U.S. patent application number 10/361607 was filed with the patent office on 2004-03-11 for joining structure of pile.
Invention is credited to Nishiwaki, Atsushi, Yabuuchi, Sadao.
Application Number | 20040047693 10/361607 |
Document ID | / |
Family ID | 31973129 |
Filed Date | 2004-03-11 |
United States Patent
Application |
20040047693 |
Kind Code |
A1 |
Nishiwaki, Atsushi ; et
al. |
March 11, 2004 |
Joining structure of pile
Abstract
The present invention, the objective of which is to provide a
pile connecting structure of high workability capable of connecting
upper pile and lower pile to each other simply and accurately, and
preventing the pile diameter from becoming a large diameter even at
this connecting portion, concerns a pile connecting structure for
connecting upper pile and lower pile to each other, by interposing
a connecting plate of about the same diameter as the piles, at the
connecting portion between the upper pile and the lower pile,
wherein the end plate of either one of the upper pile or lower pile
and the connecting plate are fixed by screwing bolts inserted in
circular-shaped bolt inserting holes formed in the connecting plate
to the bolt hole in the end plate of the pile on one side, and the
end plate of the other pile and the connecting plate are fixed, in
the state where the head of the bolts screwed to the end plate of
the pile on the other side is inserted in the large diameter
portion of heteromorphic bolt insertion holes communicating between
a large diameter portion which the head of the bolts formed on the
connecting plate can pass through and a small diameter portion
which the head of the bolts cannot pass through, by making the
other pile and the connecting plate move relatively so that the
bolts may shift from the large diameter portion of the
heteromorphic bolt insertion holes to the small diameter
portion.
Inventors: |
Nishiwaki, Atsushi; (Osaka,
JP) ; Yabuuchi, Sadao; (Osaka, JP) |
Correspondence
Address: |
WENDEROTH, LIND & PONACK, L.L.P.
2033 K STREET N. W.
SUITE 800
WASHINGTON
DC
20006-1021
US
|
Family ID: |
31973129 |
Appl. No.: |
10/361607 |
Filed: |
February 11, 2003 |
Current U.S.
Class: |
405/250 ;
405/251 |
Current CPC
Class: |
E02D 5/523 20130101 |
Class at
Publication: |
405/250 ;
405/251 |
International
Class: |
E02D 005/20 |
Foreign Application Data
Date |
Code |
Application Number |
Sep 6, 2002 |
JP |
2002-261448 |
Claims
1. A pile connecting structure for connecting upper and lower piles
to each other, by interposing a connecting plate of approximately
the same diameter as the piles at the connecting portion between
the upper and lower piles, characterized in that the end plate on
either one of the upper or lower piles and the connecting plate are
fixed by screwing bolts inserted into circular-shaped bolt
insertion holes formed on the connecting plate to the end plate of
the pile on one side, and the end plate of the other pile and the
connecting plate are fixed in a state where the heads of the bolts
screwed to the pile on the other side are inserted into the large
diameter portion of heteromorphic bolt insertion holes
communicating between the large diameter portion at which the heads
of the bolts formed on the connecting plate can pass through and
the small diameter portion of which the heads of the bolts cannot
pass through, by making the other pile and connecting plate move in
a relative fashion so that the bolts may shift from the larger
diameter portion of the heteromorphic bolt insertion holes to the
smaller diameter portion.
2. A pile connecting structure as defined in claim 1, wherein at
the outer circumference of the connecting plate, a cylindrical body
is integrally disposed in which the ends of the upper and lower
piles may be inserted.
3. A pile connecting structure as defined in claim 1, wherein on
the connecting plate is formed an operating port for fastening,
from the outer circumferential side of the connecting plate, the
bolts shifted from the larger diameter portion of the heteromorphic
bolt insertion holes to the smaller diameter portion.
4. A pile connecting structure as defined in claim 1, wherein the
connecting plate is formed by being split into a plurality of
pieces.
5. A pile connecting structure as defined in claim 1, wherein on
the connecting plates of the piles is disposed an auxiliary member
having a threaded hole different from that of the connecting plate,
so as to allow the pile connecting bolt to be screwed into that
auxiliary member.
6. A pile connecting structure as defined in claim 1, wherein
projections in the shape of bolts are provided in place of bolts,
in a way that they can be fixed to either the end parts of the
piles or the auxiliary members.
Description
BACKGROUND OF THE INVENTION
[0001] The present invention concerns a pile connecting structure,
more specifically a pile connecting structure of high workability
capable of connecting upper pile and lower pile to each other
simply and accurately.
