[OOOl]
The present invention relates to a joint structure of a steel-pipe pile for fitting
together an external fitting end portion and an internal fitting end portion capable of
being fitted to each other, at a work site, and for connecting an upper steel-pipe pile and
a lower steel-pipe pile in an axial direction, and to a steel-pipe pile using the joint
structure. More particularly, the present invention relates to a joint structure of a
steel-pipe pile and a steel-pipe pile which are used in civil engineering and construction
fields of, for example, building foundations and bridge foundations.
Priority is claimed on Japanese Patent Application No. 2012-255304, filed on
November 21,2012, the content of which is incorporated herein by reference.
[Related Art]
[0002]
In the related art, an object of a joint structure of a steel-pipe pile is to connect
an upper steel-pipe pile and a lower steel-pipe pile in an axial direction, the joint
structure of a steel-pipe pile is roughly classified into a screw-type, a key type, and a
gear-type, and joint structures of a steel-pipe pile disclosed in Patent Documents 1 to 3
are suggested.
[0003]
In the joint structure of a steel-pipe pile disclosed in Patent Document 1, a
screw-type joint structurc of a steel-pipe pile is used, a male thread portion is formed on
an end portion of one stccl-pipe pile, and a female thread portion is formed on an end
portion of the other steel-pipe pile. In the joint structure of a steel-pipe pile disclosed
in Patent Document 1, for example, a lower steel-pipe pile in which the female thread
portion is formed on the end portion is buried under the ground, the male thread portion
formed on an end portion of an upper steel-pipe pile is screwed to the female thread
portion of the lower steel-pipe pile, and thus, the upper steel-pipe pile and the lower
steel-pipe pile are connected together in an axial direction.
[0004]
In the joint structure of a steel-pipe pile disclosed in Patent Document 2, a ltey
type joint structure of a steel-pipe pile is used, a ltey member is assembled to an inward
groove portion of a female side end portion of a steel-pipe pile in advance, and aftcr a
male side end portion of the steel-pipe pile is inserted into the female side end portion
of the steel-pipe pile, the key member is pushed into a center side of the steel-pipe pile,
and thus, the male side end portion ofthe steel-pipe pile and the female side end portion
of the steel-pipe pile engage with each other.
[0005]
In the joint structure of a steel-pipe pile disclosed in Patent Document 3, a
gear-type joint structure of a steel-pipe pile is used, and although this joint structure is
based on the screw type, the problems of a screw-type joint structure of a steel-pipe pile
are solved. In the joint structure of a steel-pipe pile disclosed in Patent Document 3, a
plurality of outward engagement convex portions are provided along an axial direction
in a male side end portion of a steel-pipe pile, and a plurality of inward engagement
convex portions are provided along the axial direction in a female side end portion of
the steel-pipe pile. In the joint structure of a steel-pipe pile disclosed in Patent
Document 3, the male side end portion and the female side end portion of the steel-pipe
pile are fitted together, the steel-pipe pile is relatively rotated so that the outward
engagement convex portion and the inward engagement convex portion mesh with each
other, and thus, an upper steel-pipe pile and a lower steel-pipe pile are connected
together in the axial direction.
[0006]
In the joint structure of a steel-pipe pile disclosed in Patent Document 3, the
outward engagement convex portion and the inward engagement convex portion mesh
with each other. Accordingly, when a bending load or a tension load is applied to a
joint portion of the steel-pipe pile, the outward engagement convex portion and the
inward engagement convex portion come into contact with each other, and thus, the
loads are transmitted to a main body of the steel-pipe pile. It is necessary to set a
contact area between the outward engagement convex portion and the inward
engagement convex portion or an attachment area of the engagement convex portion
with respect to the end portion of the steel-pipe pile to sufficiently withstand the bearing
strength or shear strength used to transmit the loads. In addition, it is also necessary to
set a thickness of the end portion of the steel-pipe pile to sufficiently withstand the loads
transmitted froin the engagement convex portions.
[Citation List]
[Patent Document]
[0007]
[Patent Document 11 Japanese Unexamined Patent Application, First
Publication No. H07-82738 (Page 7 and FIG. 2)
[Patent Document 21 Japanese Unexamined Patent Application, First
PublicationNo. 2000-257058 (Page 10 and FIG. 6)
[Patent Document 31 Japanese Unexarnined Patent Application, First
Publication No. H11-43937 (Page 6 and FIG 1)
[Summary of the Invention]
[Problems to be Solved by the Invention]
[OOOX]
However, in the screw-type joint structure of a steel-pipe pile disclosed in
Patent Document 1, when the male thread portion of the upper steel-pipe pile is screwed
to the female thread portion of the lower steel-pipe pile, it is necessary to rotate the
upper steel-pipe pile a predetermined rotation number of times at a work site.
Accordingly, there is a problem that labor for the rotation increases and construction
costs increase. In the key type joint structure of a steel-pipe pile disclosed in Patent
Document 2, although the labor for rotating the steel-pipe pile in the screw-type joint
structure of a steel-pipe pile can be omitted, the ltey member is separately required, and
complicated machining is required in which the inward groove portion is formed on the
female side end portion of the steel-pipe pile and the key member is assembled in
advance. Accordingly, there is a problem that machining costs increase and the cost of
materials in a joint portion of the steel-pipe pile also increase to withstand the
complicated machining.
[0009]
Moreover, in the gear-type joint structure of a steel-pipe pile disclosed in Patent
Document 3, when the male side end portion of the steel-pipe pile is inserted into the
female side end portion of the steel-pipe pile, a notch portion is provided between
engagement convex portions adjacent in the circumferential direction of the steel-pipe
pile so that the outward engagement convex portion and the inward engagement convex
portion do not interfere with each other. Moreover, the engagement convex portions
and the notch portion are provided in a row in the axial direction. Accordingly, in the
joint structure of a steel-pipe pile disclosed in Patent Document 3, there are the
following problems.
[OOl 01
In the joint structure of a steel-pipe pile disclosed in Patent Document 3, the
engagement convex portions are intermittently provided in the circumferential direction
of the steel-pipe pile, and thus, are provided in a row in the axial direction.
Accordingly, a cross-sectional defect occurs when viewed in the axial direction, and the
bending load and the tension load which can be transmitted to the engagement convex
portion are decreased by the cross-sectional defect. Therefore, in the joint structure of
a steel-pipe pile disclosed in Patent Document 3, in order to withstand a predetermined
bending load and tension load, it is necessary to use the engagement convex portion
enlarged by the cross-sectional defect when viewed in the axial direction, and it is
necessary to increase the number of steps of the engagement convex portion in the axial
direction. Accordingly, there is a problem that machining costs and the cost of
materials in the joint structure of the steel-pipe pile increase.
[OOll]
Moreover, in the joint structure of a steel-pipe pile disclosed in Patent
Document 3, since the engagement convex portions are provided in a row in the axial
direction, the bending load and the tension load transmitted from the engagement
convex portion to the main body of the steel-pipe pile cannot be uniform in the
circumferential direction of the steel-pipe pile. Accordingly, the bending load and the
tension load are concentrated at a predetermined engagement convex portion.
Therefore, in the joint structure of a steel-pipe pile disclosed in Patent Document 3, in a
design with respect to a plate thiclcness of the steel-pipe pile, since the plate thickness is
set based on the portion at which the bending load and the tension load are concentrated,
the plate thickness increases, and thus, there is a problem that the cost of materials of
the joint structure increases.
[OO 121
In addition, in the joint structure of a steel-pipe pile disclosed in Patent
~ocimen3t, when the bending load is applied to the steel-pipe pile, the portion in
which the engagement convex portions are provided in a row in the axial direction may
not be disposed at the portion corresponding to the outermost edge end portion of the
steel-pipe pile at which tcnsile stress becomes maximum. At this time, the hending
load is applied to the portion in which the cross-sectional defect is formed, and thus,
there is a concern that the steel-pipe pile cannot withstand the bending load and the joint
portion of the steel-pipe pile may be damaged. Accordingly, in the joint structure of a
steel-pipe pile disclosed in Patent Document 3, there is a problem that a structural defect
occurs.
[0013]
Therefore, the present invention is made in consideration of the
above-described problems, and an object thereof is to provide a joint structure of a
steel-pipe pile and a steel-pipe pile in which an increase in labor for rotation of the
steel-pipe pile at a work site is prevented, an excessive increase in a plate thickness of
the steel-pipe pile is avoided, and there is no concern of damage even when the bending
load is applied.
[Means for Solving the Problem]
[0014]
In order to solve the above-described problems, the present invention adopts
the following measures.
(1) According to a first aspect of the present invention, there is provided a
joint structure of a steel-pipe pile which connects a first steel-pipe pile and a second
steel-pipe pile in series, the joint structure including: an external fitting end portion
which is an opening end of the first steel-pipe pile; and a column shaped internal fitting
end portion which configures a portion inserted into the external fitting end poi-tion on
one end of the second steel-pipe pile, in which the external fitting end portion includes a
plurality of external fitting convex portions which protrude from an inner
circumferential surfacc of the external fitting end portion toward an inner side in a radial
direction of the first steel-pipe pile, and are provided along a circumferential direction
of the first steel-pipe pile; an external fitting groove portion which is formed between
the external fitting convex portions adjacent to each other in the circumferential
direction of the first steel-pipe pile; and an external fitting engagement groove which is
formed along the circumferential direction at a position of an inner side in an axial
direction of the first steel-pipe pile from the external fitting convex portion and the
external fitting groove portion on the inner circumferential surface, the internal fitting
end portion includes a plurality of internal fitting convex portions which protrude from
an outer circumferential surface of the internal fitting end portion toward an outer side
in a radial direction of the second steel-pipe pile, and are provided along a
circumferential direction of the second steel-pipe pile, each of the internal fitting convex
portions engages with each of the external fitting convex portions in the external fitting
engagement groove after the internal frtting end portion is inserted into the external
fitting end portion and the first steel-pipe pile and the second steel-pipe pile are
relatively rotated around an axis of the first steel-pipe pile, the external fitting convex
portions and the external fitting groove portions are formed into a plurality of rows
along the axial direction of the first steel-pipe pile, and in at least one set of two rows
adjacent to each other among the plurality of rows adjacent to one another, the external
fitting convex portions of one row and the external fitting groove portions of the other
row are provided to be adjacent in the radial direction of the first steel-pipe pile when
viewed in the axial direction of the first steel-pipe pile.
