U.S. patent application number 10/830969 was filed with the patent office on 2005-10-27 for systems and methods for modular construction of large structures.
This patent application is currently assigned to Bechtel Corporation. Invention is credited to Ryan, James L..
Application Number | 20050235595 10/830969 |
Document ID | / |
Family ID | 35134999 |
Filed Date | 2005-10-27 |
United States Patent
Application |
20050235595 |
Kind Code |
A1 |
Ryan, James L. |
October 27, 2005 |
Systems and methods for modular construction of large
structures
Abstract
Systems and methods wherein large superstructures are simplified
and then constructed using prefabricated, modular components. The
components include a combined prefabricated primary support and
roof system and shop-fabricated floor panels.
Inventors: |
Ryan, James L.;
(Gaithersburg, MD) |
Correspondence
Address: |
TOWNSEND AND TOWNSEND AND CREW, LLP
TWO EMBARCADERO CENTER
EIGHTH FLOOR
SAN FRANCISCO
CA
94111-3834
US
|
Assignee: |
Bechtel Corporation
San Francisco
CA
|
Family ID: |
35134999 |
Appl. No.: |
10/830969 |
Filed: |
April 22, 2004 |
Current U.S.
Class: |
52/633 |
Current CPC
Class: |
E04H 5/02 20130101; E04B
1/24 20130101; E04B 2001/2448 20130101; E04B 2001/2484
20130101 |
Class at
Publication: |
052/633 |
International
Class: |
E04H 001/00 |
Claims
What is claimed is:
1. A method of erecting a structure for generating power with a
boiler, the method comprising: erecting a primary framing system
comprising prefabricated, modular components including a combined
prefabricated primary support and roof system and composite
columns; and constructing a plurality of intermittent floor bays
comprising prefabricated floor panels made up of at least one of
grating panels, checkered plates, and composite decks.
2. A method in accordance with claim 1 wherein a majority of floor
panel connections are with bearing connections
3. A method in accordance with claim 1 wherein no diagonal
horizontal bracing is used and no vertical bracing is used in two
of four planes defined by the structure.
4. A method in accordance with claim 1 wherein the first two steps
are performed substantially simultaneously.
5. A method in accordance with claim 1 wherein components are sized
to fit on vehicles for shipment.
6. A method in accordance with claim 6 wherein the vehicle is a
standard truck-trailer combination and the components are sized to
fit on the trailer.
7. A method in accordance with claim 1 wherein the type of
prefabricated panels may further comprise composite decking.
8. A structure comprising: a primary framing and roof support
system comprising prefabricated roof truss sections, the roof truss
sections being formed with horizontal panels consisting of
interconnected beams and vertical trusses interconnected with the
beams of the panels; a plurality of intermittent floor bays within
the primary framing and roof support system, the bays comprising
floor support structures comprising prefabricated panels of at
least one of grating and decking coupled to beams, the panels being
coupled to beams of the primary framing and roof system; and a
primary support structure comprising prefabricated panels of
checker plate panels coupled to the primary framing and roof
support system.
9. A structure in accordance with claim 8 wherein a majority of
connections between components are with bearing connections.
10. A structure in accordance with claim 8 wherein the primary
support is for a boiler for generating power and the support
comprises columns comprising composite material.
11. A structure in accordance with claim 8 wherein no diagonal
horizontal bracing is used and no vertical bracing is used in two
of four planes defined by the structure.
12. A structure in accordance with claim 8 wherein components are
sized to fit on vehicles for shipment.
13. A structure in accordance with claim 12 wherein the vehicle is
a standard truck-trailer combination and the components are sized
to fit on the trailer.
14. A structure in accordance with claim 8 wherein the types of
prefabricated panels may further comprise composite decking.
15. A method of erecting a structure for generating power with a
boiler, the method comprising: erecting a primary framing and roof
support system comprising prefabricated roof truss sections, the
roof truss sections being formed with horizontal panels consisting
of interconnected beams and vertical trusses interconnected with
the beams of the panels; creating a plurality of intermittent floor
bays within the primary framing and roof support system, the bays
comprising floor support structures comprising prefabricated panels
of at least one of one of grating and decking coupled to beams, the
panels being coupled to beams of the primary framing and roof
support system; creating a plurality of intermittent support bays
within the primary framing and roof support system, the support
bays comprising prefabricated panels of at least one of grating and
decking coupled to trusses, the modules being coupled to beams of
the stair modules; and erecting a primary support structure
comprising prefabricated panels of checker plate panels coupled to
the primary framing and roof support system.
