JP2013112953A - Steel pipe pile connection structure - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a steel pipe pile connection structure suitable as a screw-in type steel pipe pile connection structure for connecting steel pipe piles at a site where it is difficult to do welding work.SOLUTION: A plurality of approximately chevron-shaped cutout parts having same-size shapes are provided at each of the connection ends of the upper and lower steel pipe piles continuously in one direction. Plate-like members mounted on the long pieces of the plurality of cutout parts are flanges bolt-joined to each other.

Description

  TECHNICAL FIELD The present invention relates to a steel pipe pile connection structure that connects steel pipe piles at a place where the construction time can be shortened and a welding operation is difficult, and particularly relates to a connection structure for a screw-in type steel pipe pile.

  When it is intended to secure a large bearing capacity in a place where the support layer is deep on soft ground, a pile foundation that penetrates to the support layer is often used. Concrete piles and steel pipes are used as pile bodies, but the length of about 15m per pile is the limit due to restrictions on transportation and construction. It is necessary to join in the direction.

  When steel pipe piles are joined together, the outer periphery of the joint is often welded, but in that case, welding work at the construction site of the pile is required, so securing the welder, increasing costs due to welding time, quality of the welded part Management can be a problem. Welding is prohibited at construction sites where flammable gas such as methane gas is generated. Therefore, various mechanical joints that connect steel pipe piles without welding have been developed.

  For example, Patent Document 1 attaches a disk having a diameter larger than the diameter of the steel pipe to the end of the steel pipe, bolts the flange portion protruding from the periphery of the pile, and tightens the outer fitting ring having a U-shaped cross section that fits the flange. We have proposed a structure for joining steel pipes.

  In Patent Document 2, after attaching the flanges at the ends of the steel pipe, the abutting portion between the flanges is tightened with an inner ring and an outer ring that are inscribed with a tapered surface from the outer peripheral side, and the centering and engagement of the upper and lower piles are performed. We propose an easy-to-join joint structure.

  In Patent Document 3, a cylinder united with a key mechanism is attached to each end of a steel pipe to be connected, divided into male and female cylinders, and a key member made of an arcuate plate-like protrusion is provided on the fitting surface on the tip side. A joint structure is proposed in which a male cylinder is inserted into a female cylinder and then the steel pipe is rotated to insert the key member into a key groove forming portion of the female cylinder and connect it.

  The mechanical performance required for pile joints is to transmit the axial compression force, tensile force, bending and shear sufficiently, but when using the rotary penetration method as the construction method of foundation pile, In order to apply rotational torque to the end of a screw-type steel pipe pile (sometimes referred to as rotary penetration pile), the joint is required to have a function of sufficiently transmitting the rotational torque in addition to connecting the pile length direction. The

  Patent document 4 relates to a joint structure of a steel pipe pile that is driven in a rotary press manner. A gap is provided between the ends of upper and lower steel pipes at a joint, and bolts are arranged at equal intervals in the circumferential direction from the outside of a sleeve that covers the joint. Is inserted into a gap, and the bolt is screwed to a support block having a length extending over the upper and lower steel pipes, and the support block and the sleeve are fastened to connect the upper and lower steel pipes.

Japanese Patent Laid-Open No. 08-41871 JP 2009-191522 A JP 2006-28913 A JP 2006-299665 A

  However, the methods described in Patent Document 1 and Patent Document 2 cannot sufficiently transmit the rotational torque via the joint, and therefore cannot be used for a rotating penetrating steel pipe pile on which excessive torque acts. Further, in the method described in Patent Document 1, since the flange portion of the flange joint is larger than the pile diameter, resistance during penetration is caused and workability is deteriorated. Moreover, since the flange part plays the role of friction cut, there is a problem that the peripheral surface frictional force of the pile is lowered and the supporting force during service is lowered. In the joint described in Patent Document 3, the structure of the fitting portion is complicated, and the processing cost of the joint portion increases.

  In the method of Patent Document 4, torque is transmitted for forward rotation, but the joint performance is not sufficient to transmit torque for reverse rotation (pulling direction), and pulling out by reverse rotation is performed. It cannot be said that the joint is suitable for rotational penetration considering the above.

  Then, an object of this invention is to provide the steel pipe pile joint which solved the said problem.