[OO 151
(2) In the aspect according to the above (I), the external fitting end portion
may include a plurality of step portions formed along the axial direction of the first
steel-pipe pile, the external fitting convex portions and the external fitting groove
portions by at least one row may be provided in each of the plurality of step portions,
and in two step portions adjacent to each other, the external fitting convex portions of
one step portion and the external fitting groove portions of the other step portion may be
provided to be adjacent in the radial direction of the first steel-pipe pile when viewed in
the axial direction of the first steel-pipe pile.
[00 161
(3) In the aspect according to the above (2), in the two step portions adjacent
to each other, the external fitting convex portions of the one step portion may be
provided at all positions adjacent to the external fitting groove portions of the other step
portion in the radial direction of the first steel-pipe pile when viewed in the axial
direction of the first steel-pipe pile, and the external fitting convex portions may be
provided without gaps along the circumferential direction of the first steel-pipe pile
when viewed in the axial direction of the first steel-pipe pile.
[OO17]
(4) In the aspect according to the above (2) or (3), the first steel-pipe pile may
be thickened in stages along the axial direction of the first steel-pipe pile, and the
plurality of step portions adjacent to one another in the axial direction of the first
steel-pipe pile may be formed so that the external fitting convex portions of the step
portion positioned at an outer side in the axial direction of the first steel-pipe pile and
the external fitting groove portions of the step portion positioned at the inner side in the
axial direction of the first steel-pipe pile all have approximately the same thickness.
[00 181
(5) In the aspect according to any one of the above (1) to (4), the internal
fitting end portion may include an internal fitting edge which forms a gap between a tip
portion of the external fitting end portion and the internal fitting end portion at the inner
side in the axial direction of the second steel-pipe pile in a state where the internal
fitting end portion is inserted into the external fitting end portion, the external fitting
convex portion may include a first tapered portion which is inclined along the
circumferential direction of the first steel-pipe pile on an end surface in the inner side in
the axial direction of the first steel-pipe pile so that a height in the axial direction of the
first steel-pipe pile is approximately the same as a height of the gap, the external fitting
engagement groove may include a second tapered portion which is inclined in the
circumferential direction of the first steel-pipe pile to be approximately parallel with the
first tapered portion at a portion facing the first tapered portion in the axial direction of
the first steel-pipe pile, the internal fitting convex portion may include a third tapered
portion which is inclined along the circumferential direction of the second steel-pipe
pile to abut the first tapered portion on an end surface in the inner side in the axial
direction of the second steel-pipe pile, and a fourth tapered portion which is inclined
along the circumferential direction of the second steel-pipe pile to abut the second
tapered portion on an end surface in the outer side in the axial direction of the second
steel-pipe pile, and the first steel-pipe pile and the second steel-pipe pile may relatively
rotate around the axis of the first steel-pipe pile, the first tapered portion and the third
tapered portion may abut each other, the second tapered portion and the fourth tapered
portion may abut each other, the plurality of external fitting convex portions and the
plurality of internal fitting convex portions may engage with each other, thc internal
fitting edge and the tip portion may abut each other to fill the gap, and the external
fitting end portion and the internal fitting end portion may be fitted together.
[OO 191
(6) According to a second aspect of the present invention, there is provided a
steel-pipe pile including the joint structure of a steel-pipe pile according to any one of
the above (1) to (5).
[Effects of the Invention]
[OOZO]
According to the aspects of the above (1) to (6), in at least one set of two rows
among the plurality of rows adjacent to one another in the axial direction of the
steellpipe pile, since the external fitting convex portions of the one row and the external
fitting groove portions of the other row are provided to be adjacent to each other in the
radial direction of the steel-pipe pile when viewed in the axial direction of the steel-pipe
pile, a cross-sectional defect does not occur when viewed in the axial direction, and the
lower stcel-pipe pile and the upper steel-pipe pile can be connected together.
Accordingly, in order to withstand a predetermined bending load and tension load, it is
not necessary to enlarge the external fitting convex portions and the internal fitting
convex portions by the cross-sectional defects, and it is not necessary to increase the
number of steps in the external fitting step portion and the internal fitting step portion
beyond the number necessary to do something, and thus, it is possible to avoid a case
where a machining coat or the cost of materials of the joint structure of a steel-pipe pile
is increased.
[0021]
Moreover, according to the aspects of the above (1) to (6), in at least one set of
two rows among the plurality of rows adjacent to one another in the axial direction of
the steel-pipe pile, since the external fitting convex portions of the one row and the
external fitting groove portions of the other row are provided to be adjacent to each
other in the radial direction of the steel-pipe pile when viewed in the axial direction of
the steel-pipe pile, the bending load and the tension load applied to the external fitting
convex portion and the internal fitting convex portion can be uniform in the
circumferential direction. Accordingly, the loads transmitted from the external fitting
convex portions and the internal fitting convex portions to a main body of the steel-pipe
pile can be uniform in the circumferential direction, and an increase in a plate thickness
of the steel-pipe pile can be avoided. Therefore, it is possible to avoid a case where
the cost of materials of the joint structure is increased.
[0022]
According to the aspects of the above (1) to (6), in at least one set of two rows
among the plurality of rows adjacent to one another in the axial direction of the
steel-pipe pile, since the external fitting convex portions of the one row and the external
fitting groove portions of the other row are provided to be adjacent to each other in the
radial direction of the steel-pipe pile when viewed in the axial direction of the steel-pipe
pile, even when the bending load is applied to a portion at which the lower steel-pipe
pile and the upper steel-pipe pile are connected together, any external fitting convex
portion of the plurality of rows and any internal fitting convex portion of the plurality of
rows can be accurately disposed on a portion corresponding to the outermost edge end
portion of the steel-pipe pile at which tensile stress becomes the maximum.
~ccordinglt~he, bending load can be accurately applied to any external fitting convex
portion and any internal fitting convex portion, and it is possible to avoid a case where
the external fitting end portion and the internal fitting end portion are damaged.
[0023]
Particularly, according to the aspect of the above (2), in two step portions
adjacent to each other in the axial direction of the steel-pipe pile, since the external
fitting convex portions of the one step portion and the external fitting groove portions of
the other step portion are provided to be adjacent to each other in the radial direction of
the steel-pipe pile when viewed in the axial direction of the steel-pipe pile, the upper
steel-pipe pile can be inserted into the lower steel-pipe pile while the external fitting
convex portions and the internal fitting convex portions do not interfere with each other.
[0024]
Particularly, according to the aspect of the above (3), since the external fitting
convex portions provided in each of the plurality of step portions are formed to fill gaps
along the circumferential direction when viewed in the axial direction of the steel-pipe
pile, contact areas between the external fitting convex portions and the internal fitting
convex portions are maximized, and load bearing capacity with respect to the tensile
load and the bending load can be increased.
[0025]
Particularly, according to the aspect of the above (4), the plate thickness of the
steel-pipe pile is thickened in stages along the axial direction from the outer side (upper
side) in the axial direction of the lower steel-pipe pile toward the inner side (lower side)
in the axial direction, and from the outer side (lower side) in the axial direction of the
upper steel-pipe pile toward the inner side (upper side) in the axial direction, and thus, a
plurality ol step portions are formed. Accordingly, a structure in which the plate
thickness of the steel-pipe pile is increased in stages according to the number of steps of
the external fitting convex portions and the intcrnal fitting convex portions in the axial
direction can be easily realized.
[0026]
Particularly, according to the aspect of the above (5), in the state where the
external fitting convex portions and the internal fitting convex portions engage with
each other in the axial direction, the tip portion of the external fitting end portion and
the internal fitting edge of the internal fitting end portion abut each other, and thus,
complete fitting between the external fitting end portion and the internal fitting end
portion can be visually confirmed from the outside. In addition, the third tapered
portion abuts the first tapered portion, the fourth tapered portion abuts the second
tapered portion, and thus, the internal fitting convex portion can smoothly move in the
circumferential direction on the external fitting engagement groove, and the external
fitting end portion and the internal fitting end portion can be easily fitted together.
Moreover, since the internal fitting convex portion is locked by the locking portion
formed on the external fitting engagement groove, an excessive rotation of the
steel-pipe pile can be prevented.
[Brief Description of the Drawings]
[0027]
FIG. 1 is a perspective view showing a state where steel-pipe piles are
connected together using a joint structure of a steel-pipe pile according to a first
embodiment of the present invention.
FIG. 2 is a perspective view showing the joint structure of a steel-pipe pile
according to the first embodiment of the present invention.
FIG. 3 is a partially cutaway side view showing an external fitting end portion
according to the first embodiment of the present invention.
FIG. 4A is a plan view showing the external fitting end portion according to the
first embodiment of the present invention.
FIG. 4B is a plan view showing a modification of the external fitting end
portion.
FIG. 5 is an enlarged front view showing an external fitting convex portion, an
external fitting groove portion, and an external fitting engagement groove.
FIG. 6 is a view taken along line A-A of FIG. 5 and showing the external fitting
convex portion, the external fitting groove portion, and the external fitting engagement
groove.
FIG. 7 is a side view showing an internal fitting end portion according to the
first embodiment of the present invention.
FIG. 8A is a plan view showing the internal fitting end portion according to the
first embodiment ofthe present invention.
FIG. 8B is a plan view showing a modification of the internal fitting end
portion.
FIG. 9 is an enlarged front view showing an internal fitting convex portion, an
internal fitting groove portion, and an internal fitting engagemcnt groove.
FIG. 10 is a view talten along line B-B of FIG. 9 and showing the internal
fitting convex portion, the internal fitting groove portion, and the internal fitting
engagement groove.
FIG. 11 is a perspective view showing a state where the internal fitting end
portion is inserted into the external fitting end portion in the first embodiment of the
present invention.
FIG. 12 is a partial cross-sectional perspective view showing a state where the
internal fitting end portion is inserted into the external fitting end portion in the first
embodiment of the prescnt invention.
FIG. 13 is an enlarged perspective view showing a state where the internal
fitting convex portion passes through the external fitting groove portion in the first
embodiment of the present invention.
FIG. 14A is an enlarged front view showing the state where the internal fitting
convex portion passes through the external fitting groove portion in the first
embodiment of the present invention.
FIG. 14B is an enlarged view which shows a portion indicated by a two-dot
chain line of FIG. 14A and shows a modification of the external fitting convex portion.
FIG. 15 is a perspective view showing a state where an upper steel-pipe pile
relatively rotates in the first embodiment of the present invention.
