JP7288199B2 - METHOD FOR MANUFACTURING STEEL PIPE PILE WITH INTERNAL PROJECTS, CONSTRUCTION METHOD OF STEEL PIPE PILE, AND STEEL PIPE PILE WITH INNER PROJECTIONS - Google Patents

Description

TECHNICAL FIELD The present invention relates to a method for manufacturing a steel pipe pile with internal projections, a method for constructing a steel pipe pile, and a steel pipe pile with internal projections.

Axial force, shear force, and bending moment act on foundation piles that support structures in the civil engineering and construction fields due to the structure's own weight and horizontal force during an earthquake. With the rationalization of the foundation structure by reinforcement, etc., the proof strength required for foundation piles is increasing. In order to meet the demand for such foundation piles, the use of synthetic structures in which steel pipes are filled with a solidifying material such as concrete is increasing for foundation piles. In these composite structures of steel pipes and concrete, it is important to increase the adhesion between the steel pipes and concrete in order to exhibit the yield strength of the composite cross section. ing.

As a method of providing projections on the inner surface of a steel pipe, a method of producing a hot-rolled coil with projections at a factory to make a steel pipe with projections on the inner surface (Japanese Industrial Standard JIS A 5525 Annex A, etc.), or, for example, Patent Documents 1 and 2, As shown, a method of forming protrusions on the inner surface of a steel pipe with a weld bead is known.

In Patent Document 1, a welding wire is used on the inner circumference of a steel pipe, and _CO2 welding is performed under the welding conditions of a predetermined welding current, welding voltage, welding speed, and welding heat input. A method is described for applying projections of predetermined height and rise angle in a weld bead.
In Patent Document 2, a pair of backing plates are arranged on the inner surface of the steel pipe at intervals, and while these backing plates and the welding torch are moved relative to the inner surface of the steel pipe, the axial direction of the welding torch is shifted with respect to the vertical direction. Then, by inclining the upper side of the welding torch in a direction opposite to the direction of movement of the steel pipe, a method is described in which a projection that secures a sufficient amount of penetration into the steel pipe is applied to the weld bead.

JP-A-9-195443 JP 2013-248625 A

However, the conventional steel pipe pile manufacturing method has the following problems.
That is, the method of producing a hot-rolled coil with projections in a factory to make a steel pipe with internal projections is subject to severe manufacturing restrictions in the factory.
In addition, in the method of forming projections on the inner surface of the steel pipe with a weld bead as shown in the above-mentioned Patent Documents 1 and 2, since the welding posture becomes severe after driving the foundation pile, the inner surface of the steel pipe is welded before driving the foundation pile. It is based on forming protrusions on the Therefore, when the pile stops at a high level during foundation pile driving, the position of the inner surface projection shifts in the depth direction. Furthermore, in the case of Patent Documents 1 and 2, it is difficult to form projections by welding because of poor weldability with respect to steel pipes having a large carbon equivalent such as high-strength steel.

In addition, with small-diameter steel pipes, there is a problem that welding is not possible because the body or hand cannot be placed inside. There was room for improvement in that respect.

The present invention has been made in view of the above-mentioned problems, and it is possible to easily provide projections at arbitrary positions on the inner surface of a steel pipe after driving foundation piles on site without requiring a hot rolling process or a welding process. It is an object of the present invention to provide a method for manufacturing a steel pipe pile with internal projections, a method for constructing a steel pipe pile, and a steel pipe pile with internal projections.

In order to achieve the above object, a method for manufacturing a steel pipe pile with an inner surface protrusion according to the present invention includes a step of forming a concave portion on the inner surface of the steel pipe by pressing the steel pipe from the inside to the outside in the pipe radial direction. and a step of attaching a projecting member to the recess.

Moreover, the construction method of the steel pipe pile which concerns on this invention is characterized by providing the said steel pipe used with the manufacturing method of the steel pipe pile with an inner surface mentioned above in the ground, and constructing it.

Moreover, the steel-pipe pile with an internal projection which concerns on this invention was manufactured by the manufacturing method of the steel-pipe pile with an internal projection mentioned above, It is characterized by the above-mentioned.

In the present invention, the manufacturing method is such that the projecting member is attached to the inside of the steel pipe by press working. Without being subject to the above restrictions and without relying on welding, projections can be formed at arbitrary positions on the inner surface of the steel pipe after driving the foundation pile (steel pipe) on site. Therefore, even when the pile driven at the construction site stops high, the projecting member on the inner surface of the steel pipe can be provided at a desired depth position.