The above problem can be achieved by the following means.
1. A steel pipe pile connection structure in which flanges provided at connection ends of upper and lower steel pipe piles are bolted to each other, and each of the connection ends of the upper and lower steel pipe piles has a substantially notched portion having the same size and shape. A steel pipe pile connection characterized in that a plurality of flanges provided continuously in one direction and provided at the connection end of the upper and lower steel pipe piles are composed of plate-like members attached to long pieces of the plurality of notch portions. Construction.
2. The plate-like member has a shape obtained by dividing a disk by the number of substantially notch-shaped notches at the connection end, and the upper and lower steel pipe piles are formed by plate-like members on the long sides of the plurality of notch-like notches. 2. The steel pipe pile connection structure according to claim 1, wherein the outer edge of the steel pipe pile is attached so as to be a part of a substantially circular shape in the radial direction of the connection structure of the upper and lower steel pipe piles.
3. 3. The steel pipe pile connection structure according to claim 2, wherein the disk is an annular disk having a center part through which pipe soil can pass.
4). It is a steel pipe pile connection structure that bolts flanges provided at the connection ends of the upper and lower steel pipe piles, and each of the connection end parts of the upper and lower steel pipe piles is in mesh with each other, and the connection end of the upper and lower steel pipe piles The steel pipe pile connection structure according to claim 1, wherein the flange provided on the plate comprises a plate-like member attached along the spiral connection end.
5. The steel pipe pile connection structure according to any one of 1 to 4, wherein the diameters of the upper and lower steel pipe piles are different.
6). The steel pipe pile connection structure according to any one of 1 to 5, wherein flanges provided at connection end portions of the upper and lower steel pipe piles are bolted together in a sinking structure.

According to the present invention, the following effects can be obtained, which are extremely useful industrially.
1. Since the flange part is inclined, the surrounding ground is cut into a spiral like a rotary blade of a rotary intrusion pile during construction, and a propulsive force is generated.
2. If the cutting pitch of the rotating blades of the rotary penetration pile is the same as the pitching pitch of the inclined flange, the resistance to the flange portion at the time of rotary penetration is reduced, and the effect on workability is also small.
3. Further, since the ground is cut instead of being pushed apart, there is little breakage of adhesion with the surrounding ground, and sufficient circumferential friction can be ensured.
4). Furthermore, when the bearing pile is used, when the bearing capacity needs to be demonstrated due to an earthquake or the like, the flange portion resists and transmits the vertical load to the peripheral ground, so that a large bearing capacity can be secured.

The figure which shows the shape of the edge part of the steel pipe pile in the connection structure of the steel pipe pile which concerns on one Example of this invention. The figure which shows the shape of the edge part of the steel pipe pile in the connection structure of the steel pipe pile which concerns on one Example of this invention. The figure explaining the plate-shaped member in the connection structure of the steel pipe pile which concerns on one Example of this invention. The figure explaining the plate-shaped member in the connection structure of the steel pipe pile which concerns on one Example of this invention. The figure explaining the structure of the edge part of an upper steel pipe pile by the connection structure of the steel pipe pile which concerns on one Example of this invention. The figure explaining the state which has arrange | positioned the edge part of the upper and lower steel pipe pile facing each other in the connection structure of the steel pipe pile which concerns on one Example of this invention. The figure which shows the state which connected the edge part of the upper and lower steel pipe pile opposingly arranged in FIG. The figure which shows the state which attached the plate-shaped member to the edge part of the steel pipe pile made into the spiral, and opposedly arranged. The figure which applied the connection structure of the steel pipe pile which concerns on one Example of this invention in the case where a lower steel pipe pile is a screwed-type steel pipe pile. The side view of the connection structure of the steel pipe pile shown in FIG. The side view at the time of bolt-joining with the connection structure of the steel pipe pile shown in FIG. The figure explaining the flange part which carried out the bolt connection as a pillow head structure.

  The steel pipe pile connection structure according to the present invention is characterized in that the flange portion is formed obliquely with respect to the pile axis. Hereinafter, the present invention will be described in detail with reference to the drawings.

  FIG. 1 shows the shape of an end portion of a steel pipe pile 1 in a steel pipe pile connection structure according to an embodiment of the present invention, and two substantially L-shaped notches having the same dimensional shape are provided continuously in one direction. FIG. 2 shows a case where four substantially L-shaped notches are provided continuously in one direction.

  In the end portion of the steel pipe pile 1 shown in the figure, the notch is processed obliquely with respect to the pile axis direction of the short side 4a (4b, 4c, 4d) and the long side 3a (3b, 3c, 3d) with respect to the pile axis direction. Yes.

