U.S. patent number 3,594,965 [Application Number 04/764,228] was granted by the patent office on 1971-07-27 for precast building construction.
Invention is credited to Kolbjorn Saether.
United States Patent |
3,594,965 |
Saether |
July 27, 1971 |
PRECAST BUILDING CONSTRUCTION
Abstract
Floor slabs are precast in situ one upon another, temporary
steel lifting columns are mounted through aligned clearance holes
in the stack of slabs, a holding carriage and a lifting carriage
are operatively disposed about each of the columns, threaded
tension rods are coupled to removable tension rod sections properly
located and coupled to the slabs, lifting jacks mounted on the
lifting carriage actuate the tension rods to lift the entire stack
of slabs to a height adjacently above the final elevation of the
lowermost of the slabs in the stack, the pack of slabs is held by
the holding carriage until the lifting carriage is raised to a
further lifting height, the lowermost slab in the stack is
temporarily supported at its highest elevation and is released from
the lifting tension rods so that the remaining slabs can be raised
and the successive lowermost slabs dropped off at their
predetermined elevated positions, while angular wall columns are
mounted in position to provide the ultimate support for the
lowermost slab which is then lowered onto such columns and released
from the temporary holding means. After all of the slabs have been
erected, the lifting equipment is removed for reuse. To facilitate
handling and placement of the wall columns one or more cranes may
be mounted on and ride up with the topmost slab.
Inventors: |
Saether; Kolbjorn (Wilmette,
IL) |
Family
ID: |
25070065 |
Appl.
No.: |
04/764,228 |
Filed: |
October 1, 1968 |
Current U.S.
Class: |
52/125.1; 52/263;
254/89R; 52/745.13 |
Current CPC
Class: |
E04B
1/3511 (20130101) |
Current International
Class: |
E04B
1/35 (20060101); E04b 001/34 (); E04g 021/00 () |
Field of
Search: |
;52/122,126,745,263,292,293,295,294 ;254/89,89H,92,109,106 |
References Cited
[Referenced By]
U.S. Patent Documents
Foreign Patent Documents
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|
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|
|
607,826 |
|
1948 |
|
GB |
|
854,175 |
|
1960 |
|
GB |
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1,042,337 |
|
1966 |
|
GB |
|
Primary Examiner: Murtagh; John E.
Claims
I claim as my invention:
1. Apparatus for handling building floor and roof slabs formed in
situ and provided with column openings through which ground
supported lifting columns are mounted and on which columns are
supported lifting devices by which a stack of the slabs is adapted
to be lifted to raise each successive lowermost slab to a desired
elevation wherein that slab is released from the lifting means
while the remaining slabs are further lifted, comprising:
interim holding assemblies separably mountable on the respective
columns after the respective lowermost slabs have been lifted to
substantially their desired elevations;
means on said assemblies for engaging and supporting the lowermost
slab with which associated for transference of the slab load to the
columns; and
jacking means in each assembly operative for lowering and releasing
said engaging means after supporting substructure has been erected
under the lowermost slab.
2. Apparatus according to claim 1, each said assembly comprising a
lifting bracket having said slab-engaging means, and a lifting jack
comprising said jacking means supporting said bracket.
3. Apparatus according to claim 2, in which each said assembly
includes a removable backup bearing member for said bracket and
serving as a filler behind the bracket enabling removal of the
bracket from the column and the slab upon removal of the bearing
member.
4. Apparatus according to claim 1, in which said columns have
upwardly facing shoulders accessible through said openings, and
said interim holding assemblies are mountable on and removable from
said shoulders through said openings.
5. A method of constructing a multistory building, comprising:
preforming on a ground-supported base a stack of horizontal slabs
one upon the other and of a length and width to cover a substantial
building area;
providing in each of said slabs a plurality of lifting column
openings vertically aligned in the stack;
erecting in said openings ground-supported lifting columns;
mounting lifting apparatus on said columns;
operating said apparatus to lift said stack of slabs along said
columns until the lowest slab in the stack has reached an elevation
above said base higher than its intended erected position;
supporting said lowest slab at said higher elevation on said
columns and detaching it from the stack and said lifting
apparatus;
further operating said lifting apparatus on said columns to lift
the remainder of the stack from said column-supported lowest slab
while it is held at said higher elevation;
while said remainder of the stack is undergoing further lifting by
said apparatus, erecting building substructure independent of said
columns under said lowest slab to provide ultimate support for
it;
lowering said lowest slab onto said substructure for full support
by said substructure and releasing such slab from said columns;
repeating the foregoing procedure with each succeeding lowest slab;
and
finally removing said apparatus and columns.
6. A method according to claim 5, comprising preforming said
substructure into a plurality of wall columns each of which as a
plurality of integral angularly related wall panel portions
providing a self-stable unit, and placing said wall columns into
efficient load-bearing respective positions under the lowest slab
they are to support before lowering the slab thereonto.
7. A method according to claim 5, comprising mounting said columns
in said aligned openings on baseplates having grout space
thereunder, holding said columns in vertical orientation with the
baseplates normal to the vertical axes of the respective columns,
filling grout under the baseplates through tubes extending through
said plates into said spaces, and then setting the grout to assure
balanced vertical load distribution in respect to said columns
8. A method of constructing a multistory building, comprising:
preforming on a ground-supported base a stack of horizontal slabs
one upon the other and of a length and width to cover a substantial
building area;
providing in each of said slabs a plurality of column openings
vertically aligned in the stack;
erecting ground-supported columns to project upwardly through said
openings to a height at least near the elevation to which the
lowest slab in the stack is to be raised;
mounting lifting apparatus on said columns at a height which is
sufficient to enable lifting the entire stack to adjacent said
elevation;
connecting lifting rods to the slabs in the stack and attaching the
lifting rods operatively to said lifting apparatus;
actuating the lifting apparatus to raise the rods and thereby lift
the stack to adjacent said elevation but with a clearance space
between said lifting apparatus and said stack;
mounting on the columns respective holding carriages within said
space and connecting said carriages to said rods in load-supporting
holding relation to thereby support the stack from said
carriages;
disconnecting said lifting apparatus from said rods and relocating
the apparatus on the columns at a second height near the elevation
to which the next succeeding lowest slab is to be raised;
then reconnecting the lifting apparatus to said rods for operation
to continue lifting of the stack and disconnecting said holding
carriages;
continuing lifting of the stack until the lowest slab has reached
said elevation therefor;
supporting said lowest slab on said columns;
releasing said lowest slab from the stack; and
operating said apparatus to raise the stack from said lowest slab
to adjacent the elevation to which the next succeeding lowest slab
is to be raised.