FIG. 16 is an enlarged perspective view showing a state where the external
fitting convex portion and the internal fitting convex portion engage with each other in
the first embodiment of the present invention.
FIG. 17 is an enlarged front view showing a state where the external fitting
convex portion and the internal fitting convex portion engage with each other in the first
embodiment of the present invention.
FIG. 18 is a perspective view showing a modified shape of the joint structure of
the steel-pipe pile according to the first embodiment of the present invention.
FIG. 19 is a perspective view showing a modified shape of the joint structure of
the steel-pipe pile according to the first embodiment of the present invention, which is
different from FIG. 18.
FIG. 20 is a perspective view showing a joint structure of a steel-pipe pile
according to a second embodiment of the present invention.
FIG. 21A is a plan view showing an external fitting end portion in the second
embodiment of the present invention.
FIG. 21B is a plan view showing a modification of the external fitting end
portion.
FIG. 22A is a plan view showing an internal fitting end portion in the second
embodiment of the present invention.
FIG. 22B is a plan view showing a modification ofihe internal fitting end
portion.
FIG. 23 is an enlarged perspective view showing a state where an internal
fitting convex portion passes through an external fitting groove portion in the second
embodiment of the present invention.
FIG. 24 is an enlarged front view showing a state where the internal fitting
convex portion passes through the external fitting groove portion in the second
embodiment of the present invention.
FIG. 25 is a perspective view showing a state where the upper steel-pipe pile
relatively rotates in the second embodiment of the present invention.
FIG. 26 is an enlarged perspective view showing a state where the external
fitting convex portion and the internal fitting convex portion engage with each other in
the second embodiment of the present invention.
FIG. 27 is an enlarged front view showing a state where the external fitting
convex portion and the internal fitting convex portion engage with each other in the
second embodiment of the present invention.
[Embodiments ofthe Invention]
[0028]
Hereinafter, embodiments of the present invention will be described in detail
with reference to the drawings.
[0029]
(First Embodiment)
First, a joint structure of a steel-pipe pile according to a first embodiment of the
present invention will be described with reference to FIGS. 1 and 2. As shown in FIG.
1, the joint structure 1 of a steel-pipe pile according to the first embodiment is used to
connect (join) a lower steel-pipe pile 2 (first steel-pipe pile) and an upper steel-pipe pile
3 (second steel-pipe pile) along an axial direction X.
[0030]
As shown in FIG. 2, the joint structure 1 includes an external fitting end portion
20 provided on an upper end (opening end) of the lower steel-pipe pile 2, and a column
shaped internal fitting end portion 30 provided on a lower end (one end) of the upper
steel-pipe pile 3. In the joint structure 1, the internal fitting end portion 30 of the upper
steel-pipe pile 3 is fitted to the external fitting end portion 20 of the lower steel-pipe pile
2 which is buried under the ground.
[003 I]
In the joint structure 1 of the first embodiment, two external fitting step
portions 29 (29a and 29b) arranged in the axial direction X of the lower steel-pipe pile 2
are provided on the external fitting end portion 20, and two internal fitting step portions
39 (39a and 39b) arranged in the axial direction X of the upper steel-pipe pile 3 are
provided on the internal fitting end portion 30.
[0032]
As shown in FIG 3, a tip portion 28 of the external fitting end portion 20 is
formed on the external fitting end portion 20. Each external fitting step portion 29
(29a and 29b) includes a plurality of external fitting convex portions 21 which are
formed to protrude toward a center side (an inner side in a radial direction) in an axis
orthogonal direction Y (a direction (radial direction) orthogonal to the axial direction X:
refer to FIG. 1) of the lower steel-pipe pile 2 on an inner wall surface (inner
circumferential surface) of the external fitting end portion 20, a plurality of external
fitting groove portions 22 which are formed among the plurality of external fitting
convex portions 21, and an external fitting engagement groove 23 which is formed on
the inner side (lower side) in the axial direction X of the lower steel-pipe pile 2 from the
plurality of external fitting convex portions 21 and the plurality of external fitting
groove portions 22.
[0033]
A plate thickness of the lower steel-pipe pile 2 is thickened in stages in the
axial direction X and the external fitting step portion 29 is formed so that the external
fitting convex portions 21 of the first external fitting step portion 29a in the outer side
(upper side) in the axial direction X of the lower steel-pipe pile 2, and the external
fitting groove portions 22 of the second external fitting step portion 29h in the inner side
(lower side) in the axial direction X of the lower steel-pipe pile 2 have approximately
the same thickness in the axis orthogonal direction Y of the lower steel-pipe pile 2.
The external fitting convex portion 21 of the first external fitting step portion 29a has a
thickness having a predetermined width tl in the axis orthogonal direction Y on the
outer side (upper side) in the axial direction X of the lower steel-pipe pile 2.
[0034]
In each externdl fitting step portion 29 (29a and 29b), the external fitting
convex portion 21 is formed to protrude in an approximately rectangular shape in the
axis orthogonal direction Y of the lower steel-pipe pile 2. In each external fitting step
portion 29 (29a and 29b), the external fitting groove portions 22 are formed among the
plurality of external fitting convex portions 21, and each external fitting groove portion
has a predetermined width in a circumferential direction Z (refer to FIG. 1) of the lower
steel-pipe pile 2. In each external fitting step portion 29 (29a and 29b), the external
fitting engagement groove 23 is formed on the inner side (lower side) in the axial
direction X of the lower steel-pipe pile 2 from the external fitting convex portions 21
and the external fitting groove portions 22, and has a predetermined height in the axial
direction X of the lower steel-pipe pile 2 and approximately the same thickness as the
external fitting groove portion 22 in the axis orthogonal direction Y
[0035]
The external fitting convex portions 21 are formed on the first external fitting
step portion 29a on the outer side (upper side) in the axial direction X of the lower
steel-pipe pile 2, and the second external fitting step portion 29b adjacent to the first
external fitting step portion 29a on the inner side (lower side) in the axial direction X of
the lower steel-pipe pile 2 from the first external fitting step portion 29a. At this time,
the external fitting convex portions 21 ofthe first external fitting step portion 29a and
the external fitting convex portions 21 of the second external fitting step portion 29b are
formed at positions which deviate in the axial direction X. In other words, the external
fitting convex portions 21 of the first external fitting step portion 29a and the external
fitting convex portions 21 of the second external fitting step portion 29b are formed at
positions different from each other in the axial direction X.
[003 61
As shown in FIG 4A, in the external fitting end portion 20, the external fitting
convex portions 2 1 are formed on the first external fitting step portion 29a, and the
external fitting convex portions 21 of the second external fitting step portion 29b are
formed at all positions adjacent to the external fitting groove portions 22 formed on the
first external fitting step portion 29a in the axis orthogonal direction Y when viewed in
the axial direction. Accordingly, the external fitting convex portions 21 of the first
external fitting step portion 29a and the external fitting convex portions 21 of the
second external fitting step portion 29b are alternately formed without gaps in the
circumferential direction Z when viewed in the axial direction.
[0037]
In addition, the external fitting convex portions 21 are not limited to the above,
and for example, as shown in FIG. 4B, the external fitting convex portions 21 of the
second external fitting step portion 29b may be formed at partial positions adjacent to
the external fitting groove portions 22 formed on the first external fitting step portion
29a in the axis orthogonal direction Y when viewed in the axial direction. In other
words, the external fitting convex portions 21 of the first external fitting step portion
29a and the external fitting convex portions 21 of the second external fitting step
portion 29b may be alternately formed with gaps in the circumferential direction Z
when viewed in the axial direction.
[0038]
As shown in FIGS. 5 and 6, the external fitting convex portion 21 includes a
first tapered portion 2121 which is linearly inclined in the circumferential direction Z of
the lower steel-pipe pile 2 on the lower end surface in the inner side (lower side) in the
axial direction X of the lower steel-pipe pile 2. Moreover, the external fitting
engagement groove 23 includes a second tapered portion 23a which is linearly inclined
in the circumferential direction Z of the lower steel-pipe pile 2 to be approximately
parallel with the first tapered portion 21a at the portion facing the first tapered portion
21a in the axial direction X of the lower steel-pipe pile 2. The external fitting
engagement groove 23 includes a locking portion 23b extending in the axial direction X
at the termination of the second tapered portion 23a.
[0039]
The first tapered portion 21a has a predetermined height h in the axial direction
X of the lower steel-pipe pile 2. The second tapered portion 23a extends in a portion
facing the first tapered portion 21a in the axial direction X of the lower steel-pipe pile 2
and extends to the entire portion positioned below the external fitting groove portion 22.
In addition, the second tapered portion 23a is not limited to the above, and for example,
as shown in FIG. 5, the second tapered portion may extend to an intermediate portion
23c positioned below the external fitting groove portion 22. Moreover, as described
above, the first tapered portion 21a and the second tapered portion 23a are linearly
formed on the external fitting convex portion 21 and the external fitting engagement
groove 23. However, the first tapered portion 21a and the second tapered portion 23a
may be formed to be inclined in an arc shape on the external fitting convex portion 2 1
and the external fitting engagement groove 23. In addition, the first tapered portion
21a and the second tapered portion 23a may be separately formed with respect to the
external fitting convex portion 21 and the external fitting engagement groove 23.
[0040]
In the internal fitting end portion 30, as shown in FIG. 7, an internal fitting edge
38, which is formed to protrude toward the outer side in the axis orthogonal direction Y
ofthe upper steel-pipe pile 3, is formed on the inner side (upper side) in the axial
direction X of the upper steel-pipe pile 3 from the two internal fitting step portions 39
(39a and 39b).
[0041]
In each internal fitting step portion 39 (39a and 39b), the internal fitting end
portion 30 includes a plurality of internal fitting convex portions 31 which are formed to
protrude toward the outer side in an axis orthogonal direction Y of the upper steel-pipe
pile 3 on an outer wall surface (outer circumferential surface) of the internal fitting end
30, a plurality of internal fitting groove portions 32 which are formed among the
plurality of internal fitting convex portions 3 1, and an internal fitting engagement
groove 33 which is formed on the inner side (upper side) in the axial direction X of the
upper steel-pipe pile 3 from the plurality of internal fitting convex portions '3 1 and the
plurality of internal fitting groove portions 32.