16. A method in accordance with claim 15 wherein a majority of
floor panel connections are with bearing connections
17. A method in accordance with claim 15 wherein no diagonal
horizontal bracing is used and no vertical bracing is used in two
of four planes defined by the structure.
18. A method in accordance with claim 15 wherein the first two
steps are performed substantially simultaneously.
19. A method in accordance with claim 15 wherein components are
sized to fit on vehicles for shipment.
20. A method in accordance with claim 19 wherein the vehicle is a
standard truck-trailer combination and the components are sized to
fit on the trailer.
21. A method in accordance with claim 15 wherein the type of
prefabricated panels may further comprise composite decking.
Description
CROSS-REFERENCES TO RELATED APPLICATIONS
[0001] NOT APPLICABLE
STATEMENT AS TO RIGHTS TO INVENTIONS MADE UNDER FEDERALLY SPONSORED
RESEARCH OR DEVELOPMENT
[0002] NOT APPLICABLE
REFERENCE TO A "SEQUENCE LISTING," A TABLE, OR A COMPUTER PROGRAM
LISTING APPENDIX SUBMITTED ON A COMPACT DISK
[0003] NOT APPLICABLE
BACKGROUND OF THE INVENTION
[0004] 1. Field of the Invention
[0005] The present invention relates to systems and methods for a
simplified framing system that facilitates cost-efficient, modular
construction of large structures, and more particularly, to systems
and methods for erecting large power generation plant
structures.
[0006] 2. Description of the Prior Art
[0007] Large structures such as, for example, power generation
plants, petro-chemical facilities, mining and metal structures,
industrial buildings, etc. are common. Many of these structures are
now being built globally, especially in remote locations. Companies
that obtain contracts for building such structures obviously want
to minimize effort and expenses. Adding to the cost presumed, there
often are time constraints involved in erecting structures. As
steel erection is typically on the "critical path" of a project
schedule, the required steel erection duration directly impacts the
overall project schedule.
[0008] A common method for erecting such structures is a
"stick-built" approach, where conventional columns, beams, girders,
vertical braces, horizontal braces, deck, studs, grating pieces and
others are assembled at the site. Consequently, this involves a
large amount of labor. Additionally, tracking of the large number
of members can be expensive and time-consuming.
[0009] A second method involves prefabrication of large-scale,
three-dimensional modules. However, such modules are typically much
more costly, due to special shipping requirements and the
inevitable wasted space on the vehicles being used for the
shipment.
[0010] Thus, improved systems and methods for cost-effectively and
efficiently designing, fabricating and erecting large structures is
needed.
SUMMARY OF THE INVENTION
[0011] Broadly, the present invention provides systems and methods
wherein construction of structures is grossly simplified through
the use of prefabricated, modular components fabricated to a
maximum size that still may be stacked and then shipped
conventionally on trucks. The components are erected to provide a
simplified "super-frame," which comprises a combined prefabricated
primary support and roof system; shop-fabricated composite columns;
and shop-fabricated floor panels that are assembled into bays
within the primary support frame.
[0012] More particularly, the present invention provides a method
of erecting a structure for generating power with a boiler, where
the method comprises erecting a primary "super-frame" of only
approximately 650-750 pieces, preferably only approximately 700
pieces. Components of the "super-frame" include combined boiler
support/roof truss sections, large composite columns built-up from
available shapes, deep horizontal trusses that consist of lacing
adjacent floor beams and large floor panels (i.e., up to 12
feet.times.60 feet and including shop welded grating, checker plate
or composite decking) that bear on column line members. The
simplified "super-frame" greatly mitigates the required erection
duration prior to commencement of the boiler.
[0013] In accordance with one aspect of the present invention, a
majority of component connections are accomplished using bearing
connections. While conventional steel structures involve members
framing into one another, and thus lead to bolting and "fit-up"
issues, all floor panels for this structure simply set on
previously erected steel, with "stops" designed to prevent
movement.
[0014] In accordance with another aspect of the present invention,
the primary support is for a boiler for generating power and the
support comprises using a common structure for both boiler support
and roof framing.
[0015] In accordance with a further aspect of the present
invention, no diagonal horizontal bracing is used. In adddition, no
vertical bracing is used in one framing direction.
[0016] In accordance with yet another aspect of the present
invention, components are sized to fit on a standard
truck-trailer.
[0017] According to another aspect of the present invention,
grating is used integrally with framing to create a horizontal
diaphragm.
[0018] The following detailed description together with the
accompanying drawings will provide a better understanding of the
nature and advantages of the present invention.
