JPH0765319B2 - Column pile connection part of 1 column 1 pile foundation structure and its construction method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial field of application] The present invention relates to a one-column, one-pile foundation structure (without an underground beam connecting pile heads,
This is related to the joint structure between columns and piles in the structure in which the columns directly rise from the piles) and its construction method, and is used for buildings above the middle and high-rise tracks (see Fig. 4) that span the sky above existing railroad tracks.

In addition to this, it is also possible to use it for buildings with a one-pile foundation structure that spans rivers and roads.

[Conventional technology]

The prior art will be described below by classifying it into three types (1) to (3).

(1) Conventional technology of column-pile joints in low-rise railway buildings with one-column / one-pile foundation structure As shown in Figure 34, the number of floors of the above-rail building with one-column / one-pile foundation structure is 4 or less and high. In the case where the ground surface is 20 m or less from the ground surface 24 (a building over the low-rise railroad), the column pile joint has the column steel frame 22 in the reinforced concrete pile 21 as shown in FIGS. 35 (a) and 35 (b). It becomes a structure to be embedded. In the figure
Reference numeral 23 indicates an existing orbit.

A design method for this type of column pile connection has already been established through experiments and there are many examples.

(2) Conventional technique of embedding a steel frame part in a steel pipe member filled with concrete and joining the two members in the material axis direction The following is an example of this type of joining method.

36 (a) and (b) are examples of a fence such as a wire mesh fence or a foundation for a pillar when a pillar 32 such as a clothesline is erected in the ground, and is a relatively small pillar. The material is inserted into the hollow tube 31 buried in the ground, concrete 33 is placed inside the hollow tube 31 and the two are integrated (see Jitsuko Sho 48-11458). .

FIGS. 37 (a) and 37 (b) relate to the method of enforcing the underwater foundation of bridges and other structures, and show an example of the connection between the foundation slab 41 and foundation pile 42. In this example, the inner surface of the vertical hole 43 and the foundation pile
A structure is shown in which a dowel 44 made of a steel rod is fixed to the outer surface of the head of 42 and concrete 45 is filled between the two to construct a joint (see Japanese Patent Publication No. 53-10368).

Figures 38 (a) and (b) relate to the method of connecting the pillars 52 of a new transportation system structure such as viaducts and monorails to the foundation. In order to integrate the pillars 52 and foundation piles, the pillars 52 Projections 53 such as stud dowels are planted on the outer surface of the steel pipe and the inner surface of the pile steel pipe 51 (see Japanese Patent Application Laid-Open No. 55-114717). In addition, the concrete 54 in the pile steel pipe 51 is first driven to the lower surface of the pillar 52 in the figure (position H from the top end of the foundation pile downward), and after hardening, the pillar 52 is fixed at a predetermined position and joined. Inter-part concrete 54a is post-cast.

(3) Prior art relating to a composite pile of steel pipe concrete using a steel pipe having protrusions on the inner surface Figs. 39 (a) to (c) show a steel plate having protrusions continuously formed in the rolling direction by rolling. This shows a steel plate 61 used for a steel pipe for composite pile of steel pipe concrete formed by pipes, and the shape of the protrusion 62 is provided with the following numerical limits for the dimensions shown in the figure (Japanese Patent Laid-Open No. 60-37484). (See Japanese Patent Publication).

2.0 mm ≤ h ≤ 4.0 mm θ ≥ 30 ° 0.04 ≤ h / S _R ≤ 0.15 2.0 mm ≤ W _t ≤ 10.0 mm where h is the height of the protrusion θ is the rising angle of the protrusion S _R is the distance between the protrusions W _t is Width of the top part of the projection In addition, FIGS. 40 (a) to (e) show cast-in-place concrete pipes in which the head or the entire length of the cast-in-place concrete pile is reinforced using a steel pipe 72 having a protrusion formed by rolling on the inner surface. An example of the concrete pile 72 is shown (see Japanese Patent Laid-Open Nos. 60-47117 and 60-51222).

