JP4249835B2 - Joining structure and joining method between steel pipe pile and foundation concrete structure - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention is applied when a foundation concrete structure such as a foundation footing structure and a foundation beam structure is constructed on a plurality of steel pipe piles driven into the ground, and the joining structure and joining of the steel pipe pile and the foundation concrete structure. It is about the method.
[0002]
[Prior art]
Conventionally, in order to construct a civil engineering building structure, steel pipe piles are buried in the ground by the placement method, press-fitting method, rotating method, pre-boring method or Nakabori method, and foundation concrete such as a foundation footing structure is built on this steel pipe pile. There are mainly methods A and B as methods for joining the structures.
[0003]
Method A, as shown in FIG. 4 , for the purpose of preventing displacement on the head inner surface and the head outer surface of the steel pipe pile 1 embedded in the ground 10, a plurality of strips 2 are arranged in the axial direction and welded. The pile head including this misalignment weld is arranged so as to be embedded in the foundation footing structure 3 over a length L greater than the diameter D of the steel pipe pile 1, and the reinforcement for the foundation footing 6 is arranged as shown in FIG. Then, when the foundation footing structure 3 is formed, the pile head is filled with the foundation concrete 4 and the steel pipe pile 1 and the foundation footing structure 3 are joined. 6 in FIG. 6 is an arrangement hole in the head of the steel pipe pile 1.
[0004]
Further, as shown in FIG. 5 , the method B is a method in which a plurality of strips 2 are arranged in the axial direction on the head inner surface of the steel pipe pile 1 embedded in the ground 10 and welded, After the lower region of the pile head rebar 5 formed in an annular shape is disposed inside the pile head, the pile head is filled with concrete 4 over a length Lh greater than the diameter D of the steel pipe pile, Pile head joint rebar 5 is fixed, the tip of the pile head and pile head joint rebar 5 are placed so as to be embedded in the foundation footing structure 3, the foundation footing rebar 6 is placed and the foundation concrete 4 is struck In this method, the foundation footing structure 3 is formed and the steel pipe pile 1 and the foundation footing structure 3 are joined. Moreover, in method B, since the arrangement | positioning diameter of the rebar 5 for pile head joining is small, when required bending moment proof stress is not obtained, the rebar 5 for pile head joining is arrange | positioned to the pile head outer peripheral surface at the annular | circular shape. [[Technical Reference] “Road Bridge Specification / Explanation” Japan Road Association, December 1996, page 370-375 (Fig.-Solution 10.9.6)].
[0005]
In any of the above methods, in order to reliably transmit the axial force of the pile to the foundation concrete structure, the strip 2 or the like for the purpose of preventing slippage is attached to the head of the steel pipe pile 1 and the inner surface of the steel pipe pile head and It is necessary to arrange a plurality of steps on either one or both of the outer surfaces and fix them by welding. In order to prevent this slippage, it is common to install the bent strip 2 etc. on the site in consideration of the high stop of the pile, etc., and it takes a long time to form this slippage and it is difficult to shorten the construction period. Since high skill is required, there is a problem that the construction cost burden is large.
[0006]
[Problems to be solved by the invention]
The present invention eliminates the need for welding a strip for preventing the above-described displacement, reduces the work period and construction cost, and easily and reliably transmits the axial force of the pile to the foundation concrete structure and the foundation. A joining structure and a joining method with a concrete structure are provided.
[0007]
[Means for Solving the Problems]
The present invention comprises the following inventions (1) to (5) .
-In the joint structure between the steel pipe pile and the foundation concrete structure, one or more nodes of a predetermined height obtained by locally expanding the head in the head length region embedded in the foundation concrete structure of the steel pipe pile or A joining structure of a steel pipe pile and a foundation concrete structure, wherein a plurality of piles are formed at predetermined intervals.
[0008]
[0009]
(2) In the joint structure between the head of the steel pipe pile and the foundation concrete structure, one or a plurality of nodes having a predetermined height obtained by locally expanding the head in the head region are formed at predetermined intervals. Steel pipe pile, filled steel bars for joining circular pile heads arranged inside the head of this steel pipe pile, and filled concrete for fixing steel pipe pile heads and filled steel bars for annular pile head joints And a steel pipe pile head and a foundation concrete structure embedded with pile-filled reinforcing bars for joining the pile head.