In addition, since the present invention uses a manufacturing method that does not rely on welding, it is possible to form projecting members on the inner surface of the steel pipe even for steel pipes with high carbon equivalent and poor weldability such as high-strength steels. In the case of the steel pipe alone, since the concave portion is filled with the projecting member, it is possible to suppress the reduction in strength against buckling of the steel pipe. Since the projecting member is provided on the inner surface of the steel pipe, when the steel pipe is filled with concrete, it functions as a composite cross section of the steel pipe and concrete, and the strength in the vertical direction can be increased.
Furthermore, in the present invention, since projections can be formed at any position on the inner surface of the steel pipe, such as the pile head and the pile tip foot protection part, a composite structure of the steel pipe and a solidification member such as concrete can be formed at any position in the depth direction. can be increased.

In addition, the method for manufacturing a steel pipe pile with an inner surface projection according to the present invention is characterized by attaching the projection member to the inner surface of the steel pipe by simultaneously expanding the steel pipe and the projection member from the inside to the outside by press working. may be

In this case, it is possible to locally dent the wall of the steel pipe together with the protruding member from the inside to the outside of the steel pipe by press working to form a recess, and by leaving the protruding member in the recess as it is, mechanically A projecting member can be fixed to the steel pipe. As described above, in the present invention, it is possible to simultaneously perform the depression of the steel pipe and the installation of the projecting member by one press working, thereby efficiently manufacturing the steel pipe pile with the inner surface projection.

Further, the method for manufacturing a steel pipe pile with an inner surface projection according to the present invention is characterized in that the steel pipe is expanded from the inside to the outside by press working, and then the projection member is arranged on the inner surface of the steel pipe to attach it. good.

According to the present invention, first, the wall of the steel pipe is locally recessed from the inside to the outside of the steel pipe by press working to form a recess, and then the projection member is arranged in the recess to mechanically A projecting member can be fixed to the steel pipe. In this case, since the projecting member can be provided in the concave portion of the steel pipe without press working, it is also possible to partially provide the projecting member, for example, in the circumferential direction.

Further, the method for manufacturing a steel pipe pile with an inner surface projection according to the present invention may be characterized by pressing the steel pipe from the inside to the outside by press working, and then attaching the projecting member to the inner surface of the steel pipe by press working. .

In this case, first, the wall of the steel pipe is locally dented from the inside to the outside of the steel pipe by press working to form a recess, and then the projection member is placed in the recess and the projection member is pressed. The projecting member can be mechanically fixed to the steel pipe by expanding from the inside to the outside by processing. In this case, the projecting member can be reliably fitted and fixed to the recessed portion by press working, and the projecting member can be prevented from coming off or slipping out of the recessed portion.

Moreover, the manufacturing method of the steel-pipe pile with an inner surface projection which concerns on this invention is good also as the said projection member being formed in ring shape.

In this case, since the protruding member is ring-shaped, there is an advantage that the hoop stress of the protruding member facilitates fixing to the inner surface of the steel pipe.

Further, in the method for manufacturing a steel pipe pile with an inner surface projection according to the present invention, the projecting member extends in the circumferential direction along the steel pipe, and a key member for retaining is provided on a part of the projecting member in the circumferential direction. It may be characterized by being interposed.

In this case, a gap is formed at a position in the circumferential direction of the protruding member, and it becomes possible to insert and fix the key member for retaining in the gap later. Therefore, the protruding member can be easily expanded during press working, and the protruding member can be easily provided on the steel pipe by inserting a retaining key having a dimension that predicts the extent to which the shape will return due to elastic deformation after being pushed out. .

Moreover, the manufacturing method of the steel-pipe pile with an inner surface projection which concerns on this invention is good also considering the said projection member as a strength higher than the said steel pipe.

In this case, since the protruding member has a higher strength than the steel pipe, the protruding member can be easily attached by pushing the protruding member from the inside to the outside of the steel pipe. In particular, it is effective when simultaneously pushing out the projecting member and the steel pipe by press working.

Moreover, the manufacturing method of the steel-pipe pile with an inner surface projection which concerns on this invention may be smaller than the said steel pipe in the amount of elastic deformation of the said projection member.

The present invention can prevent the projecting member from falling when the projecting member is attached by pushing the projecting member from the inside to the outside of the steel pipe. In addition, since the amount of elastic deformation of the protruding member is set to be smaller than that of the steel pipe, hoop stress is likely to act when a continuous protruding member is used, making it easy to fix the steel pipe to the recess.

Moreover, the manufacturing method of the steel-pipe pile with an inner surface projection which concerns on this invention is good also as the said projection member being formed from a shape memory alloy.

Moreover, the manufacturing method of the steel pipe pile with an inner surface projection which concerns on this invention is good also as the said projection member having an inclined surface of the direction which intersects the fall direction of the said projection member.

In this case, by providing the inclined surface of the projecting member in a direction that restricts falling from the recess, the projecting member is prevented from falling out even when a downward force acts on the projecting member from a solidified member such as concrete. be able to. In addition, even when an upward force acts on the concrete during use, it is possible to prevent the projecting member from slipping out by providing an inclined surface that generates a force in the direction of pressing the projecting member against the recess.