[0042]
Aplate thickness of the upper steel-pipe pile 3 is thickened in stages in the
axial direction X and the internal fitting step portion 39 is formed so that the internal
fitting groove portions 32 of the first internal fitting step portion 39a in the inner side
(upper side) in the axial direction X of the upper steel-pipe pile 3, and the internal fitting
convex portions 3 1 of the second internal fitting step portion 39b in the outer side
(lower side) in the axial direction X of the upper steel-pipe pile 3 have approximately
the same thickness in the axis orthogonal direction Y of the upper steel-pipe pile 3.
The internal fitting engagement groove 33 of the first internal fitting step portion 39a
has a space having a predetermined width t2 in the axis orthogonal direction Y of the
upper steel-pipe pile 3.
100431
In each internal fitting step poi-tion 39 (39a and 39b), the internal fitting convex
portion 31 is formed to protrude in an approximately rectangular shape in the axis
orthogonal direction Y of the upper steel-pipe pile 3. In each internal fitting step
portion 39 (39a and 39b), the internal fitting groove portions 32 are formed among the
plurality of internal fitting convex portions 31, and each internal fitting groove portion
has a predetermined width in a circumferential direction Z of the upper steel-pipe pile 3.
The internal fitting engagement groove 33 is formed on the inner side (upper side) in the
axial direction X of the upper steel-pipe pile 3 from the internal fitting convex portions
31 and the internal fitting groove portions 32, and is formed so that the width t2 (refer to
FIG. 7) of the space between the internal fitting engagement grooves 33 in the first
internal fitting step porlion 39a is equal to or more than the width tl (refer to FIG. 3) of
the plate thickness of the external fitting convex portion 21 in the first external fitting
step portion 29a. Moreover, in each internal fitting step portion 39, the internal fitting
engagement groove 33 has a predetermined height in the axial direction X of the upper
steel-pipe pile 3 and approximately the same thickness as the internal fitting groove
portion 32 in the axis orthogonal direction Y.
[0044]
The internal fitting convex portions 3 1 are formed on the first internal fitting
step portion 39a on the inner side (upper side) in the axial direction X of the upper
steelIpipe pile 3, and the second internal fitting step portion 39b adjacent to the first
internal fitting step portion 39a on the outer side (lower side) in the axial direction X of
the upper steel-pipe pile 3 from the first internal fitting step portion 39a. At this time,
the internal fitting convex portions 3 1 of the first internal fitting step portion ?9a and the
internal fitting convex portions 31 of the second internal fitting step portion 39b are
formed at positions which deviate in the axial direction X. In other words, the internal
fitting convex portions 31 of the first internal fitting step portion 39a and the internal
fitting convex portions 31 of the second internal fitting step portion 39b are formed at
positions different from each other in the axial direction X.
[0045]
As shown in FIG. 8A, the internal fitting convex portions 31 of the second
internal fitting step portion 39b are formed at all positions adjacent to the internal fitting
groove portions 32 formed on the first internal fitting step portion 39a in the axis
orthogonal direction Y when viewed in the axial direction. Accordingly, the internal
fitting convex portions 3 1 of the first internal fitting step portion 39a and the internal
fitting convex portions 3 1 of the second internal fitting step portion 39b are alternately
formed without gaps in the circumferential direction Z when viewed in the axial
direction.
[0046]
In addition, the internal fitting convex portions 3 1 are not limited to the above.
and for example, as shown in FIG. 8B, the internal fitting convex portions 31 of the
second internal fitting step portion 39b may be formed at partial positions adjacent to
the internal fitting groove portions 32 formed on the frst internal fitting step portion
39a in the axis orthogonal direction Y when viewed in the axial direction. In other
words, the internal fitting convex portions 31 of the first internal fitting step portion 39a
and the internal fitting convex portions 3 1 ofthe second internal fitting step portion 39h
may he alternately formed with gaps in the circumferential direction Z when viewed in
the axial direction.
[0047]
As shown in FIGS. 9 and 10, the internal fitting convex portion 3 1 includes a
third tapered portion 3 la which is linearly inclined in the circumferential direction Z of
the upper steel-pipe pile 3 to abut the first tapered portion 21 a shown in FIG. 5 and to be
approximately parallel with the first tapered portion 21a on the upper end surface in the
inner side (upper side) in the axial direction X of the upper steel-pipe pile 3. Moreover,
the internal fitting convex portion 3 1 includes a fourth tapered portion 3 1h which is
linearly inclined in the circumferential direction Z of the upper steel-pipe pile 3 to abut
the second tapered portion 23a shown in FIG. 5 and to be approximately parallel with
the second tapered portion 23a and the third tapered portion 3 la on the lower end
surface in the outer side (lower side) in the axial direction X of the upper steel-pipe pile
3.
[0048]
The third tapered portion 3 1 a and the fourth tapered portion 3 1b have a
predetermined height h in the axial direction X of the upper steel-pipe pile 3.
Moreover, as described above, the third tapered portion 3 la and the fourth tapered
portion 3 1 b are linearly formed on the internal fitting convex portion 3 1. However, the
third tapered portion 3 la and the fourth tapered portion 31b may be formed to be
inclined in an arc shape on the internal fitting convex portion 3 1. In addition, the third
tapered portion 3 la and the fourth tapered portion 3 1 b may be separately formed with
respect to the internal fitting convex portion 3 1.
[0049]
Next, a method for connecting the lower steel-pipe pile 2 and the upper
steel-pipe pile 3 together using the joint structure 1 of a steel-pipe pile according to the
first embodiment will be described in detail with reference to the drawings.
[0050]
First, as shown in FIGS. 11 and 12, the internal fitting end portion 30 of the
upper steel-pipe pile 3 is inserted into the external fitting end portion 20 of the lower
steel-pipe pile 2 along thc axial direction X. I-Iere, FIG. 11 is a view showing a state
where the internal fitting end portion 30 is inserted into the external fitting end portion
20, and FIG. 12 is a view showing a state where the internal fitting end portion 30 is
further inserted into the external fitting end portion 20 from the state of FIG. 11. As
shown in FIGS. 13 and 14A, the internal fitting end portion 30 is inserted into the
external fitting end portion 20, and thus, the internal fitting convex portions 3 1 of the
first internal fitting step portion 39a pass through the external fitting groove portions 22
of the first external fitting step portion 29a and abut the lower end surface of the
external fitting engagement groove 23 of the first external fitting step portion 29a.
Moreover, the internal fitting convex portions 3 1 of the second internal fitting step
portion 39b pass through the external fitting groove portions 22 of the second external
fitting step portion 29b and abut the lower end surface of the external fitting
engagement groove 23 of the second external fitting step portion 29b. Moreover, FIG
14B shows a state where the internal fitting convex portions 31 of the first internal
fitting step portion 39a abut the lower end surface of the external fitting engagement
groove 23 of the first external fitting step portion 29a when the second tapered portion
23a extends to the intermediate portion 23c (refer to FIG. 5).
[005 11
Here, as described above, in the joint structure 1, the external fitting convex
portions 21 of the first external fitting step portion 29a and the external fittint: groove
portions 22 of the second external fitting step portion 29b are formed to all have
approximately the same thicknesses in the axis orthogonal direction Y of the lower
steel-pipe pile 2, and the internal fitting groove portions 32 of the first internal fitting
step portion 39a and thc internal fitting convex portions 3 1 of the second internal fitting
step portion 39b are formed to all have approximately the same thiclcnesses in the axis
orthogonal direction Y of the upper steel-pipe pile 3. Accordingly, the internal fitting
end portion 30 of the upper steel-pipe pile 3 can be inserted into the external fitting end
portion 20 of the lower steel-pipe pile 2 without interference between the internal fitting
convex portions 3 1 of the second internal fitting step portion 39b and the external fitting
convex portions 21 of the first external fitting step portion 29a.
[0052]
At this time, as shown in FIG. 14A, in the state where the internal fitting end
portion 30 ofthe upper steel-pipe pile 3 is inserted into the external fitting end portion
20 of the lower steel-pipe pile 2, a gap d having a predetermined height in the axial
direction X is formed between the tip portion 28 of the external fitting end portion 20
and the internal fitting edge 38 of the internal fitting end portion 30.
[0053]
Next, as shown in FIG. 15, the lower steel-pipe pile 2 and the upper steel-pipe
pile 3 are relatively rotated in the circumferential direction Z around the axis.
Accordingly, as shown in FIGS. 16 and 17, the internal fitting convex portions 3 1 move
to portions under the external fitting convex portions 21 along the circumferential
direction Z and engage with the external fitting convex portions 21 in the axial direction
X. In this way, the external fitting end portion 20 of the lower steel-pipe pile 2 and the
internal fitting end portion 30 of the upper steel-pipe pile 3 are fitted together.
[0054]
Here, the first tapered portion 21a and the second tapered portion 23a shown in
FIG. 5 and the third tapered portion 3 la and the fourth tapered portion 31 b shown in FIG.
9 have thc predetermined height h in the axial direction X of the lower steel-pipe pile 2
and the upper steel-pipe pile 3. The height h is set to be approximately the same as the
height of the gap d which is formed between the tip portion 28 of the external fitting end
portion 20 and the internal fitting edge 38 of the internal fitting end portion 30.
[0055]
At this time, as shown in FIG. 17, the third tapered portion 3 la (refer to FIG. 9)
abuts the first tapered portion 2la (refer to FIG. 5), and the fourth tapered portion 31b
(refer to FIG. 9) abuts the second tapered portion 23a (refer to FIG. 5), and thus, the
internal fitting convex portion 3 1 of the upper steel-pipe pile 3 moves in the
circumferential direction Z on the external fitting engagement groove 23 of the lower
steel-pipe pile 2. Accordingly, the lower steel-pipe pile 2 and the upper steel-pipe pile
3 approach each other in the axial direction X, and thus, the tip portion 28 of the
external fitting end portion 20 and the internal fitting edge 38 of the internal fitting end
portion 30 abut each other to fill the gap d.
[0056]
Accordingly, in the joint structure 1, in the state where the external fitting
convex portions 21 and the internal fitting convex portions 31 engage with each other in
the axial direction X, the tip portion 28 of the external fitting end portion 20 and the
internal fitting edge 38 of the internal fitting end portion 30 abut each other to fill the
gap d. Accordingly, whether or not the external fitting end portion 20 of the lower
steel-pipe pile 2 and the internal fitting end portion 30 of the upper steel-pipe pile 3 are
completely fitted together can be determined by visually confirming the gap d from the
outside.