  In the steel pipe pile connection structure according to the present invention, the flange portion is configured by attaching a plate-like member to the long piece of the notch portion that is processed obliquely with respect to the pile axis direction by welding or the like. The shape of the plate-like member is not particularly limited as long as it has a shape with low resistance when the steel pipe pile is screwed into the ground.

  A shape obtained by dividing the disk by the number of notches at the end of the steel pipe pile is preferable because resistance when screwing the steel pipe pile into the ground is reduced. FIG. 4 (a) shows semicircular plate-like members 5a and 5b used as flanges when there are two substantially L-shaped notches at the connection end (in the case of the steel pipe of FIG. 1). The plate-like members 5a and 5b are provided with a plurality of bolt holes 8a and 8b for bolting flanges together.

  The figure shows a state in which the plate-like members 5a and 5b are attached to the long side (not shown) of the substantially L-shaped notch, and the plate-like members 5a and 5b intersect in the pile axis direction.

  FIG. 4B shows fan-like plate-like members 5c, 5d, 5e, and 5f that are used as flanges when there are four substantially L-shaped notches at the connection end (in the case of the steel pipe of FIG. 2). The plate-like members 5c, 5d, 5e, and 5f are provided with a plurality of bolt holes 8c, 8d, 8e, and 8f for bolting the flanges together.

The figure shows a state in which the plate-like members 5c, 5d, 5e, and 5f are attached to the long side (not shown) of the substantially L-shaped notch, and the plate-like members 5c, 5d, 5e, and 5f intersect in the pile axis direction. doing.
When the pile tip is opened, earth and sand enter the steel pipe at the time of construction, but in order to improve the workability, the pipe soil can be divided into plate-like members 5a and 5b. The disc is an annular disc having a central part through which the pipe soil can pass (FIG. 3).

  When a plate-like member is attached to the long side of the notch at the end of the steel pipe pile, a virtual line connecting the outside of the attached plate-like members (the outer edge on the outer periphery side of the steel pipe pile) is connected to the upper and lower steel pipe piles. It is attached so as to draw a substantially circular shape in the radial direction of the structure. The outer edge of each plate-like member is a part of the substantially circular shape.

  The procedure which comprises the connection structure of the steel pipe pile concerning this invention to FIGS. 5-7 is shown about the case of the head-expansion joint from which the diameter of an upper and lower steel pipe pile differs. First, the semicircular plate-like members 5a and 5b having the bolt holes 8a and 8b are attached to the long sides of the notches at the steel pipe ends of the steel pipe pile 1 by the above-described method (FIG. 5).

  If the diameters of the upper and lower steel pipe piles are different, attaching semi-circular plate-like members 5a and 5b to the notch will create an opening corresponding to the pile diameter difference at the step (short side of the notch). In order to firmly bond the flange, it is preferable that the closing plate 7 is attached to the opening, and the plate-like members 5a and 5b are joined inside the steel pipe pile. However, at the stage where the upper and lower steel pipe piles are connected by bolt connection, the meshing of the notch portions is important, and therefore, when the closing plate 7 has an adverse effect, it is not attached.

  Next, the steel pipe pile 1 to which the semicircular plate-like members 5a and 5b are attached as flanges is used as the upper steel pipe pile, and the steel pipe pile 2 to which the semicircular plate-like members 6a and 6b are attached in the same manner. As the lower steel pipe piles, the semi-circular plate-like members 5a and 5b and the plate-like members 6a and 6b are overlapped so as to face each other so that the notches processed at the respective pile ends engage with each other (FIG. 6). These are combined to form a flange portion and bolted with bolts 9 (FIG. 7). FIG. 10 shows a side view of the upper and lower steel pipe piles arranged opposite to each other shown in FIG. 6, and FIG. 11 shows a side view of the upper and lower steel pipe piles to which the flange shown in FIG.

  In the steel pipe pile connection structure according to the present invention, the plate-like members constituting the flange portion are attached to the pile end portions so as to cross each other in a propeller shape, oblique to the pile axis direction. When it is screwed into the flange, it plays a role as a wing that causes a propulsion force that the flange portion cuts through the peripheral ground.