Further, in the method for manufacturing a steel pipe pile with an inner surface projection according to the present invention, the center of gravity of the projection member is positioned outside the center position of the thickness of the steel pipe before spreading in the steel pipe in the pipe radial direction, or at the same position. It may be characterized by being in

In this case, since the projecting member is stably fixed to the concave portion of the steel pipe, it is possible to prevent the projecting member from falling.

A steel pipe pile construction method according to the present invention includes a step of driving the steel pipe into the ground, and a step of attaching the projecting member to the recess formed in the inner surface of the steel pipe driven into the ground. and placing concrete inside the steel pipe to which the projecting member is attached.

In this case, after forming a recess on the inner surface of a steel pipe placed in the ground, a projecting member is attached to the recess, and concrete is placed inside the steel pipe to form a steel pipe pile with an inner surface projection in the ground. can be constructed. At this time, it functions as a composite section of the steel pipe and concrete, and the strength against buckling can be increased.

Further, a method for constructing a steel pipe pile according to the present invention includes a step of forming the recess on the inner surface of a steel pipe of an existing steel pipe pile by press working, a step of attaching the projecting member to the recess, and a step of attaching the projecting member. and placing concrete inside the existing steel pipe pile.

In this case, since it can be applied to existing steel pipe piles, it can be used when it is desired to form a steel pipe concrete filling structure for the purpose of reinforcing existing structures.

According to the method for manufacturing a steel pipe pile with internal projections, the method for constructing a steel pipe pile, and the steel pipe pile with internal projections of the present invention, the inner surface of the steel pipe is , the projection can be easily provided at any position.

BRIEF DESCRIPTION OF THE DRAWINGS It is a half section perspective view which shows the structure of the steel pipe pile by 1st Embodiment of this invention. FIG. 11 is a partially cutaway perspective view showing the configuration of a projecting member and a key member according to a first modified example; (a) to (c) are side views showing a procedure for placing a steel pipe. 4(a) to 4(c) are side views showing a procedure for simultaneously pressing a steel pipe and a protruding member using a press machine. FIG. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a horizontal cross-sectional view showing a working state in which a steel pipe and a projecting member are simultaneously pressed using the press working apparatus according to the first embodiment of the present invention, in which (a) is a view of the state before press working; ) is a diagram of the state during press working, and (c) is a diagram of the state after press working. FIG. 4 is a horizontal cross-sectional view showing a working state in which a steel pipe and a projecting member are pressed simultaneously using a press working apparatus according to a first modified example, where (a) is a view of the state before press working, and (b) is a press machine. FIG. 2C is a diagram of a state during processing, and FIG. 4C is a diagram of a state after press working. (a) to (c) are side views showing the construction procedure of the steel pipe pile according to the second embodiment. (a) to (c) are side views showing the construction procedure of the steel pipe pile following FIG. 7(c). 8A is a horizontal cross-sectional view showing the state of the protruding member during construction, where (a) corresponds to FIG. 8A and the protruding member is fixed with a fixing jig, and (b) corresponds to FIG. 9(a) is inserted into the steel pipe, and FIG. 9(c) is a view of the projection member attached to the groove of the steel pipe corresponding to FIG. 8(c). (a) to (c) are side views showing the construction procedure of the steel pipe pile according to the third embodiment. FIG. 13 is a horizontal cross-sectional view showing a steel pipe pile according to a second modification, and is a cross-sectional view taken along the line BB shown in FIG. 12; It is a principal part longitudinal cross-sectional view which shows the structure of the protrusion member of the steel pipe pile by a 2nd modification. It is a principal part longitudinal cross-sectional view which shows the structure of the protrusion member of the steel pipe pile by a 3rd modification.

EMBODIMENT OF THE INVENTION Hereinafter, the manufacturing method of the steel-pipe pile with an internal surface projection, the construction method of a steel pipe pile, and the steel-pipe pile with an internal surface projection by embodiment of this invention are demonstrated based on drawing.

(First embodiment)
As shown in FIG. 1, the steel pipe pile with inner projections (hereinafter simply referred to as steel pipe pile 1) according to this embodiment is constructed by driving into the ground, and is a composite structure in which the steel pipe is filled with a solidification member such as concrete 3. In order to exhibit the yield strength as a composite cross section, a protruding member 4 is attached to the inner surface 2a in order to increase the adhesion between the steel pipe 2 and the concrete 3. The steel pipe pile 1 is manufactured by a method in which the steel pipe 2 is pressed from the inside to the outside in the pipe radial direction using a press working device 6 to be described later, and the projecting member 4 is attached to the inner surface 2a of the steel pipe 2. is.

As shown in FIG. 1, the steel pipe 2 has a plurality of tiers (two tiers in the figure) of circumferentially continuous ridges 21 spaced apart in the pipe axis O direction. That is, the steel pipe 2 is formed in a knot shape when viewed from the outer peripheral side. The outer peripheral surface 4a of the ring-shaped protruding member 4 is fitted into the recessed groove portion 21a formed on the inner surface 2a side of the steel pipe 2 in the protruding line 21 in a non-dropping state.
As the steel pipe 2 of the present embodiment, for example, spiral steel pipes such as SKK400 and SKK490, electric resistance welded steel pipes such as STK400 and STK490, steel pipes manufactured by other manufacturing methods such as UO steel pipes, and higher strength steel pipes can be adopted. .

