U.S. patent application number 13/953102 was filed with the patent office on 2013-11-21 for concrete platform.
This patent application is currently assigned to MITSUBISHI HEAVY INDUSTRIES, LTD.. The applicant listed for this patent is Naohiro ASADA, Takeo TAKAKURA, Yumi TANAKA. Invention is credited to Naohiro ASADA, Takeo TAKAKURA, Yumi TANAKA.
Application Number | 20130306835 13/953102 |
Document ID | / |
Family ID | 43386344 |
Filed Date | 2013-11-21 |
United States Patent
Application |
20130306835 |
Kind Code |
A1 |
ASADA; Naohiro ; et
al. |
November 21, 2013 |
CONCRETE PLATFORM
Abstract
A concrete platform has at a top portion, a table-deck portion
that has a form, a load portion formed in the form, and an
attachment part. The form has a cross-sectional U-shape, and is
formed by a pair of concrete side walls and a concrete bottom plate
that connects the pair of concrete side walls. The form has
reinforcing members provided to extend linearly in a longitudinal
direction inside the concrete side walls and inside the concrete
bottom plate.
Inventors: |
ASADA; Naohiro; (Tokyo,
JP) ; TANAKA; Yumi; (Tokyo, JP) ; TAKAKURA;
Takeo; (Tokyo, JP) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
ASADA; Naohiro
TANAKA; Yumi
TAKAKURA; Takeo |
Tokyo
Tokyo
Tokyo |
|
JP
JP
JP |
|
|
Assignee: |
MITSUBISHI HEAVY INDUSTRIES,
LTD.
Tokyo,
JP
|
Family ID: |
43386344 |
Appl. No.: |
13/953102 |
Filed: |
July 29, 2013 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
13148812 |
Aug 10, 2011 |
8522507 |
|
|
PCT/JP2010/050018 |
Jan 5, 2010 |
|
|
|
13953102 |
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Current U.S.
Class: |
248/679 |
Current CPC
Class: |
E04G 21/185 20130101;
B28B 23/0056 20130101; E04B 1/4157 20130101; E04C 3/20 20130101;
E04B 1/41 20130101; E04G 17/12 20130101; E02D 27/02 20130101; F16M
5/00 20130101 |
Class at
Publication: |
248/679 |
International
Class: |
F16M 5/00 20060101
F16M005/00 |
Foreign Application Data
Date |
Code |
Application Number |
Jun 24, 2009 |
JP |
2009-149634 |
Claims
1. A concrete platform comprising, at a top portion, a table-deck
portion that has a form, a load portion formed in the form, and an
attachment part, wherein the form has a cross-sectional U-shape,
and is formed by a pair of concrete side walls and a concrete
bottom plate that connects the pair of concrete side walls, and
wherein the form comprises reinforcing members provided to extend
linearly in a longitudinal direction inside the concrete side walls
and inside the concrete bottom plate.
2. A concrete platform according to claim 1 wherein the form is
configured so that a connecting member is detachably attached in
such a manner that top end parts of the concrete side walls are
connected by the connecting member, the connecting member is for
connecting the top end parts of the concrete side walls to form the
load portion by pouring concrete into the form.
3. A concrete platform according to claim 2, the connecting member
comprising: an elongated member that is formed to have
substantially the same length as the width of the gap between the
pair of concrete side walls of the form; a first adjusting part
that enables inserting the attachment part into the elongated
member; and a second adjusting part that enables the attachment
part to move relative to the elongated member along a top surface
of the table-deck portion that is formed by pouring the concrete
into the form.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] The present application is a divisional of U.S. Ser. No.
13/148,812 filed on August 10, which is a National Phase of
International Application No. PCT/JP2010/050018 filed on Jan. 5,
2010. The application claims priority to Japanese patent
application number 2009-149634 filed on Jun. 24, 2009, which is
incorporated by reference in its entirety.
TECHNICAL FIELD
[0002] The present invention relates to a concrete platform onto
which a heavy structure, such as a turbine, a generator, and so
forth, is mounted.
BACKGROUND ART
[0003] In general, a known concrete platform on which is mounted a
heavy structure that vibrates during operation, such as a turbine,
a generator, and so forth, is constructed with a large volume of
mass concrete and reinforcing bars.
