JP2015183388A - Steel pipe connection structure and steel pipe connection method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide highly reliable steel pipe connection structure and steel pipe connection method without making a rotation suppressing key fall off, even when falling off or being ruptured by loosening of a bolt for fixing the rotation suppressing key straddlingly provided in a joint of both steel pipes for suppressing relative rotation around the axis of a vertically arranged steel pipe for constituting a steel pipe pile in erection construction of the steel pipe pile.SOLUTION: A steel pipe connection structure constitutes a key arranging part 40 by cooperating between an upper side cutout part 40A formed along the circumferential direction on the peripheral edge of a lower end part of an upper side steel pipe 10A and capable of inserting a rotation suppressing key 50 upward from the lower end part and a lower side cutout part 40B formed in a position corresponding to the upper side cutout part 40A along the circumferential direction on the peripheral edge of an upper end part of a lower side steel pipe 10B and capable of inserting the rotation suppressing key 50 downward from the upper end part, and is provided with a falling-off preventive mechanism for suppressing the rotation suppressing key 50 from falling off from the key arranging part 40, on a side surface of the rotation suppressing key 50 and a side surface of the key arranging part 40.

Description

  The present invention relates to a steel pipe coupling structure configured to inhibit relative rotation around the axis of both steel pipes by straddling a rotation inhibition key across the joints of the steel pipes arranged on the top and bottom of the steel pipe pile, and The present invention relates to a steel pipe connection method.

  Conventionally, steel pipe piles have been widely used as foundation structures such as bridges, harbor structures, and building structures.

  Such steel pipe piles need to be built several tens of meters in the ground to reach the support layer, which is hard ground below the soft ground. Therefore, a predetermined length is ensured by connecting steel pipes of a fixed length of about several meters, which are manufactured at the factory, while being built underground at the site.

Regarding the steel pipe connection structure, Patent Document 1 discloses a mechanical joint in order to improve the efficiency of the steel pipe pile joint work at the construction site from the viewpoint of labor saving and shortening the work period.
The mechanical joint is made by fitting a female box joint welded to the lower end of the upper steel pipe and a male pin joint welded to the upper end of the lower steel pipe together to form a key groove in the box joint. The built-in load transmission key is pushed and fixed to the groove on the pin joint side using bolts. And in order to suppress that both the said steel pipe mutually rotate around an axis | shaft, the rotation suppression key is being fixed with the volt | bolt so that the joint line of both the said steel pipes may be straddled.

JP 2000-319874 A

  Such a steel pipe pile is installed in the ground while hitting a hydraulic hammer or the like, installed in the ground while applying vibration with a vibro hammer, excavating the hollow part of the pile body It is built in the ground by the Nakabori method, a rotary press-fitting method that presses into the ground while rotating with blades attached to the tip.

  When installing steel pipe piles, the bolts that fix the rotation depressing key loosen and fall off or break because the hammer or vibration acts on the joints of the steel pipe piles. There is a possibility that the rotation inhibition key may drop off. In particular, in the rotary press-fitting method, the rotation of the upper steel pipe is not transmitted to the lower steel pipe, and there is a possibility that the construction cannot be performed.

  An object of the present invention is to provide a rotation straddling the joint of both the steel pipes in order to suppress relative rotation around the axis of the steel pipes arranged above and below that constitute the steel pipe piles during the construction of the steel pipe piles. An object of the present invention is to provide a highly reliable steel pipe connection structure and a steel pipe connection method in which the rotation suppression key does not drop even if a bolt for fixing the inhibition key is loosened and dropped or broken.

  The characteristic structure of the steel pipe connection structure according to the present invention is to suppress relative rotation around the axis of both the steel pipes by straddling a rotation inhibition key at the joint of the steel pipes arranged on the top and bottom constituting the steel pipe pile. It is a steel pipe connection structure comprised in this, It is formed along the peripheral direction of the lower end part of an upper steel pipe along the peripheral direction, and can insert the above-mentioned rotation inhibition key from the said lower end part along the axial direction of the upper steel pipe The upper notch and the peripheral edge of the upper end of the lower steel pipe are formed along the circumferential direction at a position corresponding to the upper notch, and downward from the upper end along the axial direction of the lower steel pipe. A key disposition portion for disposing the rotation restraining key, a side surface of the rotation restraining key, and the key disposition formed by cooperation of a lower notch portion into which the rotation restraining key can be inserted. On the side of the part, the rotation inhibiting key is detached from the key arrangement part. There in that and a captive to suppress Rukoto, risk is eliminated that the rotation inhibiting key by captive from falling from the key arrangement portion.

  The drop-off prevention mechanism includes an engaging portion provided in the rotation suppression key and an engaged portion provided in the key disposing portion, and the engaging portion faces outward in the radial direction. A first abutting surface, and the engaged portion includes a second abutting surface facing inward in the radial direction and facing the first abutting surface; With the simple configuration of physical contact of the second contact surface, it is possible to reliably prevent the rotation suppression key from falling off the key arrangement portion.

  Further, the drop-off prevention mechanism may be constituted by a reverse taper portion formed on a side surface of the rotation inhibition key and a side surface of the key arrangement portion, and the rotation inhibition key is arranged on the key by the inverse taper configuration. The possibility of falling off the part is reliably suppressed. In addition, the surface which comprises the said reverse taper part may be either a plane or a curved surface.

  Since a hole for inserting a bolt is drilled in the rotation inhibition key, and the rotation inhibition key is fixed to the lower steel pipe by a bolt, the rotation inhibition key is attached to the lower steel pipe. Since it can be fixed, rattling of the rotation suppression key provided in the key arrangement portion is prevented.

  A characteristic configuration of a steel pipe connection method according to the present invention is a steel pipe connection method of steel pipes arranged vertically with a steel pipe connection structure having the above-described characteristic configuration, and is a lower steel pipe standing on the ground After disposing the rotation restraining key in the lower notch portion, the upper steel pipe is located on the lower steel pipe so that the rotation restraining key is disposed in the upper notch portion. Simultaneously with connecting the steel pipes, the fall prevention key is prevented from dropping from the key arrangement portion by the drop-off prevention mechanism.