[0002] Conventionally, as pile connecting structure for connecting
upper pile and lower pile to each other, the following methods,
etc. are widely adopted:
[0003] (1) Method of connecting the end plates of upper pile and
lower pile to each other.
[0004] (2) Method of providing a flange joint in projection at the
outer circumference of the end plates, and tightening those flange
joints facing each other by means of bolt & nut.
[0005] (3) Method of providing a pair of inner fitting and outer
fitting distributed on both sides at the end of the upper pile and
at the end of the lower pile, and forming threaded part on both the
inner fitting and the outer fitting, to connect the inner fitting
and the outer fitting to each other by screwing.
[0006] By the way, the conventional pile connecting structures for
connecting upper pile and lower pile to each other mentioned above
have the following problems respectively:
[0007] (1) A pile connecting structure by welding presents such
problems as necessity of much time for welding, impossibility of
welding work at the field of execution depending on the weather
condition. Moreover, to prevent weld defects or embrittlement of
weld, prescribed equipment and facilities and skilled technicians
are required, and this is liable to be rather costly or cause a
shortage of technicians.
[0008] (2) In a connecting method by flange joint, the outside
diameter of the joint portion is larger than the outside diameter
of the steel pipe pile and greatly protrudes from the outer
circumferential face of the steel pipe pile. As a result, a large
penetration resistance is produced when the piles are buried in the
ground, a bending moment acts on the joint part and, moreover, an
open space is produced at the outer circumference of the piles
between the joints, presenting a risk of impossibility of securing
the required horizontal supporting force.
[0009] (3) A pile connecting structure for connecting the inner
fitting and the outer fitting, provided at the end of the upper
pile and at the end of the lower pile, to each other by screwing
leads to high cost of machining for forming threaded part on the
inner fitting and the outer fitting of larger diameter.
Furthermore, the connecting work by screwing of piles which are
heavy materials is rather poor in workability, and requires a lot
of time and labor and, in addition, the threaded part formed on the
inner fitting and the outer fitting is liable to be damaged, making
the connecting work by screwing difficult in this last case.
SUMMARY OF THE INVENTION
[0010] The objective of the present invention, realized in view of
various problems with said conventional pile connecting structures,
is to provide a pile connecting structure of high workability
capable of simply and accurately connecting the upper and lower
piles to each other, and preventing the pile diameter from becoming
large, even at the connection portion.
[0011] To achieve said objective, the pile connecting structure
according to the present invention is a pile connecting structure
for connecting upper and lower piles to each other by interposing a
connecting plate of approximately the same diameter as the piles at
the connection portion between the upper and lower piles,
characterized in that the end plate on either one of the upper or
lower piles and the connecting plate are fixed by screwing bolts
inserted into circular-shaped bolt insertion holes formed on the
connecting plate to the end plate of the pile on one side, and the
end plate of the other pile and the connecting plate are fixed in
the state where the heads of the bolts screwed to the pile on the
other side is inserted into the large diameter portion of the
heteromorphic bolt insertion holes communicating between a large
diameter portion which the heads of the bolts formed on the
connecting plate can pass through, and a small diameter portion
which the heads of the bolts cannot pass through, by making the
other pile and the connecting plate move in a relative fashion so
that the bolts may shift from the large diameter portion of the
heteromorphic bolt insertion holes to the small diameter
portion.
[0012] This pile connecting structure is capable of fixing, in a
pile connecting structure for connecting upper and lower piles to
each other, the end plates of the upper and lower piles and the
respective connecting plates to each other by bolting, and by
interposing a connecting plate of approximately the same diameter
as the piles at the connecting portion between the upper and lower
piles, thus quickly enabling the establishment of a connection
between the upper and lower piles at low cost, without having any
influence on pile length thanks to the comparatively small
thickness of the connecting portion, and further enabling the
burying of piles in the ground without presenting any obstacle to
the pile driving work, thanks to the absence of any projections at
the outer circumference of the piles.
[0013] For such cases, at the outer circumference of the connecting
plate, a cylindrical body is integrally disposed in which the end
of the upper and lower piles may be inserted.
[0014] This helps reinforce the end portions of the upper and lower
piles to be connected to each other, and increases their bending
strength, enabling the prevention of breaking at the connecting
portion of the piles even if a strong bending force acts on the
connected portion, and facilitating centering of the upper and
lower piles.