[0010]
[0011]
(3) In the method of joining the steel pipe pile and the foundation concrete structure, before placing the foundation concrete, insert a diameter expansion device from the steel pipe pile head, and the head length area of the steel pipe pile embedded in the foundation concrete is localized from the inside. A method for joining a steel pipe pile and a foundation concrete structure, wherein the foundation concrete is placed after expanding and plastically deforming and forming one or a plurality of nodes having a predetermined height at predetermined intervals.
[0012]
[0013]
The joining method between the head and the foundation concrete structure (4) steel pipe pile, the foundation concrete設前, insert the diameter device than the head of the steel pipe pile, and local diameter head region from within the plastic After deforming and forming one or a plurality of nodes with a predetermined height at predetermined intervals, the lower region of the solid reinforcing bars for pile head joining formed in a ring shape with a plurality of reinforcing bars is placed inside the steel pipe pile head After the concrete is filled and the steel pipe pile head and the pile head joint rebar are fixed, the tip of the steel pipe pile head and the pile head joint rebar are embedded in the foundation concrete structure. A method of joining a steel pipe pile and a foundation concrete structure, characterized in that a steel pipe pile is placed.
[0014]
(5) The insertion of the diameter expanding device from the steel pipe pile head and the local diameter expansion from the inside of the head region are after the steel pipe pile is cast and before the foundation concrete is cast. The joining method of the steel pipe pile and foundation concrete structure as described in said (3) or (4) characterized by the above-mentioned.
[0015]
DETAILED DESCRIPTION OF THE INVENTION
In the present invention, a steel pipe pile head having a node with a predetermined height in the head region is directly or within a foundation concrete structure (hereinafter referred to as “foundation concrete structure”) such as a foundation footing structure or a foundation beam structure. It is embedded using pile reinforcing steel bars and pile reinforcing steel bars and fixed to the foundation concrete structure. Basically, the steel pipe pile head is filled with concrete (may also be used as foundation concrete), and the joints are cut into the filling concrete and foundation concrete structure to provide a function to prevent slippage. is there.
[0016]
Each invention of the present invention will be described individually below. In the invention of (5) which cites (1), (3) and (3) of the present invention, a steel pipe pile having a node portion of a predetermined height obtained by locally expanding the head in the head region. The head is embedded in the foundation concrete structure to fix the steel pipe pile and the foundation concrete structure, and the inside of the steel pipe pile head is filled with concrete (may also serve as the foundation concrete), and the joint is It has a function to prevent slippage by biting into the filled concrete and foundation concrete structures.
[0017]
The joining structure of the steel pipe pile and the foundation concrete structure of this invention can be constructed in the following procedure, for example.
a. A steel pipe pile is placed on the ground.
b. A diameter expanding device is inserted into the steel pipe pile head, and the diameter is increased locally from inside to form a node.
c. Arrange the formwork for the foundation concrete structure and arrange the reinforcing bars.
d. Place a disc to prevent concrete spillage in the steel pipe head.
e. The steel pipe pile and the foundation concrete structure are joined by pouring the foundation concrete into the formwork, filling the foundation concrete into the steel pipe pile head, embedding the steel pipe pile head in the foundation concrete, and curing and solidifying. .
[0018]
In the joint structure of the present invention constructed as described above, the axial force acting on the steel pipe pile is caused to penetrate into the foundation concrete structure such as the foundation footing structure arranged outside the steel pipe pile. By transmitting, it is possible to obtain the same effect as when the slip stopper is fixed. In addition, since the foundation concrete that has been laid is also filled and biting into the expanded diameter of the steel pipe pile head, a strip or the like is fixed between the filled concrete and the steel pipe pile head. It is possible to obtain the same locking effect as when locking.
[0019]
In general, when a steel pipe pile has a node part, it is known that this node part promotes the occurrence of local buckling of the steel pipe, so that the axial strength is reduced. In addition, when the joint is filled with concrete, local buckling which causes a problem does not occur, so that the axial strength of the steel pipe does not decrease. Therefore, it is possible to provide a joint structure having a structural performance equivalent to that of the conventional method A without welding the stopper.
[0020]
[0021]
[0022]
[0023]
[0024]
In the invention of (5) that cites (2), (4) and (4) of the present invention, one or a predetermined number of nodes having a predetermined height obtained by locally expanding the head in the head region. Inside the steel pipe pile heads that are formed at intervals, a ring-shaped pile head joint for reinforcing the pile head is arranged and filled with concrete to fill the steel pipe pile head and the circular pile head joint. The steel pipe pile and the basic concrete structure are fixed by embedding the steel pipe pile head end portion and the ring-filled reinforcing bar for joining the circular pile head in the basic concrete structure.