The protruding members 4 are formed at predetermined intervals on the entire inner surface of the steel pipe 2a or on predetermined regions regardless of whether they are in the ground or out of the ground, depending on ground conditions, required cross-sectional performance, strength, and the like. In addition, in the first embodiment, the protruding member 4 is attached to extend over the entire circumference of the steel pipe 2 .

It is preferable that the projection member 4 is attached in two or more stages with the height dimension h. That is, for example, the height dimension h of the projecting member 4 is set to 9 mm when the pile diameter is less than 800 mm, set to 12 mm when it is 800 mm or more and less than 1200 mm, and is set to 16 mm when it is 1200 mm or more and less than 1500 mm. be.
In addition, the width dimension d of the projecting member 4 (the length dimension in the tube axis direction of the projecting member 4 fitted in the groove 21a of the steel pipe 2) is preferably at least twice the height dimension h (public interest Japan Road Association Specifications for Highway Bridges, Commentary IV Substructure Edition, November 2017).

Further, as the projecting member 4, a member obtained by processing a flat steel into a ring shape is adopted. A method for manufacturing the projecting member 4 will be described later, but for example, if the projecting member 4 does not have a notch (see FIGS. 5A to 5C) and is attached by pushing it outward from the inside of the steel pipe 2, the projecting member The amount of elastic deformation of 4 is preferably smaller than that of steel pipe 2 . In order to reduce the amount of elastic deformation, it is preferable to use high Young's modulus steel. The projecting member 4 is not limited to flat steel as in the present embodiment, and may be square steel, round steel, bar steel, or the like.

The projecting member 4 configured in this manner will be described in detail in the manufacturing method described later. It is manufactured by a method of attaching by spreading, or a method of pressing the steel pipe 2 from the inside to the outside in the pipe radial direction and then attaching the projecting member 4 arranged on the inner surface 2a of the steel pipe by pressing.

As shown in FIGS. 4(a), 4(b) and 5(a), 5(b), the press working device 6 is inserted into the steel pipe 2 to push the steel pipe 2 and the projecting member 4 outward in the pipe radial direction. It comprises a press body 61 that pushes out and expands its diameter, and a moving mechanism 62 that is provided so as to be able to move the press body 61 in the tube axis O direction (depth direction) via a shaft portion 63 . The shaft portion 63 is located at the center of the press machine main body 61, and arranged in a state of being aligned with the center (pipe axis O) of the steel pipe 2 during press working.

The press main body 61 includes a plurality of (here, six) cylinders 64 radially arranged from the shaft portion 63, and a pressing plate 65 fixed to the tip of each cylinder 64 on the outer peripheral side. . The pressing plate 65 is formed in a block shape divided into six parts in the circumferential direction, and is pushed out from the inside of the steel pipe 2 and pulled in by the advance and retreat of the rod of each cylinder 64 driven hydraulically or electrically. there is That is, when the rod of each cylinder 64 protrudes, the outer diameter (virtual line formed by each pressing surface 65a) at which the pressing surface 65a, which is the outer peripheral surface of the six pressing plates 65, is located can be enlarged. A pressing surface 65 a of each pressing plate 65 is formed with a curved surface having a radius of curvature substantially equal to the radius of curvature of the inner surface 2 a of the steel pipe 2 in the circumferential direction. By expanding the diameter of the six pressing plates 65 , a large diameter expanding force can be applied to the inner surface 2 a of the steel pipe 2 via the projecting member 4 to form the ridges 21 on the steel pipe 2 . The position of the pressing plate 65 in the depth direction can be adjusted by the moving mechanism 62 .

The solidifying member to be filled in the steel pipe 2 having the projecting member 4 on the inner surface 2a is not limited to the concrete 3 as in the present embodiment, and may be other fluid solidifying member such as mortar or soil cement.

Next, the manufacturing method of the steel pipe pile 1 and the construction procedure of the steel pipe pile 1 described above will be specifically described based on the drawings.
First, as shown in FIGS. 3(a) to 3(c), the steel pipe 2 of the steel pipe pile 1 is driven into the ground G. As a method for placing the steel pipe 2, it is possible to apply, for example, the Nakadori method, the pre-boring method, the impact method, the rotary press-in method, etc., but here, the installation procedure by the general Nakadori method will be explained. do.
As shown in FIG. 3( a ), the ground G is excavated with a spiral auger 51 inserted into the steel pipe 2 . As shown in FIG. 3(b), the steel pipe 2 is inserted into the excavation hole Ga while excavating by the spiral auger 51, and the embedding of the steel pipe 2 into the ground G is completed as shown in FIG. 3(c). .