9. A method according to claim 8, comprising supporting said
carriages on top of the stack to ride upwardly therewith adjacent
to said columns when the carriages are not mounted on the columns
or attached supportingly to said rods.
10. Apparatus according to claim 4, said means for lowering and
releasing the engaging means comprising hydraulic jacks seated on
said shoulders, said means for engaging and supporting the
lowermost slab comprising respective brackets supported by said
jacks for raising and lowering of the brackets.
11. Apparatus for lifting into position floor and roof slabs which
have been formed in situ, comprising:
columns along which the slabs are to be lifted and which columns
are in one-story building height sections;
means for securing said column sections vertically end to end;
means on lower portions of said sections providing seats including
upwardly facing shoulders;
a respective carriage movable vertically along each column in a
manner to leave the top of the associated column free for mounting
thereon of another section as a column extension is needed;
lifting means supported by each of the carriages and having means
detachably connectable to the slabs for lifting the slabs upon
operation of the lifting means; and
means on said carriage separably engaging said seats in
load-bearing relation.
12. Apparatus according to claim 11, said last-mentioned means
comprising respective brace bars having lower ends engageable with
said seats and upper ends, and load transfer structure on the
respective carriages engaging said upper ends and thereby
transferring the load to said brace bars by which the load is
transferred to the associated column seat.
13. Apparatus according to claim 12, each of said bars being
pivotally and relatively movably mounted with respect to said
structure to enable passage of said brace bars along said shoulders
during movement of the carriages upwardly along the columns.
14. Apparatus according to claim 12, in which said structure in
each instance provides a reentrant seat, and the upper end of the
associated brace bar is of complementary shape to thrust
efficiently into engagement with such seat.
15. Apparatus according to claim 11, in which said seats comprise
foot flanges on said column sections.
16. Apparatus according to claim 11, in which said column sections
have vertical webs, and respective shoulder plates fixedly secured
to said webs and providing said seats.
17. Apparatus according to claim 11, comprising second upwardly
facing seat shoulders on said lower portions of the column sections
at a different elevation from the first-mentioned seats enabling
the lifting means carriages and holding carriages both equipped
with means for separably engaging the seats to be supported
simultaneously in adjacent relation on the column sections.
18. A method of constructing buildings comprising:
forming a stack of reinforced separate concrete building floor and
roof slabs successively one on top of the other;
during the forming of each slab forming respective column receiving
holes therein aligned with the similar holes in the other
slabs;
adjacent to each of said holes removably mounting in the slabs a
plurality of vertical slab-connecting lifting rod extension
elements having their upper ends above the topmost slab for
coupling thereto of lifting rods of lifting apparatus to be carried
by columns mounted through said aligned holes;
removably securing lifting plates on said lifting rod extension
elements under each of the slabs;
whereby all of the slabs can be lifted in unison and then each
lower slab can be released successively from the bottom of the
lifted stack; and
supporting for each slab to be formed a hole core and lifting plate
socket-forming spider as a thickness gauge on said extension
elements above the surface upon which the slab is to be formed.
19. A method according to claim 18, comprising coupling rod
sections together in a train to form said extension elements and
with the sections in the topmost slab extending thereabove for
coupling thereto of the lifting rods of the lifting apparatus, and
securing removable retaining means to said rod sections under said
lifting plates.
20. A method of constructing a multistory building, comprising:
preforming on a ground-supported base a stack of horizontal slabs
one upon the other and of a length and width to cover a substantial
building area;
providing in each of said slabs a plurality of lifting column
openings vertically aligned in the stack;
erecting in said openings ground-supported lifting columns;
mounting lifting apparatus on said columns;
operating said apparatus to lift said stack of slabs along said
columns until the lowest slab in the stack has reached an elevation
above said base higher than its intended erected position;
supporting said lowest slab at said higher elevation on said
columns and detaching it from the stack and said lifting
apparatus;
further operating said lifting apparatus on said columns to lift
the remainder of the stack from said column-supported lowest
slab;
preforming substructure in a plurality of load-supporting column
units having opposite end upper and lower respective bearing
faces;
erecting said column units as building substructure independent of
said columns and locating said units at desirable locations and
supporting the units on their lower bearing faces whereby to
provide ultimate support under said lowest slab,
placing grout retaining generally ring-shaped gaskets onto the
upper bearing faces of the units to surround the major areas of
such faces;
placing load-bearing shims which are slightly thinner than said
gaskets between said upper faces and said lowest slab whereby to
prevent collapse of said gaskets from the weight of the slab but
permitting sealing compression of the gaskets by said weight;
lowering said lowest slab onto the gaskets and thereby enclosing
grout spaces within said gaskets;
filling said spaces with grout to assure stable and efficient full
support load distribution from the lowest slab onto the units;
releasing said lowest slab from said columns;
repeating the foregoing procedure with each succeeding lowest slab;
and
finally removing said apparatus and columns. 21In a method of
constructing a building wherein a preformed slab is lifted along
columns mounted in openings in the slab;
mounting said columns on baseplates;
mounting said baseplates on grout-retaining gaskets;
holding said columns in vertical orientation with the baseplates
normal to the vertical axes of the respective columns;
filling grout under the baseplates into areas enclosed by said
gaskets;
setting the grout to assure balanced vertical load distribution
through said columns;
said gaskets comprising elastomeric material;
floatingly supporting said baseplates and effecting said vertical
orientation aided by said floating mounting of the baseplates;
said baseplates having respective holes therethrough to the space
within the gaskets; and
filling the grout through said holes.
Description
This invention relates to precast building construction involving
the in situ casting of concrete slabs one upon another in the total
number required and then elevating the slabs to and mounting them
permanently in their intended positions in the building.