[0004] A beam etc. of a table-deck portion in such a concrete
platform, onto which a heavy structure is mounted, is formed to
have a larger cross-sectional area (for instance, having a width
equal to or more than 2 m and a height equal to or more than 2 m)
in comparison with a beam that is used for buildings such as
condominiums etc., so as to be able to support a heavy load. At the
same time, many metal parts used for fixing the above-mentioned
heavy structure to the table-deck portion are embedded in the
table-deck portion. The embedded metal parts can include templates,
bolts, anchor blocks, and so forth.
[0005] Upon producing (hereinafter referred to as "building") the
concrete platform as mentioned above, form is put in place, and
fresh concrete is subsequently introduced inside the form, in other
words, fresh concrete is poured.
[0006] Known form includes one that is removed after the concrete
is poured (for example, see PTL 1) and one that makes up part of a
concrete platform without being removed (for example, see PTL
2).
[0007] For example, when the concrete platform is built using the
form described in PTL 1, in order to construct a reinforced
concrete beam, which has a large sectional area, of the table-deck
portion, the form, supports for supporting the form, scaffolding,
and so forth are first put in place. Thereafter, fresh concrete is
poured. Once the reinforced concrete beam has been constructed, the
form, the support, the scaffolding, and so forth are removed.
[0008] For example, when the concrete platform is built using the
form described in PTL 2, in other words, steel form, in order to
construct a reinforced concrete beam, which has a large sectional
area, of the table-deck portion, as in the case with PTL 1, fresh
concrete is poured after the steel form, supports for supporting
the form, scaffolding, and so forth are put in place first.
[0009] Although the supports, the scaffolding, and so forth are
removed thereafter, the steel form is not removed and it makes up
part of the concrete platform.
CITATION LIST
Patent Literature
[0010] {PTL 1} Japanese Unexamined Patent Application, Publication
No. 2001-027281
[0011] {PTL 2} Japanese Unexamined Patent Application, Publication
No. Shou 59-006495
SUMMARY OF INVENTION
Technical Problem
[0012] However, because the form, the supports, the scaffolding,
and so forth are required in the process described in the
above-mentioned PTL 1, there has been a problem in that the
construction period required for building a concrete platform is
extended. In particular, there have been problems in that the form
and the supports for supporting the form must be put in place and
then removed, which extends the construction period.
[0013] At the same time, because embedded metal parts that are
embedded in the table-deck portion are required to be set at a
prescribed accuracy, there has been a problem in that the
construction period is extended even further.
[0014] On the other hand, because the steel form, which is
fabricated in a factory, is used in the process described in the
above-mentioned PTL 2, a reduction in the construction period at
the building site of the concrete platform can be achieved.
[0015] However, when the steel form is used, because the steel form
deforms upon pouring of the fresh concrete, additional separate
supports are required for supporting the steel form. Therefore, the
separate supports are required to be put in place and then removed,
resulting in the problem that the construction period is
extended.
[0016] Because the steel form is made of steel, the steel form is
required to be produced in a factory, and this results in the need
for transport in a container. Thus, there has been a problem in
that, in comparison with conventional form made of wood, the cost
of the transport etc. becomes high.
[0017] The present invention has been conceived to solve the
problems described above, and an object thereof is to provide a
concrete platform capable of reducing a construction period in a
concrete platform production process and capable of preventing an
increase in the costs of building the concrete platform.
Solution to Problem
[0018] In order to realize the object described above, the present
invention provides the following solutions.
[0019] A process for producing a concrete platform according to a
first aspect of the present invention is a process for producing a
concrete platform on which an object to be supported is fixed,
including: a step of forming form having a pair of concrete side
walls and a concrete bottom slab that connects the pair of side
walls; a step of setting the form on a plurality of piers; and a
step of pouring concrete into the form that is set on the plurality
of piers.
[0020] According to a process for producing a concrete platform
according to the first aspect of the present invention, the step of
making the form and the step of building the plurality of piers can
be conducted simultaneously, and at the same time, the form can be
made at a different site from the construction site of a plurality
of piers, in other words, the construction site of the concrete
platform. Therefore, a reduction in the construction period, that
is, the production period of the concrete platform, can be
afforded.