  FIG. 9 shows a case in which the lower steel pipe pile 2 is a screwed steel pipe pile among the upper and lower steel pipe piles, and the plate-like member 5a attached to the rotation pitch of the rotary blades 10a and 10b of the screwed steel pipe pile 2 and the notch. When the shape of the notch portion is selected so that the rotation pitches of 5b and 5b are the same, the threaded penetration of the steel pipe pile 2 becomes smooth. A propeller wing may be separately provided in the middle of the pile.

  In the case of a head-expansion joint, the short side in the pile axis direction of the notch portion at the flange portion becomes a stepped portion, so that the steel pipe pile is supported by the peripheral ground. Therefore, the pile axis does not tilt from the vertical direction even when a rotational torque is applied in the forward rotation direction (clockwise penetration direction when the flange is configured to be a right-hand thread), and the steel pipe pile is screwed into the ground. The rotational torque from the rotary drive device is transmitted well to the steel pipe pile.

  The number, nominal diameter, and tightening force of the bolts 9 used to join the flanges with bolts should have sufficient strength against the axial tensile force, shear, bending, and rotational torque acting on the connection part of the upper and lower steel pipe piles. Select. For example, when joining steel pipe piles of φ600 × t12 (mm), it is good to join by tightening a total of 12 M18 bolts at equal intervals to both flanges. The surface of the flange may be processed so as to increase the frictional force.

  Since the flange portion acts as a rotor blade during rotation penetration, if the bolt hole 8 in the flange portion is a counterbore and the nut 10 at the head of the bolt 9 is embedded (a subsidence structure), the flow of sediment around the flange Is preferable because it is smooth (FIG. 12).

Although the above description was given about the case where a plurality of notch parts were provided in the upper and lower steel pipe pile end parts, the pile end parts may be spiral. However, when the upper and lower steel pipe pile ends are connected, the pile end spirals are provided so that the pile axes of the upper and lower steel pipe piles are straight. FIG. 8 shows a connection structure in which the ends of the upper steel pipe pile 1 and the lower steel pipe pile 2 are spiral, and the spiral plate-like members 5 and 6 are attached to the respective ends.
When the lower steel pipe pile 2 is a screwed steel pipe pile, if the spiral pitch at the end of the steel pipe and the pitch of the screwed steel pipe pile are the same, the screw penetration is smooth and desirable.

  In addition, the connection structure of the steel pipe pile which concerns on this invention is applicable not only to a rotation pile but to a Nakabori pile, a pre-boring pile, etc.

1 Steel pipe pile (upper)
2 Steel pipe pile (downward)
3a, 3b, 3c, 3d Long side 4a, 4b, 4c, 4d Short side 5, 5a, 5b Plate member (upper)
6, 6a, 6b Plate member (downward)
7 Blocking plate 8, 8a, 8b Bolt hole 9 Bolt 10 Nut 10a, 10b Rotary blade

Claims (6)

  A steel pipe pile connection structure in which flanges provided at connection ends of upper and lower steel pipe piles are bolted to each other, and each of the connection ends of the upper and lower steel pipe piles has a substantially notched portion having the same size and shape. A steel pipe pile connection characterized in that a plurality of flanges provided continuously in one direction and provided at the connection end of the upper and lower steel pipe piles are composed of plate-like members attached to long pieces of the plurality of notch portions. Construction.   The plate-like member has a shape obtained by dividing a disk by the number of substantially notch-shaped notches at the connection end, and the upper and lower steel pipe piles are formed by plate-like members on the long sides of the plurality of notch-like notches. 2. The steel pipe pile connection structure according to claim 1, wherein the outer edge of the steel pipe pile is attached so as to be a part of a substantially circular shape in the radial direction of the connection structure of the upper and lower steel pipe piles.   The steel pipe pile connection structure according to claim 2, wherein the disk is an annular disk having a central portion through which pipe soil can pass.   It is a steel pipe pile connection structure that bolts flanges provided at the connection ends of the upper and lower steel pipe piles, and each of the connection end parts of the upper and lower steel pipe piles is in mesh with each other, and the connection end of the upper and lower steel pipe piles The steel pipe pile connection structure according to claim 1, wherein the flange provided on the plate comprises a plate-like member attached along the spiral connection end.   The steel pipe pile connection structure according to any one of claims 1 to 4, wherein the upper and lower steel pipe piles have different diameters.   The steel pipe pile connection structure according to any one of claims 1 to 5, wherein the flanges provided at the connection end portions of the upper and lower steel pipe piles are bolted together in a sinking structure.

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