Building construction utilizing reinforced or post-tensioned
concrete deck or floor slabs is now a reasonably well-developed art
as represented in Phillip N. Youtz, U.S. Pat. Nos. 2,686,420
entitled "SLAB LIFTING APPARATUS" and 2,720,017 entitled "METHOD OF
ERECTING BUILDINGS."According to those patents permanent steel
supporting columns are erected for the intended building, concrete
slabs are poured in situ one upon another about and between the
columns with attachment collars fixed in the slabs and engaged
about the respective columns. Slab-lifting jacks are mounted on the
tops of the columns with threaded tension rods depending therefrom
and attached to successive batches of two or three slabs which are
successively raised by temporarily supporting the uppermost batches
of slabs while the lower batches are raised to respective positions
and the successive lowermost slabs are permanently attached to the
columns by securing their collars in place. The collars serve as
guides for the slabs along the columns as well as ultimate means
through which the slabs are secured to the columns.
The slab-lifting jacks have an arrangement of respective hydraulic
jacks mounted between a holding yoke and a lifting yoke, the jacks
raising their lifting yokes by predetermined increments such as in
a 1/2-inch stroke by hydraulic power, thereby correspondingly
raising the lifting rods through the holding yoke. Holding nuts are
run down the threaded rods onto the holding yoke while the lifting
yoke is lowered and takeup nuts run down the upper extensions of
the rods onto the lifting yoke, and the cycle repeated. In this
manner the heavy loads of the slabs are inched upwardly. At least
to the extent of details of the slab-lifting jacks and their
mechanical and hydraulic operation, the disclosures of the
aforesaid patents are incorporated herein by reference as is also
U.S. Pat. No. 2,758,467.
One of the disadvantages of prior constructions has resided in the
necessity for erection of supporting columns before pouring or
casting the concrete slabs, wherein the columns are obviously
obstructions preventing the use of fully automated equipment, but
requiring a great deal of manual labor. Further, because the slabs
are mounted on the columns, attachment collars must be secured in
the slabs about the respective columns requiring tie-in with the
reinforcement, and placing limitations upon location of the
reinforcement within the slabs.
The prior construction has also placed definite limitations
architecturally, being quite restrictive on the architectural
layouts due to the need for efficient location of the supporting
columns. The best location for the columns is somewhere inside the
edge of the slab and away from the slab corners. This results in
great architechtural conflicts because of the permanent location of
such columns. In addition, fireproofing codes require that the
steel columns be fireproofed.
In the permanent column arrangement mounting of the lifting jacks
directly on top of the columns creates certain problems. The tall
unbraced towerlike columns presented certain lateral instability
hazards and thus severe limitation upon the weight and thus the
number of slabs that could be lifted. Then, it has been necessary
where column extensions are employed to remove the lift jacks from
the top of the lower column, and lift the same to the top of the
extension column after the latter has been secured in place on top
of the lower column.
All of the foregoing and other deficiencies and shortcomings of the
prior construction are overcome by the method, structures and
apparatus of the present invention whereby floor slabs are precast
in situ one upon another, temporary steel lifting columns are
mounted through aligned clearance holes in the stack of slabs, a
holding carriage and a lifting carriage are operatively disposed
about each of the columns, threaded tension rods are coupled to
removable tension rod sections properly located and coupled to the
slabs, lifting jacks mounted on the lifting carriage actuate the
tension rods to lift the entire stack of slabs to a height
adjacently above the final elevation of the lowermost of the slabs
in the stack, the pack of slabs is held by the holding carriage
until the lifting carriage is raised to a further lifting height,
the lowermost slab in the stack is temporarily supported at its
highest elevation and is released from the lifting tension rods so
that the remaining slabs can be raised and the successive lowermost
slabs dropped off at their predetermined elevated positions, while
angular wall columns are mounted in position to provide the
ultimate support for the lowermost slab which is then lowered onto
such columns and released from the temporary holding means. After
all of the slabs have been erected, the lifting equipment is
removed for reuse. To facilitate handling and placement of the wall
columns one or more cranes may be mounted on and ride up with the
topmost slab.
An important object of the present invention is to provide a novel
precast building construction wherein elevation of the slabs to
their functioning position is effected along temporary columns.
Another object of the invention is to provide a new and improved
method of constructing precast concrete buildings in which roof and
floor deck slabs are precast in situ one upon another and are all
lifted in a one-shot manner wherein each successive lower slab is
dropped off as erection progresses.
A further object of the invention is to provide a new and improved
method of constructing precast buildings by lifting a stack of
precast slabs and successively mounting the lowermost slabs in
load-supporting relation on substructure erected under the raised
slabs.
Still another object of the invention is to provide a new and
improved precast building construction in which precast deck slabs
are lifted up and mounted directly onto preformed wall-column
members.
Yet another object of the invention is to provide novel apparatus
for erecting precast building structures.
A still further object of the invention is to provide a new method
of and means for mounting columns in full load-bearing relation to
supporting and supported structures.
