JPH08284159A - Connection structure of pile head - Google Patents

Abstract

PURPOSE: To obtain a connection structure which requires only a small space and which can be easily constructed, by fixing a steel pipe provided with external protrusions to the head of a foundation pile and fitting a large diameter steel pipe provided with internal protrusions on the above pipe and placing concrete in the inside to unify them. CONSTITUTION: A steel pipe 2 provided with protrusions 4 at the external face is fixed to the head of a foundation pile made of a driving steel pipe pile, a soil cement composite steel pipe pile, a cast-in-place steel pipe concrete pile, etc. and a large diameter steel pipe 1 provided with protrusions 4 at the internal face is fitted. The protrusions 4 are formed as spirals or intermittent stripes to place concrete without voids and unify them more securely. Concrete 3 is placed in the inside of steel pipes 1, 2 to connect together and a footing or a column base is connected through the steel pipe 1. This structure dispenses with auxiliary metal fittings for connection of a foundation slab or a steel cage or the like. In this way, a connection structure which is easily constructed can be obtained.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a joint structure for joining a foundation member such as a building structure, for example, a footing or a column base and a pile foundation buried in the ground.

[0002]

2. Description of the Related Art As a joint structure between a foundation member constituting a building and a pile foundation, a pile head reinforced by a reinforcing bar or the like is inserted into a foundation slab in order to transmit a load acting on a column base to the pile. Various structures have been proposed. This joining structure has been implemented many times so far and is an established technology.

For example, the joint structure proposed in Japanese Utility Model Laid-Open No. 62-185747 (hereinafter referred to as Conventional Example A) is for joining a pile and a footing, and as shown in FIG. The cylindrical rebar cage 8 is inserted into the inside of the pile head, and part of the rebar cage 8 is projected from the pile head into the inside of the footing 9 to fill the concrete 3.

In addition, the joint structure proposed in Japanese Patent Laid-Open No. 3-51428 (hereinafter referred to as Conventional Example B) is a pillar having a protrusion embedded in the inside of a steel pipe, so that the pillar does not have to interpose a base slab. The leg load is directly transmitted to the pile. As shown in FIGS. 7 and 8, the steel pipe 1 with the inner surface projection is used as a pile steel pipe, and the concrete 3 is inserted after the column steel frame 10 is inserted into the steel pipe 1 with the inner surface projection. 1 column to fill
It is a pile-type foundation structure.

[0005]

In the pile foundation structure of the conventional example A, the pile and footing can be easily joined by using the reinforcing bar cage in the pile head, and the yield strength and toughness of the pile head can be increased. . Further, since the conventional slab structure type does not require a foundation slab, it is effective for construction in a narrow urban area.

[0006] However, the pile foundation structure using the joint metal like the conventional example A is to transfer the load to the pile through the foundation slab, but the foundation slab is constructed by the steel reinforcement work, the formwork work etc. Since it is a so-called labor-intensive construction method that requires construction, it is becoming more and more difficult to apply such a basic structure under the current serious labor shortage at construction sites. Moreover, since it requires a space for assembling and processing the reinforcing bars, it is not suitable for the limited construction conditions in urban areas.

In addition, since the one-column / one-pile structure of the conventional example B is a structure in which the columns are inserted inside the pile steel pipe, the columns are embedded more than necessary for the pile size determined from the ground conditions. The pile diameter may be forced to be selected, resulting in an uneconomical design. Further, it is difficult to improve the accuracy of installing the pillars, and the workability when installing the pillars is not good.

Therefore, an object of the present invention is to solve the above-mentioned drawbacks of the prior art, simplify the construction work on site as much as possible, and facilitate the construction even in a limited narrow construction space. Is to provide.

[0009]

In the pile head joint structure of the present invention, a steel pipe with an outer surface projection is arranged on the pile head, and the head of the steel tube with an outer surface projection is projected from the ground or the excavated surface,
The projecting portion is inserted from the lower portion of the steel pipe with an inner surface protrusion having a diameter larger than the outer diameter of the steel pipe with the outer surface protrusion, and the inside of the steel pipe with the inner surface protrusion is filled with concrete and joined.

It is preferable that the steel pipe with an outer surface projection protruding from the ground or the excavated surface is formed of any of a driven steel pipe pile, a soil cement synthetic steel pipe pile, and a cast-in-place concrete pipe pile.

[0011]

EXAMPLE FIG. 1 shows an example of a composite pile in which the pile head joint structure of the present invention is applied to a driven steel pipe pile. The steel pipe pile 2 with the outer surface projection is driven and buried in the ground with the head portion protruding from the excavation surface 5. Next, the steel pipe with an inner surface projection 1 having a diameter larger than the diameter of the protruding portion of the steel pipe pile with an outer surface projection 2 is fitted to the outside of the protruding portion of the steel pipe pile with an outer surface projection 2. Then, the concrete 3 is filled inside the steel pipe 1 with the inner surface projection.