  The characteristic structure of the steel pipe connection structure according to the present invention is to suppress relative rotation around the axis of both the steel pipes by straddling a rotation inhibition key at the joint of the steel pipes arranged on the top and bottom constituting the steel pipe pile. A steel pipe connection structure configured in the upper steel notch portion formed along the circumferential direction of the lower end portion of the upper steel pipe, and the circumferential direction of the upper edge portion of the lower steel pipe along the circumferential direction, and A key disposition portion for disposing the rotation inhibition key, which is configured by cooperation of a lower notch portion formed at a position corresponding to the upper notch portion, and an outer surface of the rotation inhibition key. The engagement portion provided and the engagement portion and the engagement portion provided on the inner surface of the key arrangement portion, the inner width being shorter than the outer width of the engagement portion in a front view of the rotation suppression key. A drop-off prevention mechanism configured with a matable engaged portion, and at least the rotation inhibiting key or the front The length of the outer width any key arrangement portion is in that it has an elastically deformable deformation portion as relatively shorter than the length of the inner width. According to this configuration, the wide rotation suppression key can be inserted into the narrow key arrangement portion by elastically deforming the rotation inhibition key or the key arrangement portion. After the rotation inhibiting key is arranged in the key arrangement part, the rotation inhibiting key may be dropped from the key arranging part by engaging the engaging part and the engaged part. Deterred.

  Further, the engaging portion includes a first contact surface facing outward in the radial direction, and the engaged portion faces inward in the radial direction and faces the first contact surface. A second contact surface, and an inclined surface that contacts the back surface of the second contact surface on the back surface of the first contact surface. While being guided by the back surface of the two abutting surfaces, the key is smoothly inserted into the key arrangement portion. At this time, deformation of the rotation suppression key is urged by a pressing force acting on the inclined surface from the back surface of the second contact surface.

  In addition, the deformation portion includes a groove portion formed in a direction orthogonal to the outer width direction on the front surface of the rotation suppression key, so that when the rotation suppression key is inserted into the key arrangement portion, The rotation inhibiting key can be elastically bent with the groove portion as a base point.

  A characteristic configuration of a steel pipe connection method according to the present invention is a steel pipe connection method of steel pipes arranged vertically with a steel pipe connection structure having the above-described characteristic configuration, and is a lower steel pipe standing on the ground An upper steel pipe is suspended above, and a key arrangement portion is formed by hanging the upper steel pipe so that the upper notch portion of the upper steel pipe corresponds to the lower notch portion of the lower steel pipe. The rotation inhibiting key is elastically deformed and inserted, and the rotation inhibiting key or the key disposing portion is elastically deformed, so that the wide key disposing key is widened. The rotation inhibiting key can be inserted, and after the rotation inhibiting key is arranged at the key arrangement portion provided at the joint of the steel pipe arranged above and below, the engagement portion and the When the engaged portion is engaged, the rotation suppression key becomes the key It is prevented from falling off the portion.

  According to the present invention, during the construction of the steel pipe pile, the rotation straddled between the joints of the two steel pipes in order to suppress relative rotation around the axis of the steel pipe disposed above and below the steel pipe pile. It is possible to provide a highly reliable steel pipe connection structure and a steel pipe connection method in which the rotation suppression key does not drop even if a bolt for fixing the inhibition key is loosened and dropped or broken.

It is a perspective view of the steel pipe provided with the steel pipe connection structure of 1st embodiment by the 1st aspect of this invention. It is the perspective view which cut and showed the principal part of the steel pipe connection structure shown in FIG. 1 among some circumferences, Comprising: (a) is a figure which shows the state before the connection of an upper and lower steel pipe, (b) It is a figure which shows the state after the connection of an upper and lower steel pipe. It is a perspective view of the rotation suppression key and key arrangement | positioning part of 1st embodiment by a 1st aspect. It is sectional drawing of the rotation suppression key and key arrangement | positioning part of 1st embodiment by a 1st aspect. It is a perspective view of the rotation suppression key of 2nd embodiment by a 1st aspect. It is sectional drawing of the rotation suppression key and key arrangement | positioning part of 2nd embodiment by a 1st aspect. It is a perspective view of the rotation suppression key of 3rd embodiment by a 1st aspect. It is sectional drawing of the rotation suppression key and key arrangement | positioning part of 3rd embodiment by a 1st aspect. It is a perspective view of the rotation suppression key of 4th embodiment by a 1st aspect. It is sectional drawing of the rotation suppression key and key arrangement | positioning part of 4th embodiment by a 1st aspect. It is a perspective view of the rotation suppression key of 5th embodiment by a 1st aspect. It is sectional drawing of the rotation suppression key and key arrangement | positioning part of 5th embodiment by a 1st aspect. It is sectional drawing of the rotation suppression key and key arrangement | positioning part of 6th embodiment by a 1st aspect. It is sectional drawing of the rotation suppression key and key arrangement | positioning part of 7th embodiment by a 1st aspect. It is sectional drawing of the rotation suppression key and key arrangement | positioning part of 8th embodiment by a 1st aspect. It is sectional drawing of the rotation suppression key and key arrangement | positioning part of 9th embodiment by a 1st aspect. It is a perspective view of the steel pipe provided with the steel pipe connection structure of a first embodiment by the 2nd mode of the present invention. It is the perspective view which cut and showed the principal part of the steel pipe connection structure shown in FIG. 17 among some circumferences, Comprising: (a) is a figure which shows the state before the connection of an upper and lower steel pipe, (b) It is a figure which shows the state after the connection of an upper and lower steel pipe. It is a perspective view of the rotation suppression key of 1st embodiment by a 2nd aspect. It is sectional drawing of the rotation suppression key and key arrangement | positioning part of 1st embodiment by a 2nd aspect, Comprising: (a) is a figure which shows the state before inserting a rotation inhibition key in a key arrangement | positioning part, (b) ) Is a diagram showing a state where a rotation inhibiting key is inserted into the key arrangement part, and (c) is a diagram showing a state after the rotation inhibiting key is fitted into the key arrangement part. It is a perspective view of the rotation suppression key of 2nd embodiment by a 2nd aspect. It is sectional drawing of the rotation suppression key and key arrangement | positioning part of 2nd embodiment by a 2nd aspect. It is a perspective view of the rotation suppression key of 3rd embodiment by a 2nd aspect. It is sectional drawing of the rotation suppression key and key arrangement | positioning part of 3rd embodiment by a 2nd aspect. It is a perspective view of the rotation suppression key of 4th embodiment by a 2nd aspect. It is sectional drawing of the rotation suppression key and key arrangement | positioning part of 4th embodiment by a 2nd aspect.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. In the drawings, the same or corresponding parts are denoted by the same reference numerals.