Next, as shown in FIGS. 4(a) and 5(a), a press working device holding a ring-shaped protruding member 4 at a predetermined height position in the pipe axis O direction inside the placed steel pipe 2. Insert 6. Then, as shown in FIGS. 4(b) and 5(b), the pressing plate 65 of the press working device 6 is projected outward in the pipe radial direction to widen the projecting member 4 and the steel pipe 2 simultaneously. By pressing from the inside to the outside, the projecting member 4 is attached to the inner surface 2a of the steel pipe 2 as shown in FIGS. 4(c) and 5(c). That is, the steel pipe 2 is provided with a ridge 21 that protrudes outward in the pipe radial direction, and the protruding member 4 is fitted in the concave groove 21a formed by the ridge 21 on the inner surface 2a side. Become. After that, only the press working device 6 is pulled out from the steel pipe 2 .

Then, concrete 3 (see FIG. 1) is placed inside the steel pipe pile 1 with the projecting member 4 attached to the inner surface 2a of the steel pipe 2, and the construction of the steel pipe pile 1 is completed.

Next, the manufacturing method of the steel-pipe pile with an inner surface protrusion mentioned above, the construction method of a steel pipe pile, and the effect|action of a steel-pipe pile with an inner surface protrusion are demonstrated in detail based on drawing.
In the steel pipe pile manufacturing method according to this embodiment, as shown in FIGS. Therefore, as in the case of manufacturing hot-rolled coils with projections at a factory to manufacture steel pipes with internal projections, the foundation can be formed on site without being subject to manufacturing restrictions at the factory and without welding. After the pile (steel pipe 2) is driven, projections can be formed at arbitrary positions on the steel pipe inner surface 2a. Therefore, even when the pile driven at the construction site stops high, the projecting member 4 on the steel pipe inner surface 2a can be provided at a desired depth position.

In addition, since this embodiment uses a manufacturing method that does not rely on welding, it is possible to form the projecting members 4 on the inner surface 2a of the steel pipe even for a steel pipe with a large carbon equivalent and poor weldability such as high-strength steel. be. When the steel pipe is viewed alone, since the recessed groove portion 21a is filled with the protruding member 4, it is possible to suppress the reduction in strength against buckling of the steel pipe 2. FIG. Since the projecting member 4 is provided on the steel pipe inner surface 2a, when the steel pipe 2 is filled with the concrete 3, it functions as a composite cross section of the steel pipe 2 and the concrete 3, and the strength in the vertical direction can be increased.
Furthermore, in this embodiment, since projections can be formed at arbitrary positions on the steel pipe inner surface 2a such as the pile head and the pile tip foot protection part, the steel pipe 2 and the solidification member such as concrete 3 can be synthesized at arbitrary positions in the depth direction. structure to increase bearing capacity.

In addition, in the method for manufacturing the steel pipe pile 1 according to the first embodiment, the groove portion 21a is formed by locally recessing the wall of the steel pipe 2 together with the projecting member 4 from the inside to the outside of the steel pipe 2 by press working. The projection member 4 can be mechanically fixed to the steel pipe 2 by leaving the projection member 4 in the concave groove portion 21a as it is. As described above, in this embodiment, the concave groove portion 21a of the steel pipe 2 and the installation of the projecting member 4 can be simultaneously performed by one press working, and the steel pipe pile 1 with the inner surface projection can be efficiently manufactured.

Further, in this embodiment, since the projecting member 4 is ring-shaped, there is an advantage that the hoop stress of the projecting member 4 facilitates fixing to the steel pipe inner surface 2a.

In addition, in the present embodiment, by making the amount of elastic deformation of the projecting member 4 smaller than that of the steel pipe 2, the projecting member 4 is prevented from falling when the projecting member 4 is pushed outward from the inside of the steel pipe 2 and attached. can be done. In addition, since the amount of elastic deformation of the projecting member 4 is set to be smaller than that of the steel pipe 2, the hoop stress of the projecting member 4 is likely to act, and the steel pipe 2 can be easily fixed to the concave groove portion 21a. Therefore, it is preferable that the projecting member 4 is made of high Young's modulus steel that can reduce the amount of elastic deformation.

In the method for manufacturing the steel pipe pile with inner protrusions, the method for constructing the steel pipe pile 1, and the steel pipe pile with inner protrusions according to the present embodiment described above, the steel pipe 2 is driven on site without the need for a hot rolling process or a welding process. After that, projections can be easily formed at arbitrary positions on the inner surface 2a of the steel pipe.

(First modification)
FIG. 2 shows a modification (first modification) of the first embodiment. A cutout portion 4b may be formed in a portion of the projection member 4 in the circumferential direction, and a detachable locking key member 41 may be provided in the cutout portion 4b.