Moreover, after the external fitting end portion 20 of the lower steel-pipe pile 2
and the internal fitting end portion 30 of the upper steel-pipe pile 3 are fitted together, a
feeler gauge abuts the gap d, and the fitting between the external fitting end portion 20
and the internal fitting end portion 30 may be confirmed according to whether or not the
feeler gauge passes through the gap d. In this case, compared to the above-described
visual confirmation method, whether or not the external fitting end portion 20 and the
internal fitting end portion 30 are fitted together can be more accurately determined.
[0057]
In addition, as shown in FIG. 17, the third tapered portion 3 la (refer to FIG. 9)
abuts the first tapered portion 21a (refer to FIG. 5), and the fourth tapered portion 3 lb
(refer to FIG. 9) abuts the second tapered portion 23a (refer to FIG. 5), and thus, the
internal fitting convex portion 3 1 of the upper steel-pipe pile 3 can smoothly move in
the circumferential direction Z on the external fitting engagement groove 23 of the
lower steel-pipe pile 2, and the external fitting end portion 20 of the lower steel-pipe
pile 2 and the internal fitting end portion 30 of the upper steel-pipe pile 3 can be easily
fitted together. In addition, in the joint structure 1, the internal fitting convex portion
3 1 of the upper steel-pipe pile 3 is locked to the locking portion 23b (refer to FIG. 5) of
the external fitting engagement groove 23 of the lower steel-pipe pile 2. Accordingly,
the external fitting end portion 20 of the lower stcel-pipe pile 2 and the internal fitting
end portion 30 of the upper steel-pipe pile 3 can be fitted together while the upper
steel-pipe pile 3 is not rotated more than necessary.
[OOSS]
In the joint structure 1, in the state where the external fitting end portion 20 of
the lower steel-pipe pile 2 and the internal fitting end portion 30 of the upper steel-pipe
pile 3 are fitted together, the internal fitting convex portions 3 1 formed on the first
internal fitting step portion 39a engage with the external fitting convex portions 21
formed on the first external fitting step portion 29a, the internal fitting convex portions
3 1 formed on the second internal fitting step portion 39b engage with the external fitting
convex portions 21 formed on the second external fitting step portion 29b, and thus, a
bending load and a tension load are transmitted to the main body of the steel-pipe pile.
Moreover, in the joint structure 1, the external fitting convex portions 21 formed on the
first external fitting step portion 29a and the external fitting convex portions 21 formed
on the second external fitting step portion 29b are provided at positions which deviate in
the axial direction X. Accordingly, in the joint structure 1 of a steel-pipe pile, the
lower steel-pipe pile 2 and the upper steel-pipe pile 3 can be connected together without
a cross-sectional defect when viewed in the axial direction.
[0059]
Accordingly, in the joint structure 1, in the state where the external fitting end
portion 20 of the lower steel-pipe pile 2 and the internal fitting end portion 30 of the
upper steel-pipe pile 3 are fitted together, it is possible to avoid a case where the
bending load and the tension load which can be transmitted by the external fitting
convex portions 21 and the internal fitting convex portions 3 1 are decreased by the
cross-sectional defect when viewed in the axial direction. Accordingly, in the joint
structure 1 of a steel-pipe pile, it is not necessary to enlarge the external fitling convex
portions 21 and the internal fitting convex portions 3 1 by the cross-sectional defect to
withstand the predetermined bending load and tension load, and it is not necessary to
increase the number of steps of the external fitting step portion 29 and the internal
fitting step portion 39 in the axial direction X. Accordingly, it is possible to avoid a
case where the machining cost and the cost of materials of the joint structure between
the lower steel-pipe pile 2 and the upper steel-pipe pile 3 are increased.
[0060]
In the joint structure 1, since the external fitting convex portion 21 formed on
the first external fitting step portion 29a and the external fitting convex portion 21
formed on the second external fitting step portion 29b are provided at positions which
deviate in the axial direction X, the bending load and tlie tension load applied to the
external fitting convex portions 21 and the internal fitting convex portions 3 1 can be
uniform in the circumferential direction Z. Accordingly, in the joint structure 1, it is
possible to avoid a case where the bending load and the tension load are concentrated on
partial external fitting convex portions 21 and internal fitting convex portions 3 1 in the
circumferential direction Z. Therefore, in the joint structure 1, the loads transmitted
from the external fitting convex portion 2 1 and the internal fitting convex portion 3 1 to
the main bodies of the lower steel-pipe pile 2 and the upper steel-pipe pile 3 can be
uniform in the circumferential direction Z, and thus, increases in the plate thicknesses of
the lower stcel-pipe pile 2 and the upper steel-pipe pile 3 can be avoided. Accordingly,
it is possible to avoid a case where the costs of materials of the joint structure between
the lower steel-pipe pile 2 and the upper steel-pipe pile 3 is increased.
[0061]
Here, in the joint structure 1, in the first external fitting step portion 29a and the
first internal fitting step portion 39a, each of the external fitting convex portions 21 and
the internal fitting convex portions 31 is formed in one step (one row), and the plate
thicknesses of the lower steel-pipe pile 2 and the upper steel-pipe pile 3 are sufficient if
the platc has load bearing capacity with respect to the bending load and the tension load
by the one step. Meanwhile, in the second external fitting step portion 29b and the
second internal fitting step portion 39b, the number of steps (the number of rows) ofthe
external fitting convex portion 21 and the internal fitting convex portion 3 1 increases,
and it is necessary to set the plate thicknesses of the lower steel-pipe pile 2 and the
upper steel-pipe pile 3 according to the increase in the number of steps. In the joint
structure 1, the plate thicknesses of the lower steel-pipe pile 2 and the upper steel-pipe
pile 3 are thickened in stages from the outer side (upper side) toward the inner side
(lower side) in the axial direction X of the lower steel-pipe pile 2 and from the outer
side (lower side) toward the inner side (upper side) in the axial direction X of the upper
steel-pipe pile 3, and the external fitting step portion 29 and the internal fitting step
portion 39 are formed. Accordingly, in the joint structure 1, the structure in which the
plate thiclmesses of the lower steel-pipe pile 2 and the upper steel-pipe pile 3 increase in
stages according to the number of steps of the external fitting convex portions 21 and
the internal fitting convex portions 31 can be easily realized.
[0062]
In addition, in the joint structure 1, the external fitting convex portions 2 1
formed on the first external fitting step portion 29a and the external fitting convex
portions 21 formed on the second external fitting step portion 29b are provided at
posi60ns which deviate in the axial direction X. Accordingly, in the joint structure 1,
even when the bending load is applied to the portion at which the lower steel-pipe pile 2
and the upper steel-pipe pile 3 are connected together, the external fitting convex
portions 21 of either thc first external fitting step portion 29a or the second cxtcrnal
fitting step portion 29b and the internal fitting convex portions 3 1 of either the first
internal fitting step portion 39a or the second internal fitting step portion 39b can be
accurately disposed at the portions corresponding to the outermost edge ends of the
lower steel-pipe pile 2 and the upper steel-pipe pile 3 at which the tensile stress is
maximized. Therefore, in the joint structure 1, the bending load is accurately applied
to any of the external fitting convex portions 21 and any of the internal fitting convex
portions 31, and it is possible to avoid a case where the external fitting end portion 20 of
the lower steel-pipe pile 2 and the internal fitting end portion 30 of the upper steel-pipe
pile 3 are damaged.
[0063]
In the first embodiment, the case is shown, in which the external fitting end
portion 20 includes the plurality of step portions (first external fitting step portion 29a
and second external fitting step portion 29b), and the internal fitting end portion 30
includes the plurality of step portions (first internal fitting step portion 39a and second
internal fitting step portion 39b). However, for example, as shown in FIG. 18, each of
the external fitting end portion 20 and the internal fitting end portion 30 may include
one step portion (external f~ttingst ep portion 29 or internal fitting step portion 39), and
the external fitting convex portions 21 and the internal fitting convex portions 3 1 may
be formed at positions which deviate in the axial direction X.
Also in this case, the cross-sectional defect does not occur when viewed in the
axial direction, and the loads transmitted from the external fitting convex portions 21
and the internal fitting convex portions 3 1 to the main bodies of the lower steel-pipe pile
2 and the upper steel-pipe pile 3 can be uniform in the circumferential direction.
In addition, in this case, since the plurality of step portions are not formed on
the external fitting end portion 20 and the internal fitting end portion 30, compared to
the first embodiment, it is possible to decrease the machining costs.
[0064]
In addition, in the first embodiment, the case is shown, in which the external
fitting convex portions 21 are formed in one step (one row) on each of the first external
fitting step portion 29a and the second external fitting step portion 29b and the internal
fitting convex portions 3 1 are formed in one step (one row) on each of the first internal
fitting step portion 39a and the second internal fitting step portion 39b. However, for
example, as shown in FIG. 19, the external fitting convex portions 21 may be formed in
two stcps (two rows) on the first external fitting step portion 29a, and the external fitting
convex portions 2 1 may be formed in one step (one row) on the second external fitting
step portion 29b.
Also in this case, the cross-sectional defect does not occur when viewed in the
axial direction, and the loads transmitted from the external fitting convex portions 21
and the internal fitting convex portions 3 1 to the main bodies of the lower steel-pipe pile
2 and the upper steel-pipe pile 3 can be uniform in the circumferential direction.
In addition, in this case, compared to the first embodiment, the number of the
external fitting convex portions 21 and the internal fitting convex portions 3 1 can be
increased, and thus, the loads applied to one external fitting convex portion 21 and one
internal fitting convex portion 3 1 can be decreased.
Moreover, in FIG. 19, the case is shown, in which the external fitting convex
portions 21 are formed in two steps (two rows) on the first external fitting stcp portion
29a and the internal fitting convex portions 3 1 are formed in two steps (two rows) on
the first internal fitting step portion 39a. However, the external fitting convex portions
21 and the internal fitting convex portions 3 1 may be formed in a plurality of step
portions (a plurality of rows) on the second external fitting step portion 29b and the
second internal fitting step portion 39b.
[0065]
As described above, from the viewpoint that the cross-sectional defect does not
occur when viewed in the axial direction, the external fitting convex portions 21 and the
external fitting groove portions 22 are formed in the plurality of rows in the axial
direction X, and among the plurality of rows adjacent to one another along the axial
direction X, in at least (one set of) two rows adjacent to each other, the external fitting
convex portions 21 of one row and the external fitting groove portions 22 of the other
row may be formed to be adjacent to each other in the axis orthogonal direction Y when
viewed in the axial direction.