[Problems to be Solved by the Invention]

In the case of a building with a maximum height of about 10 floors with a 1 pillar 1 pile foundation structure, piles with a large bending moment will be filled with concrete with a compact cross-section and a large bending strength in consideration of construction between narrow tracks. Designed with steel pipe piles. For example, in the example of the trial design of an 8-story building on the track,
The outer diameter (φ) and wall thickness (t) of the pile steel pipe are 2000φ × 20t
~ 2400φ x 22t (unit: mm), and at the column-pile joint, the pile steel pipe, the filled concrete, and the individual components of the column steel frame are integrated. A steel pipe with protrusions is used.

However, as mentioned above, there are no previous research results on the method of joining concrete-filled steel pipe members using steel pipes with internal projections with a large diameter-to-thickness ratio of 100 or more, and (column) steel frame members. The technology to ensure the seismic safety of is not yet established.

In addition, in the one-column, one-pile foundation structure, since the filling concrete in the pile steel pipe is laid at a stretch over several tens of meters, the vicinity of the top end of the pile steel pipe is formed of malicious concrete mixed with slime or the like. Therefore, after removing the malicious concrete, the column steel frame is inserted into the pile steel pipe, and after the fixation, the space between the column steel pipe and the column steel frame between the column pile joints is refilled with concrete.

However, so far, there is no workable method of removing the bad concrete near the top of the pillar steel pipe.

The present invention is intended to solve the above-mentioned problems, and provides a pillar-pile joint portion having excellent structural performance and workability for a building over a medium-high-rise line with a one-pillar one-pile foundation structure. Is.

[Means for Solving the Problems]

Hereinafter, the outline of the present invention will be described using the reference numerals of the drawings corresponding to the embodiments.

The pillar-pile joint part which is the object of the present invention uses a steel pipe with an inner surface protrusion provided with an inner surface protrusion 2 as a pile steel pipe 1 of a concrete-filled steel pipe pile, and a pillar steel frame 4 is embedded in the concrete 3 in the pile steel pipe 1. It is a complicated format.

Then, within the section of Y ≦ 0.5 × L (L is the embedded length of the column steel frame 4) from the top end of the pile steel pipe 1, the pile steel pipe 1 is continuous in the circumferential direction of the cross section of the pile steel pipe 1, It is characterized in that a reinforcing member made of steel is provided to suppress the tensile strain in the circumferential direction generated inside.

As the reinforcing material, for example, a band type reinforcing material 6 as shown in FIGS. 1 (a) and (b) or a ring type reinforcing material 7 as shown in FIGS. 2 (a) and 2 (b) are used. Further, as shown in FIGS. 3 (a) and 3 (b), these may be used together.
The ring-shaped reinforcing material 7 is provided in the range of Y ≦ 0.5 × L, and is not necessarily the top end of the pile steel pipe 1.

On the other hand, regarding the above-mentioned pillar-pile connection part, the construction method for removing poor quality concrete near the top of the pile steel pipe 1 is that the filling concrete 3 in the pile steel pipe 1 is restrained from being deformed in the circumferential direction by the pile steel pipe 1. , And inner projection 2 of pile steel pipe 1
As a result, the deformation in the axial direction of the material is constrained, so the removal work after hardening the concrete is extremely difficult.

Therefore, in the construction method of the present invention, the filling concrete 3 in the pile steel pipe 1 is placed after the material having high deformability such as styrofoam is pasted as the spacer 8 on the inner surface of the pile steel pipe 1 between the column pile joints in advance. , It was decided to carry out the removal work after the curing.

The range in which the spacer 8 is provided is a section corresponding to the embedded length L of the pillar steel frame 4 or more, and the filled concrete 3
After hardening, the concrete 3 and the spacers 8 in the section are removed, the column steel frame 4 is inserted into the pile steel pipe 1, and then the concrete 3a is filled in the gap between the contact portion between the pile steel pipe 1 and the column steel frame 4.

Regarding the attachment of the reinforcing material provided in the section of Y ≦ 0.5 × L, the reinforcing material may be attached to the pile steel pipe in advance or may be attached later.

[Work]

The column pile joint of the skyscraper in the middle-high-rise railway with the one-column one-pile foundation structure is of the type in which a steel frame column is embedded in a concrete-filled steel pipe pile. According to the trial design, the dimensions of the column pile joint are In addition, the following conditions are added due to the construction restrictions described in the section "Problems to be solved by the invention".