FIG. 1 shows a steel pipe 10 having a steel pipe connection structure according to a first embodiment of the first aspect of the present invention.
A male pin joint 20 is attached to the upper end of the steel pipe 10 by being welded at the welded portion 12 in the factory, and a female box joint 30 is attached to the lower end by being welded by the welded portion 13 in the factory. .

The steel pipe pile is configured by connecting such steel pipes 10 up and down, but the steel pipe connection structure between the steel pipes 10 connected up and down has the same configuration at all the connection points.
In the following description, the steel pipe connection structure of the steel pipe 10 will be described by paying attention to a specific upper steel pipe and lower steel pipe that are in a vertical relationship.

  As shown in FIGS. 2 (a) and 2 (b), among the “up and down steel pipes” according to the present invention, the upper steel pipe 10A is a relatively lower steel pipe located on the upper side. The steel pipe located in is called the lower steel pipe 10B.

  The upper steel pipe 10A and the lower steel pipe 10B have the pin joint 20 of the lower steel pipe 10B inserted into the box joint 30 of the upper steel pipe 10A, and the load transmission key 31 (31A, 31B) incorporated in the box joint 30 is a pin joint. By being inserted into the 20 key grooves 21, they are coupled so that relative movement in the vertical direction is impossible. A rotation inhibition key 50 is straddled across the joint 14 between the pin joint 20 and the box joint 30 so that relative rotation around the axis is impossible.

The pin joint 20 is formed in a cylindrical shape, and a fitting insertion portion 22A having a diameter smaller than that of the cylindrical portion 22B is extended continuously to the cylindrical portion 22B having the same diameter as the outer diameter of the lower steel pipe 10B.
An engagement recess 23 into which an engagement protrusion 33 provided at the lower end portion of the box joint 30 is inserted is provided at the base end portion of the outer periphery of the fitting insertion portion 22A.
At the upper end portion of the fitting insertion portion 22A, an engagement convex portion 24 for insertion into an engagement concave portion 34 provided over the entire circumference at the proximal end portion of the inner periphery of the box joint 30 is provided over the entire circumference.
Further, two key grooves 21 (21A, 21B) into which the upper and lower two-stage load transmission keys 31 (31A, 31B) are fitted are provided on the outer periphery of the insertion portion 22A.

  The box joint 30 is formed in a cylindrical shape having an outer diameter substantially the same as the outer diameter of the upper steel pipe 10A. The inner periphery of the box joint 30 is a non-insertion portion of the insertion portion 22 </ b> A of the pin joint 20, and the engagement convex portion 33 is inserted into the engagement concave portion 23 of the pin joint 20. In addition, an engagement recess 34 into which the engagement projection 24 of the pin joint 20 is inserted is provided on the inner periphery on the proximal end side of the box joint 30 over the entire circumference.

  Two key grooves 35 (35A, 35B) are formed in the inner periphery of the box joint 30 in the circumferential direction. In the key groove 35 (35A, 35B), arc-shaped load transmission keys 31 (31A, 31B) that are appropriately divided over the entire circumference are disposed.

  A plurality of bolt holes 32 (32A, 32B) communicating with the key grooves 35 (35A, 35B) are formed in the outer periphery of the box joint 30 at intervals along the circumferential direction. The bolt holes 32 are screwed with set bolts 36 (36A, 36B) made up of hexagon socket bolts or the like, and the set bolts 36 (36A, 36B) are tightened from the outside of the box joint 30. It can be screwed inward in the radial direction by the insertion operation.

  When the set bolt 36 (36A, 36B) is tightened, the load transmission key 31 (31A, 31B) disposed at the tip of the set bolt 36 (36A, 36B) has a diameter from the key groove 35 (35A, 35B). Can project inward. By making the thickness of the load transmission key 31 (31A, 31B) larger than the depth of the keyway 21 (21A, 21B), the load transmission key 31 (31A, 31B) is attached to both the box joint 30 and the pin joint 20. It is arranged across.

  In this way, the load transmission key 31 (31A, 31B) protruding radially inward from the key groove 35 (35A, 35B) is fitted into the key groove 21 (21A, 21B) formed on the outer periphery of the pin joint 20. Thus, the box joint 30 and the pin joint 20 are mechanically coupled via the load transmission key 31 (31A, 31B) so that relative movement in the vertical direction is impossible.

  The load transmission key 31 (31A, 31B) is not limited to two stages, and may be one stage or a plurality of three or more stages. The number of load transmission keys 31 (31A, 31B), and the thickness and width thereof are also appropriately designed according to the strength of the vertical connection required for the connection between the upper steel pipe 10A and the lower steel pipe 10B.

  On the other hand, the relative rotation around the axis between the pin joint 20 and the box joint 30 is caused by the rotation suppression key 50 provided in the key arrangement portion 40 provided so as to straddle the joint 14 of the pin joint and the box joint 30. Deterred. In the present embodiment, the key arrangement portions 40 are arranged at eight positions at equal intervals along the circumferential direction of the seam 14, and the rotation suppression key 50 is arranged in each key arrangement portion 40.

First, the rotation suppression key 50 will be described.
As shown in FIG. 3, the rotation suppression key 50 includes a key body 51 made of a flat plate-like member having a rectangular shape in front view and sectional view.

  The key body 51 is integrally formed with a flange portion 52 so as to extend outward along the vertical direction on both side surfaces in a front view of the key body 51. The flange portion 52 is provided flush with the back surface of the key body 51 in a side view.

  Further, the key body 51 is formed with a counterbore hole 53 having a circular shape in plan view. A through hole for the bolt 15 that fixes the rotation suppression key 50 to the steel pipe 10 is formed in the counterbore 53. The planar shape of the countersink hole 53 is larger than the head of the bolt 15, and the cross-sectional shape of the countersink hole 53 is obtained by adding the thickness of the head of the bolt 15 in the rotation axis direction and the thickness of the washer for the bolt 15. It is formed deeper than the thickness. That is, when the bolt 15 is fastened to the steel pipe 10, the head of the bolt 15 does not protrude outward from the surface of the key body 51.