[0021] Furthermore, because the form is made of concrete, the form
is not required to be removed after the concrete has been poured
into the form, and therefore, the construction period can be
reduced.
[0022] On the other hand, when form made of steel plates is used,
it is necessary to perform welding management, and it is necessary
to make the form in a factory in order to ensure dimensional
precision. In contrast, when form made of concrete is used, because
the form can be made integrally, it is not necessary to perform
welding management etc. Therefore, the site for producing the form
is not limited to the factory; the form can be produced at a
suitable site close to the construction site, and it is possible to
reduce the costs related to transport of the form.
[0023] Furthermore, because concrete is poured after the form
having the pair of side walls and the bottom slab has been set on
the piers, a reduction in the size of a crane used for setting the
form can be afforded compared with a case where the form into which
concrete has been poured is set on the piers, or a case where a
concrete table-deck portion from which the form has been removed
after concrete has been poured is set on the piers.
[0024] In the process for producing a concrete platform according
to the first aspect of the present invention, in the step of
setting the form on the plurality of piers, the form may be set on
the plurality of piers after a connecting member that connects each
of the upper edge portions of the pair of side walls of the form by
being placed on the upper edge portions is attached to the pair of
side walls.
[0025] According to this configuration, by connecting each of the
upper edge portions of the pair of side walls by the connecting
member, a part of the cross-section of the form forms a
box-structure; therefore, it is possible to prevent a reduction in
the sectional stiffness of form due to the widening of the gap
between the side wall edge portions (upper edges). Therefore,
deformation of the form during pouring of the concrete is
prevented, and no supports for supporting the form need to be
set.
[0026] On the other hand, if steel form is used, in order to
prevent a reduction in the sectional stiffness of the form,
stiffening parts for maintaining the relative positions between the
side walls and the bottom slab may be provided on the bonding
portions between the side walls and the bottom slabs. However, if
the stiffening parts are provided, because the internal
cross-sectional area (internal space) of the form becomes smaller,
the space available for arranging the reinforcing bars (internal
space in the form) will be limited.
[0027] In this case, in the space for arranging the reinforcing
bars of the form, the reinforcing bars will not be able to be
arranged in the region in the vicinity of the bottom slab, where
the bending stress acting thereon is large. As a result, the
strength of the table-deck portion can be lowered. In the case of
concrete form, which has a greater form thickness compared with
steel form, the impact is particularly significant. This problem
can be solved by connecting each of the upper edge portions of the
pair of side walls by using the connecting member in the present
invention.
[0028] In the process for producing a concrete platform according
to the first aspect of the present invention, an attachment part
that is partially embedded in concrete that is poured into the form
so as to fix the object to be supported may be aligned with the
connecting member in a positionable manner.
[0029] According to this configuration, because the arrangement
positions of the attachment parts are maintained with the
connecting member, it is possible to align the attachment parts
easily and with high precision without using a separate massive
template and temporary supporting members that temporarily support
this template from above. Furthermore, the construction period can
be reduced compared with a process where the attachment parts are
arranged directly in the form and their arrangement positions are
adjusted.
[0030] Here, the attachment part can include, for example, a metal
part that is used for fixing a heavy structure that is mounted on
the concrete platform, and can include an embedded metal part etc.,
such as an anchor bolt.
[0031] In the process for producing a concrete platform according
to the first aspect of the present invention, the connecting member
may be removed from the upper edge portions of the pair of side
walls after the step of pouring concrete.
[0032] According to this configuration, it is possible to reuse the
connecting member.
[0033] A concrete platform according to a second aspect of the
present invention is produced by the process for producing a
concrete platform according to the above-mentioned present
invention.
[0034] According to the concrete platform of the second aspect of
the present invention, by making the form from concrete, the form
is not required to be removed, and it is possible to reduce the
construction period compared with a case where form made of wood
etc. is used.
[0035] In addition, when steel form is used, it is necessary to
perform welding management, and it is necessary to make the form in
a factory in order to ensure dimensional precision. In contrast,
when form made of concrete is used, it is not necessary to perform
welding management etc. Therefore, the site for producing the form
is not limited to a factory; the form can be produced at a suitable
site close to the construction site, and it is possible to reduce
costs related to transport of the form.