The outer diameter of the pile steel pipe is about 2000-2400mm, and the diameter-thickness ratio is
Around 100 Pile steel pipe diameter / column steel frame diameter ratio is about 2.5 to 3.0 The depth of the column steel frame embedded in the pile steel pipe is preferably as shallow as possible in the range where seismic safety of the joint is secured. Regarding the mechanical performance, it is unknown because there are almost no previous research results except that the rigidity and proof stress are improved by providing protrusions such as stud dowels on the inner surface of the pile steel pipe described in the section "Prior art". Is.

Therefore, this time, we conducted a scale model experiment of about 1/4 of the joints shown in (1) to (3) and found the following facts regarding the mechanical performance.

The tensile stress in the pile steel pipe cross section at the joint is dominated by tensile in the circumferential direction.

At the same time that the cross section of the pile steel pipe at the top position yields due to circumferential tension, it also presents an unstable phenomenon in the load-deformation relationship of the joint (an unstable phenomenon in the load-deformation relationship means that deformation occurs under the same load during repeated loading. Gradually progress, defined as a phenomenon that does not converge to a certain value).

The maximum yield strength of the joint is determined by the filled concrete coming out of the pile steel pipe.

The band-type reinforcement and the ring-type reinforcement at the top of the pile steel pipe suppress the circumferential tensile strain that occurs in the pile steel pipe cross section between the joints, delay the occurrence of instability phenomena in the load-deformation relationship, and increase the maximum of the joint. Effective in improving yield strength.

Therefore, the maximum yield strength of the joint is analyzed to quantitatively clarify the mechanical effects of the band-type reinforcement 6 and the ring-type reinforcement 7 on the top of the pile steel pipe 1, and as a result, from the top of the pile steel pipe 1. It was found that the reinforcing material should be provided in the section of Y ≦ 0.5 × L.

In the present invention, a steel pipe having a projection formed by rolling on the inner surface (steel pipe with an inner surface protrusion) is used as a pile steel pipe of a column pile joint, but a conventionally known steel pipe with an inner surface protrusion can be used. .

Hereinafter, the experiment and analysis regarding the column pile connection part of the present invention will be described in detail.

First, for the purpose of clarifying the structural performance of the column pile joint portion of the present invention and grasping the effect of the band type reinforcing material and the ring type reinforcing material at the top of the pile steel pipe, Table-1 and Figs. 11 (a) to (e). )
Using the specimens ELP-1 to 5 shown in Fig. 12, a static cyclic loading test was carried out by the simple beam type loading method shown in Fig. 12. In addition, in Table-1, 200b of the pillar steel frame is 200x200m
It means m square steel tube column. Further, in FIG. 12, 11 is a test bed, 12 is a 500tonf hydraulic ram, 13 is a 500tonf load cell, 14 is a 100tonf load cell for measuring stigma shearing force Q, 1
5 is a PC steel rod.

The mechanical properties of the steel materials and concrete used are shown in Table-2 and Table-3, respectively.

Next, the findings obtained by this experiment will be described.

(A) The maximum proof stress of the specimen is irrespective of the experimental variables (root winding length and top reinforcement of pile steel pipe), as shown in FIG. It was decided by the matter.

In addition, the pile steel pipe 1 at the joint was removed by gas cutting, and the fracture properties of the filled concrete 3 were investigated. As a result, as shown in Fig. 14, the specimen without the ring-type reinforcement 7 at the top of the steel pipe was a column steel base plate. The occurrence of cracks rising at an angle of about 45 ° from 5 was observed, and the filling concrete 3 inside the cracks had come out of the pile steel pipe 1, while
As shown in FIG. 15, in the test piece having the ring-shaped reinforcement 7, cracks from the column steel frame base plate 5 to the inner circumference of the ring-shaped reinforcement 7 were observed, and the filling concrete 3 inside the crack was more than the pile steel pipe 1. It was recognized that each of them had escaped.

Thus, it can be seen that the ring-shaped reinforcement 7 on the top of the pile steel pipe 1 restrains the filled concrete 3 from coming out of the pile steel pipe 1 and is effective in increasing the yield strength of the joint.