Other objects, features and advantages of the present invention
will be readily apparent from the following detailed description of
certain preferred embodiments, taken in conjunction with the
accompanying drawings, in which:
FIG. 1 is a fragmentary top plan view of a stack of precast
building deck slabs depicted during the slab pouring or casting
operation;
FIG. 2 is a sectional detail view taken substantially along the
line II-II of FIG. 1;
FIG. 3 is a sectional detail view similar to FIG. 2 but showing a
slight modification in the slab making technique and depicting
certain additional details;
FIG. 4 is a schematic elevational view depicting the assembly
preparatory to lifting a stack of horizontal floor and roof deck
slabs;
FIG. 5 is a similar sectional view depicting an arrangement for
doubling the lifting capacity as compared to the arrangement in
FIG. 4;
FIG. 6 is an enlarged side elevational view looking toward the left
in FIG. 4;
FIG. 7 is a vertical sectional detail view taken substantially
along the line VII-VII in FIG. 6;
FIG. 8 is an enlarged sectional elevational detail view of one of
the takeup nuts employed in the lifting apparatus;
FIG. 9 is a vertical sectional detail view depicting the manner in
which a horizontal slab is maneuvered in placing it on its supports
after it has been raised and released from the bottom of the
stack;
FIG. 10 is a side elevational view looking toward either the left
or right in FIG. 9;
FIG. 11 is an isometric view of a bearing yoke member employed in
the slab maneuvering device of FIGS. 9 and 10;
FIG. 12 is an isometric view of a supporting bracket used in the
slab handling device of FIGS. 9 and 10;
FIG. 13 is a schematic illustration depicting various features and
steps employed in the erection of a building pursuant to the
invention;
FIG. 14 is a schematic top plan view depicting the layout of a
typical floor slab and angular wall columns;
FIG. 15 is an isometric view showing a precast angular wall column
in course of erection;
FIG. 16 is a fragmentary top plan view illustrating placement of
grouting gaskets and shims for a wall column;
FIG. 17 is a fragmentary vertical sectional detail view taken
substantially along the line XVII-XVII of FIG. 16;
FIG. 18 is an isometric view of a steel structure angular wall
column,
FIG. 19 is a fragmentary vertical elevational view, partially in
section depicting the erected relationship of steel frame wall
columns to a floor slab;
FIG. 20 is an enlarged top plan view of one form of grouting
gasket;
FIG. 21 is a similar top plan view of a modified form of the
grouting gasket;
FIG. 22 is a fragmentary side elevational view of a grouting gasket
with an air bleed plate assembled therewith;
FIG. 23 is a top plan view of another grouting gasket arrangement;
and
FIG. 24 is a fragmentary vertical sectional detail view of a
building assembly employing the grouting gasket arrangement of FIG.
23 taken substantially on the line XXIV-XXIV of FIG. 23.
According to the present invention horizontal floor and roof deck
slabs are poured in situ one upon the other in an area entirely
free from columns so that the slabs can be poured and finished by
means of mechanical equipment on the order of that utilized for
paving and precasting of sectional and like concrete slabs which
are then transported to the building position. This is accomplished
by the elimination of building load supporting columns in the
building area. To this end, a stack of concrete slabs 25 (FIGS. 1
and 2) is successively poured in situ upon a base slab 27 of at
least the same total area and which may be a basement slab or a
ground level slab as preferred. Suitable footings 28 are provided
under the slab 27 and desirably in suitable locations to afford
base support for temporary lifting columns to be hereinafter
described. Over the footings, the slab 27 is provided at the
locations desired with respective wells 29 of adequate dimensions
to receive therein respective heavy steel foundation plates 30 each
of which rests upon a suitable elastomeric grouting gasket 31.
Column anchor bolts 32 extend up from the footing and through
respective clearance holes 33 in the plate 30 for receiving the
foot of a column.
As each of the slabs 25 is successively poured provisions are made
for accommodating slab lifting equipment. Before the first slab 25
is laid upon the base slab 27, a parting agent is coated upon the
top surface of the slab 27, and such a parting agent is coated upon
the top surface of each succeeding slab so that all of the slabs 25
will be separable. It will be understood that suitable edge forms
are also employed.
Since according to this invention the slabs 25 are not mounted on
common vertical columns, the need for attachment and lifting
collars in the slabs as in conventional construction is entirely
eliminated. Instead, each of the slabs 25 is provided with a simple
temporary lifting column clearance opening 34 aligned with the
column base well 29 and with each of the openings in the other
slabs of the stack. This greatly simplifies structurally efficient
placement of reinforcement (not shown) in the slabs.
Where, as shown, the opening 34 is of smaller horizontal
cross-sectional dimensions than the well 29, suitable removable
filler, such as rigid foam plastic commercially available as
Styrofoam, pieces 35 may be applied over the foundation plate 30 in
the overhanging area of the lowermost slab 25 to maintain the slab
thickness and to maintain the well accessible for subsequent
removal of the baseplate 30 whereafter the well may be grouted
closed or utilized for another purpose if desired.
To form the openings 34 during the pouring and finishing of each of
the slabs 25, a removable, flattop box core form 37 is desirably
employed which is mounted, for each of the slabs 25, at an
elevation flush with the intended top surface plane of the slab to
be poured so that it may also serve as a thickness gauge. Such
placement of the form 37 is desirably effected by mounting it
through respective radially extending spiderarms 38 upon the upper
ends of respective internally threaded coupling sleeves 39 which
are screwed onto the upper end portions of respective threaded stub
rods 40 resting upon respective spacer sleeves 41 which in turn
rest upon respective lifting plates 42 lying flush within the top
surface of the underlying slab and mounted to the associated stub
rod 40. Under the lowermost of the slabs 25, the lifting plate 42
is recessed within the top surface of the base slab 27 which has
respective recesses 43 accommodating the lower end portion of the
adjacent stub rod 40 and an attachment nut 44 by which the adjacent
plate 42 is secured in place on its stub rod. Preparatory to
pouring each of the slabs 25, a core plate 45 on the outer end of
each of the spiderarms 38 is aligned with a respective coupling 39
of one of the four upwardly projecting stub rods 40, with a
downwardly projecting alignment boss 47 fitting into the socket
provided by the upper portion of the coupling sleeve. Leveling of
the forming spider is easily effected by rotary threaded
manipulation of the respective couplings 39. Each of the forming or
core plates 45 is of the same dimensions as the lifting plates 42
so that after each slab has set and the core forming spider is
removed as by lifting it through a device 48 attached through a
slot 49 in the top of the mold body 37, a recess will be provided
in the top surface of each of the slabs 25 to receive the lifting
plates 42.
Where instead pouring and finishing the slabs with equipment of the
generally road paver type, the so-called conveyor bridge type of
equipment is to be used, longer tension rod sections 50 (FIG. 3)
may replace the single slab length sections 40 thus reducing the
number of pieces of equipment that need be handled. For example,
the sections 50 may be of a length to accommodate four slab
thicknesses. Where the longer sections 50 are used, the coupling
sleeves 39 need be only at the splice joints, while the nuts 44 may
be used at all other of the lifting plates 42. An approximately 3
-foot maximum upward extension of the rod sections 50 is tolerable
for conveyor bridge slab pouring. Where the rod extensions 50 are
employed, the coring mold former 37 may have openings through the
forming plates 45 thereof to receive the extensions therethrough,
instead of the locating bosses 47 previously described.