  The counterbore 53 is such that the bolt 15 is screwed into the bolt hole 16 formed in the pin joint 20 with the key body 51 straddling the pin joint 20 and the box joint 30 through the through hole. The key body 51 is provided at a position closer to the pin joint 20 side than the center in the vertical direction.

  In addition, although it is preferable to provide the volt | bolt 15 from a viewpoint which prevents the shakiness of the rotation suppression key 50 arrange | positioned in the key arrangement | positioning part 40, the relative rotation of the upper steel pipe 10A and the lower steel pipe 10B around the axial center is carried out. It is not an essential configuration from the viewpoint of deterrence. When the bolt 15 is not provided, it is not necessary to form the counterbore 53 or the through hole in the key body 51.

Next, the key arrangement part 40 will be described.
In the pin joint 20, a lower notch 40 </ b> B is formed along the circumferential direction on the periphery of the lower joint surface 27 that forms the joint 14, outside the engagement recess 23. The lower notch portion 40B is a rotation suppression key that extends along the circumferential direction of the lower joint surface 27 of the upper end portion of the lower steel pipe 10B and downward from the lower joint surface 27 along the axial direction of the lower steel pipe 10B. 50 can be inserted.

  The box joint 30 has a lower side when the pin joint 20 is inserted into the box joint 30 along the circumferential direction on the outer periphery of the upper joint surface 37 constituting the seam 14, outside the engagement convex portion 33. An upper notch 40A is formed at a position corresponding to the notch 40B. The upper notch 40 is formed along the circumferential direction of the upper joint surface 37 at the lower end of the upper steel pipe 10A along the circumferential direction, and the rotation suppression key 50 is inserted upward from the upper joint surface 37 along the axial direction of the upper steel pipe 10A. It is configured to be possible.

  The circumferential length of the lower notch 40B and the circumferential length of the upper notch 40A are made to coincide with each other. The vertical length of the lower notch 40B and the vertical length of the upper notch 40A are also made to coincide with each other.

  When the pin joint 20 is inserted into the box joint 30, the lower notch 40 </ b> B and the upper notch 40 </ b> A cooperate to form one key arrangement portion 40 that is rectangular in front view and cross-sectional view. The inner dimension of the key arrangement part 40 is slightly larger than the outer dimension of the rotation suppression key 50 arranged inside.

  A key disposing portion 40 is formed at the joint 14 between the box joint 30 and the pin joint 20 and straddles both the box joint 30 and the pin joint 20, and the rotation inhibiting key 50 is disposed in the key disposing portion 40. Thus, the box joint 30 and the pin joint 20 that are connected, that is, the upper steel pipe 10A and the lower steel pipe 10B are prevented from rotating relative to each other.

  Furthermore, engaging grooves 42 having a width slightly larger than the thickness of the flange portion 52 are formed on both side surfaces of the upper notch portion 40A and the lower notch portion 40B in front view so as to correspond to the flange portion 52 of the rotation suppression key 50. Has been.

  As shown in FIG. 4, the outer surface 52 </ b> A of the flange portion 52 of the rotation restraining key 50 disposed in the key placement portion 40 and the inner surface 42 </ b> A of the engagement groove 42 of the key placement portion 40 come into contact with each other. Thus, the rotation inhibition key 50 is inhibited from falling off the key arrangement portion 40.

  Although only the lower notch 40B has been described here, the outer surface 52A of the flange 52 abuts the inner surface 42A of the engagement groove 42 also in the upper notch 40A.

That is, the flange portion 52 constitutes an engagement portion provided in the rotation suppression key 50, and the outer surface 52 </ b> A of the flange portion 52 constitutes a first contact surface facing outward in the radial direction of the steel pipe 10.
The engagement groove 42 constitutes an engaged portion provided in the key arrangement portion 40, the inner surface 42A of the engagement groove 42 faces inward in the radial direction of the steel pipe 10, and the first contact surface A second abutting surface that faces the surface.
In other words, the drop prevention mechanism is configured by the flange portion 52 as the engaging portion provided in the rotation suppression key 50 and the engaging groove 42 as the engaged portion provided in the key disposing portion 40.

  In addition, the magnitude | size, the number, the arrangement | positioning location, etc. of the rotation suppression key 50 and the key arrangement | positioning part 40 can be appropriately determined by design based on the diameter of a steel pipe pile, an erection method, etc.

A method of connecting the upper steel pipe 10A and the lower steel pipe 10B will be described with reference to FIGS. 2 (a) and 2 (b).
When the steel pipe 10 (lower steel pipe 10B) is built with respect to the ground and the steel pipe 10 (lower steel pipe 10B) is stood to some extent, the upper notch 40A of the steel pipe 10 (lower steel pipe 10B) is formed. The rotation suppression key 50 is disposed and fixed to the steel pipe 10 (lower steel pipe 10B) using the bolt 15.

Next, another steel pipe 10 (upper steel pipe 10A) is lifted with a crane and is carried directly above the steel pipe 10 (lower steel pipe 10B) that has been stood in the ground, and the rotation suppression key 50 is moved to the steel pipe 10 (upper steel pipe 10A). The steel pipe 10 (upper steel pipe 10A) is rotated and adjusted so as to fit the upper notch 40A of the lower-end box joint 30 at the lower end of the steel pipe 10 (upper steel pipe 10A). The pin joint 20 of the steel pipe 10B) is inserted.
By engaging the engagement convex portion 33 of the box joint 30 and the engagement concave portion 23 of the pin joint 20, the engagement convex portion 24 of the pin joint 20 and the engagement concave portion 34 of the box joint 30, respectively, the box joint 30 and the pin The joint 20 is positioned in the vertical direction, and the rotation suppression key 50 is disposed in the upper notch 40A. Thereby, the upper steel pipe 10A and the lower steel pipe 10B are coupled via the rotation suppression key 50 so that relative rotation around the axis is impossible.