(B) Typical examples of the shear force Q of the stigma-deformation δ in the force direction are shown in FIGS. 16 and 17.

19 to 23 show the circumferential strain distribution (the position where the strain gauge 16 is attached is shown in FIG. 18) in the cross section of the end portion of the welded joint of the pile steel pipe 1 for each specimen.

From these, in the shear force Q of the stigma-deformation δ in the applied direction, the level of the shear force Q which exhibits an unstable phenomenon in which the deformation gradually progresses under the same load during repeated loading and does not converge to a constant value, and the pile steel pipe end portion It can be seen that is substantially in agreement with the level of the shearing force Q that yields in the circumferential direction.

In addition, from Fig. 19 to Fig. 23, by providing a ring-type reinforcement or band-type reinforcement on the top of the pile steel pipe, the circumferential strain at the end of the pile steel pipe is reduced, and the stable limit proof stress (unstable It can be seen that it is effective in increasing the maximum yield strength without the phenomenon.

From the above, the fracture mode of the column pile connection and the effect of the ring type reinforcement and band type reinforcement at the top of the pile steel pipe were clarified experimentally. Therefore, next, the analysis results of the joints, which were performed to quantitatively understand the effects of these reinforcing materials, will be described.

The fracture model of the joint at the maximum proof stress is considered as shown in FIGS. 24 (a) to (f) with reference to the test results.

That is, (1) Only rigid body deformation with the point O (x, y) as the center of rotation is allowed for the column steel frame 4 (see FIG. 24 (d)).

(2) The filling concrete 3 in the pile steel pipe 1 has cracks a and cracks b in the 45 ° direction that occur in the low load region (24th
According to FIGS. (A) to (c)), it is divided into four parts (front side, rear side and side surface), and each behaves independently at the maximum proof stress.

Below, the failure modes of the concrete 3 and the steel pipe 1 which enable the rigid deformation of the column steel frame 4 will be described.

(3) The front concrete 3f undergoes shear failure or bearing failure in the Y-axis direction (0 to y) (see Fig. 24 (d)).

In the case of shear failure, the top reinforcing member and the pile steel pipe 1 on the outer circumference of the front side concrete 3f are tensile-yield in the circumferential direction in the section (o to y) and are flexurally yielded on the intersection line with the horizontal plane crossing Y = y ( See FIG. 24 (d)).

(4) On the back side concrete 3r, the adhesion with the pile steel pipe 1 is broken due to the influence of the pulling force generated in the base plate 5, and it comes out in the Y-axis negative direction, and on the horizontal plane crossing Y = y,
Bending failure occurs (see FIG. 24 (d)).

(5) The concrete 3s on the side surface side is destroyed due to the pulling force generated in the base plate 5 to be attached to the pile steel pipe 1 and comes out in the negative direction of the Y axis (see FIG. 24 (e)).

(6) The concrete under the base plate 5 is
Bearing failure occurs in the section of x) (see Fig. 24 (d)).

(7) When the ring-shaped reinforcement 7 is provided on the top of the steel pipe 1,
A shear failure surface of concrete occurs from the ring inner diameter in the y-axis direction.

In this case, the shear strength of the concrete is equal to the concrete adhesion strength of the pile steel pipe 1 as described later.

FIGS. 31 (a) and 31 (b) are explanatory views of symbols used in the analysis. In the following analysis, _p σ _y : Yield point of steel pipe _b σ _y : Yield point of band-type reinforcement _r σ _y : Yield point of ring-shaped reinforcement F _c : Compressive strength of concrete _c f _n : Bearing capacity of concrete _c f _s : Shear strength of concrete _c f _b : Bond strength of concrete to steel pipe with inner surface projection R: Steel pipe diameter R _o : Inner diameter of ring-type reinforcement t _p : Steel tube sheet thickness W _r : Ring-type reinforcement material width t _r : Ring-type reinforcement material thickness W _b : Band-type reinforcement material width t _b : Band-type reinforcement sheet Thickness L: The embedded length of the column steel frame.

Forces in the X direction ₁ F _x and bending moment ₁ M around point O caused by the fracture mode of the steel pipe shown in Figs. 25 (a) and (b)
Are respectively given by the following equations.