After all of the slabs 25 for a particular building structure have
been completed and are ready to be erected, namely, after the
topmost slab of the stack has been sufficiently cured, temporary
steel lifting columns 51 of preferably H-beam section are inserted
through the aligned clearance holes 34. Respective foot plates 52
rigid on the lower ends of the columns 51 are secured to the tops
of the respective baseplates 30 by means of the bolts 32 onto which
are driven retaining nuts 53. These nuts are placed by any suitable
means such as magnetic extension wrenches and tightened lightly.
The abutting surfaces of the baseplate 30 and the foot plate 52 are
desirably milled to make thorough bearing contact. Since the
baseplate 30 is floatingly supported by the elastomeric gasket 31
thereunder, the full bearing contact is assured between the plates
when the column 51 is perfectly vertically adjusted and maintained
in such adjustment as by means of suitable wedges 54 inserted
between the column 51 and the edge defining the uppermost clearance
hole 34 which is enabled because the clearance holes are of
sufficiently larger size than the beam section to provide complete
clearance about the column. After the column has been thus fixed in
its vertical orientation, grout is driven into the space under the
baseplate 30 within the gasket 31 and supports the column in full
load bearing relation upon its footing 28. Introduction of the
grout may be through a grout tube 55 delivering through a suitable
hole 57 in the margin of the baseplate 30.
After the grout under the columns 51 has set to load bearing
strength, lifting of the stack of slabs 25 as a unit may be
effected upwardly along the columns, and the arrangement is such
that the lifting is expedited to the full height of the building by
suitable floor-by-floor increments with utmost efficiency, avoiding
unduly tall and laterally unsupported columns, without any
necessity for dropping lifting rods downwardly to reach for packs
of slabs underneath previously raised slabs, and without requiring
dismounting of lifting jacks from the tops of columns in order to
mount column extensions. To this end, the columns 51 are
constructed in substantially one floor sections, being typically of
about 8feet 8 inches in length and constructed to be bolted in
alignment. Each column section 51 has on its upper end a cap plate
58 (FIGS. 6 and 7) upon which is received the foot plate 52 of a
superposed aligned column section in full bearing relation with
countersunk flatheaded bolts 59 securing the plates fixedly
together. It will be understood, of course, that there are as many
of the sectional columns as required for efficiently handling the
slab span to be lifted.
Initially there is supported on the lower end portion of the second
column section a lifting carriage 60 upon which are mounted in
balanced lifting relation a pair of hydraulic lifting jacks 61
illustrated schematically in FIGS. 4, 6 and 7 and for details of
structure and operation reference may be had to the aforesaid U.S.
Pat. No. 2,758,467. Suffice it to say that each of the jack
assemblies comprises a holding yoke 62 on which is mounted a
hydraulically operating jack unit 63 supporting a lifting yoke 64.
Depending freely through the aligned outer end portions of the
yokes 62 and 64 are threaded lifting rods 65 secured to the slabs
to be lifted and about which are threadedly engaged holding nut
assemblies 67 over the yoke 62 and lifting nut assemblies 68 over
the yoke 64. Operation of the jack unit 63 causes the lifting yoke
64 to be raised incremently such as about one-half inch in a
typical instance such that the lifting nuts 68 which have
theretofore been run down onto the yoke 64 as by means of an
operating chain 69, effect similar lifting of the lifting rods 65.
Thereupon the holding nuts 67 are run down onto the holding yoke 62
as by means of a chain drive 70. This lifting cycle is repeated
until the lifting rods 65 have raised the slabs the desired
distance.
For supporting the jack assemblies 61 in a manner to have the
supporting column assume the lifting load in an efficient, balanced
relation, the carriage 60 comprises a rugged steel frame having
respective opposite coextensive parallel sideplates extending to a
substantial length beyond the associated column 51 and slidably
engaging the side flanges of the column. Extending between and
secured to the opposite end portions of the sideplates 71 are
respective angle bar cross-frame members 72 which provide
respective right angular inwardly and downwardly facing reentrant
seats into which thrust complementary upper ends of respective
supporting brace bars 73 which have their lower ends shaped
complementary to an upwardly and outwardly facing seat or shoulder
provided by the web of the column 51 and the upper end of a
respective shoulder plate 74 fixedly secured to the web.
To enable ready shifting of the carriage 60 from the column section
to column section, the brace bars 73 are generally hingedly mounted
on the carriage. Hinging is effected in a manner to enable full
thrusting seating of the upper end of the brace bars in their
load-carrying function while nevertheless permitting relatively
free swinging of the bars into and out of the loading engagement
with the respective carriage and column seats when moving the
carriage along the column. For this purpose, each of the brace bars
73 has adjacent to its upper end aligned pintles 75 projecting
sidewardly and received in respective arcuate clearance slots 77 in
the carriage sideplates 71 dimensioned to enable swinging of the
brace bars downwardly and outwardly as indicated in dash outline in
FIG. 7, into clearance relation to the associated column. To
facilitate return to and maintenance in the column shoulder seat
engaging position, the brace bars are desirably provided with
biasing means normally urging them to swing inwardly, herein
comprising a respective counterweight 78 mounted on a rigid lever
arm 79 extending outwardly from the upper end portion of the
bar.
In the operation of the carriage 60, it is mounted on the column
assembly, initially supported on the seating shoulders of the
second column section in the assembly. All four of the lifting rods
65 are coupled at their lower ends as by means of internally
threaded coupling sleeves 80 (FIG. 3) to the upper ends of the stub
rod chains mounted in lifting relation to the slabs 25. Then, with
the holding nuts backed off from the holding yoke 62, and the
lifting nuts 68 run down firmly against the lifting yoke 64, the
jack unit 63 is actuated in unison with all of the other lifting
jacks which are similarly operatively disposed in respect to the
slab stack until the stack has been raised to the maximum height
permitted by the initial setting of the carriage 60. Schematically
FIG. 4 shows the initial phase of lifting the stack of slabs, on
comparison of the full outline and dash outline positions.