As shown in FIG. 6(a), a press machine 6 holding a protruding member 4 having a ring-shaped notch 4b formed at a predetermined height position in the direction of the pipe axis O inside the cast steel pipe 2 is used. insert. Then, as shown in FIG. 6(b), the pressing plate 65 of the press working device 6 is projected outward in the pipe radial direction to expand the projecting member 4 and the steel pipe 2 from the inside to the outside. Pressing is performed, and the key member 41 is inserted into the gap (notch portion 4b) of the projecting member 4 whose diameter is expanded at this time by using the inserting device 68, thereby forming the projecting member as shown in FIG. 4 is attached to the inner surface 2 a of the steel pipe 2 . As a result, the steel pipe 2 is formed with a ridge 21 projecting outward in the pipe radial direction, and the protruding member 4 is fitted in the groove 21a formed by the ridge 21 on the inner surface 2a side. become.

In the first modified example, as shown in FIG. 2, a gap (notch portion 4b) is formed at a position in the circumferential direction of the projecting member 4, and a key member 41 for preventing removal is interposed in the notch portion 4b later. It can be inserted and fixed. In the first modified example, since a gap is formed by the notch 4b at a position in the circumferential direction of the projecting member 4, it is easy to spread during press working, and after spreading, the shape is predicted to return due to elastic deformation. By inserting the key member 41 for retaining the projection member 4, a hoop stress is generated in the projection member 4, and the projection member 4 can be easily provided on the steel pipe 2. - 特許庁In addition, in the present first modified example, the projecting member 4 may have a large elastic deformation, and a high-strength material may be used.

Next, another embodiment of the method for manufacturing a steel pipe pile with internal projections, the method for constructing the steel pipe pile 1, and the steel pipe pile with internal projections of the present invention will be described with reference to the accompanying drawings. The same or similar members and portions are denoted by the same reference numerals, and the description thereof is omitted, and the configuration different from that of the first embodiment will be described.

(Second embodiment)
The method for manufacturing the steel pipe pile 1 according to the second embodiment is a method in which the steel pipe 2 is pushed out from the inside to the outside by press working, and then the projecting member 4 is arranged on the steel pipe inner surface 2a to attach it.
Specifically, first, as shown in FIG. 7( a ), the press working device 6 is inserted at a predetermined height position in the pipe axis O direction inside the placed steel pipe 2 . Then, as shown in FIG. 7B, the pressing plate 65 of the press working device 6 is extended outward in the pipe radial direction to press the steel pipe 2 from the inside to the outside. Then, as shown in FIG. 7(c), a ridge 21 is formed on the steel pipe 2 so as to protrude outward in the pipe radial direction. After that, only the press working device 6 is pulled out from the steel pipe 2 .

Subsequently, as shown in FIGS. 8(a) and 9(a), the fixing jig 42 is used to reduce the diameter, that is, the notch 4b of the projecting member 4 is temporarily fixed in a state of being elastically deformed in a contracting direction. The projecting member 4 thus formed is lifted by a crane 52 while maintaining its deformed state.
Here, the ring-shaped projecting member 4 of the second embodiment is formed to have a diameter larger than the inner diameter of the steel pipe 2, and can be reduced in diameter in the circumferential direction within the range of elastic deformation of the projecting member 4 at the notch 4b. there is

Then, as shown in FIGS. 8(b) and 9(b), the suspended projection member 4 is lowered to a predetermined depth in the pipe by a crane 52, and a fixing jig is attached from above the steel pipe 2 by, for example, a string or a switch. 42 is removed. By removing the fixing jig 42, as shown in FIGS. 8(c) and 9(c), the elastic deformation of the projecting member 4 is released and elastic deformation occurs, and the previously formed ridges are removed. 21 is attached in a state of being integrally fitted into the recessed groove portion 21a. Thereafter, the suspension wire 53 is removed from the projecting member 4 by the crane 52, thereby completing the manufacture of the steel pipe pile 1. Therefore, it is preferable that the projecting member 4 in the second embodiment is made of a high-strength material having a large amount of elastic deformation.

According to the second embodiment, the press working device 6 is used in advance to locally dent the wall of the steel pipe 2 from the inner side to the outer side of the steel pipe 2 by press working to form the concave groove portion 21a, After that, the projecting member 4 can be mechanically fixed to the steel pipe 2 by arranging the projecting member 4 in the concave groove portion 21a. In this case, since the projecting member 4 is only provided by being fitted into the concave groove portion 21a of the steel pipe 2 without pressing itself, the press working device can be specialized for processing the wall of the steel pipe. .

(Third Embodiment)
Next, in the third embodiment, the projecting members 4 are formed on the inner surface 2a of the steel pipe 2 by press working after forming the ridges 21 by pressing the inner surface 2a of the steel pipe 2 at predetermined positions from the inside to the outside. How to install.
Specifically, in the above-described second embodiment, as shown in FIGS. The pressing device 6 is inserted inside, and as shown in FIG. 10(b), the protruding member 4 arranged in the concave groove portion 21a is expanded from the inside to the outside by pressing. Then, after the projecting member 4 is fitted into the recessed groove portion 21a and fixed, as shown in FIG. (illustration omitted) is filled, and construction of the steel pipe pile 1 is completed.