[0015] Moreover, there may be formed on the connecting plate an
operating port for fastening, from the outer circumferential side
of the connecting plate, the bolts shifted from the large diameter
portion of the heteromorphic bolt insertion holes to the small
diameter portion.
[0016] This makes it possible to firmly fix the end plate of the
pile on the other side and the connecting plate to each other.
[0017] Furthermore, the connecting plate may be formed by being
split into a plurality of pieces.
[0018] This enables reduction of the shape of the unit component
members constituting the connecting plate and reduces their weight,
thus improving workability and handling ease.
[0019] Also, on the connecting plates of the piles, there may be
disposed an auxiliary member having a threaded hole different from
that of the connecting plate, so that the pile connecting bolts may
be screwed into that auxiliary member.
[0020] This makes it possible to freely change the diameter, the
number of pieces, etc. of the bolts used for the connection of
piles, and improve the strength of the end part of the piles.
[0021] Moreover, in place of bolts, projections in the shape of
bolts may be provided in a way that they can be fixed to either the
end parts of the piles or the auxiliary members.
[0022] This enables the promotion of diversification of the
members.
BRIEF DESCRIPTION OF THE DRAWINGS
[0023] FIG. 1 indicates the first embodiment of the pile connecting
structure according to the present invention, (A) being a bottom
view, (B) a sectional view at line A-B of (A), and (C) a sectional
view at line B-C of (A).
[0024] FIG. 2 indicates the sequence of execution of the first
embodiment of the pile connecting structure according to the
present invention, (A) being a sectional view showing the state of
fixing of the lower pile and the connecting plate, and (B) a
sectional view showing the state of fixing of the lower pile and
the connecting plate on the left half and that of the upper pile
and the connecting plate on the right half, respectively.
[0025] FIG. 3 indicates the second embodiment of the pile
connecting structure according to the present invention, (A) being
a bottom view, (B) a sectional view at line X-X of (A), (C) a
sectional view at line A-B of (A), and (D) a sectional view at line
B-C of (A).
[0026] FIG. 4 indicates the sequence of execution of the second
embodiment of the pile connecting structure according to the
present invention, (A) being a sectional view showing the state of
fixing of the lower pile and the connecting plate, and (B) a
sectional view showing the state of fixing of the lower pile and
the connecting plate on the left half and that of the upper pile
and the connecting plate on the right half, respectively.
[0027] FIG. 5 is an exploded perspective view of the second
embodiment of the pile connecting structure according to the
present invention.
[0028] FIG. 6 is an expanded sectional view of an end plate of pile
in the second embodiment of the pile connecting structure according
to the present invention.
[0029] FIG. 7 indicates an example in which the connecting plate
(cylindrical body) is split in the circumferential direction, (A)
being a bottom view, and (B) a sectional view at line A-B of
(A).
[0030] FIG. 8 is a perspective view for above.
[0031] FIG. 9 indicates an example in which the connecting plate
(cylindrical body) is split in the horizontal direction, (A) being
a bottom view, (B) a sectional view at line X-X of (A), and (C) a
sectional view at line A-B of (A).
[0032] FIG. 10 is a perspective view of the example in which the
connecting plate (cylindrical body) is split in the horizontal
direction.
[0033] FIG. 11 indicates an example in which auxiliary member is
disposed on the end place of pile, (A) being a sectional view
before connection, and (B) a sectional view showing the connected
state.
DETAILED DESCRIPTION OF THE INVENTION
[0034] Embodiments of the pile connecting structure according to
the present invention will be explained hereafter based on
drawings.
[0035] FIG. 1 to FIG. 2 indicate the first embodiment of the pile
connecting structure according to the present invention.
[0036] This pile connecting structure is a pile connecting
structure for connecting an upper pile 1 and a lower pile 3 to each
other, by interposing a connecting plate 5 of about the same
diameter as the piles, at the connecting portion between the upper
pile 1 and the lower pile 3, wherein the end plate 4 of either one
of the upper pile 1 or lower pile 3, lower pile 3 in this
embodiment, and the connecting plate 5 are fixed by screwing bolts
6 inserted in circular bolt inserting holes 51 formed on the
connecting plate 5 to the bolt holes 41 in the end plate 4 of the
lower pile 3, and the end plate 2 of the other pile, upper pile 1
in this embodiment, and the connecting plate 5 are fixed, in the
state in which the head 71 of the bolts 7 screwed to the end plate
2 of the upper pile 1 is inserted in the large diameter portion 52d
of heteromorphic bolt insertion holes 52 communicating between a
large diameter portion 52d which the head 71 of the bolts 7 formed
on the connecting plate 5 can pass through and a small diameter
portion 52c which the head 71 of the bolts 7 cannot pass through,
by making the upper pile 1 and the connecting plate 5 move
relatively, in the state in which the connecting plate 5 is fixed
in the lower pile 3 so that the bolts 7 may shift from the large
diameter portion 52d of the heteromorphic bolt insertion holes 52
to the small diameter portion 52c.