[0036] A connecting member according to a third aspect of the
present invention is a connecting member that is used in the
process for producing a concrete platform according to the
above-mentioned present invention, including: an elongated member
that is formed to have substantially the same length as the gap
between the pair of side walls of the form; a fixing member that
anchors the attachment part to the elongated member; and an
adjusting part that enables the attachment part to move along the
top surface of the table-deck portion that is formed by pouring
concrete into the form.
[0037] According to the connecting member of the third aspect of
the present invention, the connecting member is composed of an
elongated member, thereby affording weight saving. By doing so, the
connecting member can easily be attached to and detached from the
form. In addition, by using the adjusting parts, the arrangement
positions of the attachment parts are two-dimensionally adjustable
along the top surface of the table-deck portion, in other words, in
the horizontal plane.
Advantageous Effects of Invention
[0038] According to a concrete platform production process, a
concrete platform, and a connecting member of the present
invention, form having a pair of concrete side walls and a concrete
bottom slab that connects the pair of side walls is formed, and
concrete is poured into the form after the form is set on a
plurality of piers; therefore, advantages are afforded in that the
construction period can be reduced, and an increase in the building
costs can be prevented.
BRIEF DESCRIPTION OF DRAWINGS
[0039] {FIG. 1} FIG. 1 is a schematic view for explaining the
configuration of a turbine generator platform according to one
embodiment of the present invention.
[0040] {FIG. 2} FIG. 2 is a sectional view, taken along line A-A,
for explaining the configuration of the table-deck portion of FIG.
1.
[0041] {FIG. 3} FIG. 3 is a view for explaining construction steps
of the platform in FIG. 1.
[0042] {FIG. 4} FIG. 4 is a schematic view for explaining a state
in which piers in FIG. 1 are constructed.
[0043] {FIG. 5} FIG. 5 is a sectional view for explaining the
configuration of form in FIG. 1.
[0044] {FIG. 6} FIG. 6 is a schematic view for explaining a state
in which the form is set on the piers in FIG. 4.
[0045] {FIG. 7} FIG. 7 is a perspective view for explaining the
configuration of the form that is set on the piers in FIG. 6.
[0046] {FIG. 8} FIG. 8 is a sectional view for explaining the
configuration of the form in FIG. 6 before inner concrete is
poured.
[0047] {FIG. 9} FIG. 9 is a schematic view for explaining a state
for constructing connecting portions between the piers and the
form.
DESCRIPTION OF EMBODIMENTS
[0048] A platform according to an embodiment of this invention will
be described with reference to FIGS. 1 to 9.
[0049] FIG. 1 is a schematic view for explaining the configuration
of a turbine generator platform according to this embodiment.
[0050] A platform (concrete platform) 1 is a structure onto which a
turbine (a steam turbine or a gas turbine) or a generator is
mounted and is a structure mainly formed of concrete and
reinforcing bars.
[0051] In this embodiment, the present invention is described as
applied to the platform 1 onto which a turbine or a generator is
mounted. However, the object to be mounted on the platform 1 is not
limited to a turbine or a generator, and it includes other heavy
structures, including those that vibrate during operation; it is
not particularly limited.
[0052] As shown in FIG. 1, the platform 1 is mainly provided with a
plurality of piers 2 and a table-deck portion 3.
[0053] As shown in FIG. 1, the piers 2 are members that extend
upwards from the ground G, and are mainly formed of concrete and
reinforcing bars to support the table-deck portion 3. Known
structures can be used for the piers 2, and they are not
particularly limited.
[0054] As shown in FIG. 1, the table-deck portion 3 is a beam
member that is arranged over the upper ends (the ends at the upper
side in FIG. 1) of the piers 2, and a turbine or a generator is
mounted thereon.
[0055] FIG. 2 is a sectional view, taken along line A-A, for
explaining the configuration of the table-deck portion in FIG.
1.
[0056] As shown in FIGS. 1 and 2, the table-deck portion 3 is
mainly provided with form 4, a load portion 5, embedded metal parts
(attachment parts) 6, and so forth.
[0057] As shown in FIG. 2, the form 4 forms the side surfaces and
the bottom surface of the table-deck portion 3, and the load
portion 5, the embedded metal parts 6, and so forth are arranged
inside the form 4. Furthermore, the form 4 is formed so as to have
a U-shaped cross-section, and so as to extend between the piers
2.