In order to enable the lifting carriage 60 to be raised to the next
higher position on the column assembly and free from the stack of
slabs, the stack is held immobile for an interim while the lifting
carriages are raised to their next position. For this purpose,
holding means are provided at each of the columns, desirably
comprising respective holding carriages 81 which in all essential
respects are identical and interchangeable with the lifting
carriages 60. Inasmuch as the lifting and holding carriages are
depicted herein as identical, the same reference numerals are
applied to the elements of the carriage 81 in FIG. 7 as applied to
the carriage 60 and it will be understood that the description of
the structure and function of the elements is identical. Since the
holding carriages 81 need function only to hold the slab stack in
the interim while the lifting carriages are elevated to new
positions, the holding carriages are permitted to ride freely on
the stack until the respective interim holding positions are
reached. As shown in FIG. 4, the holding carriage 81 is disposed in
position about the column 51 but rests upon the slab stack, being
desirably supported on suitable blocks 82 to afford clearance for
the downwardly extending brace bars 73. As the slab stack is
lifted, the brace bars 73 of the holding carriage 81 may be
permitted to idle freely along the web of the adjacent column 51.
When the slab stack has been raised as far as practicable by the
lifting carriage 60 without resetting the same, the holding
carriage 81 will have been brought into substantial alignment with
the upwardly facing shoulder provided by the foot plate 52 of the
next upper column section. To avoid any necessity for overlifting
and then dropping the stack and lifting carriage 81 down into
holding position, the holding carriage may be otherwise, such as
manually, lifted upwardly relative to the lifting rods 65 until the
brace bars 73 automatically snap into seating relation to the foot
plate shoulder under their counterweight bias. Then with the
carriage 81 supported in holding position on the column assembly,
respective holding nuts 83 are run down on the lifting bars 65
firmly against respective holding yokes 84 carried by the holding
carriage. Thereby the slab stack load is assumed by the holding
carriages 81. This frees the lifting carriages 60 for repositioning
upwardly along the column and relative to the upwardly projecting
portions of the lifting rods 65 which have been raised to a
sufficient height to be reengaged at the next higher setting of the
lifting carriage.
In order to facilitate freeing the lifting carriage in each
instance, from the lifting rods, the holding nuts 67 and the
lifting nuts 68 are preferably constructed to be freed from the
rods so as to avoid having to turn them threadedly up the rods,
although that may be done if preferred. In a convenient
construction, all of the nuts embody the construction best shown in
FIG. 8, namely each may comprise a pair of complementary split nut
sections 85, such as a standard hexagonal nut cut in half. In
operation, a complementary steel shield 87 encompasses the nut
sections and holds them in threaded engagement with the associated
lifting rod. On the upper end of the shield is a sprocket-toothed
collar 88 which is drivingly engaged by the associated drive chain.
When the carriage 60 is to be repositioned, the respective nut
shields 87 are lifted off of the associated nuts and the nut
sections 85 are removed from the associated rods 65. After the
carriage 60 has been repositioned, the nut assemblies are
reassembled for further operation. Since the split nut structure
also facilitates mounting and demounting of the nuts relative to
the lifting rods, the holding nuts 83 associated with the holding
carriages 81 may embody the same structure if desired.
After the lifting carriages 60 have been repositioned at the next
operating level resumption of the lifting cycles of the lifting
jacks may be resumed and the lowermost slab 25 in the stack is
lifted into a position to be dropped off for its chosen building
level. For this purpose the lowermost slab is raised with the stack
to an overlifted position wherein its lower face is sufficiently
high to afford clearance therebelow and above footings or the next
lower slab, as the case may be, to enable erection of load-bearing
wall columns upon the lower slab, whereafter the overlifted slab is
lowered into supported relation upon the load-bearing substructure
which has been erected thereunder while the slab has been held in
the overlifted position for headroom.
While the use of two lifting jack assemblies 61 at each column
enables lifting double the load of the customary single jack on
each column, means may be provided for again doubling the load of
slabs to be raised by the present one-shot lift method. For this
purpose, the arrangement shown in FIG. 5 may be employed wherein in
addition to the lifting carriage 60 and the two jack assemblies 61
carried thereby and operating four lifting rods 65, a second and in
this instance longer lifting carriage 89 is provided to operate in
tandem with the carriage 60. A pair of lifting jack assemblies 90
mounted on the carriage 89 have lifting rods 91 depending therefrom
and attached in lifting relation to the upper portion of a stack of
precast slabs 25, which may be of the same number as the slabs in
the lower portion of the stack to which the jack assemblies 61 are
attached through their lifting rods 65. In this arrangement the
holding carriage 81 may be of substantially the same length as the
lifting carriage 89, and supplied with four holding yokes 84' and
associated holding nuts, to accommodate all of the lifting rods 65
and 91.
For supporting each successive slab 25 when it reaches its drop-off
position, reusable apparatus is provided desirably at each of the
columns 51 to afford substantially stress-free support of the slab.
In a desirable construction this apparatus comprises a three part
separable assembly 92 (FIGS. 9--12) arranged to mounted on the
shoulder provided by the foot flange plate 52 of the adjacent
column section joint and within the vertical channel space between
the side flanges of the column. To this end, the apparatus 92
includes a generally inverted U-shaped supporting yoke bracket 93
having lower outwardly extending supporting lugs 94 and a head 95
extending inwardly on its upper end portion and engageable in
thrusting relation from below by a ram 97 of a hydraulic jack 98
arranged to be seated on the supporting shoulder of the foot flange
bearing plate 52. A slidable bearing guide is provided by filler
member 99 of inverted U-shape seated at the lower ends of its
vertical legs on the foot plate shoulder and receiving the bracket
93 slidably thereagainst and with ample clearance above the head 95
to enable a full range of operational vertical movement of the
supporting bracket 93 under the control of the jack 98.
The construction and arrangement of the apparatus 92 is such that
it can be readily installed from below the slab 25 which has been
raised to the overlift position shown in dash outline in FIG. 9.