[0037] The piles to which can be applied this pile connecting
structure are concrete piles such as prestressed concrete piles,
etc., steel piles, SC piles, and composite piles such as PRC piles,
etc. provided with end plate at the end, though not particularly
restricted to them. Explanation will be given below by taking an
example of prestressed concrete piles.
[0038] The upper pile 1 and lower pile 3 consisting of prestressed
concrete piles have end plates 2, 4 disposed at their end, and in
these end plates 2, 4 are formed bolt holes 21, 41 which were used
for introducing prestressed (concrete) when manufacturing
prestressed concrete piles. Those bolt holes 21, 41 are utilized in
this embodiment.
[0039] The bolt holes 21, 41 may be newly formed separately from
the bolt holes used for introducing prestressed (concrete), as a
matter of course.
[0040] The connecting plate 5 has a donut shape of about the same
diameter as that of the upper pile 1 and lower pile 3, more
concretely the end plates 2, 4 of the upper pile 1 and lower pile 3
are manufactured with steel sheet (including molded sheet) of a
thickness about 1.5 to 2 times the heads 61, 71 of the bolts 6, 7,
for example, though not particularly restricted to it.
[0041] On the connecting plate 5 are formed bolt holes 51 at the
position corresponding to the bolt holes 41 formed in the end plate
4 of the lower pile 3, and at proper position between those bolt
holes 51 are formed bolt holes 52 at the position corresponding to
the bolt holes 21 formed in the end plate 2 of the upper pile
1.
[0042] These bolt holes 51, 52 are formed on one face of the
connecting plate 5 respectively, preferably alternately in the
circumferential direction, though not particularly restricted to
it.
[0043] And, the bolt holes 51 will be provided with a bolt head
inserting portion 51a formed deeper than the height of the head 61
of the bolt 6, as shown in FIGS. 1(A), (B), so that the head 61 of
the bolt 6 may be inserted without being exposed to outside.
[0044] This bolt head inserting portion 51a will be formed in a
size enabling to tighten the bolt 6 by fitting a box wrench (not
illustrated) at the head 61 of the bolt 6.
[0045] This makes it possible to prevent the top face of the head
61 of the bolt 6 from getting in contact with the end plate 2 of
the upper pile 1, when the end plate 4 of the lower pile 3 and the
connecting plate 5 are fixed and the end plate 2 of the upper pile
1 is placed on it.
[0046] Moreover, the bolt holes 52 will be in a heteromorphic shape
like that of a snowman communicating between a large diameter
portion 52d which the head 71 of the bolts 7 can pass through and a
small diameter portion 52c which the head 71 of the bolts 7 cannot
pass through, and be provided with a bolt head inserting portion
52a formed deeper than the height of the head 71 of the bolt 7, so
that the head 71 of the bolt 7 may be inserted without being
exposed, as shown in FIGS. 1(A), (C).
[0047] This makes it possible to prevent the bottom face of the
head 71 of the bolt 7 from getting in contact with the end plate 4
of the lower pile 3, when the end plate 2 of the upper pile 1 and
the connecting plate 5 are fixed through the bolt 7.
[0048] This bolt insertion holes 52 will be provided on the outer
circumferential side of the connecting plate 5, so that it may also
serve as an operating port So for fastening the bolt 7 shifted from
the large diameter portion 52d of the bolt insertion hole 52 to the
small diameter portion 52c, from outside the outer circumference of
the connecting plate 5, by inserting a tool S such as spanner,
etc.
[0049] Furthermore, to prevent detachment, etc. of the connecting
portion with loosening of bolt 7 or relative reverse turn of the
upper pile 1 and the connecting plate 5, it is desirable to fit a
wedge-shaped filler made of metal piece, etc., for example, in the
open space of the large diameter portion 52d through the operating
port So from outside the outer circumference of the connecting
plate 5, after shifting the bolt 7 from the large diameter portion
52d of the bolt insertion hole 52 to the small diameter portion
52c, to fill the open space of the large diameter portion 52d.