[0025]
The joining structure of the steel pipe pile and the foundation concrete structure of this invention can be constructed in the following procedure, for example.
a. A steel pipe pile is placed on the ground.
b. A diameter expanding device is inserted into the steel pipe pile head, and the diameter is increased locally from inside to form a node.
c. Arrange the formwork for the foundation concrete structure and arrange the reinforcing bars.
d. A disk for preventing concrete spillage is placed in the steel pipe pile head, and a solid reinforcing bar for circular pile head joint formed by multiple reinforcing bars is arranged.
e. Pour the foundation concrete into the formwork, fill the steel pipe pile head with this foundation concrete, and embed the solid steel reinforcing bars for joining the tip of the steel pipe pile head and the annular pile head into the foundation concrete for curing and solidification. By doing so, the steel pipe pile and the foundation concrete structure are joined.
[0026]
In the joint structure of the present invention constructed in this way, the annular reinforcing steel bar for pile connection formed inside the steel pipe pile head is firmly fixed to the steel pipe pile head and the foundation concrete. Since concrete is also filled in and bites into the joints of the steel pipe pile head, the same detent effect can be obtained between the foundation concrete structure and the steel pipe pile head as if the strips were fixed and detained. Can do.
[0027]
In this invention, the axial force is transmitted to the filled concrete, as in each of the above inventions, so that there is almost no decrease in the axial strength as a pile, and a joint structure having a structural performance equal to or higher than that of the conventional method is prevented. Can be provided without welding. Also, the construction time is short and less skill is required, so construction costs can be reduced.
[0028]
[0029]
[0030]
[0031]
[0032]
In each invention of the present invention, all have a structure in which the diameter of the steel pipe pile is locally expanded from the inside to form a node. This joint can be formed by inserting a diameter expanding device into the steel pipe pile head, and expanding the steel pipe pile locally from the inside and plastically deforming it, so the construction time is also short and the construction cost is also low. Less is enough.
[0033]
Regarding the formation of this joint, when steel pipe piles are driven or press-fitted into the ground, if the joint is formed before placing or press-fitting, there is a concern that buckling will occur at the joint during placement or press-fitting. For this reason, it is preferable to form the joint after placing or pressing the steel pipe pile on the ground. In this case, it is easy to perform the diameter expansion work by suspending the vertical diameter expansion apparatus with a crane, for example.
[0034]
As the shape of the node portion, for example, a ring shape having a discontinuous protrusion in the circumferential direction, a hemispherical shape, or the like can be used in addition to a ring shape having a circular arc shape that is continuous in the circumferential direction of the steel pipe pile 1. The height of this node is from 10 mm to about 1/10 of the outer diameter of the steel pipe pile, and 1 to 3 stages are formed in the axial direction in the head region of the steel pipe pile.
[0035]
When a steel pipe pile is built on the ground by the pre-boring method, mid-digging method, rotating method, etc., when a load that causes buckling of the steel pipe pile is not applied during construction, A knot may be formed. In this case, it is easy to perform the diameter expansion work on the work table using a horizontal diameter expansion apparatus.
[0036]
Further, the reinforcing rods (including strips and wires) are wound around the outer periphery of the annular pile head reinforcing bars and the pile-filled reinforcing bars used in the above invention, and are fixed with a wire or the like . It is combined with the reinforcement of the foundation concrete structure.
[0037]
【Example】
Embodiments of the present invention will be described below with reference to FIGS . In each figure, after the steel pipe pile 9 is built on the ground 10, the head region is expanded from the inside to form the two-stage nodes 11a and 11b in the axial direction, and the foundation footing structure is formed at the top. 3 shows an example of a joining structure in which 3 are joined. However, reinforcement rebar foundation footing structure 3 is basically performs similarly to the conventional example shown in FIG 6.
[0038]
In this embodiment, the diameter expansion device used for locally expanding the head region of the steel pipe pile 9 from the inside is a vertical diameter expansion device 12 as shown in FIG. It is of a type that can be moved up and down by a crane 13 and is equipped with a diameter expansion mechanism 15 that can be adjusted in the vertical direction via a lifting device 14.
[0039]
More specifically, the diameter expansion mechanism 15 is advanced and retracted by hydraulic cylinders 18a to 18f that are radially arranged and operated via a hydraulic hose 17 by a hydraulic device 16, as shown in FIGS. 1 (b) and 1 (c). In this case, the hydraulic cylinders 18a to 18f are simultaneously actuated by the hydraulic device 16 via the hydraulic hose 17 to form the enlarged diameter blocks 20a to 20f. By expanding the diameter of 20f, a strong expanding force can be applied from the inside, and the steel pipe pile 9 can be locally expanded. This local enlarged diameter region can be adjusted by adjusting the position of the enlarged diameter mechanism 15 with a crane (not shown) and the lifting device 14.