[0058] The form 4 is mainly formed of concrete and reinforcing
bars, and as shown in FIG. 2, is produced in one integral form from
a bottom slab 42 and a pair of side walls 41 that are erected on
both edges of this bottom slab 42. The form 4 can have a size, for
example, equal to or more than 2 m in width and equal to or more
than 2 m in height.
[0059] The respective side walls 41 are formed into a plate shape,
and they form the side surfaces of the table-deck portion 3 and
also the side surfaces of the form 4. The side walls 41 can have a
size of, for example, about 150 mm to 200 mm in plate thickness and
equal to or more than 2 m in the height-wise dimension.
[0060] The side walls 41 are mainly provided with side-wall
concrete portions 41A and side-wall tension parts 41B.
[0061] The side-wall concrete portions 41A mainly form the side
walls 41, and they are precast concrete that has been poured
separately from an inner concrete portion 51 in the load portion
5.
[0062] The side-wall tension parts 41B are linear reinforcing
members extending in the longitudinal direction of the table-deck
portion 3 (a direction perpendicular to the plane of the drawing in
FIG. 2), and the side-wall tension parts 41B compress the side-wall
concrete portions 41A in their longitudinal direction, by being
arranged inside the side-wall concrete portions 41A in a state
tensioned in the above-mentioned longitudinal direction.
[0063] This embodiment is described as applied to an example in
which the side-wall tension parts 41B are arranged on the upper
edge side of the side-wall concrete portions 41A (the upper edge
portion side in FIG. 2).
[0064] The bottom slab 42 is formed into a plate-shape, and the
bottom slab 42 forms the bottom surface of the table-deck portion 3
and also the bottom surface of the form 4. The bottom slab 42 can
have a size of, for example, about 150 mm to 200 mm in plate
thickness and equal to or more than 2 m in the width-wise
dimension.
[0065] The bottom slab 42 is mainly provided with a bottom slab
concrete portion 42A and bottom slab tension parts 42B.
[0066] The bottom slab concrete portion 42A mainly forms the bottom
slab 42, and it is precast concrete that has been poured separately
from the inner concrete portion 51 in the load portion 5.
[0067] The bottom slab tension parts 42B are linear reinforcing
members extending in the longitudinal direction of the table-deck
portion 3, and the bottom slab tension parts 42B compress the
bottom slab concrete portion 42A in its longitudinal direction, by
being arranged inside the bottom slab concrete portion 42A in a
state tensioned in the above-mentioned longitudinal direction.
[0068] This embodiment is described as applied to an example in
which a plurality of bottom slab tension parts 42B are arranged in
one line, at equal intervals, within the bottom slab concrete
portion 42A.
[0069] Known members, such as wires, reinforcing bars, and so
forth, can be used as the side-wall tension parts 41B and the
bottom slab tension parts 42B, and they are not particularly
limited.
[0070] This embodiment illustrates an example in which the side
walls 41 and the bottom slab 42 forming the form 4 are produced in
one integral form; however, the embodiment is not particularly
limited to this form, and separately produced ones may be
connected.
[0071] The load portion 5 is arranged inside the form 4 to form the
table-deck portion 3 together with the form 4 and supports a
turbine or a generator that is mounted on the table-deck portion
3.
[0072] The load portion 5 is mainly provided with the inner
concrete portion 51 and inner reinforcing bars 52.
[0073] The inner concrete portion 51 mainly forms the load portion
5 and mainly receives force related to compressive stress among the
forces acting on the table-deck portion 3. Furthermore, the inner
concrete portion 51 is formed by pouring concrete into the form 4
and is formed separately from the side-wall concrete portions 41A
and the bottom slab concrete portion 42A of the form 4.
[0074] The inner reinforcing bars 52 are linear reinforcing members
that have been placed throughout the load portion 5 and that mainly
receive the force related to tensile stress among the force acting
on the table-deck portion 3. Any known arrangement pattern can be
used for the inner reinforcing bars 52, and it is not particularly
limited.
[0075] As shown in FIGS. 1 and 2, the embedded metal parts 6 are
partially embedded in the top surface (the surface on the upper
side in FIG. 1) of the table-deck portion 3 and are used for fixing
a turbine or a generator that is to be mounted on the table-deck
portion 3. Examples of the embedded metal parts 6 can include
anchor bolts, anchor blocks and so forth.