[0050] Instead of opening the bolt insertion hole 52 on the outer
circumferential side of the connecting plate 5 (form an operating
port So), it may be all right to construct (the bolt insertion hole
52) in a way to either make the bolt 7, the head 71 of which is
inserted in the large diameter portion 52d of the heteromorphic
bolt insertion hole 52, turn in the fastening direction, when
shifting it from the large diameter portion 52d to the small
diameter portion 52c of the heteromorphic bolt insertion hole 52,
with the difference in contact resistance between the bolt seating
face 52b and the head 71 of the bolt 7 [To make the contact
resistance between the bolt seating face 52b on the outer
circumference side of the connecting plate 5 and the head 71 of the
bolt 7 larger than that on the inner circumference side of the
connecting plate 5 (case where the bolt 7 is right threaded, in
this embodiment) (or smaller (case where the bolt 7 is left
threaded, in this embodiment)), either perform surface treatment to
the bolt seating face 52b, or dispose a member increasing the
contact resistance such as soft metal plate such as aluminium, etc.
or synthetic resin plate, etc. on the bolt seating face 52b], or
form the height of the bolt seating face 52b on the large diameter
portion 52d side and the small diameter portion 52c side of the
heteromorphic bolt insertion hole 52 in a way to become gradually
higher from the large diameter portion 52d side toward the small
diameter portion 52c side and shift the bolt 7, the head 71 of
which is inserted in the large diameter portion 52d of the
heteromorphic bolt insertion hole 52, from the large diameter
portion 52d to the small diameter portion 52c of the heteromorphic
bolt insertion hole 52, so that the bolt 7 may be seated on the
bolt seating face 52b at the position of the small diameter portion
52c of the heteromorphic bolt insertion hole 52.
[0051] This makes it possible to firmly fix the end plate 2 of the
upper pile 1 and the connecting plate 5 to each other.
[0052] Next, explanation will be given on the method for connecting
the upper pile 1 and the lower pile 3 to each other, by using this
connecting plate 5.
[0053] As shown in FIG. 2(A), install the lower pile 3 in a pile
hole dug in the ground and, in the state in which the lower pile 3
is provisionally fixed so that the lower pile 3 may not make any
up-down movement or turn, when the end plate 4 disposed at the end
part of the lower pile 3 reached a prescribed position from the
ground such as a height easy for execution of work by workers on
the ground, for example, though not particularly restricted to it,
place the connecting plate 5 concentrically on the end plate 4 of
the lower pile 3, make the bolt hole 41 formed in the end plate 4
agree with the bolt insertion hole 51 in the connecting plate 5,
insert the bolt 6 in the bolt insertion hole 51, and fit the bolt 6
in the bolt hole 41 by screwing, by using a box wrench (not
illustrated).
[0054] This makes it possible to prevent the top face of the head
61 of the bolt 6 from getting in contact with the end plate 2 of
the upper pile 1, when the end plate 4 of the lower pile 3 and the
connecting plate 5 are fixed to each other through the bolt 6 and
the end plate 2 of the upper pile 1 is placed on it.
[0055] The fixing work of the end plate 4 of the lower pile 3 and
the connecting plate 5 may be performed before the lower pile 3 is
installed in the pile hole.
[0056] Next, as shown in FIG. 2(B), lift and let down the upper
pile 1 on the connecting plate 5 fixed to the end plate 4 of the
lower pile 3, by using a crane, etc., in a way to be concentric
with the lower pile 3, for installation.
[0057] At that time, screw the bolt 7 in advance, in the bolt hole
21 in the end plate 2 of the upper pile 1, and, in the state in
which the head 71 of the bolt 7 is positioned to the large diameter
portion 52d of the heteromorphic bolt insertion hole 52 formed in
the connecting plate 5, lift and let down the upper pile 1, so that
the head 71 of the bolt 7 may be inserted in the large diameter
portion 52d of the heteromorphic bolt insertion hole 52.
[0058] In screwing the bolt 7 in the bolt hole 21 in the end plate
2 of the upper pile 1, set the amount of projection of the bolt
head 71, in a way to secure a small clearance between the seating
face of the bolt head 71 and the bolt seating face 52b of the bolt
insertion hole 52, so that the bolt 7 may be shifted from the large
diameter portion 52d to the small diameter portion 52c of the
heteromorphic bolt insertion hole 52, in the state in which the
bolt head 71 is inserted in the large diameter portion 52d of the
bolt insertion hole 52. It will be so arranged that the bottom face
of the head 71 of the bolt 7 may not get in contact with the end
plate 4 of the lower pile 3, when the end plate 2 of the upper pile
1 and the connecting plate 5 are fixed to each other through the
bolt 7.