For this purpose, the filler bearing member 99 is first inserted
upwardly into position. The supporting bracket 93 is then inserted
upwardly into position within and against the bearing member 99 and
held there while the associated jack 98 is placed upwardly into
operating position with its ram 97 supportingly under the bracket
head 95. Cushions 100 which may be of elastomeric material are
desirably interposed between the supporting lugs 94 and engage the
undersurface of the slab 25. It will be observed that for maximum
stability and stress-free operation, two sets of the slab-handling
apparatus 92 are associated with each column. Suitable hydraulic
control means are provided for operating the jacks 98 and may
comprise manual pumping and release means for each pair of jacks or
the jacks on all columns may be connected for operation in unison.
Initially the jacks 98 are operated to effect a lifting thrust on
the engaged slab 25 sufficient to enable releasing the slab from
the lifting rods 65 or 91, as the case may be, by detaching the
lifting plates 42 from beneath the slab which is now supported by
the brackets 93. Thereupon the remainder of the stack of slabs 25
above the released slab can be lifted on toward dropping off of the
next succeeding lower slab. In the meantime, supporting
substructure is erected under the stationarily held slab 25 while
the remaining slabs may continue their upward travel.
By virtue of the lifting of the total stack of floor and roof
slabs, and the freedom under the lowermost slab for building
erection activity as soon as it has reached its headroom overlifted
position, on the order of 6 inches above final position in the
building, work on the floor area under such lowermost slab can
proceed immediately and without interruption while the temporary
supporting apparatus 92 is placed on the columns, the slab is
released from the bottom of the stack and lifting of the remainder
of the stack continues. This lends itself exceptionally well to
rapid placement of prefabricated load-bearing wall columns 101 on
the floor deck or footings, as the case may be, below the
overlifted slab, whereafter such slab is lowered into supported
relation on the wall columns 101 by retraction of the jack rams 97,
to the full line position shown in FIG. 9. With the slab load thus
transferred from the holding jacks 98 to the load-bearing
substructure, the assemblies 92 can be removed for reuse. Such
removal is easily effected by removing the filler bearing members
99 upwardly, swinging the brackets 93 from the lower unloaded
position shown in dot-dash outline in FIG. 9 to clear the
supporting lugs 94 into the vertical channel of the column and pass
the slab while the bracket is withdrawn upwardly. Thereafter the
jack 98 may also be withdrawn upwardly for reuse. After each floor
slab has been mounted and the temporary or interim handling
apparatus 92 has been removed, stabilizing wedges 102 (FIG. 13)
which may be hardwood, may be driven into engagement between the
lifting columns 51 and the erected horizontal slab 25 to provide
lateral stability for the columns taking advantage of the great
lateral stability inherent in the building structure of which the
slab is now a part.
To assist in the erection of the preformed load-bearing wall
columns 101, a ground-supported crane may be used, but because of
the highly stable, large load capacity means for lifting the stack
of slabs 25 herein, a crane 103 is adapted to be mounted on the
uppermost or roof slab 25, as by bolting the same thereto. Thereby
the ground area around the building is left relatively free for
other purposes, and the top mounted crane is constantly available
for lifting materials including the wall columns 101 to each floor
space as it becomes available. On the floor on which the wall
columns 101 are to be mounted, forklift truck means or dollies may
be utilized for moving the wall columns into position.
By having the preformed load-bearing wall columns 101 of angular
shape (FIG. 14) they may set into place to be both stable and plumb
without any type of temporary bracing. After they are grouted-in
between the slabs below and above, they furnish shear walls in two
directions and make the building immediately laterally stable, up
to the level of the slab above the wall. These angular wall columns
furnish moment stiff connection at all slab supports even in the
exterior slab corners. This moment connection is provided with very
little reduction in the vertical carrying capacity of the wall
column. This result accrues from the fact that there is no bending
over a weak axis in any of the wall column units. The moment stiff
connection along exterior walls enables great savings in slab
design and greatly reduces damaging deflections in the slab and
slab edges as compared to conventional column supported slabs.
Where the horizontal slabs are supported on columns extending
therethrough as has been conventional practice, the slabs are
subjected to large peak moments at the columns and these moments
largely control the selection of the required slab thickness and
the amount of reinforcing steel therein. In post-tensioned slabs,
these conditions are even more pronounced because of the need to
carry the same steel tendon through negative and positive bending
zones from one edge of the slab to the opposite edge. By using the
angular preformed wall columns of the present invention negative
peak moments are greatly reduced and large savings in material and
labor are permitted. Another decided advantage of the angular
load-supporting wall columns is that fireproofing is substantially
facilitated and enhanced, especially where such columns are of
precast concrete as compared with conventional steel columns.
Typical arrangements of the angular wall columns 101 are
schematically depicted in FIG. 14 on a large area floor slab 25 and
demonstrate the great versatility of this mode of construction. The
great architectural design latitude as to floor plan and wall
treatment is readily apparent. Exterior walls, partitions,
enclosures and reinforcement about elevator shafts 104, stairwells
105, utility openings 107, and the like in the floor slab are
readily accommodated. Location of the temporary column clearance
openings 34 in the slab can be readily related to the predetermined
positions desired for the wall columns 101 to avoid interference
with placement of the columns and yet provide for substantially
strain-free lifting and handling of the slab in the manner already
described.
In order to secure full and uniformly distributed load bearing by
and onto the angular wall column 101 in each instance, a
three-point post assembly injected grouting arrangement is provided
for, utilizing the same general method and arrangement hereinbefore
described in respect to providing a thorough supporting base for
the temporary lifting columns 51. To this end, as shown in FIGS.
15, 16 and 17, grout-retaining elastomeric gaskets 108 are
positioned between the ends of the wall column and the confronting
slabs 25 at preferably three areas, namely adjacent the respective
opposite ends of the end edge areas and adjacent the convergence of
the end edge areas. Lead-gauging shims 109 are desirably placed
between the column edges and the slabs adjacent to but outside the
quadrangular grout gaskets 108. Such shims are of a thickness
sufficiently less than the thickness of the gaskets 108 to permit
adequate sealing compression of the gaskets, but avoiding collapse
of the gaskets beyond useful grout-receptive thickness. Grout is
then filled into the areas within the gasket under pressure to
afford a desirable density and load-bearing capacity of the set
grout. Any remaining gaps between the ends of the wall columns 101
and the slabs may be grouted or calked.