The X-direction force ₂ F _x and the bending moment ₂ M around the point O caused by the failure mode (shear failure) of the front side concrete shown in FIGS. 26 (a) and 26 (b) are respectively given by the following equations.

Forces in the X direction ₃ F _x and O caused by the failure mode (bearing failure) of front side concrete shown in Figures 27 (a) and (b)
The bending moment ₃ M around the point is given by the following equations.

here, The X-direction force ₄ F _x and the bending moment ₄ M around the point O, which are caused by the concrete bearing failure of the bottom surface of the base plate shown in FIGS. 28 (a) and 28 (b), are given by the following equations.

The Y-direction force ₅ F _y and the bending moment ₅ M around the O point, which are caused by the concrete adhesion failure of the back side concrete shown in FIGS. 29 (a) to (c), are given by the following equations.

The Y-direction force ₆ F _y and the bending moment ₆ M around the point O, which are caused by the concrete adhesion failure of the side concrete shown in FIGS. 30 (a) and 30 (b), are given by the following equations.

From the above FIGS. 25 to 30, the following balance equation can be obtained.

Case 1 When the concrete on the front side undergoes shear failure and W _b <y Case 2 When the concrete on the front side is shear fractured and W _b > y The shearing force _c Q _{max of the} joint represented by and can be obtained by solving the above-mentioned equilibrium equations of ~.

Case 1 here, Case 2 here, And in the formula, _c f _n = 10 F _c (F _c = compressive strength of concrete shown in Table 3), _c f _s = 0.1 F _c , _c f _b = 80 kg / cm
The maximum strength of ² Distant specimen was calculated. The results are shown in Table 4 in comparison with the experimental results. From this, it can be seen that this analysis method is almost valid.

From the above results, the reinforcing material at the top of the pile steel pipe is the region where the steel pipe yields in the circumferential direction, that is, the top of the pile steel pipe and R _o in the formula,
It can be seen that the mechanical effect can be exhibited by providing W _r , _tr , W _b , and t _b between y _n obtained as zero.

In the dimensions of the column pile joint obtained from the trial design example described above, when using general steel and concrete,
Y _n which is calculated by the formula 0.38 before and after the time of the pillars of the embedded length is 1.5H _s (H _s) = blame sectional pillars steel), and 0.52 before and after the time of 2.0H _s.

Therefore, the area where the reinforcing steel is installed is 0.5 from the top of the pile steel pipe.
A reinforcement effect can be obtained by setting a section of L (L = embedded length of column steel frame), and reinforcement outside this range has a small effect.

Further, regarding the method of constructing a pillar-pile joint portion of the present invention, in the filled concrete 3 in the steel pipe 1 with the inner surface protrusion, the circumferential deformation is restrained by the circumferential stress of the pile steel pipe 1 as shown in FIG. 32,
And since the deformation in the axial direction is restrained by the inner surface projection 2,
It is extremely difficult to remove them by the usual method. Therefore, as shown in FIG. 33, a soft material such as Styrofoam but capable of maintaining moldability is provided in the section _Lo to be removed.
Preliminarily attached as a spacer 8 to the entire inner surface of the pile steel pipe 1,
After that, the filled concrete 3 is poured. Concrete 3
After hardening, there is no deformation restraint of the concrete 3 by the pile steel pipe 1 in the _Lo section, so the removal work becomes easier.

〔Example〕

FIG. 1 to FIG. 3 show an embodiment in which the pillar pile connection portion of the present invention is applied to a middle-high rise railway upper structure 9 extending over the existing sky of an existing railway track as shown in FIG. It is a thing.

FIGS. 1 (a) and 1 (b) show an embodiment in which the above-mentioned band-type reinforcing material 6 is used as a reinforcing material. That is, Y ≦ 0.5 × L (L
A band type reinforcing member 6 having a predetermined width is attached by welding or the like within the range of the embedded length of the pillar steel frame 4. The pile steel pipe 1 made of a steel pipe with an inner surface projection has not been known so far, but as described above, a large diameter steel pipe having a diameter of 2000 to 2400 mm is used.