According to the third embodiment, the press working device 6 is used in advance to locally dent the wall of the steel pipe 2 from the inner side to the outer side of the steel pipe 2 by press working to form the concave groove portion 21a, Thereafter, the projecting member 4 can be mechanically fixed to the steel pipe 2 by disposing the projecting member 4 in the concave groove portion 21a and expanding the projecting member 4 from the inside to the outside by press working. In this case, the projecting member 4 can be reliably fitted and fixed to the recessed groove 21a by press working, and the projecting member 4 can be prevented from coming off or shifting from the recessed groove 21a.

(Second modification)
Next, a steel pipe pile 1A (a steel pipe pile with an inner surface projection) according to a second modification shown in FIGS. is partially provided with a projecting member 4A. A plurality of projecting members 4A according to the second modification are provided at intervals in the circumferential direction in the recessed groove portion 21a extending along the circumferential direction. These projecting members 4A may be manufactured by simultaneously pressing the steel pipe 2 and the projecting members 4A as in the first embodiment, or may be manufactured by previously forming recesses as in the third embodiment. A plurality of projecting members 4A may be arranged in the groove portion 21a.
The configuration such as the number, shape, arrangement intervals, etc., of these projecting members 4A can be appropriately set.

For example, the projecting member 4A is formed in an inclined shape having a first inclined surface 4c and a second inclined surface 4d in a direction that intersects the dropping direction of the projecting member 4A (direction of arrow E1 in FIG. 12).
The first inclined surface 4c is formed on the inner upper edge of the protruding member 4A and is inclined gradually upward from the inside toward the outside. The first inclined surface 4c is formed so as to be positioned inside the steel pipe 2 relative to the inner surface 2a of the steel pipe 2 in the pipe radial direction when the projecting member 4A is attached to the concave groove portion 21a.

In this case, when the axial force E1 due to the load on the top of the pile acts through the concrete 3, a force (arrow E2 ) acts to prevent the projecting member 4A from slipping out of the concave groove portion 21a.

4 d of 2nd inclined surfaces are formed in the inner lower edge of 4 A of protrusion members, and become an inclination which becomes downward gradually as it goes to an outer side from an inner side. 4 d of this 2nd inclined surface is formed so that it may be located inside the steel pipe 2 rather than the inner surface 2a of the steel pipe 2 in a pipe radial direction in the state which 4 A of projecting members were attached to the groove part 21a.
In this case, even when an upward force (arrow E3) acts on the concrete 3, a force (arrow E4) is generated in the direction of pressing the projecting member 4A against the concave groove portion 21a. It is possible to prevent slipping out of the groove portion 21a.

12 is set so that the center of gravity P of the projecting member 4A according to the second modification shown in FIG. there is The center of gravity P of the projecting member 4A may be the same position as the center position C of the steel pipe plate thickness t before the steel pipe 2 is spread. In this case, since the projecting member 4B is stably fixed to the concave groove portion 21a of the steel pipe 2, it is possible to suppress the projecting member 4A from falling. Here, in FIG. 12, symbol h indicates the projection dimension of the projecting member 4A inward from the steel pipe inner surface 2a, and symbol d indicates the vertical height of the projecting member 4A.

(Third modification)
A protruding member 4B made of a steel pipe pile 1B (a steel pipe pile with an inner surface protrusion) according to the third modification shown in FIG. It is The sharp piece 43 penetrates the steel pipe 2 and is firmly fixed when the projection member 4C is fitted into the concave groove portion 21a of the steel pipe 2 using the press working device 6 described above.
Furthermore, since a plurality of convex portions 44 are provided on the inner peripheral surface 4d of the protruding member 4C, the strength of adhesion to the concrete 3 filled in the steel pipe 2 can be increased.

Although the method for manufacturing a steel pipe pile with internal projections, the method for constructing a steel pipe pile, and the steel pipe pile with internal projections according to the present invention have been described above, the present invention is not limited to the above-described embodiments. It can be changed as appropriate without departing from the spirit.

For example, in the above-described embodiment, the object is construction for newly installing a steel pipe pile on the ground G, but it is also possible to apply the above-described method for manufacturing a steel pipe pile with an inner surface protrusion to an existing steel pipe pile. As a construction method in this case, a step of forming a recessed groove portion 21a (recessed portion) on the inner surface 2a of the steel pipe 2 of the existing steel pipe pile by press working, a step of attaching the projecting member 4 to the recessed groove portion 21a, and a step of attaching the projecting member 4 and a step of placing concrete 3 inside the attached existing steel pipe pile. Since it can be applied to existing steel pipe piles in this way, it can be used when it is desired to form a steel pipe concrete filling structure for the purpose of reinforcing existing structures.