[0059] And, in the state in which the bolt head 71 of the bolt 7
screwed in the end plate 2 of the upper pile 1 is inserted in the
large diameter portion 52d of the heteromorphic bolt insertion hole
52, shift the bolt 7 from the large diameter portion 52d to the
small diameter portion 52c of the heteromorphic bolt insertion hole
52, by making the upper pile 1 and the connecting plate 5
relatively turn to move (upper pile 1 in the case of this
embodiment) in the state where the connecting plate 5 is fixed to
the lower pile 3.
[0060] After that, fasten the bolt 7 shifted to the small diameter
portion 52c of the bolt insertion hole 52, from outside the outer
circumference of the connecting plate 5, through the operating port
(bolt insertion holes 52) provided on the outer circumferential
side of the connecting plate 5, by inserting a tool S such as
spanner, etc., to firmly fix the end plate 2 of the upper pile 1
and the connecting plate 5 to each other through the bolt 7.
[0061] As described above, the upper pile 1 and the lower pile 3
can be fixed with the bolt 6 and the bolt 7 respectively, by
interposing one piece of connecting plate 5 at the connecting
portion between the two, enabling to perform the connection between
upper pile 1 and lower pile 3 quickly and at low cost, without
having any influence on the pile length because the thickness of
the connecting portion can be kept comparatively small. In
addition, absence of any projection at the outer circumference of
the piles makes it possible to bury the piles in the ground without
putting any obstacle to the pile driving work, and execute the
piles with high reliability and accuracy and efficiently.
[0062] Next, the second embodiment of the pile connecting structure
according to the present invention is indicated in FIG. 3 to FIG.
6.
[0063] This pile connecting structure is identical to said pile
connecting structure of first embodiment in that it is a pile
connecting structure for connecting an upper pile 1 and a lower
pile 3 to each other, by interposing a connecting plate 5 of about
the same diameter as the piles, at the connecting portion between
the upper pile 1 and the lower pile 3, wherein the end plate 4 of
either one of the upper pile 1 or lower pile 3, lower pile 3 in
this embodiment, and the connecting plate 5 are fixed by screwing
bolts 6 inserted in circular bolt inserting holes 51 formed on the
connecting plate 5 to the bolt holes 41 in the end plate 4 of the
lower pile 3, and the end plate 2 of the other pile, upper pile 1
in this embodiment, and the connecting plate 5 are fixed, in the
state where the head 71 of the bolts 7 screwed to the end plate 2
of the upper pile 1 is inserted in the large diameter portion 52d
of heteromorphic bolt insertion holes 52 communicating between a
large diameter portion 52d which the head 71 of the bolts 7 formed
on the connecting plate 5 can pass through and a small diameter
portion 52c which the head 71 of the bolts 7 cannot pass through,
by making the upper pile 1 and the connecting plate 5 move
relatively, in the state in which the connecting plate 5 is fixed
in the lower pile 3 so that the bolts 7 may shift from the large
diameter portion 52d of the heteromorphic bolt insertion holes 52
to the small diameter portion 52c and, in addition to such
construction, at the outer circumference of the connecting plate 5
is integrally disposed a cylindrical body 8 in which the end of the
upper pile 1 and the lower pile 3 may be inserted.
[0064] The cylindrical body 8 will be made of steel, in the same
way as the connecting plate 5, integrally disposed on the
connecting plate 5 by welding, etc. (the cylindrical body 8 may be
integrally formed with the connecting plate 5, in the case where it
is made of casting), and will be formed in dimensions enabling to
insert the end of the upper pile 1 and the lower pile 3 by several
centimeters to tens of centimeter, though not particularly
restricted to it.
[0065] As described above, by integrally disposing, at the outer
circumference of the connecting plate 5, the cylindrical body 8 in
which the end of the upper pile 1 and the lower pile 3 may be
inserted, it becomes possible to reinforce the end of the upper
pile 1 and the lower pile 3 to be connected to each other, and
increase their bending strength, thus preventing breaking of the
connecting portion of the piles even if a large bending moment acts
on the connecting portion, and facilitating centering of the upper
pile 1 and the lower pile 3.