BRIEF DESCRIPTION OF THE DRAWINGS
[0019] FIG. 1 is an elevational view of a superstructure
constructed with prefabricated components in accordance with the
present invention;
[0020] FIG. 2 is perspective view of a combined primary/roof
support structure;
[0021] FIG. 3 is a perspective view of a shop prefabricated panel
for grating;
[0022] FIG. 4 is a perspective view of a shop prefabricated panel
for checker plates;
[0023] FIG. 5 is a top perspective view of a shop-fabricated
composite panel;
[0024] FIG. 6 is a perspective bottom view of the shop-fabricated
floor panel illustrated in FIG. 5; and
[0025] FIG. 7 is an illustration of a bearing-type connection.
DESCRIPTION OF PREFERRED EXEMPLARY EMBODIMENTS
[0026] The present invention provides systems and methods for
erecting large structures or "superstructures" through the use of
prefabricated modular components. While the present invention will
be described with reference to a power-generating plant, those
skilled in the art will understand that the present invention may
be used for other large structures such as, for example,
petro-chemical facilities, mining and metals facilities, industrial
buildings, etc.
[0027] With reference to FIG. 1, a boiler building volume 9 may be
viewed as three discrete sections. Specifically, a combined boiler
and roof support system 10 at the top of the structure is one
primary section. The second discrete section comprises soot blower
floors in the form of bays made up of prefabricated panels for
grating 11, checker plates 12, and floor panels 13. Lower levels,
also in the form of bays and made up of panels 11, 12 and 13, are a
third discrete section and support coal conduits, large ductwork
ash conveyors, and miscellaneous commodity supports.
[0028] To reduce the amount of time to assemble such a structure,
the first two discrete sections may be assembled simultaneously.
Generally, as an example for this type of power generating plant,
only approximately 700 primary structural members are used. These
members include building columns and column line members, boiler
support systems, including trusses, stair tower modules, and soot
blower floor grating panels and boiler front checker plate burner
panels placed adjacent the boiler cavity. Preferably, these modules
include 60-foot super columns.
[0029] The lower levels may be installed and assembled subsequent
to assembly of the first two sections since it can be done at the
same time as the primary boiler structure erection.
[0030] As may be seen in FIG. 1, preferably the bottom level of the
structure includes bays 18 wherein trucks may drive for unloading
of fuel and other supplies.
[0031] Combined primary (in this case, boiler)/roof support
structure 10 is illustrated in FIG. 2. Shop prefabricated panels
for grating 11 and checker plates 12 are illustrated in FIGS. 3 and
4, respectively. Shop-fabricated composite panels 13 are
illustrated in FIGS. 5 and 6.
[0032] The combined boiler roof system is sloped perpendicular to
the centerline of the boiler. Thus, as may be seen in FIG. 1, the
pieces that are preformed and illustrated in FIG. 3 are used as the
center of the structure at the top. This allows for outer bays to
be reduced in elevation relative to the boiler, thus reducing steel
quantity and lateral loads.
[0033] The unique shop-fabricated grating panels preferably
comprise two standard-weight parallel beams 30, 31 with
perpendicular channels 32 across the beams to support the grating
33. This design essentially uses the channels and beam top flanges
as a horizontal Vierendeel truss. Superimposed on this truss are
shop-welded grating bearing bars that function as supplemental
chord members to significantly increase the rigidity of the panel.
Through use of the grating members, diaphragm stiffness may satisfy
AISC stability bracing requirements.
[0034] Channels 32 also facilitate framing around pipe and other
commodity penetrations and mitigate tripping hazards between
adjacent panels by providing means of attaching overhanging grating
from adjacent panels. The grating floor panels, which generally
span from column line girder to column line girder, are installed
more quickly and safely because they include bearing-type
connections (see FIG. 7). Heavily coped ends simulating precast
double-T bearings in parking garages allow the structure to be
arranged with an eight and a half foot floor-to-floor height
without affecting headroom requirements.
[0035] While vertical Vierendeel trusses are common for prior art
walkways, the present invention is actually utilizing them
horizontally with grating as a reinforcing structural component.
Preferably, the frames are coped seated connections and the
channels located with web horizontals such that they have
sufficient flexibility to align with channels of adjacent panels
when brought together via the grating overlap. Preferably, the
grating panels are sized for standard trucks. Thus, when stacked,
the weight approximately equals the maximum capacity of the trucks
such that the trucks are not shipping "air."