[0076] A construction step (production process) of the platform 1
having the above-mentioned configuration will be explained
below.
[0077] FIG. 3 is a view for explaining a construction step of the
platform in FIG. 1. FIG. 4 is a schematic view for explaining a
state in which the piers in FIG. 1 are constructed. FIG. 5 is a
sectional view for explaining the configuration of the form in FIG.
1.
[0078] As shown in FIGS. 3 and 4, in the construction of the
platform 1 of this embodiment, a step for constructing the piers 2
(Step S1) is conducted, and as shown in FIGS. 3 and 5, a step for
forming the form 4 (Step S2) is conducted concurrently.
[0079] As shown in FIG. 4, in the step for constructing the piers
2, a plurality of piers 2 are constructed on the ground G.
[0080] On the other hand, as shown in FIG. 5, in the step for
forming the form 4, the form 4, having the pair of side walls 41
and the bottom slab 42 that are arranged in the U-shape, is formed
at a different site from the construction site of the platform 1.
More specifically, when the side-wall concrete portions 41A of the
side walls 41 and the bottom slab concrete portion 42A of the
bottom slab 42 are formed, the side-wall tension parts 41B and the
bottom slab tension parts 42B are respectively embedded in a
longitudinal tensioned state. By doing so, compressive stress in
the longitudinal direction is applied to the side-wall concrete
portions 41A and the bottom slab concrete portion 42A.
[0081] By doing so, for example, even when the table-deck portion
is deformed downward and tensile force acts on the form 4 that
forms the side surfaces and the bottom surface of the table-deck
portion, because the compressive stress is pre-applied to the
side-wall concrete portions 41A and the bottom slab concrete
portion 42A, the tensile stress is prevented from acting, or the
tensile stress is reduced.
[0082] The thus-formed form 4 is transported to the construction
site of the piers 2, in other words, the construction site of the
platform 1, by transportation means, such as a trailer.
[0083] FIG. 6 is a schematic view for explaining a state in which
the form is placed on the piers of FIG. 4.
[0084] Once the form 4 is transported to the construction site of
the platform 1, a step of setting the form 4 on the piers 2, as
shown in FIGS. 3 and 6, is conducted (Step S3).
[0085] FIG. 7 is a perspective view for explaining the
configuration of the form that is set on the piers in FIG. 6.
[0086] As shown in FIG. 7, when the form 4 is set on the piers 2,
an upper-surface connecting part (connecting member) 7 is set on
the form 4. The upper-surface connecting part 7 is arranged over
the upper edge portions of the side walls 41 of the form 4 so as to
connect the upper edge portions of the pair of side walls 41.
[0087] The upper-surface connecting part 7 is an elongated member
that is formed to have substantially the same length as the gap
between the pair of side walls 41 of the form 4. The upper-surface
connecting part 7 is provided with two slotted holes 71 that extend
in the longitudinal direction of the upper-surface connecting part
7 so as to be aligned along the longitudinal direction.
[0088] In addition, the upper-surface connecting part 7 is provided
with, on the four corners thereof, projecting portions 74, each
having a slotted hole 75 that extends in the width-wise direction
of the upper-surface connecting part 7. The embedded metal parts 6
are anchored to the upper-surface connecting part 7 by being
fastened by nuts 61 in a state inserted though the slotted holes
71.
[0089] By attaching the upper-surface connecting part 7, the part
of the form 4 having a U-shaped cross-section forms a
box-structure; therefore, it is possible to prevent a reduction in
the sectional stiffness due to widening of the gap between the
side-wall edge portions (the upper edges). Therefore, when the form
4 is hoisted, when the form 4 is set on a plurality of piers 2, and
then, when concrete is poured into the form 4 to form the inner
concrete portion 51, because the gap between the upper edges of the
side walls 41 does not become wider, the form 4 becomes more
resistant to deformation.
[0090] The upper-surface connecting part 7 is attached to the form
4, for example, as described below.
[0091] The upper-surface connecting part 7 is first positioned such
that the upper-surface connecting part 7 is set over the upper edge
portions of the pair of side walls 41. Next, as shown in FIG. 7,
anchor bolts 73 are inserted into the respective slotted holes 75
provided in the projecting portions 74. Then, these anchor bolts 73
are fastened to the upper edge portions of the pair of side walls
41.