Instead of precast reinforced concrete construction for the wall
columns, a prefabricated metal angular wall column 110 (FIG. 19)
may be employed. In a typical construction, the wall column 110
comprises three substantially identical vertical posts which may be
of H-beam configuration rigidly connected together coextensively in
the preferred spaced relatively angular column outline by
horizontal bars 112 and diagonal brace bars 113. On the respective
opposite ends of the posts 111 are rigidly affixed coplanar bearing
pad flange plates 114. In mounting the metal frame wall columns
110, elastomeric grout-retaining ring gaskets 115 are interposed
between the bearing pads 114 and respective metal bearing plates
117 mounted in the confronting faces of the floor slab 25.
Respective spacers 118 are preferably disposed between the column
units 110, and within the areas confined by the gaskets 115 if
desired, and the slab 25 or other load-engaged surfaced in order to
maintain a desired depth of grout space within the gaskets 115.
After erection of the floor slabs and metal frame wall columns has
been effected, any desirable wall covering 119 may be applied onto
and over the columns and over the exposed edges of the slab 25, as
preferred
In loading grout into any of the gasket-enclosed areas under the
column base, and between wall columns and the slab surfaces, not
only are means for injecting the grout required but also means for
venting air and water to prevent formation of pockets or voids. In
one arrangement as depicted in FIG. 20, the elastomeric gasket G in
angular ring form in order to present a quadrangular enclosure for
maximum efficiency in the generally quadrangular bearing areas of
the respective load-bearing members, may be provided through one
corner thereof with a charging hole 120 provided with a semirigid,
but resilient reinforcing liner 121 to prevent collapse under
pressure and through which discharges a loading hose 122 attached
to the gasket and connected with a suitable low-pressure grout pump
or injector. Extending from within at least the remaining corners
of the gasket to the exterior are vent means comprising small
diameter bleed tubes 123. After the assembly has been completed and
the gasket placed under limited compression between the parts to be
grouted, grout is injected through the hose 122 until fluid
constituents thereof bleed from each of the bleed tubes 123 which
may be successively pinched off as the bleedout is observed, as by
means of a suitable respective clamp 124. After the gasket-enclosed
area has been filled with grout, the charging tube 122 may be
pinched off as by means of a clamp 125 to avoid regression of
fluent grout. After-the grout has set, the tube 122 may be cut off
close to the gasket G, as indicated at S.
In another arrangement, as shown in FIG. 21, the gasket loading
tube 122 may be fixed within the reinforcing lines 121 and provided
with a pressure bulb 127. As the gasket area is loaded with grout
and back pressure develops the bulb 127 expands as shown in dash
outline and, being of elastomeric material, the resiliency
maintains the grout under pressure while it is setting up and after
the tube has been pinched off as by means of the clamp 125 applied
to the loading tube outwardly beyond the pressure bulb 127.
Alternatively, bleed tubes, the gasket G may be provided with bleed
grooves 128 extending across the corner areas on at least one side
of the gasket from the inside to the outside and of such
shallowness that although air and water will be permitted to
escape, when grout material enters the grooves they will be sealed
off so that a self-sealing relationship is attained after air and
water has been ejected from the grout area.
Where it is desired to maintain positive bleed passage groove
openings even though the gasket may be liable to substantial
pressures which might prematurely close off bleed grooves in the
actual surface of the gasket, the structure shown in FIG. 22 may be
employed comprising a bleed groove plate 129 which may be made from
rigid or semirigid plastic or metal and has on its exposed surface
bleed grooves 130 while the opposite surface is engaged against and
may be compressed into the confronting surface of the gasket. If
desired the bleed plate 129 may be adhesively or otherwise secured
to the gasket. At its sides, the plate 129 may be chamfered as
shown to avoid cutting into the gasket under pressure.
Where it is desired to effect not only bearing uniformity by means
of the grout, but also to provide moment continuity, means may be
provided for distributing the grout in keying relation to the
grouted structural members. Such an arrangement is shown in FIGS.
23 and 24 wherein the gasket encompasses an area within which one
of the members has a keying recess 131 to which leads a grouting
passage 132 from the outside receptive of a grout delivery hose
133. From the other of the members there extends into the recess
131 a key projection 134 which remains in spaced relation to the
surfaces defining the recess 131 such that when grout is injected
into the space around the key and into the gasket enclosed area the
key will be set and interlock the members against lateral
displacement pressures or stresses. Additional keying may be
effected by providing the members with sleeves or aligned core
bores 135 within which a dowel 137 of smaller diameter is placed
and the grout fills into the bores and about the dowel so that a
thoroughly keyed structure results. Bleed off may be effected in a
preferred manner such as by means of bleed ducts 138 bleeding
through one or more of the building members to the outside and
which ducts are self-sealing due to their length and the relative
clogging nature of the grout material in respect to small openings.
Similar bleed ducts 139 may lead from the dead ends of the keying
bores 135. If desired, either or both of the grout delivery tubes
133 may be provided with the expansible pressure bulb 127. Further,
either or both of the delivery may be pinched off as by means of
the clamp 125 if desired to prevent regression of the grout
load.
The gaskets G may be made from any suitable elastomeric material
such as neoprene. In order to facilitate placement and retention of
the grout gaskets during handling of the building parts and
placement thereof, the gaskets may be adhesively secured to the
surface on which first mounted. For example, where the gaskets are
mounted on a slab surface, they may be adhesively secured thereto
in the desired position. Where they are mounted on wall columns,
they may be adhesively secured thereto. As delivered to the
building site, the gaskets may be provided on one surface with a
pressure sensitive adhesive and with a suitable protective cover
thereon which is stripped off before the gaskets are applied,
according to known practice in the use of such pressure sensitive
adhesively coated members.
After all of the precast slabs have been lifted to their final
locations and set upon their supporting substructures, all of the
stabilizing wedges and hardware employed in the lifting operation,
including the lifting jacks, lifting and holding carriages, lifting
rods, stub rod chains, couplings, lifting plates, lifting nuts,
intermediate holding and handling apparatus, sectional lifting
columns and their baseplates are removed from the building for
reuse at another building site.
It will be understood that variations and modifications may be
effected without departing from the spirit and scope of the novel
concepts of this invention.
* * * * *