[0066]
(Second Embodiment)
Next, a joint structure 100 of a steel-pipe pile according to a second
embodiment of the present invention will be described. Moreover, the same numeral
references are assigned to the same components as the above-described components,
and descriptions thereof are omitted below.
[0067]
In the joint structure 100 of a steel-pipe pile according to the second
embodiment, as shown in FIG. 20, three external fitting step portions 29 (29a, 29b, and
29c) arranged in the axial direction X of the lower steel-pipe pile 2 are provided on the
external fitting end portion 20. Moreover, three internal fitting step portions 39 (39a,
39b, and 39c) arranged in the axial direction X of the upper steel-pipe pile 3 are
provided on the internal litling end portion 30.
[0068]
The plate thickness of the lower steel-pipe pile 2 is thickened in stages in the
axial direction X and the external fitting step portion 29 is formed so that the external
frtting convex portions 21 of the first external fitting step portion 29a in the outer side
(upper side) in the axial direction X of the lower steel-pipe pile 2, and the external
fitting groove portions 22 of the second external fitting step portion 29b in the inner side
(lower side) in the axial direction X of the lower steel-pipe pile 2 from the first external
fitting step portion 29a have approximately the same thickness in the axis orthogonal
direction Y of the lower steel-pipe pile 2, and the external fitting convex portions 21 of
the second external fitting step portion 29b, and the external fitting groove portions 22
of the third cxternal fitting step portion 29c in the inner side (lower side) in the axial
direction X of the lower steel-pipe pile 2 from the second external fitting step portion
29b have approximately the same thiclmcss in the axis orthogonal direction Y of the
lower steel-pipe pile 2.
100691
The external fitting convex portions 21 formed on the first external fitting step
portion 29a and the external fitting convex portions 21 formed on the second external
fitting step portion 29b are provided at positions which deviate in the axial direction X.
In addition, the external fitting convex portions 21 formed on the second external fitting
step portion 29b and the external fitting convex portions 21 formed on the third external
fitting step portion 29c are provided at positions which deviate in the axial direction X.
[0070]
As shown in FIG. 21A, the external fitting convex portions 21 of thc second
external fitting step portion 29b are formed at all positions adjacent to the external
fitting groove portions 22 formed on the first external fitting step portion 29a in the axis
orthogonal direction Y when viewed in the axial direction. In addition, the external
fitting convex portions 21 of the third external fitting step portion 29c are formed at all
positions adjacent to the external fitting groove portions 22 formed on the second
external fitting step portion 29b in the axis orthogonal direction Y when viewed in the
axial direction. Accordingly, the external fitting convex portions 21 of the first
external fitting step portion 29a and the external fitting convex portions 21 of the
second external fitting step portion 29b are alternately formed without gaps in the
circumferential direction Z when viewed in the axial direction, and the external firting
convex portions 21 of the second external fitting step portion 29b and the external
fitting convex portions 21 of the third external fitting step portion 29c are altcmately
formed without gaps in the circumferential direction Z when viewed in the axial
direction.
[0071]
In addition, the external fitting convex portions 21 are not limited to the above,
and as shown in FIG. 21B, the external fitting convex portions 21 of the second external
fitting step portion 29b may be formed at partial positions adjacent to the external fitting
groove portions 22 formed on the first external fitting step portion 29a in the axis
orthogonal direction Y when viewed in the axial direction, and the external fitting
convex portions 21 of the third external fitting step portion 29c may be formed at partial
positions adjacent to the cxternal fitting groove portions 22 formed on the second
external fitting step portion 29b in the axis orthogonal direction Y when viewed in the
axial direction. At this time, the external fitting convex portions 21 of the first external
fitting step portion 29a and the external fitting convex portions 21 of the second
external fitting step portion 29h are alternately formed with gaps in the circumferential
direction Z when viewed in the axial direction, and the external fitting convex portions
21 of the second external fitting step portion 29b and the external fitting convex
portions 21 of the third external fitting step portion 29c are alternately formed with gaps
in the circumferential direction Z when viewed in the axial direction.
[0072]
The plate thickness of the upper steel-pipe pile 3 is thickened in stages in the
axial direction X and the internal fitting step portion 39 is formcd so that the internal
fitting groove portions 32 of the first internal fitting step portion 39a in the inner side
(upper side) in the axial direction X of the upper steel-pipe pile 3, and the internal fitting
convex portions 31 of the second internal fitting step portion 39b in the outer side
(lower side) in the axial direction X of the upper steel-pipe pile 3 from the first internal
fitting step portion 39a have approximately the same thickness in the axis orthogonal
direction Y of the upper steel-pipe pile 3, and the internal fitting groove portions 32 of
the second internal fitting step portion 39h, and the internal fitting convex portions 3 1 of
the third internal fitting step portion 39c in the outer side (lower side) in the axial
direction X from the second internal fitting step portion 39b have approximately the
same thickness in the axis orthogonal direction Y.
[0073]
The internal fitting convex portions 31 formed on the first internal fitting step
portion 39a and the internal fitting convex portions 31 formed on the second internal
fitting step portion 39b are provided at positions which deviate in the axial direction X.
In addition, the internal frtting convex portions 3 1 formed on the second internal fitting
step portion 39b and the internal fitting convex portions 3 1 formed on the third internal
fitting step portion 39c are provided at positions which deviate in the axial direction X.
[0074]
As shown in FIG. 22A, the internal fitting convex portions 3 1 of the second
internal fitting step portion 39b are formed at all positions adjacent to the internal fitting
groove portions 32 formed on the first internal fitting step portion 39a in the axis
orthogonal direction Y when viewed in the axial direction. In addition, the internal
fitting convex portions 31 of the third internal fitting step portion 39c are formed at all
positions adjacent to the internal fitting groove portions 32 formed on the second
internal fitting step portion 39h in the axis orthogonal direction Y when viewed in the
axial direction. Accordingly, the internal fitting convex portions 3 1 of the first internal
fitting step portion 39a and the internal fitting convex portions 3 1 of the second internal
fitting step portion 39b are alternately formed without gaps in the circumferential
direction Z when viewed in the axial direction, and the internal fitting convex portions
3 1 of the second internal fitting step portion 39b and the internal fitting convex portions
31 of the third internal fitting step portion 39c are alternately formed without gaps in the
circumferential direction Z when viewed in the axial direction.
[0075]
In addition, the internal fitting convex portions 3 1 are not limited to the above,
and as shown in FIG. 22B, the internal fitting convex portions 31 of the second internal
fitting step portion 39b may be formed at partial positions adjacent to the internal fitting
groove portions 32 formed on the first internal fitting step portion 39a in the axis
orthogonal direction Y when viewed in the axial direction. Moreover, the internal
fitting convex portions 3 1 of the third internal fitting step portion 39c may be formed at
partial positions adjacent to the internal fitting groove portions 32 formed on the second
internal fitting step portion 39b in the axis orthogonal direction Y when viewed in the
axial direction. At this time, in the internal fitting convex portions 3 1, the internal
fitting convex portions 31 of the first internal fitting step portion 39a and the internal
fitting convex portions 31 of the second internal fitting step portion 39b are alternately
formed with gaps in the circumferential direction Z when viewed in the axial direction,
and the internal fitting convex portions 3 1 of the second internal fitting step portion 39b
and the internal fitting convex portions 3 1 of the third internal fitting step portion 39c
are alternately formed with gaps in the circumferential direction Z when viewed in the
axial direction.
[0076]
Next, a method for connecting the lower steel-pipe pile 2 and the upper
steel-pipe pile 3 together using the joint structure 100 of a steel-pipe pile according to
the second embodiment will be described in detail with reference to the drawings.
[0077]
First, the internal fitting end portion 30 of the upper steel-pipe pile 3 is inserted
into the external fitting end portion 20 of the lower steel-pipe pile 2 in the axial
direction X. Accordingly, as shown in FIGS. 23 and 24, the internal fitting convex
portions 31 of the first internal fitting step portion 39a pass through the external fitting
groove portions 22 of the first external fitting step portion 29a and abut the lower end
surface of the external fitting engagement groove 23 of the first external fitting step
portion 29a. Moreover, the internal fitting convex portions 3 1 of the second internal
fitting step portion 39b pass through the external fitting groove portions 22 of the
second external fitting step portion 29b and abut the lower end surface of the external
fitting engagement groove 23 of the second external fitting step portion 29b. In
addition, the internal fitting convex portions 3 1 of the third internal fitting step portion
39c pass through the external fitting groove portions 22 of the third external fitting step
portion 29c and abut the lower end surface of the external fitting engagement groove 23
of the third external fitting step portion 29c.
100781
Here, in the joint structure 100, the external fitting convex portions 21 of the
first external fitting step portion 29a and the external fitting groove portions 22 of the
second external fitting step portion 29b are formed to all have approximately the same
thicknesses in the axis orthogonal direction Y of the lower steel-pipe pile 2, and the
internal fitting groove portions 32 of the first internal fitting step portion 39a and the
internal fitting convex portions 31 of the second internal fitting step portion 39b are
formed to all have approxiinately the same thicknessesin the axis orthogonal direction
Y of the upper steel-pipe pile 3. In addition, the external fitting convex portions 21 of
the second external fitting step portion 29b and the external fitting groove portions 22 of
the third external fitting step portion 29c are formed to all have approximately the same
thicknesses in the axis orthogonal direction Y of the lower steel-pipe pile 2, and the
internal fitting groove portions 32 of the second internal fitting step portion 39b and the
internal fitting convex portions 3 1 of the third internal fitting step portion 39c are
formed to all have approximately the same thicknesses in the axis orthogonal direction
Y ofthe upper steel-pipe pile 3. Accordingly, the internal fitting end portion 30 of the
upper steel-pipe pile 3 is inserted into the external fitting end portion 20 of the lower
steel-pipe pile 2 without interference between the internal fitting convex portions 3 1 of
the third internal fitting step portion 39c and the external fitting convex pollinns 21 of
the first external fitting step portion 29a and the second external fitting step portion 29b,
and without interference between the internal fitting convex portions 3 1 of the second
internal fitting step portion 39b and the external fitting convex portions 21 of the first
external fitting step portion 29a.