[0036] Similar to the process of creating the grating panels,
partially shop-fabricated stair towers are fabricated to a maximum
extent that allows them to be shipped by rail or truck without
special provisions. End frames include platform level grating and
girts. Shop-assembled stair stringer frames also function as
vertical bracing for open stair towers and the upper two tiers of
enclosed stair towers.
[0037] Shop-fabricated composite panels, such as floor panels 13
and checkered plate burner panels 12, are created at the shop in
order to avoid shipping beams that are loose with studs, decking,
closure strips, etc. When these panels are assembled together to
form a superstructure, concrete work, including rebar installation
and concrete placement, may be performed at ground level or,
depending upon panel height in the building, at the installed
level. FIG. 4 illustrates examples of two types of checkered plate
burner panels, 13a, 13b. FIG. 5 illustrates a top view of examples
of floor panels 12a, 12b, while FIG. 7 illustrates a bottom view of
examples of floor panels 12a, 12b.
[0038] Generally, standard tripper floor framing is conventionally
"stick-built" steel. Due to the elevation of at least 150 feet
above ground level or grade, the erection is generally
time-consuming in crane usage as well as craft job hours. Thus, use
of prefabricated panels allows for three framing panels to be used
per bay as opposed to several hundered pieces (between 16 and 24
framing members, deck panels, edge angles, studs, closure strips,
etc) when done with the prior art "stick-built" method. Composite
decking is shop-installed within the panel periphery. Structural
steel members are situated to function as pour stops. Panel bearing
connections are used on primary steel beams. Reinforcing steel and
concrete is placed at ground level or grade rather than more than
150 above grade. When the panels are used to form operating decks
for turbine buildings, wood panels are generally placed over the
openings to serve as a temporary cover to satisfy safety
requirements.
[0039] FIG. 5 illustrates checkered plate burner panels. The former
approach of discrete plates supported by framing members yielded
many "levels" of framing before loads were delivered to the
columns. For example, checkered plates spanned to angle stiffeners,
stiffeners spanned to beams, beams framed to girders, girders
framed into transfer girders, and transfer girders framed into a
major transfer girder before loads finally were transferred to a
column.
[0040] Preferably, the checkered plate burner panels are sized (up
to 12 feet by 60 feet maximum) to fit within a conventional
oversized truck known in the art. Indeed, preferably all of the
preformed components are sized to fit together on such a truck. The
panels may be fabricated on a shop floor upside-down with all
downward fillet welds. Preferably, bearing connections are used on
primary steel beams to couple the panels to the superstructure.
[0041] Those skilled in the art will understand that many other
components may be included in designing and erecting a
superstructure in accordance with the present invention. For
example, other components are often used in designing and erecting
a power generation plant that uses a boiler as described herein but
their description has been omitted for clarity. Preferably, most
components used for designing and erecting a superstructure in
accordance with the present invention are prefabricated and sized
to fit together on a truck or other form of transportation.
Additionally, those skilled in the art will understand that there
are numerous ways to connect and interlink the various
components.
[0042] Thus, the present invention provides a concept that uses
larger building components, most of which have been wholly or
partially preassembled off-site. With the present invention, no
horizontal bracing is required on the sides of the boiler. This
lack of heavy diaphragm is feasible by having each column line act
as a horizontal moment frame, including the combined boiler/roof
support at the top of the frame. Horizontal Vierendeel trusses
serve to introduce structural redundancy and function as a light
horizontal frame. Additionally, no east-west vertical bracing is
required. This attribute avoids the numerous interferences and
inefficient vertical bracing typically found with the large
ductwork lying parallel to the boiler. Use of shop-fabricated
10-to-12-foot-deep vertical trusses that function as horizontals is
also beneficial. The present invention also permits the extremely
"commodity heavy" first hundred feet of the superstructure to be
installed in parallel with the boiler. Each soot blower bay
(generally 30 feet by 40 feet) is simply constructed with four
framing/floor panels and a total of only four bolts.
[0043] Thus, the superstructure may be erected more quickly and
efficiently in a cost-saving manner as opposed to the standard
shipping of loose materials to the drop site and then assembling
all the loose materials into the superstructure.
[0044] The foregoing descriptions of specific embodiments of the
present invention have been presented for purposes of illustration
and description. They are not intended to be exhaustive or to limit
the invention to the precise forms disclosed, and obviously many
modifications and variations are possible in light of the above
teaching. The embodiments were chosen and described in order to
best explain the principles of the invention and its practical
application, to thereby enable others skilled in the art to best
utilize the invention and various embodiments with various
modifications as are suited to the particular use contemplated. It
is intended that the scope of the invention be defined by the
Claims appended hereto and their equivalents.
* * * * *