[0066] By the way, in this embodiment, no operating port is formed
for fastening, by inserting a tool S such as spanner, etc. from
outside the outer circumference of the connecting plate 5, the
bolts 7 shifted from the large diameter portion 52d of the
heteromorphic bolt insertion holes 52 to the small diameter portion
52c by making the upper pile 1 and the connecting plate 5
relatively turn to move in the state where the connecting plate 5
is fixed to the lower pile 3 (it is possible, of course, to form an
operating port So to that end, in the cylindrical body 8 and the
connecting plate 5, in a way to communicate with the bolt insertion
holes 52, as shown in FIG. 3 to FIG. 4 with dotted line, and in
FIG. 5 with solid line), it is possible to fix the end plate 2 of
the upper pile 1 and the connecting plate 5 to each other through
the bolt 7, by simply making the upper pile 1 and the connecting
plate 5 move relatively so that the bolts 7 may shift from the
large diameter portion 52d of the heteromorphic bolt insertion
holes 52 to the small diameter portion 52c with the connecting
plate 5 fixed in the lower pile 3, in the state in which the head
71 of the bolts 7 screwed to the end plate 2 of the upper pile 1 is
inserted in the large diameter portion 52d of heteromorphic bolt
insertion holes 52, in combination with the arrangement of
integrally disposing the cylindrical body 8 in which the end of the
upper pile 1 and the lower pile 3 may be inserted.
[0067] In this embodiment, it is further possible to dispose a
shift control means for controlling relative turn and movement of
the upper pile 1 and the connecting plate 5 (also the lower pile 3
and the connecting plate 5, as required) after shifting the upper
pile 1 and the connecting plate 5 from the large diameter portion
52d of the bolt insertion holes 52 to the small diameter portion
52c by making them relatively turn and move, with the connecting
plate 5 fixed in the lower pile 3.
[0068] This shift control means is constructed, in this embodiment,
with a bolt insertion hole 81 formed in the cylindrical body 8, and
a bolt 9 designed to be either inserted or screwed in this bolt
insertion hole 81 and either screwed or fixed to the upper pile 1
(lower pile 3).
[0069] Moreover, as shown in FIG. 6, on the outer circumferential
face of the end plate 2 of the upper pile 1 (the end plate 4 of the
lower pile 3) may be formed a groove 22 (groove 42) in which to
insert the tip of the bolt 9, so that the upper pile 1 and the
connecting plate 5 (the lower pile 3 and the connecting plate 5)
may be fixed firmly to each other, by the bolt 9 screwed in the
bolt insertion hole 81.
[0070] This groove 22 (groove 42) may take any desired sectional
shape such as U-shaped groove, etc. or may also be realized as a
hole or threaded hole in which to either insert or screw the tip of
the bolt 9, in place of a groove.
[0071] A pin, etc. may also be used, in place of the bolt 9, as
shift control means.
[0072] This makes it possible to prevent detachment, etc. of the
connecting portion with relative reverse turn of the upper pile 1
and the connecting plate 5 (the lower pile 3 and the connecting
plate 5), thus ensuring fixing not only of the upper pile 1 and the
connecting plate 5 (the lower pile 3 and the connecting plate 5)
but also of the upper pile 1 and the lower pile 3.
[0073] Furthermore, by disposing this shift control means, it
becomes possible to set short the required dimensions for inserting
the end of the upper pile 1 and the lower pile 3 in the cylindrical
body 8.
[0074] By the way, while, in the respective embodiments described
above, the connecting plate 5 (cylindrical body 8) was formed as a
single body, the connecting plate 5 (cylindrical body 8) may also
be formed by splitting into a plurality of pieces.
[0075] As a method of splitting, the connecting plate 5
(cylindrical body 8) may be split into a plurality of unit
component members 5A, 5B in the circumferential direction (vertical
splitting), as shown in FIG. 7 to FIG. 8 (Split into 2 pieces in
the illustrated embodiment. Splitting into 3 or more pieces is also
possible. Moreover, in that case, it is desirable to construct the
unit component members 5A, 5B in a way to share a single bolt 6, by
providing a fitting portion so that they may fit at the position of
the bolt insertion holes 51A, 51B formed on the unit component
members 5A, 5B, so that the integrity of the split unit component
members 5A, 5B may be maintained easily.), or split into a
plurality of unit component members 5C, 5D, 5E in the horizontal
direction (horizontal splitting), as shown in FIG. 9 to FIG. 10
(Split into 3 pieces in the illustrated embodiment. Splitting into
2 pieces or 4 or more pieces is also possible.).