Also, the configuration of the press working device 6 is not limited to the configuration of the embodiment described above. For example, the shape and quantity of the pressing plate 65 can be arbitrarily set.

Furthermore, the shape and size of the projecting member 4 can be set appropriately. For example, in the above-described second modification, the projecting member 4 has a first inclined surface 4c and a second inclined surface 4d that intersect the falling direction of the projecting member 4 and intersect the falling direction of the projecting member 4. However, a shape without such inclined surfaces 4c and 4d may be employed, or only one of the inclined surfaces 4c and 4d may be provided. Alternatively, as in the second modification, the center of gravity of the protruding member may be limited to a position outside the central position of the thickness of the steel pipe before spreading in the pipe radial direction, or at the same position. no.

Moreover, it is also possible to employ a projecting member made of a shape memory alloy. For example, as a shape memory alloy, it is possible to adopt a material having a property that it expands when the projecting member is heated and retains its shape. As a construction method in this case, for example, when the projecting member is installed, it may be heated by applying a heater, or may be heated by directly applying an electric current to the projecting member. Further, other shape memory alloys may be made of a material that shrinks when the projecting member is cooled and returns to its original size when the temperature reaches room temperature. As a construction method in this case, for example, a method of cooling with liquid nitrogen, cold water, a freezer, or the like before installing the projecting member can be adopted.

In addition, it is possible to appropriately replace the components in the above-described embodiments with well-known components without departing from the scope of the present invention.

1, 1A, 1B Steel pipe piles (steel pipe piles with internal protrusions)
2 Steel pipe (foundation pile)
2a inner surface 3 concrete (solidifying member)
4, 4A, 4B Protruding member 4b Notch 6 Press working device 21 Ridge 21a Groove (recess)
41 Key member 42 Fixing jig 65 Pressing plate O Tube shaft

Claims (15)

forming recesses in the inner surface of the steel pipe by pressing the steel pipe from the inner side to the outer side in the pipe radial direction;
attaching a projecting member to the recess;
A method for manufacturing a steel pipe pile with an inner surface protrusion, characterized by having The method for manufacturing a steel pipe pile with an internal projection according to claim 1, wherein the steel pipe and the projecting member are simultaneously pushed outward from the inside by pressing to attach the projecting member to the inner surface of the steel pipe. . The method for manufacturing a steel pipe pile with an inner surface projection according to claim 1, wherein the steel pipe is expanded from the inside to the outside by press working, and then the projection member is arranged on the inner surface of the steel pipe to be attached. The method for manufacturing a steel pipe pile with internal projections according to claim 1, wherein the projecting member is attached to the inner surface of the steel pipe by press working after the steel pipe is expanded from the inside to the outside by press working. The method for manufacturing a steel pipe pile with an inner surface projection according to any one of claims 1 to 4, wherein the projection member is formed in a ring shape. 6. The method according to any one of claims 1 to 5, wherein the projecting member extends in the circumferential direction along the steel pipe, and a retaining key member is inserted in a part of the projecting member in the circumferential direction. A method for manufacturing a steel pipe pile with internal projections according to any one of the above items. The method of manufacturing a steel pipe pile with internal projections according to any one of claims 1 to 6, wherein the projection member is formed with a higher strength than the steel pipe. The method for manufacturing a steel pipe pile with an inner surface projection according to any one of claims 1 to 7, wherein the amount of elastic deformation of the projection member is smaller than that of the steel pipe. The method for manufacturing a steel pipe pile with an inner surface projection according to any one of claims 1 to 8, wherein the projection member is made of a shape memory alloy. The method for manufacturing a steel pipe pile with an inner surface projection according to any one of claims 1 to 9, wherein the projecting member has an inclined surface in a direction intersecting the fall direction of the projecting member. 11. The center of gravity of the protruding member is located outside or at the same position as the central position of the thickness of the steel pipe before spreading in the steel pipe in the radial direction of the pipe. A method for manufacturing a steel pipe pile with an inner surface projection according to the item. A construction method for a steel pipe pile, wherein the steel pipe used in the method for manufacturing a steel pipe pile with an internal projection according to any one of claims 1 to 11 is installed in the ground and constructed. A step of driving the steel pipe into the ground;
a step of attaching the projecting member to the recess formed in the inner surface of the steel pipe driven into the ground;
placing concrete inside the steel pipe to which the projecting member is attached;
The steel pipe pile construction method according to claim 12, characterized by comprising: A step of forming the recess by press working on the inner surface of the steel pipe of the existing steel pipe pile;
a step of attaching the projecting member to the recess;
placing concrete inside the existing steel pipe pile to which the projecting member is attached;
The steel pipe pile construction method according to claim 12, characterized by comprising: A steel pipe pile with internal projections, characterized by being manufactured by the method for manufacturing a steel pipe pile with internal projections according to any one of claims 1 to 11.

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