[0092] Side panels 72 are bonded to both side surfaces (both end
surfaces in longitudinal direction) of the upper-surface connecting
part 7 by welding or another bonding process. Here, only the upper
half portions of the side panels 72 are bonded. Therefore, the
lower portions of the side panels 72 can hold the pair of side
walls 41 from both sides. In this way, the side panels 72 and the
anchor bolts cooperate to prevent the gap between the upper edges
of the side walls 41 from being widened.
[0093] In the case of steel form, in order to prevent a reduction
in the sectional stiffness, stiffening parts for maintaining the
relative positions between the side walls 41 and the bottom slab 42
may be provided on the bonding portions between the side walls 41
and the bottom slab 42. However, by providing the stiffening parts,
the cross-sectional area of the interior of the form 4, in other
words, the inner concrete portion 51, becomes smaller, and the
space available for arranging the reinforcing bars 52 will be
limited.
[0094] In addition, the reinforcing bars 52 will not be arranged in
the vicinity of the bottom slab 42 within the inner concrete
portion 51 where the bending stress is large; as a result, there is
a possibility that the strength of the table deck will be lowered.
In the case of concrete form, which has a greater thickness
compared with steel form, the impact is particularly
significant.
[0095] This problem can be solved by connecting the upper edge
portions of the pair of side walls by using the upper-surface
connecting part 7 according to the present invention. By attaching
the upper-surface connecting part 7 so as to be set over the pair
of side walls 41 in this way, when the form 4 is hoisted by a crane
and when concrete is poured into the form 4 to form the inner
concrete portion 51, the gap between the upper edge portions of the
pair of side walls 41 is prevented from being widened.
[0096] FIG. 8 is a sectional view for explaining the configuration
of the form of FIG. 6 before the inner concrete is poured.
[0097] Furthermore, as shown in FIG. 8, the inner reinforcing bars
52 of the load portion 5 are arranged inside the form 4.
[0098] At the same time, as shown in FIG. 7, the embedded metal
parts 6 are supported by the slotted holes 71 provided in the
upper-surface connecting part 7, and the arrangement positions of
the embedded metal parts 6 are maintained by the upper-surface
connecting part 7.
[0099] FIG. 9 is a schematic view for explaining a state for
constructing connecting portions between the piers and the
form.
[0100] As shown in FIGS. 3 and 9, a step of constructing connecting
portions 21 is conducted after the form 4 is set on the piers 2
(Step S4).
[0101] The connecting portions 21 connect the piers 2 with the form
4, in other words, with the table-deck portion 3, and connect both
end portions of the form 4 with the upper ends of the piers 2.
[0102] More specifically, the construction is conducted as
described below.
[0103] The form 4 is first placed on the two piers 2 such that the
form 4 is set on the two piers 2. Next, the reinforcing bars
provided inside the form 4 and the reinforcing bars sticking out
from the upper ends of the piers 2 are connected by reinforcing
bars for connection. Then, form 22 is set around the space in which
the connected reinforcing bars are positioned.
[0104] Thereafter, as shown in FIG. 3, a step of adjusting the
arrangement positions of the embedded metal parts 6 is conducted
(Step S5). For example, as shown in FIG. 7, the arrangement
positions of the embedded metal parts 6 are adjusted by moving the
embedded metal parts 6 along the slotted hole 71 of the
upper-surface connecting part 7.
[0105] Furthermore, by loosening the two anchor bolts 73, the
upper-surface connecting part 7 can be shifted in its width-wise
direction to achieve fine adjustment. By doing so, two-dimensional
fine adjustment of the embedded metal parts 6 in the horizontal
plane can be conducted.
[0106] In this embodiment, although a configuration in which the
slotted holes 71 extend in the longitudinal direction of the
upper-surface connecting part 7 and the slotted holes 75 extend in
the width-wise direction of the upper-surface connecting part 7 is
illustrated, a configuration in which the slotted holes 71 extend
in the width-wise direction of the upper-surface connecting part 7
and the slotted holes 75 extend in the longitudinal direction of
the upper-surface connecting part 7 is also possible.