[0040]
The shapes of the node portions 11a and 11b by the diameter expansion mechanism 15 are determined by the outer surface shapes of the diameter expansion blocks 20a to 20f. Here, the shape of the nodes 11a and 11b is a ring shape with a circular arc section that is continuous in the circumferential direction, and the nodes are formed in two stages one by one in the steel pipe pile axis direction. For example, when three stages are formed in the axial direction, the position of the diameter expansion mechanism 15 is changed by the lifting device 14 and the diameter expansion operation may be performed three times. By selecting the outer surface shape of the diameter-enlarged blocks 20a to 20f, two steps can be simultaneously formed in the pile axis direction.
[0041]
FIG. 2 shows an embodiment of the invention of (5) citing (1), (3) and (3) . In the figure, 9 is a steel pipe pile driven on the ground 10, and after the steel pipe pile 9 is driven, two head portions 11a and 11b are formed in the axial direction in the head region. When the foundation concrete 4 is filled in the head, a disc 21 is arranged to prevent the outflow.
[0042]
In this example, the form frame (not shown) is placed on the formwork (not shown) so that the range of the length L of the head region where the node portions 11a and 11b of the steel pipe pile 9 are formed is embedded in the formation region of the foundation footing structure 3. By placing the foundation concrete 4 by placing the reinforcing bars 6 for the foundation footing structure as shown in FIG. 2, the inside of the head region of the steel pipe pile 9 is filled with the foundation concrete 4, The basic footing structure 3 is fixed.
[0043]
By comprising in this way, the node parts 11a and 11b can be made to bite into the foundation concrete 4 of the foundation concrete structure 3, and a strong slip prevention function can be given.
[0044]
[0045]
[0046]
[0047]
FIG. 3 shows an embodiment of the invention of (5) citing (2), (4) and (4) . In the figure, 9 is a steel pipe pile driven on the ground 10, and after the steel pipe pile 9 is driven, two head portions 11a and 11b are formed in the axial direction in the head region. the projections 25o provided in the middle portion of the Chutsume reinforcing bar 25 for the pile joint annular comprising a plurality of reinforcing bars 22 and reinforcement 23 inside of the head has a solid wear.
[0048]
A lower region of the inside reinforcing bar 25 is inserted into the steel pipe head in a range of length Lh, and a disc 21 is disposed at the lower end thereof to prevent the outflow when the foundation concrete 4 is filled. Yes.
[0049]
In this example, the formwork is formed such that the range of the length L on the upper side of the steel pile pile head and the upper portion of the annular reinforcing bar 25 for joining the circular pile head is embedded in the formation region of the foundation footing structure 3. The foundation concrete 4 is also filled inside the head region of the steel pipe pile 9 by arranging the reinforcement for the foundation footing structure as shown in FIG. Thus, the steel pipe pile 9 and the foundation footing structure 3 are fixed.
[0050]
By configuring in this way, it is possible to cause the ring-filled reinforcing bars 25 for jointing pile heads and the joint portions 11a and 11b to bite into the foundation concrete 4 of the foundation concrete structure 3 and to have a powerful anti-slipping function. it can.
[0051]
[0052]
[0053]
[0054]
[0055]
In addition, this invention is not limited to the said Example. For example, the structural conditions of steel pipe piles to be used (including nodal formation conditions), the structural conditions of the diameter expansion device, the erection conditions, the pile head joint reinforcement conditions, the disk conditions, the construction procedures, etc. In accordance with the structure conditions, the load conditions, the required support pressure conditions, and the like, the range is changed within a range that satisfies the above claims.
[0056]
【The invention's effect】
In the present invention, a node portion is formed in the steel pipe pile head portion, and the node portion formation portion is embedded in the foundation concrete structure, or an annular surface is formed on the outer peripheral surface and / or inside of the steel pipe pile head portion where the node portion is formed. fixing a pile head joining reinforcing bars (Chutsume rebar for pile head joint), joining a steel pipe pile and foundation concrete structure by embedding pile head joint reinforcing bar tip and annular steel pipe pile head to foundation concrete structure However, it is designed to firmly prevent slippage with the joints between the joints and the circular pile heads, eliminating the need for welding strips to prevent slippage, reducing the work period and construction cost, Axial forces can be transmitted easily and reliably to the foundation concrete structure.