[0076] By forming, as described above, the connecting plate 5
(cylindrical body 8) by splitting it into a plurality of unit
component members, it becomes possible to reduce the shape and
weight of the unit component members constituting the connecting
plate 5 (cylindrical body 8), and thus improve its workability and
ease of handling.
[0077] Still more, on the end plates 2, 4 of the upper pile 1 and
the lower pile 3 may be disposed auxiliary members 2A, 4A having
threaded hole different from that of the end plates 2, 4, to screw
the pile connecting bolt to these auxiliary members.
[0078] This auxiliary member will be constructed with auxiliary
members 2A, 4A of the same shape as end plates 2, 4 disposed along
the end plates 2, 4 of the upper pile 1 and the lower pile 3, as
shown in FIG. 11, for example, and the auxiliary members 2A, 4A
will be integrated with the end plates 2, 4 by welding or bolting,
etc.
[0079] By disposing, as described above, auxiliary members 2A, 4A
having threaded hole different from that of the end plates 2, 4 on
the end plates 2, 4 of the upper pile 1 and the lower pile 3 and
enabling to screw the pile connecting bolts 6, 7 to these auxiliary
members 2A, 4A, it becomes possible to freely change the diameter,
number of pieces, etc. of the bolts used for the connection of
piles, and to also improve the strength at the end of the
piles.
[0080] The pile connecting structure according to the present
invention has so far been explained based on a plurality of
embodiments. However, the present invention is not restricted to
the constructions indicated in the embodiments described above, but
may be changed in construction as required in the extent not
deviating from its purpose, by either combining the constructions
indicated in the respective embodiments, or connecting the upper
pile 1 and the lower pile 3 and the connecting plate 5 in different
positional relations, or fixing bolt-shaped projection to the end
plate of the piles by welding, fitting, etc., in place of the bolts
6, 7 to be screwed to the end plates 2, 4 of the upper pile 1 and
the lower pile 3, or extending the range of application widely to
such objects as concrete piles provided with end plate at end
portion, steel piles, SC piles, composite piles such as PRC piles,
etc., for example, in addition to the prestressed concrete piles in
the above-described embodiments.
[0081] According to the pile connecting structure of the present
invention, which is a pile connecting structure for connecting
upper pile and lower pile to each other, by interposing a
connecting plate of about the same diameter as the piles, at the
connecting portion between the upper pile and the lower pile, and
which enables to fix the end plates 2, 4 of the upper pile 1 and
the lower pile 3 and the connecting plate 5 to each other, it
becomes possible to perform the connection between upper pile 1 and
lower pile 3 quickly and at low cost, without having any influence
on the pile length because the thickness of the connecting portion
can be kept comparatively small. In addition, absence of any
projection at the outer circumference of the piles makes it
possible to bury the piles in the ground without putting any
obstacle to the pile driving work, and execute the piles with high
reliability and accuracy and efficiently.
[0082] Moreover, by integrally disposing, at the outer
circumference of the connecting plate, a cylindrical body in which
the end of the upper pile and the lower pile may be inserted, it
becomes possible to reinforce the end portion of the upper pile and
the lower pile to be connected to each other, and increase their
bending strength, enabling to prevent breaking of the connecting
portion of the piles even if a large bending moment acts on the
connecting portion, and facilitating centering of the upper and
lower piles.
[0083] Furthermore, by forming, on the connecting plate, an
operating port for fastening, from the outer circumferential side
of the connecting plate, the bolts shifted from the large diameter
portion of the heteromorphic bolt insertion holes to the small
diameter portion, it becomes possible to firmly fix the end plate
of the pile on the other side and the connecting plate to each
other.
[0084] Still more, by forming the connecting plate by splitting
into a plurality of pieces, it becomes possible to reduce the shape
of the unit component members constituting the connecting plate and
reduce their weight, thus improving workability and ease of
handling.
[0085] Yet more, by disposing, on the connecting plate of piles, an
auxiliary member having a threaded hole different from that of the
connecting plate, so as to screw the pile connecting bolt in that
auxiliary member, it becomes possible to freely change the
diameter, number of pieces, etc. of the bolts used for the
connection of piles, and improve the strength of the end part of
piles.
[0086] In addition, by providing, in place of bolts, projections in
the shape of bolts in a way to be fixed to either the end part of
piles or the auxiliary member, it becomes possible to promote
diversification of the members.
* * * * *