the lower pile is the SC pile 1 and the upper pile is the steel pipe pile 31. In this example, an end plate 32 and a reinforcing rib 33 are provided at the lower end of the steel pipe 31 so that the compressive stress is smoothly transmitted between the SC pile 1 and the steel pipe pile 31.
[0026]
FIG. 2 (c) shows a case where the upper pile is the SC pile 1 in which the end portion of the steel pipe 2 according to the present invention is projected, and the lower pile is the SC pile 41 in which the concrete 43 is projected for a predetermined length. The protrusion 43a of the concrete 43 of the lower pile is fitted into the fitting recess 4 of the upper pile and joined. In this case, by providing a slight gap between the lower end of the upper pile steel pipe 2 (lower end of the projecting portion 2a) and the upper end of the lower pile steel pipe 42, the compressive stress is directly transmitted in the concrete portions 3 and 43. be able to.
[0027]
FIG. 2 (d) shows a case where the lower pile is the SC pile 1 in which the end of the steel pipe 2 according to the present invention is projected, and the upper pile is the SC pile 51 having a small diameter corresponding to the thickness of the steel pipe 2. This can be considered that the reinforced concrete pile 21 in FIG.
[0028]
In each of the above examples, the integrity can be enhanced by applying an adhesive into the fitting recess 4.
[0029]
In addition, the above shows some examples of combinations, and various combinations are possible as long as they can be fitted into the fitting recesses 4 of the SC pile 1.
[0030]
【The invention's effect】
(1) In the present invention, the SC piles or SC piles and other piles can be joined simply by using the fitting recesses formed in the SC piles or not by welding. Depending on the situation, it can be done easily and quickly by using an adhesive or the like, and the field work is greatly simplified.
[0031]
(2) No special skill is required for joining and the joining can be done in a short time, so the construction cost can be greatly reduced.
[0032]
(3) The overall construction cost can be reduced by joining different types of piles such as high-strength SC piles and relatively low-cost concrete piles according to the conditions at the site.
[0033]
(4) The structure of the SC pile is a simple structure in which the steel pipe portion protrudes by a predetermined length from the conventional SC pile, and is easy to manufacture.
[Brief description of the drawings]
FIG. 1 (a) is a vertical sectional view of a joint showing an embodiment of the present invention, and FIG. 1 (b) is a vertical sectional view of only an SC pile.
FIGS. 2A to 2D are vertical sectional views showing various examples of combinations of piles to be joined with respect to the joint portion of the present invention.
FIG. 3 is a vertical sectional view showing a joint portion between a joint pile and SC pile by conventional field butt welding.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 ... SC pile, 2 ... Steel pipe, 2a ... Steel pipe protrusion part, 3 ... Concrete, 4 ... Fitting recessed part, 5 ... Adhesive agent, 11 ... Node pile, 12 ... Body part, 13 ... Node part, 14 ... End plate, DESCRIPTION OF SYMBOLS 21 ... Reinforced concrete pile, 31 ... Steel pipe pile, 32 ... End plate, 33 ... Rib, 41 ... SC pile, 42 ... Steel pipe, 43 ... Concrete, 43a ... Concrete protrusion, 51 ... SC pile, 61 ... SC pile, 62 ... Steel pipe, 63 ... concrete, 64 ... end plate, 65 ... welded part

Claims (4)

At least one of the two piles to be joined to each other is an SC pile composed of a steel pipe and concrete integrated on the inner surface side of the steel pipe, and the end of the steel pipe of the SC pile is directly longer than the end of the concrete by a predetermined length. the in the fitting recess formed on the inner side of the projecting portion of the steel pipe, the joining method of pile with SC piles, characterized in that formed by joining by fitting the end of the other pile by protruding. The joint part of the pile using SC pile of Claim 1 whose one of the two piles mutually joined is SC pile as an upper pile, and the other is a node pile as a lower pile. The joint part of the pile using the SC pile of Claim 1 or 2 which apply | coated the adhesive agent to the inner surface of the said fitting recessed part. In SC piles consisting of integrated concrete on the inner surface side of the steel pipe and the steel pipe, by a predetermined length protrudes from the end portion of the intact concrete ends of a steel pipe, the other pile on the inside of the projecting portion of the steel pipe SC pile characterized by forming a fitting recess for joining.

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