  Next, by turning the set bolt 36 (36A, 36B) in the forward direction with a hexagon wrench from the outside of the bolt hole 32 (32A, 32B), the load transmission key 31 (31A, 31B) is set to the set bolt 36 (36A, 36B). ) And move into the keyway 21 (21A, 21B). The upper steel pipe and the lower steel pipe are coupled to each other through a load transmission key 31 (31A, 31B) so that relative movement in the vertical direction is impossible.

After the set bolt 36 (36A, 36B) is screwed in, the embedding depth of the set bolt 36 (36A, 36B) is measured from the outside of the box joint 30 with a depth gauge or the like, and the load transmission key 31 (31A, 31A, 31B) is measured. 31B) is confirmed to be securely fitted in the keyway 21 (21A, 21B).
Thus, the connection between the box joint 30 and the pin joint 20 is completed. By repeating this operation until the steel pipe pile has a predetermined length, a steel pipe pile in which a plurality of steel pipes 10 are connected vertically is configured.

  With the above-described steel pipe connection structure, it is possible to realize a steel pipe connection method that can significantly reduce the working time of the steel pipe 10 as compared with the joining by welding, regardless of the diameter and thickness of the steel pipe 10. Further, during the construction of the steel pipe pile, the rotation suppression provided in the joint 14 of the both steel pipes 10 in order to suppress the relative rotation around the axial center of the steel pipe 10 provided above and below that constitutes the steel pipe pile. Even if the bolt 15 that fixes the key 50 is loosened and falls off or breaks, the rotation suppression key 50 is not likely to fall off from the key arrangement portion 40.

Another embodiment of the steel pipe connection structure according to the first aspect of the present invention will be described.
In the following description, components corresponding to those in the first embodiment described above are described with the same reference numerals.

  In the steel pipe connection structure according to the second embodiment, the engaging groove 42 is not provided in both the upper notch 40A and the lower notch 40B, but only in one. The rotation suppression key 50 includes a flange portion 52 only at a portion corresponding to the engagement groove 42. The flange portion 52 is not flush with the back surface of the key body 51 in a side view, but is provided at the center in the thickness direction of the key body 51 in a side view.

  That is, as shown in FIG. 5 and FIG. 6, the rotation suppression key 50 has the flange portion 52 so that it extends outward from the center only along the vertical direction on both sides in the front view of the key body 51. The flange portion 52 is formed integrally and is provided at the center in the thickness direction of the key body 51 in a side view. The engaging groove 42 is provided at a position corresponding to the flange portion 42 only in the lower cutout portion 40B.

  Even in the steel pipe connection structure according to the second embodiment, the outer surface 52A of the flange portion 52 of the rotation restraining key 50 arranged in the key arrangement portion 40 and the inside of the engagement groove 42 of the key arrangement portion 40 can be obtained. The contact with the direction 42 </ b> A prevents the rotation inhibition key 50 from moving outward in the radial direction of the steel pipe 10.

  In the steel pipe connection structure according to the third embodiment, a flange portion 44 is provided on one of the upper notch portion 40A and the lower notch portion 40B. The rotation suppression key 50 includes an engagement groove 54 only in a portion corresponding to the flange portion 44.

  That is, as shown in FIGS. 7 and 8, the rotation suppression key 50 is integrally formed with the engagement groove 54 so that the key body 51 is retracted inward on both sides along the vertical direction only upward from the center. The engaging groove 54 is provided at the center in the thickness direction of the key body 51 in a side view. The flange portion 44 is provided at a position corresponding to the engagement groove 54 only in the upper cutout portion 40A.

  Even in the steel pipe connection structure according to the third embodiment, the outer surface 54A of the engagement groove 54 of the rotation restraining key 50 disposed in the key disposing portion 40 and the inside of the flange portion 44 of the key disposing portion 40 The contact with the direction 44 </ b> A prevents the rotation inhibition key 50 from falling off the key arrangement portion 40.

  In the steel pipe connection structure according to the fourth embodiment, as shown in FIGS. 9 and 10, the rotation inhibiting key 50 extends outward along the left-right direction on both the top surface and the bottom surface in a front view of the key body 51. A flange portion 52 is integrally formed so as to protrude. The flange portion 52 is provided flush with the back surface of the key body 51 in a side view. Then, the engagement groove 42 is provided at a position corresponding to the flange portion 52 of the rotation suppression key 50 in both the upper cutout portion 40A and the lower cutout portion 40B.

  Even in the steel pipe connection structure according to the fourth embodiment, the outer surface 52A of the flange portion 52 of the rotation restraining key 50 disposed in the key disposition portion 40 and the inside of the engagement groove 42 of the key disposition portion 40. The contact with the direction 42 </ b> A prevents the rotation suppression key 50 from falling off the key arrangement portion 40.

  In the first embodiment, the drop prevention mechanism includes a flange portion 52 as an engagement portion provided in the rotation suppression key 50 and an engagement groove 42 as an engaged portion provided in the key arrangement portion 40. However, in the steel pipe connection structure according to the fifth embodiment, the drop-off prevention mechanism is constituted by the reverse taper portion formed on the side surface of the rotation restraining key 50 and the side surface of the key disposing portion 40.

That is, as shown in FIGS. 11 and 12, the rotation suppression key 50 includes first inclined surfaces 55 that are trapezoidal in plan view on both side surfaces of the key body 51 in front view.
On the other hand, the lower notch 40B is provided with a second inclined surface 45 that faces the first inclined surface 55.

  Even in the steel pipe connection structure according to the fifth embodiment, the first inclined surface 55 of the rotation restraining key 50 arranged in the key arrangement portion 40 and the second inclined surface 45 of the key arrangement portion 40 are reversed. By coming into contact with the taper, the rotation inhibition key 50 is prevented from falling off the key arrangement portion 40.

  In addition, the 1st inclined surface 55 with which the rotation suppression key 50 is provided is not restricted to the structure provided over the whole thickness direction of the rotation suppression key 50, What is necessary is just to be provided somewhere in the thickness direction.

  For example, as shown in FIG. 13, the first inclined surface 55 may be provided only on the radially outer side of the steel pipe 10 from the center in the thickness direction of the rotation inhibition key 50, or as shown in FIG. You may provide only in the radial direction inner side of the steel pipe 10 from the center of 50 thickness directions.