[0079]
At this time, in the joint structure 100, as shown in FIG. 24, in the state where
the internal fitting end portion 30 of the upper steel-pipe pile 3 is inserted into the
external fitting end portion 20 of the lower steel-pipe pile 2, the gap d having a
predetermined height in the axial direction X is formed between the tip portion 28 of the
external fitting end portion 20 and the internal fitting edge 38 of the internal fitting end
portion 30.
[0080]
Next, in the joint structure 100, as shown in FIG. 25, the lower steel-pipe pile 2
and the upper steel-pipe pile 3 are relatively rotated in the circumferential direction Z
around the axis. Accordingly, as shown in FIGS. 26 and 27, the internal fitting convex
portions 3 1 move in the circumferential direction Z in the external fitting engagement
groove 23 to portions under the external fitting convex portions 21. Moreover, the
internal fitting convex portions 3 1 engage with the external fitting convex portions 2 1 in
the axial direction X, and the external fitting end portion 20 of the lower steel-pipe pile
2 and the internal fitting end portion 30 of the upper steel-pipe pile 3 are fitted together.
[0081]
At this time, in the joint structure 100, as shown in FIG. 27, the third tapered
portion 3 la (refer to FIG. 9) abuts the first tapered portion 21a (refer to FIG. S), the
fourth tapered portion 3 lb (refer to FIG. 9) abuts the second tapered portion 23a (refer
to FIG. 5), and thus, the internal fitting convex portion 3 1 moves in the circumferential
direction Z on the external fitting engagement groove 23. Accordingly, the lower
steel-pipe pile 2 and the upper steel-pipe pile 3 approach each other in the axial
direction X, and thus, the tip portion 28 of the external fitting end portion 20 and the
internal fitting edge 38 of the internal fitting end portion 30 abut each other to fill the
gap d.
[0082]
Similar to the first embodiment, as described above, in the second embodiment,
in the state where the external fitting convex portions 21 and the internal fitting convex
portions 3 1 engage with each other in the axial direction X, the tip portion 28 of the
external fitting end portion 20 and the internal fitting edge 38 of the internal fitting end
portion 30 abut each other to fill the gap d. Accordingly, whether or not thc cxternal
fitting end portion 20 of the lower steel-pipe pile 2 and the internal fitting end portion
30 of the upper steel-pipe pile 3 are completely fitted together can be determined by
visually confirming the gap d from the outside.
In addition, similar to the first embodiment, also in the second embodiment,
after the external fitting end portion 20 of the lower steel-pipe pile 2 and the internal
fitting end portion 30 of the upper steel-pipe pile 3 are fitted together, the feeler gauge
abuts the gap d, and the fitting between the external fitting end portion 20 and the
internal fitting end portion 30 may be confirmed according to whether or not the feeler
gauge passes through the gap d. In this case, compared to the above-described visual
confirmation method, whether or not the external fitting end portion 20 and the internal
fitting end portion 30 are fittcd together can be more accurately determined.
[0083]
Moreover, similar to the first embodiment, in the second embodiment, as
shown in FIG. 27, the third tapered portion 3 la (refer to FIG. 9) abuts the first tapered
portion 21 a (refer to FIG. 5), and the fourth tapered portion 3 1 b (refer to FIG. 9) abuts
the second tapered portion 23a (refer to FIG. 5), and thus, the internal fitting convex
portion 3 1 of the upper sieel-pipe pile 3 can smoothly move in the circumferential
direction Z on the external fitting engagement groove 23 of the lower steel-pipe pile 2.
Accordingly, the external fitting end portion 20 of the lower steel-pipe pile 2 and the
internal fitting end portion 30 of the upper steel-pipe pile 3 can be easily fitted together.
In addition, the internal fitting convex portion 3 1 is locked to the locking portion 23b
(refer to FIG. 5) of the external fitting engagement groove 23, and thus, it is possible to
prevent the upper steel-pipe pile 3 from being rotated more than necessary.
[0084]
In the joint structure 100 of a steel-pipe pile according to the second
embodiment, in the state where the external fitting end portion 20 of the lower
steel-pipe pile 2 and the internal fitting end portion 30 of the upper steel-pipe pile 3 are
fitted together, the internal fitting convex portions 3 1 of the first internal fitting step
portion 39a engage with the external fitting convex portions 21 of the first external
fitting step portion 29a, the internal fitting convex portions 31 of the second internal
fitting step portion 39b engage with the external fitting convex portions 21 ofthe
second external fitting step portion 29b, and the internal fitting convex portions 3 1 of
the third internal fitting step portion 39c engage with the external fitting convex
portions 21 of the third external fitting step portion 29c. In addition, the bending load
and the tension load are transmitted to the main body of the steel-pipe pile. Moreover,
the external fitting convex portions 21 of the first external fitting step portion 29a and
the external fitting convex portions 21 ofthe second external fitting step portion 29b are
provided at positions which deviate in the axial direction X, and the external fitting
convex portions 21 of the second external fitting step portion 29b and the external
fitting convex portions 21 of the third external fitting step portion 29c are provided at
positions which deviate in the axial direction X. Accordingly, in the joint structure 100
of a steel-pipe pile according to the second embodiment, and the lower steel-pipe pile 2
and the upper steel-pipe pile 3 can be connected together without the cross-sectional
defect when viewed in the axial direction.
[0085]
Therefore, similar to the first embodiment, also in the second embodiment, in
the state where the external fitting end portion 20 of the lower steel-pipe pile 2 and the
internal fitting end portion 30 of the upper steel-pipe pile 3 are fitted together, it is
possible to avoid a case where the bending load and the tension load which can be
transmitted by the external fitting convex portions 21 and the internal fitting convex
portions 3 1 are decreased by the cross-sectional defect when viewed in the axial
direction. Accordingly, it is not necessary to enlarge the external fitting convex
portions 21 and the interilal fitting convex portions 3 1 by the cross-sectional defect to
withstand predetermined bending load and tension load, and it is not necessary to
increase the number of steps of the extcrnal fitting step portion 29 and the internal
fitting step portion 39 in the axial direction X, and thus, it is possible to avoid a case
where the machining cost and the cost of materials of the joint structure of a steel-pipe
pile are increased.
[OOS6]
In the second embodiment, the external fitting convex portion 21 ol'the first
external fitting step portion 29a and the external fitting convex portion 21 of the second
external fitting step portion 29b are provided at positions which deviate in the axial
direction X, the external fitting convex portion 21 of the second external fitting step
portion 29b and the external fitting convex portion 21 of the third external fitting step
portion 29c are provided at positions which deviate in the axial direction X, and thus,
the bending load and the tension load applied to the external fitting convex portions 21
and the internal fitting convex portions 3 1 can be uniform in the circumferential
direction 2. Accordingly, it is possible to avoid a case where the bending load and the
tensibn load are concentrated on partial external fitting convex portions 21 and internal
fitting convex portions 3 1 in the circumferential direction Z. Therefore, also in the
second embodiment, the loads transmitted from the external fitting convex portion 21
and the internal fitting convex portion 3 1 to the main bodies of the lower stccl-pipe pile
2 and the upper steel-pipe pile 3 can be uniform in the circumferential direction Z, and
thus, increases in the plate thiclcnesses of the lower steel-pipe pile 2 and the upper
steel-pipe pile 3 can be avoided. Accordingly, it is possible to avoid a case where the
cost of materials of the joint structure between the lowcr steel-pipe pile 2 and the upper
steel-pipe pile 3 is increased.
[OOS7]
Here, in the first external fitting step portion 29a and the first internal fitting
step portion 39a, the external fitting convex portions 21 and the internal fitting convex
portions 3 1 are formed in one step (one row), and the plate thicltnesses of the lower
steel-pipe pile 2 and the upper steel-pipe pile 3 are sufficient if the plate has load
bearing capacity with respect to the bending load and the tension load by the one step.
Meanwhile, the number of steps (the number of rows) of the external fitting convex
portion 2 1 and the internal fitting convex portion 3 1 increases in the second external
fitting step portion 29b and the second internal fitting step portion 39b, the number of
steps of the external fitting convex portion 21 and the internal fitting convex portion 3 1
increases in the third external fitting step portion 29c and the third internal fitting step
portion 39c, and thus, it is necessary to set the plate thicknesses of the lower steel-pipe
pile 2 and the upper steel-pipe pile 3 according to the increase in the number of steps.
In the joint structure 100, the plate thicknesses of the lower steel-pipe pile 2 and the
upper steel-pipe pile 3 are thickened in stages from the outer side (upper side) toward
the inner side (lower side) in the axial direction X of the lower steel-pipe pile 2 and
from the outer side (lower side) toward the inner side (upper side) in the axial direction
X of the upper steel-pipe pile 3, and the external fitting step portion 29 and the internal
fitting step portion 39 are formed. Accordingly, also in the second embodiment, the
structure in which the plate thicknesses of the lower steel-pipe pile 2 and the upper
steel-pipe pile 3 increase in stages according to the number of steps of the external
fitting convex portions 21 and the internal fitting convex portions 3 1 can be easily
realized.
[OOSS]
In addition, in the joint structure 100, the external fitting convex portions 21 of
the first external fitting step portion 29a and the external fitting convex portions 21 of
the second external fitting step portion 29b are provided at positions which deviate in
the axial direction X, and the external fitting convex portions 21 of the second external
fitting step portion 29b and the external fitting convex portions 21 of the third external
fitting step portion 29c are provided at positions which deviate in the axial direction X.
Accordingly, even when the bending load is applied to the portion at which the lower
steel-pipe pile 2 and the upper steel-pipe pile 3 are connected together, the external
fitting convex portions 21 of any of the first external fitting step portion 29a, the second
external fitting step portion 29b, and the third external fitting step portion 29c, and the
internal fitting convex portions 3 1 of any of the first internal fitting step portion 39a, the
second internal fitting step portion 39b, and the third internal fitting step portion 39c can
be accurately disposed at the portions corresponding to the outermost edge ends of the
lower steel-pipe pile 2 and the upper steel-pipe pile 3 at which the tensile stress is
maximized. Therefore, also in the second embodiment, the bending load is accnrately
applied to any of the external fitting convex portions 21 and any of the internal fitting
convex portions 3 1, and it is possible to avoid a case where the external fitting end
portion 20 of the lower steel-pipe pile 2 and the internal fitting end portion 30 of the
upper steel-pipe pile 3 are damaged.