FIGS. 2 (a) and 2 (b) show an embodiment in the case where the above-mentioned ring type reinforcing material 7 is used as a reinforcing material. In this embodiment, the ring-shaped reinforcing member 7 is provided at the top end position of the pile steel pipe 1, but it may be provided on the way from the top end in the range of Y ≦ 0.5 × L. Further, as described above, in the case of the ring-type reinforcing material 7, there is also an effect of restraining the extraction of the filled concrete 3.

FIGS. 3 (a) and 3 (b) show still another embodiment in which the band type reinforcing member 6 and the ring type reinforcing member 7 are used in combination.

5 to 10 show an embodiment of the construction method of the present invention, and the construction is carried out in the following procedure.

(1) The section of the L _o than Tentan all around the inner surface of the pile steel pipe 1 is provided with a spacer 8 (see FIG. 5).

(2) Fill concrete 3 into pile steel pipe 1 (see Fig. 6).

(3) after curing of the filling concrete 3 to remove the concrete between the L _o (see Figure 7).

(4) After removing the spacer 8, the column steel frame 4 is inserted into the pile steel pipe 1 and fixed (see FIG. 8).

(5) Concrete 3 between the pile steel pipe 1 and the column steel frame 4 between the joints
Fill a (see FIG. 9).

(6) Construction completed (see Figure 10).

〔The invention's effect〕

In the joint between the concrete-filled steel pipe pile using the steel pipe with the inner surface projection of the one-column-one-pile foundation structure and the column steel frame, by using the reinforcing material of the present invention in a predetermined section from the top end of the pile steel pipe, A column pile joint that suppresses circumferential tensile strain that occurs in the pile steel pipe cross section, delays the occurrence of instability in the load-deformation relationship, improves the maximum yield strength of the joint, and has excellent mechanical performance and workability. Can be built. Also,
The reinforcement is efficient because it consists of a minimum of materials and is easy to install.

Further, according to the construction method of the present invention, in the above-mentioned column pile joint portion, it is possible to easily remove the poor quality concrete of the steel pipe upper end portion with the inner surface projection, and it is possible to significantly improve the construction workability. .

[Brief description of drawings]

1 (a) and 1 (b) are a horizontal sectional view and a vertical sectional view showing an embodiment of a joint portion of the present invention, and FIGS. 2 (a) and 2 (b).
Is a horizontal sectional view and a vertical sectional view showing another embodiment of the joint portion of the present invention, and FIGS. 3 (a) and 3 (b) are a horizontal sectional view and a vertical sectional view showing still another embodiment of the joint portion of the present invention. Cross section,
FIG. 4 is a schematic diagram showing an example of a structure to which the present invention is applied,
5 to 10 are vertical cross-sectional views showing an example of the construction procedure in the construction method of the present invention, and FIGS. 11 (a) to (e) are vertical cross-sectional views showing the specimen used in the experiment, and FIG. Fig. 13 is a side view showing the loading method in the experiment, Fig. 13 is a side view showing the state of extraction of filled concrete by the experiment, Fig. 14 and Fig.
Fig. 15 is a side view showing the destruction of filled concrete with and without ring-type reinforcement,
Figure and Figure 17 are typical examples of stigma shear force-deformation in the applied direction, and Figures 18 to 23 are circumferential strain distributions at the end section of the pile steel pipe of each specimen used in the experiment. Fig. 24 (a) to (f) is an explanatory view showing a fracture model of a joint, Figs. 25 (a) and (b) are explanatory diagrams of a fracture mode of a steel pipe, and Fig. 26 (a). , (B) are explanatory views of the failure mode (shear failure) of the front side concrete, FIGS. 27 (a) and (b) are explanatory views of the failure mode of the front side concrete (bearing failure), and FIG. 28 (a) ) And (b) are illustrations of concrete bearing failure on the bottom surface of the base plate, Figures 29 (a) to (c) are illustrations of concrete adhesion failure of backside concrete, and Figures 30 (a) and (b) are Fig. 31 (a) and 31 (b) are illustrations of concrete adhesion failure of side concrete, and the symbols in the analysis are explained. Figures 32 (a) and 32 (b) are horizontal and vertical cross-sectional views showing how the filled concrete is constrained by steel pipes with inner projections, and Figures 33 (a) and 33 (b) show inner projections. Horizontal and vertical cross-sectional views showing spacers provided on the inner surface of the attached steel pipe, FIG. 34 is a schematic view of a building above the low-rise line, and FIGS. 35 (a) and 35 (b) are horizontal cross-sections showing the first conventional technique. Fig. 36 (a), Fig. 36 (a), Fig. 36 (a) and Fig. 36 (b) are vertical sectional views showing the second conventional technique.
(B) is a vertical cross-sectional view showing a third conventional technique and an enlarged view of a main part thereof, and FIGS. 38 (a) and (b) are a vertical cross-sectional view showing a fourth conventional technique and a horizontal sectional view, FIG. 39. (A)-(c)
Is an explanatory view of a protrusion shape of a steel plate with protrusions as a fifth conventional technique, and FIGS. 40 (a) to (e) are schematic diagrams showing a sixth conventional technique. 1 ... Pile steel pipe, 2 ... Inner surface projection, 3 ... Concrete,
4 ... Column steel frame, 5 ... Base plate, 6 ... Band type reinforcing material, 7 ... Ring type reinforcing material, 8 ... Spacer