In this way, when the pile head of the steel pipe pile 2 with the outer surface projection is projected from the excavation surface 5 and inserted and placed inside the steel pipe 1 with the inner surface protrusion, the concrete 3 is filled into the steel pipe 1 with the inner surface protrusion. In doing so, the concrete 3 and the pile head of the steel pipe pile 2 with an outer surface protrusion and the steel pipe 1 with an inner surface protrusion are firmly attached, and high adhesion strength is secured.

The penetration length of the protruding portion of the steel pipe with outer surface projection 2 into the steel pipe with inner surface projection 1 may be appropriately determined according to the size of the steel pipe 2 with outer surface projection and the strength of concrete to be used, and is not particularly limited. Absent.

Further, although the projections 4 provided on the steel pipe 2 with outer surface projections and the steel tube 1 with inner surface projections may have any shape, they may be formed in a spiral shape as shown in FIG. 4 or as shown in FIG. When the striped shape is formed, the filled concrete 3 and the steel pipe 2 with the outer surface protrusion and the steel pipe 1 with the inner surface protrusion are integrated more accurately.

In FIG. 1, the head of the steel pipe 2 with an outer surface projection is projected from the excavation surface 5 excavated to a certain depth from the ground 6. However, in some cases, the steel pipe 2 with an outer surface projection 2 is not excavated from the ground 6. It is also possible to project the head part and fit and join the steel pipe 1 with the inner surface projection so as to cover the projecting head part.

Further, the steel pipe 2 with the outer surface projection which is almost buried in the ground is not limited to the driving type steel pipe pile as shown in FIG. 1, but also the soil cement synthetic steel pipe pile as shown in FIG. It can also be formed from cast-in-place steel pipe concrete piles as shown.

[0017]

INDUSTRIAL APPLICABILITY As described above, in the pile head joint structure of the present invention, the head portion of the steel pipe with the outer surface projection is projected from the ground or the excavated surface, and the steel pipe with the inner surface projection having a diameter larger than that of the steel tube with the outer surface projection is used. Since the projection of the steel pipe with the outer surface projection is covered and the inside of the steel pipe with the inner surface projection is filled with concrete, the foundation slab is not required, and the worker conventionally required for the reinforcing bar work and the formwork work becomes unnecessary. Further, since the pile head of the steel pipe with the outer surface projection is inserted into the steel pipe with the inner surface projection on the upper portion, the reinforcing metal for joining such as the rebar cage can be eliminated.

Since the steel pipe with the inner surface projection fitted in the upper part is a factory product and does not require an assembly processing site on site, it is possible to save the construction space, which is particularly effective in the construction in urban areas. Further, unlike the one-pillar-one-pile type foundation structure, it does not cause an uneconomical increase in the required pile diameter, and it is also possible to eliminate the poor workability at the time of building and installing the column.

[Brief description of drawings]

FIG. 1 is a longitudinal sectional view showing an example in which the joining structure of the present invention is applied to a driven steel pipe pile.

FIG. 2 is a vertical sectional view showing an example in which the joint structure of the present invention is applied to a soil cement composite pile.

FIG. 3 is a longitudinal sectional view showing an example in which the joint structure of the present invention is applied to a cast-in-place steel pipe concrete pile.

FIG. 4 shows an example of a steel pipe with an inner surface protrusion used in the joint structure of the present invention, in which the inner surface protrusion is formed in a spiral shape.

FIG. 5 shows an example of a steel pipe with an inner surface protrusion used in the joint structure of the present invention, in which the inner surface protrusion is formed in a striped shape.

FIG. 6 is a vertical cross-sectional view showing a joint structure of a pile head and a footing joined by a conventional rebar cage.

FIG. 7 is a plan view showing a conventional one-column / one-pile foundation type joint structure.

8 is a vertical cross-sectional view of the joint structure of FIG.

[Explanation of symbols]

 1 Steel pipe with inner surface protrusion 2 Steel pipe with outer surface protrusion 3 Concrete 4 Inner or outer surface protrusion 5 Excavation surface 6 Ground 7 Steel pipe pile 8 Rebar cage 9 Footing 10 Steel column 11 Soil cement 12 Concrete

Claims (2)

[Claims] 1. A steel pipe with an outer surface protrusion is arranged on a pile head, the head of the steel pipe with an outer surface protrusion is projected from the ground or an excavated surface, and the protruding portion is an inner surface having a diameter larger than the outer diameter of the steel pipe with an outer surface protrusion. A joint structure for pile heads, characterized in that the steel pipe with protrusions is inserted from the lower part, and the inside of the steel pipes with protrusions is filled with concrete and joined. 2. The steel pipe with an outer surface protrusion for projecting the head from the ground or the excavated surface is formed of either a drive-in steel pipe pile, a soil cement synthetic steel pipe pile or a cast-in-place concrete pipe pile. The joint structure for a pile head according to claim 1.