  Furthermore, as shown in FIGS. 15 and 16, the first inclined surface 55 and the second inclined surface 45 can be configured by curved surfaces instead of flat surfaces.

  As described above, the steel pipe connection structure according to the first aspect of the present invention includes any one of the above-described dropout prevention mechanisms, thereby preventing the rotation suppression key 50 from dropping from the key arrangement portion 40.

Next, the steel pipe connection structure according to the second aspect of the present invention will be described.
The steel pipe 10 provided with the steel pipe connection structure of 1st embodiment by the 2nd aspect of this invention is shown by FIG.
Since the steel pipe 10 has the same configuration as that of the steel pipe 10 shown in FIG. 1 except for the steel pipe connection structure according to the second aspect, the same reference numerals are given to the same configurations and the description thereof is omitted.

The steel pipe connection structure of the first embodiment according to the second aspect will be described.
First, the rotation suppression key 250 will be described.
As shown in FIG. 19, the rotation suppression key 250 includes a key body 251 made of a flat plate member having a rectangular shape in front view and sectional view.

The key body 251 is integrally formed with a flange portion 252 so as to extend outward along the vertical direction on both side surfaces in a front view of the key body 251.
The flange portion 252 includes an outer surface 252A facing outward in the radial direction of the steel pipe 10, and includes an inclined surface 252B that extends from the tip of the outer surface 252A to the side surface of the key body portion 251 on the back surface of the outer surface 252A. . An outer surface 252A of the flange portion 252 is provided flush with the front surface of the key body 251 in a side view.

  Further, the key body 251 has a counterbore hole 253 that is circular in plan view. The counterbore hole 253 is formed with a through hole for the bolt 15 that fixes the rotation suppression key 250 to the steel pipe 10. The planar shape of the counterbore hole 253 is larger than the head of the bolt 15, and the cross-sectional shape of the counterbore hole 253 is obtained by adding the thickness of the head of the bolt 15 in the rotation axis direction and the thickness of the washer for the bolt 15. It is formed deeper than the thickness. That is, when the bolt 15 is fastened to the steel pipe 10, the head of the bolt 15 does not protrude outward from the surface of the key body 251.

  The counterbore hole 253 is such that the bolt 15 is screwed into the bolt hole 16 formed in the pin joint 20 through the through hole in a state where the key body 251 straddles the pin joint 20 and the box joint 30. The key body 251 is provided at a position closer to the pin joint 20 side than the center in the vertical direction.

  The bolt 15 is preferably provided from the viewpoint of preventing the rotation restraining key 250 provided in the key arrangement part 240 from rattling, but the relative rotation around the axis of the upper steel pipe 10A and the lower steel pipe 10B is performed. It is not an essential configuration from the viewpoint of deterrence. When the bolt 15 is not provided, it is not necessary to form the counterbore hole 253 or the through hole in the key body 251.

Next, the key arrangement part 240 will be described.
In the pin joint 20, a lower notch 240 </ b> B is formed along the circumferential direction on the outer periphery of the lower joint surface 27 that forms the joint 14, outside the engaging recess 23.
The box joint 30 has a lower side when the pin joint 20 is inserted into the box joint 30 along the circumferential direction on the outer periphery of the upper joint surface 37 constituting the seam 14, outside the engagement convex portion 33. An upper notch 240A is formed at a position corresponding to the notch 240B.
The circumferential length of the lower notch 240B and the circumferential length of the upper notch 240A are made to coincide with each other. The vertical length of the lower notch 240B and the vertical length of the upper notch 240A are also made to coincide with each other.

  Each of the upper notch 240A and the lower notch 240B is integrally provided with a protruding edge extending inward along the vertical direction on both sides in the front view of the upper notch 240A and the lower notch 240B. Is formed.

  When the pin joint 20 is inserted into the box joint 30, the lower notch portion 240 </ b> B and the upper notch portion 240 </ b> A cooperate to constitute one key arrangement portion 240 that is rectangular in front view and cross-sectional view. At this time, the projecting edge portions are integrally connected to form the flange portion 242.

  The minimum inner width of the flange portion 242 of the key arrangement portion 240 is set to be narrower than the maximum outer width of the flange portion 252 of the rotation suppression key 250. In addition, the inner dimension of the key arrangement | positioning part 240 is a shape slightly larger than the maximum outer width of the rotation suppression key 250 arrange | positioned inside.

As shown in FIG. 20A, a key disposition portion 240 is formed at the joint 14 between the box joint 30 and the pin joint 20 so as to straddle both the box joint 30 and the pin joint 20.
As shown in FIG. 20B, the rotation inhibiting key 250 is inserted into the key disposing portion 240 from the outside. At this time, the inclined surface 252B on the back surface of the flange portion 252 is pressed by the flange portion 242, and the flange portion 252 is elastically deformed. That is, the flange portion 252 becomes a deformed portion.
As shown in FIG. 20 (c), when the rotation restraining key 250 is arranged in the key arrangement part 240, the connected box joint 30 and the pin joint 20, that is, the upper steel pipe 10A and the lower steel pipe 10B are connected to each other. Relative rotation is suppressed. At this time, the outer surface 522A of the flange portion 252 of the rotation restraining key 250 disposed in the key disposing portion 240 and the inner surface 242A of the flange portion 242 of the key disposing portion 240 are in contact with each other. It is suppressed that 250 falls out of the key arrangement | positioning part 240. FIG.

That is, the flange portion 252 constitutes an engaging portion provided on the outer surface of the rotation suppression key 250, and the first abutting surface in which the outer surface 252A of the flange portion 252 faces outward in the radial direction of the steel pipe 10. Configure.
The flange portion 242 constitutes an engaged portion provided on the inner side surface of the key arrangement portion 240, the inner surface 242A of the flange portion 242 faces the radially inner side of the steel pipe 10, and the first contact A second abutting surface facing the surface is configured.
That is, the flange portion 252 as an engaging portion provided in the rotation suppression key 250 and the flange portion 242 as an engaged portion provided in the key disposing portion 240 constitute a drop-off preventing mechanism.

  In addition, the magnitude | size, the number, the arrangement | positioning location, etc. of the rotation suppression key 250 and the key arrangement | positioning part 240 can be appropriately determined by design based on the diameter of a steel pipe pile, an erection method, etc.