[Brief description of the drawings]
FIG. 1A is a side explanatory view showing a structural example of a diameter expanding device for forming a node portion in a head portion of a steel pipe pile used in a joint structure between a steel pipe pile and a foundation concrete structure in an embodiment of the present invention. FIGS. 4A and 4B are partially cutaway cross-sectional explanatory views showing an example of the structure of the diameter expansion mechanism in the diameter expansion device of FIG. 4A, and FIG. 4C is a partially cutaway view taken along arrow Aa-Ab of FIG. FIG.
FIG. 2A is a partially cutaway side cross-sectional explanatory view showing an example of a joint structure between a steel pipe pile and a foundation concrete structure in an embodiment of the present invention, and FIG. 2B is a view taken along line Aa- in FIG. Ab arrow plane explanatory drawing.
FIG. 3 (a) is a partially cutaway side cross-sectional explanatory view showing another example of a joint structure between a steel pipe pile and a foundation concrete structure in an embodiment of the present invention, and FIG . 3 (b) is a diagram of FIG. 3 (a). Aa-Ab arrow plane explanatory drawing.
FIG. 4 is an explanatory side sectional view showing an example of a joining structure between a conventional steel pipe pile and a foundation footing structure.
FIG. 5 is an explanatory side sectional view showing another example of a joining structure between a conventional steel pipe pile and a foundation footing structure.
FIG. 6 is an explanatory plan view showing an example of reinforcing bar arrangement in a conventional steel pipe pile and foundation footing structure.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Steel pipe pile 2 Band plate 3 Foundation footing structure 4 Foundation concrete 5 Pile head joint reinforcement 6 Reinforcement reinforcement 7 Steel pipe pile arrangement hole 8 Foundation footing main reinforcement 9 Steel pipe pile 10 Ground 11a, 11b Node 12 Expanding device 13 Crane DESCRIPTION OF SYMBOLS 14 Lifting device 15 Diameter expansion mechanism 16 Hydraulic device 17 Hydraulic hose 18a-18f Hydraulic cylinder 19a-19f Rod 20a-20f Diameter expansion block 21 Disc 22 Reinforcement 23 Reinforcement reinforcement 24 Pile head joint reinforcement 25 Pile head joint filling Reinforcing bar 25o Protrusion

Claims (5)

In a joint structure between a steel pipe pile and a foundation concrete structure, one or a predetermined node having a predetermined height obtained by locally expanding the head is embedded in the head length region embedded in the foundation concrete structure of the steel pipe pile. Joint structure of steel pipe pile and foundation concrete structure, characterized in that a plurality of them are formed at intervals. In the joining structure of the steel pipe pile and the foundation concrete structure, a steel pipe pile in which one or a plurality of nodes having a predetermined height obtained by locally expanding the head in the head region is formed at predetermined intervals, and Filled concrete that is fixed inside the steel pipe pile head and is used to join the circular pile head joint, and the steel pipe pile head and the solid concrete reinforcement that is used to join the circular pile head joint and the steel pipe pile head. A steel pipe pile and a foundation concrete structure, characterized by the fact that it consists of a foundation concrete structure with embedded steel bars for pile head joints.   In the method of joining the steel pipe pile and the foundation concrete structure, before placing the foundation concrete, a diameter expansion device is inserted from the steel pipe pile head, and the length region of the steel pipe pile head embedded in the foundation concrete is locally expanded from the inside. A method of joining a steel pipe pile and a foundation concrete structure, wherein the foundation concrete is placed after plastic deformation and forming one or more nodes having a predetermined height at predetermined intervals.   In the method of joining the steel pipe pile and the foundation concrete structure, before placing the foundation concrete, a diameter expansion device is inserted from the steel pipe pile head, and the head region is locally expanded from the inside to be plastically deformed to have a predetermined height. After forming one or more knots at a predetermined interval, the lower region of the pile reinforcement for pile head joint formed in an annular shape with multiple rebars is arranged inside the steel pipe pile head, and the concrete is After filling and fixing the steel pipe pile head and pile head joint rebar, foundation concrete is cast so that the tip of steel pipe pile head and pile head joint rebar are embedded in the foundation concrete structure Joining method of steel pipe pile and foundation concrete structure. The insertion of the diameter expanding device from the steel pipe pile head and the local diameter expansion from the inside of the head region are after the steel pipe pile is cast and before the foundation concrete is cast. The joining method of the steel pipe pile and foundation concrete structure of Claim 3 or 4.

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