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Teruki Ishibashi 2-8, Hikarimachi, Kokubunji, Tokyo 38 Inside the Railway Technical Research Institute (72) Inventor Tsuneo Hasuda 2-8, Hikaricho, Kokubunji, Tokyo 38 Inside the Railway Technical Research Institute (72) Inventor Koichiro Keira 2-6-3 Otemachi, Chiyoda-ku, Tokyo Inside Nippon Steel Co., Ltd. (72) Noriyuki Kawabata 2-6-Otemachi, Chiyoda-ku, Tokyo No. 3 In Nippon Steel Co., Ltd. (72) Inventor Hiroaki Nagaoka 1-2-1, Marunouchi, Chiyoda-ku, Tokyo Nihon Kokan Co., Ltd. (72) Inventor ▲ Sakaki Nobuaki 1-1, Marunouchi, Chiyoda-ku, Tokyo No. 2 Nihon Kokan KK (72) Inventor Keiichi Takada 1-3-1 Otemachi, Chiyoda-ku, Tokyo Sumitomo Metal Industries Co., Ltd. (72) Akito Toshi Kato 1-3-3 Otemachi, Chiyoda-ku, Tokyo Sumitomo Metal Industries, Ltd. (56) Reference JP-A-55-114717 (JP, A) JP-A-62-284825 (JP, A) Actual public Sho 44-116970 (JP, Y1)

Claims (2)

[Claims] 1. A pillar-pile joint in which a steel pipe with an inner surface is used as a pile steel pipe of a concrete-filled steel pipe pile and a column steel frame is embedded in the pile steel pipe, and Y ≦ 0.5 × L from the top end of the pile steel pipe. Band type for suppressing the circumferential tensile strain generated in the pile steel pipe cross section of the column pile joint, which is continuous in the section circumferential direction of the pile steel pipe within the section (L is the embedded length of the column steel frame) Alternatively, a pillar-pile joint portion of a one-pillar-one-pile foundation structure is characterized in that a reinforcing material made of a ring-shaped steel material is provided. 2. A method for constructing a pillar pile joint, in which a steel pipe with an inner surface projection is used as a pile steel pipe of a concrete-filled steel pipe pile, and a column steel frame is embedded in the pile steel pipe. Spacers are provided in advance on the entire circumference of the inner surface of the predetermined section, the filled concrete is placed in the pile steel pipe, and after hardening of the filled concrete, the concrete and the spacer in the predetermined section are removed, and the column steel frame is placed in the pile steel pipe. After inserting, while filling the space between the joints of the pile steel pipe and the column steel frame with concrete, within the section of Y ≦ 0.5 × L (L is the embedded length of the column steel frame) from the top end of the pile steel pipe, A reinforcing member made of a band-type or ring-type steel material, which is continuous in the cross-section circumferential direction of the pile steel pipe and suppresses the circumferential tensile strain generated in the pile steel pipe cross-section of the column pile joint, 1 pillar 1 pile foundation structure Construction method of Hashirakui junction.