A method for connecting the upper steel pipe 10A and the lower steel pipe 10B will be described with reference to FIGS. 18 (a) and 18 (b).
The steel pipe 10 (lower steel pipe 10B) is built against the ground, and when the steel pipe 10 (lower steel pipe 10B) is set to the ground to some extent, another steel pipe 10 (upper steel pipe 10A) is lifted with a crane, The steel pipe 10 (upper steel pipe 10A) that has been stood in the ground is carried directly above and suspended while adjusting the rotation of the steel pipe 10 (upper steel pipe 10A) so that the upper notch 240A is aligned with the lower notch 240B. The pin joint 20 of the steel pipe 10 (lower steel pipe 10B) is inserted into the box joint 30 of the steel pipe 10 (upper steel pipe 10A).

  Next, the engagement protrusion 33 of the box joint 30 and the engagement recess 23 of the pin joint 20, and the engagement protrusion 24 of the pin joint 20 and the engagement recess 34 of the box joint 30 are attached to each other, whereby the box joint 30 and the pin joint 20 are positioned in the vertical direction.

  Next, by turning the set bolt 36 (36A, 36B) in the forward direction with a hexagon wrench from the outside of the bolt hole 32 (32A, 32B), the load transmission key 31 (31A, 31B) is set to the set bolt 36 (36A, 36B). ) And move into the keyway 21 (21A, 21B). The upper steel pipe and the lower steel pipe are coupled to each other through a load transmission key 31 (31A, 31B) so that relative movement in the vertical direction is impossible.

  After the set bolt 36 (36A, 36B) is screwed in, the embedding depth of the set bolt 36 (36A, 36B) is measured from the outside of the box joint 30 with a depth gauge or the like, and the load transmission key 31 (31A, 31A, 31B) is measured. 31B) is confirmed to be securely fitted in the keyway 21 (21A, 21B).

  Before and after the operation of the set bolt 36, the rotation restraining key 250 is elastically deformed and inserted into the key arrangement portion 240 constituted by the upper notch portion 240A and the lower notch portion 240B. Fix to (lower steel pipe 10B). As a result, the upper steel pipe 10A and the lower steel pipe 10B are coupled via the rotation inhibition key 250 so that relative rotation around the axis is impossible. Thus, the connection between the box joint 30 and the pin joint 20 is completed. By repeating this operation until the steel pipe pile has a predetermined length, a steel pipe pile in which a plurality of steel pipes 10 are connected vertically is configured.

  With the above-described steel pipe connection structure, it is possible to realize a steel pipe connection method that can significantly reduce the working time of the steel pipe 10 as compared with the joining by welding, regardless of the diameter and thickness of the steel pipe 10. Further, during the construction of the steel pipe pile, the rotation suppression provided in the joint 14 of the both steel pipes 10 in order to suppress the relative rotation around the axial center of the steel pipe 10 provided above and below that constitutes the steel pipe pile. Even if the bolt 15 for fixing the key 250 is loosened and falls off or breaks, the rotation inhibiting key 50 is not likely to fall off from the key disposing portion 240.

Another embodiment of the steel pipe connection structure according to the present invention will be described.
In the following description, components corresponding to those in the first embodiment described above are described with the same reference numerals.

  In the steel pipe connection structure according to the second embodiment, as shown in FIG. 21, the flange portion 252 of the rotation suppression key 250 is formed only at the center in the vertical direction of the key body 251. In addition, the key arrangement | positioning part 242 should be provided with the flange part 242 only in the position corresponding to the flange part 252 at least.

  In the second embodiment, since the overall length of the flange portion 252 is short, the flange portion 252 can be smoothly and elastically deformed when fitted into the key arrangement portion 240. Even in such a flange portion 252, after fitting into the key arrangement portion 240, the outer surface 252A of the flange portion 252 and the inner surface 242A of the flange portion 242 of the key arrangement portion 240 abut, The rotation inhibition key 250 is prevented from falling off the key arrangement portion 240.

  In the steel pipe connection structure according to the third embodiment, as shown in FIG. 22, the flange portion 252 of the rotation suppression key 250 is not flush with the front surface of the key body 251 in a cross-sectional view, but in the center in the thickness direction of the key body 251. It is provided in the vicinity.

  Even in the steel pipe connection structure according to the third embodiment, the outer surface 252A of the flange portion 252 of the rotation restraining key 250 disposed in the key disposition portion 240 and the inner surface of the flange portion 242 of the key disposition portion 240. The contact with 242A prevents the rotation inhibition key 250 from falling off the key arrangement portion 240. In addition, since the front surface of the rotation suppression key 250 can be flush with the outer peripheral surface of the steel pipe pile (box joint 20) after the rotation suppression key 250 is inserted into the key arrangement portion 240, the outer peripheral surface of the steel pipe pile can be smoothed. can do.

In the steel pipe connection structure according to the fourth embodiment, as shown in FIG. 23, the key body 251 of the rotation suppression key 250 is provided with a groove portion 60 having a V-shaped cross section. The groove portion 60 is formed in the direction orthogonal to the maximum outer width direction of the flange portion 252, that is, along the vertical direction of the key body 251 on the front surface of the rotation suppression key 250. In this case, the counterbore hole 253 and the through hole for the bolt 15 may or may not be provided inside the V-shaped groove 60.
By providing the groove portion 60, the rotation inhibition key 250 can be elastically bent with the groove portion 60 as a base point when the rotation inhibition key 250 is fitted into the key arrangement portion 240.

  Even in the steel pipe connection structure according to the fourth embodiment, as shown in FIG. 24, the outer surface 252A of the flange portion 252 of the rotation restraining key 250 arranged in the key arrangement portion 240 and the key arrangement portion 240. The contact with the inner surface 242A of the flange portion 242 prevents the rotation suppression key 250 from falling off the key arrangement portion 240.

  In the steel pipe connection structure according to the fifth embodiment, as shown in FIGS. 25 and 26, the rotation suppression key 250 extends outward along the left-right direction on both the top surface and the bottom surface of the key body 251 in a front view. A flange portion 252 is integrally formed so as to protrude. The flange portion 252 is provided flush with the front surface of the key body 251 in a side view. Further, the key body 251 of the rotation suppression key 250 is provided with a groove portion 60 having a V-shaped cross section. The groove part 60 is formed in the direction orthogonal to the maximum outer width direction of the flange part 252, that is, along the left-right direction of the key body 251 on the front face of the rotation suppression key 250.