[0107] Thereafter, as shown in FIG. 3, concrete is poured into the
form 4 to form the inner concrete portion 51, and at the same time,
concrete is also poured into the form 22, and a concrete curing
step is conducted (Step S6).
[0108] As shown in FIG. 2, once the concrete is poured into the
form 4 to form the inner concrete portion 51, the interior of the
form 4 is filled with the inner concrete portion 51 to form the
load portion 5, and parts of the embedded metal parts 6 are
embedded in the inner concrete portion 51.
[0109] Thereafter, while the poured concrete is curing, a step of
removing the scaffolding set around the platform 1 is conducted
(Step S7), and subsequently, the upper-surface connecting part 7 is
removed from the side walls 41 by removing the anchor bolt 73.
Thus, the platform 1 as shown in FIG. 1 is completed.
[0110] According to the configuration described above, a step of
forming the form 4 and a step of building a plurality of piers 2
can be conducted simultaneously, and at the same time, the form 4
can be made at a different site from the construction site of the
plurality of piers 2, in other words, the construction site of the
platform 1. Therefore, a reduction in the construction period, that
is, the production period of the platform 1, can be achieved.
[0111] Furthermore, because the form 4 is made of concrete, the
form 4 is not required to be removed after the concrete has been
poured into the form 4 to form the inner concrete portion 51, and
therefore, the construction period can be reduced.
[0112] In addition, when form made of steel plates is used, it is
necessary to perform welding management, and it is necessary to
make the form in a factory in order to ensure dimensional
precision. In contrast, when form made of concrete is used, it is
not necessary to perform welding management etc. Therefore, the
site for producing the form is not limited to the factory; the form
can be produced at a suitable site close to the construction site,
and it is possible to reduce the costs related to transport of the
form.
[0113] On the other hand, because concrete is poured to form the
inner concrete portion 51 after the form 4 having the pair of side
walls 41 and the bottom slab 42 has been set on the piers, a
reduction in the size of a crane used for setting the form can be
afforded compared with a case where the form 4 is set on the piers
2 after concrete has been poured to form the inner concrete portion
51.
[0114] By connecting each of the edge portions of the pair of side
walls 41 with the upper-surface connecting part 7, a part of the
cross-section of the form 4 forms a box-structure; therefore, it is
possible to prevent a reduction in the sectional stiffness of the
form 4 due to the widening of the gap between the edge portions
(upper edges) of the side walls 41. Therefore, deformation of the
form 4 during pouring of the concrete for the inner concrete
portion 51 is prevented, and no supports for supporting the form 4
need to be set.
[0115] Because the embedded metal parts 6 are supported with the
slotted holes 71 of the upper-surface connecting part 7, it is
possible to align the embedded metal parts 6 easily and with high
precision without using a separate massive template and temporary
supporting members that temporarily support this template from
above. Furthermore, the construction period can be reduced compared
with a process where the embedded metal parts 6 are arranged
directly in the form 4 and their arrangement positions are
adjusted.
[0116] In addition, as shown in FIG. 7, the upper-surface
connecting part 7 is composed of an elongated member, thereby
achieving weight saving. By doing so, the upper-surface connecting
part 7 can easily be attached to and detached from the form 4. In
addition, because the upper-surface connecting part 7 is finely
adjustable in two dimensions in the planar direction of the region
that will form the top surface of the table-deck portion 3 after
concrete has been poured, the positions of the embedded metal parts
6 are two-dimensionally adjustable in the horizontal plane by using
this fine adjustment.
[0117] The process of constructing the table-deck portion 3 using
the above-described form 4 can also be applied to the construction
of the piers 2, and it is not particularly limited.
REFERENCE SIGNS LIST
[0118] 1 platform (concrete platform) [0119] 2 pier [0120] 3
table-deck portion [0121] 4 form [0122] 6 embedded metal part
(attachment part) [0123] 7 upper-surface connecting part
(connecting member) [0124] 41 pair of side walls [0125] 42 bottom
slab [0126] 51 inner concrete portion [0127] 61 nut (fixing member)
[0128] 71 slotted hole (adjusting part) [0129] 75 slotted hole
(adjusting part) [0130] S2 step (Step for forming form) [0131] S3
step (Step for setting form) [0132] S6 step (Step for pouring
concrete)
* * * * *