[0089]
111 the second embodiment, the case is shown, in which the number of steps in
each of the external fitting step portion 29 and the internal fitting step portion 39 is three,
the external fitting convex portions 21 of the first external fitting step portion 29a and
the external fitting convex portions 21 of the second external fitting step portion 29b are
provided at positions which deviate in the axial direction X, and the external fitting
convex portions 21 ofthe second external fitting step portion 29b and the external
fitting convex portions 21 of the third external fitting step portion 29c are provided at
positions which deviate in the axial direction X.
I-Iowever, the present invention is not limited to the above, and for example, the
external fitting convex portions 21 of the first external fitting step portion 29a and the
external fitting convex portions 21 of the second external fitting step portion 29b may
be provided at positions which deviate in the axial direction X, and the external frtting
convex portions 21 of the second external fitting step portion 29h and the external
fitting convex portions 21 of the third external fitting step portion 29c are provided at
positions matched in the axial direction X. Also in this case, the cross-sectional defect
does not occur when viewed in the axial direction, and the loads transmitted from the
external fitting convex portions 21 and the internal fitting convex portions 3 1 to the
main body of a steel-pipe pile can be uniform in the circumferential direction.
Accordingly, in the plurality of external fitting step portions 29 formed on the
external fitting end portion 20 along the axial direction X, the external fitting convex
portions 21 of the external fitting step portion 29 positioned at the outermost side (upper
side) in the axial direction X and the external fitting convex portions 21 of at least one
external fitting step portion 29 positioned at the inner side (lower side) in the axial
direction X may he provided at positions which deviate in the axial direction X. In
other words, in at least (one set oQ the external fitting step portions 29 adjacent to each
other among the plurality of external fitting step portions 29 adjacent to one another, the
external fitting convex portions 21 of one external fitting step portion 29 and the
external fitting groove portion 22 of the other external fitting step portion 29 may be
provided to be adjacent in the axis orthogonal direction Y when viewed in the axial
direction X.
[0090]
The first embodiment shows the case in which the number of steps in each of
the external fitting step portion 29 and the internal fitting step portion 39 is two, and the
second embodiment shows the case in which the number of steps in each of the external
fitting step portion 29 and the internal fitting step portion 39 is three. However,
preferably, the number of steps is two. When the number of steps is increased, the
thicknesses of the tip portions (the outer side in the axial direction X) of the external
fitting step portion and the internal fitting step portion in the steel-pipe pile are
inevitably decreased. The damage by the loads easily occurs as the thickness of the tip
portion is decreased. As a result, the joint structure is easily damaged. On the other
hand, if the number of steps is two, the thicknesses in the inner sides in the axial
direction X can be thinned while the thicknesses of the tip portions (the outer sides in
the axial direction X) of the external fitting step portion and the internal fitting step
portion are maintained in certain thicknesses or more. Accordingly, the increase in the
cost of materials due to the increase in the plate thiclmess ofthe steel-pipe pile can be
prevented.
[0091]
As the above, embodiments of the present invention are described in detail.
However, the above-described embodiments are only specific examples for embodying
the present invention, and the technical scope of the present invention should not be
interpreted as being limited by the embodiments.
[0092]
For example, a joint structure may be adopted in which the lower steel-pipe
pile 2 (first steel-pipe pile) includes the internal fitting end portion 30, and the upper
steel-pipe pile 3 (second steel-pipe pile) includes the external fitting end portion 20.
In addition, a joint structure may be adopt, which includes a rotation prevention
unit (not shown) for preventing reverse rotations of the lower steel-pipe pile 2 and the
upper steel-pipe pile 3 connected together in the axial direction X. For example, as the
rotation prevention unit, in the state where the lower steel-pipe pile 2 and thc upper
steel-pipe pile 3 are connected together in the axial direction X, a screw may be inserted
into the lower steel-pipe pile 2 to prevent the reverse rotation.
Moreover, the external fitting step portion 29 having any number of steps may
be arranged in the axial direction X of the lower steel-pipe pile 2 on the external fitting
end portion 20, and the internal fitting step portion 39 having any number of steps may
be arranged in the axial direction X of the upper steel-pipe pile 3 on the internal fitting
end portion 30.
[Industrial Applicability]
[0093]
It is possible to provide a joint structure of a steel-pipe pile and a steel-pipe pile
in which an increase in labor for rotation of a steel-pipe pile at a work site is prevented,
an excessive increase in a plate thickness of the steel-pipe pile is avoided, and there is
no concern of damage even when the bending load is applied
[Brief Description of the Reference Symbols]
[0094]
1 :joint structure of steel-pipe pile
2: lower steel-pipe pile (first steel-pipe pile)
20: external fitting end portion
2 1 : external fitting convex portion
21a: first tapered portion
22: external fitting groove portion
23: external fitting engagement groove
23a: second tapered portion
23b: locking portion
28: tip portion
29: external fitting step portion
29a: first external fitting step portion
29b: second external fitting step portion
29c: third external fitting step portion
3: upper steel-pipe pile (second steel-pipe pile)
30: internal fitting end portion
3 1 : internal fitting convex portion
3 1 a: third tapered portion
3 1 b: fourth tapered portion
32: internal fitting groove portion
33: internal fitting engagement groove
38: internal fitting edge
39: internal fitting step portion
39a: first internal fitting step portion
39b: second internal fitting step portion
39c: third internal fitting step portion
100: joint structure of steel-pipe pile
X: axial direction
Y axis orthogonal direction
Z: circumferential direction
d: gap
h: height of tapered portion

WE CLAIMS:-
1. Ajoint structure of a steel-pipe pile, which connects a first steel-pipe pile and a
second steel-pipe pile in series, the joint structure comprising:
an external fitting end portion which is an opening end of the first steel-pipe
pile; and
a column shaped internal fitting end portion which configures a portion
inserted into the external fitting end portion on one end of the second steel-pipe pile,
wherein the external fitting end portion includes
a plurality of external fitting convex portions which protrude from an
inner circumferential surface of the external fitting end portion toward an inner side in a
radial direction of the first steel-pipe pile, and are provided along a circumferential
direction of the first steel-pipe pile;
an external fitting groove portion which is formed between the
external fitting convex portions adjacent to each other in the circumferential direction of
the first steel-pipe pile; and
an external fitting engagement groove which is formed along the
circumferential direction at a position of an inner side in an axial direction of the first
steel-pipe pile from the external fitting convex portion and the external fitting groove
portion on the inner circumferential surface,
the internal fitting end portion includes a plurality of internal fitting convex
portions which protrude from an outer circumferential surface of the internal fitting end
portion toward an outer side in a radial direction of the second steel-pipe pile, and are
provided along a circumferential direction of the second steel-pipe pile,
each of the internal fitting convex portions engages with each of thc external
fitting convex portions in the external fitting engagement groove after the internal
fitting end portion is inserted into the external fitting end portion and the first steel-pipe
pile and the second steel-pipe pile are relatively rotated around an axis of the first
steel-pipe pile,
the external fitting convex portions and the external fitting groove portions are
formed in a plurality of rows along the axial direction of the first steel-pipe pile, and
in at least one set of two rows adjacent to each other among the plurality of
rows adjacent to one another, the external fitting convex portions of one row and the
external fitting groove portions of the other row are provided to be adjacent in the radial
direction of the first steel-pipe pile when viewed in the axial direction of the first
steel-pipe pile.
2. The joint structure of a steel-pipe pile according to Claim 1,
wherein the external Eltting end portion includes a plurality of step portions
formed along the axial direction of the first steel-pipe pile,
the external fitting convex portions and the external fitting groove portions by
at least one row are provided in each of the plurality of step portions, and
in two step portions adjacent to each other, the external fitting convex portions
of one step portion and the external fitting groove portions of the other step portion are
provided to be adjacent in the radial direction of the first steel-pipe pile when viewed in
the axial direction of the first steel-pipe pile.
3. The joint structure of a steel-pipe pile according to Claim 2,
wherein in the two step portions adjacent to each other, the external fitting
convex portions of the one step portion are provided at all positions adjacent to the
external fitting groove portions of the other step portion in the radial direction of the
first steel-pipe pile when viewed in the axial direction of the first steel-pipe pile, and
the external fitting convex portions are provided without gaps along the
circumferential direction of the first steel-pipe pile when viewed in the axial direction of
the first steel-pipe pile.
4. The joint structure of a steel-pipe pile according to Claim 2 or 3,
wherein the first steel-pipe pile is thickened in stages along the axial direction
of the first steel-pipe pile, and the plurality of step portions adjacent to one another in
the axial dircction of the first steel-pipe pile are formed so that the external fitting
convex portions of the step portion positioned at an outer side in the axial dircction of
the first steel-pipe pile and the external fitting groove portions of the step portion
positioned at the inner side in the axial direction of the first steel-pipe pile all have
approximately the same thickness.
5. The joint structure of a steel-pipe pile according to any one of Claims 1 to 4,
wherein the internal fitting end portion includes an internal fitting edge which
forms a gap between a tip portion of the external fitting end portion and the internal
fitting end portion, at the inner side in the axial direction of the second steel-pipe pile, in
a state where the internal fitting end portion is inserted into the external fitting end
portion,
the external fitting convex portion includes a first tapered portion which is
inclined along the circumferential direction ofthe first steel-pipe pile on an end surface
in the inner side in the axial direction of the first steel-pipe pile so that a height in the
axial direction of the first steel-pipe pile is approximately the same as a height of the
gap,
the external fitting engagement groove includes a second tapered portion which
is inclined in the circumferential direction of the first steel-pipe pile to be approximately
parallel with the first tapered portion at a portion facing the first tapered portion in the
axial direction of the first steel-pipe pile,
the internal fitting convex portion includes a third tapered portion which is
inclined along the circumferential direction of the second steel-pipe pile to abut the first
tapered portion on an end surface in the inner side in the axial direction of the second
steel-pipe pile, and a fourth tapered portion which is inclined along the circumferential
direction of the second steel-pipe pile to abut the second tapered portion on an end
surface in the outer side in the axial direction of the second steel-pipe pile, and
the first steel-pipe pile and the second steel-pipe pile relatively rotate around
the axis of the first steel-pipe pile, the first tapered portion and the third tapered portion
abut each other, the second tapered portion and the fourth tapered portion abut each
other, the plurality of external fitting convex portions and ihe plurality of internal fitting
convex portions engage with each other, the internal fitting edge and the tip portion abut
each other to fill the gap, and the external fitting end portion and the internal fitting end
portion are fitted together.
6. A steel-pipe pile comprising the joint structure of a steel-pipe pile according to any
one of Claims 1 to 5.