  And both the upper notch part 240A and the lower notch part 240B are provided with a flange part 242 at a position corresponding to the flange part 252 of the rotation suppression key 250.

  Even in the steel pipe connection structure according to the fifth embodiment, the outer surface 252A of the flange portion 252 of the rotation restraining key 250 disposed in the key disposition portion 240 and the inner surface of the flange portion 242 of the key disposition portion 240. The contact with 242A prevents the rotation inhibition key 250 from falling off the key arrangement portion 240.

  In any of the above-described embodiments, the case where the flange portion 252 of the rotation suppression key 250 is elastically deformed has been described, but the configuration of the deformable portion is not limited thereto. For example, the flange portion 242 of the key arrangement portion 240 may be elastically deformed by being pressed by the flange portion 252 when the rotation suppression key 250 is fitted. In this case, if the inclined surface is provided on the front surface of the flange portion 242, the flange portion 242 is smoothly deformed.

  As described above, the steel pipe connection structure according to the second aspect of the present invention is provided with any one of the above-described drop-off prevention mechanisms, thereby preventing the rotation-inhibiting key 250 from dropping from the key arrangement portion 240.

  Each of the above-described embodiments is an example of the present invention, and the present invention is not limited by the description. The specific configuration of each part can be appropriately changed and designed within the range where the effects of the present invention are exhibited. is there.

DESCRIPTION OF SYMBOLS 10 Steel pipe 10A Upper steel pipe 10B Lower steel pipe 13 Joint 15 Bolt 40 Key installation part 40A Upper notch part 40B Lower notch part 42 Engaging groove (engaged part)
42A Inner surface (second contact surface)
50 Rotation suppression key 52 Flange part (engagement part)
52A Outer surface (first contact surface)
60 Groove 240 Key Arrangement 240A Upper Notch 240B Lower Notch 242 Flange (engaged)
242A Inner surface (second contact surface)
250 Rotation inhibition key 252 Flange part (engagement part)
252A Outer surface (first contact surface)

Claims (10)

A steel pipe coupling structure configured to inhibit relative rotation around the axis of both steel pipes by straddling a rotation inhibition key across the joints of the steel pipes arranged above and below constituting the steel pipe pile,
An upper notch portion formed along the circumferential direction of the lower end portion of the upper steel pipe along the circumferential direction and capable of inserting the rotation suppression key upward along the axial direction of the upper steel pipe from the lower end portion, and an upper end portion of the lower steel pipe A lower notch that is formed in a circumferential direction at a position corresponding to the upper notch and is capable of inserting the rotation suppression key downward from the upper end along the axial direction of the lower steel pipe. The rotation inhibiting key is disposed on a side surface of the rotation inhibiting key and a side surface of the key arranging portion. A steel pipe coupling structure comprising a drop-off prevention mechanism that prevents the key from being dropped from the key arrangement portion. The drop-off prevention mechanism is
An engaging portion provided in the rotation inhibiting key;
It consists of engaged parts provided in the key arrangement part,
The engagement portion includes a first contact surface facing outward in the radial direction,
The steel pipe connection structure according to claim 1, wherein the engaged portion includes a second contact surface facing inward in the radial direction and facing the first contact surface. The drop-off prevention mechanism is
The steel pipe connection structure according to claim 1, comprising a reverse taper portion formed on a side surface of the rotation suppression key and a side surface of the key arrangement portion.   The steel pipe connection structure according to claim 3, wherein a surface constituting the reverse tapered portion is a flat surface or a curved surface. A hole for inserting a bolt into the rotation inhibition key is formed,
The steel pipe connection structure according to any one of claims 1 to 4, wherein the rotation suppression key is fixed to the lower steel pipe by a bolt. It is a steel pipe connection method of the steel pipe arrange | positioned up and down provided with the steel pipe connection structure as described in any one of Claim 1-5, Comprising: Rotation suppression in the lower notch part of the lower steel pipe stood in the ground After arranging the key,
A method of connecting a steel pipe, wherein the upper steel pipe is suspended on the lower steel pipe so that the rotation suppression key is disposed in the upper notch. A steel pipe coupling structure configured to inhibit relative rotation around the axis of both steel pipes by straddling a rotation inhibition key across the joints of the steel pipes arranged above and below constituting the steel pipe pile,
The upper notch formed along the circumferential direction of the lower end of the upper steel pipe, and the circumferential edge of the upper end of the lower steel pipe formed along the circumferential direction at a position corresponding to the upper notch. A key arrangement part for arranging the rotation suppression key, which is configured by cooperation of a lower notch part;
An engagement portion provided on an outer surface of the rotation suppression key and an inner width shorter than an outer width of the engagement portion in a front view of the rotation suppression key are provided on an inner surface of the key arrangement portion. Further, a drop-off prevention mechanism configured by an engaged portion that can be engaged with the engaging portion,
At least one of the rotation inhibition key and the key arrangement portion has a deformable portion that can be elastically deformed so that the length of the outer width is relatively shorter than the length of the inner width. Steel pipe connection structure. The engagement portion includes a first contact surface facing outward in the radial direction,
The engaged portion includes a second contact surface facing inward in the radial direction and facing the first contact surface;
The steel pipe connection structure according to claim 7, further comprising an inclined surface in contact with the back surface of the second contact surface on the back surface of the first contact surface.   The steel pipe connection structure according to claim 7 or 8, wherein the deforming portion includes a groove portion formed in a direction orthogonal to the outer width direction on a front surface of the rotation suppression key. A steel pipe connection method for steel pipes arranged vertically with the steel pipe connection structure according to any one of claims 7 to 9, wherein the upper steel pipe is placed on the lower steel pipe standing on the ground, Hanging down so that the upper notch of the upper steel pipe corresponds to the lower notch of the lower steel pipe,
A steel pipe connecting method, wherein a rotation restraining key is elastically deformed and inserted into a key arrangement part constituted by the upper notch part and the lower notch part.

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