Note : Les descriptions sont présentées dans la langue officielle dans laquelle elles ont été soumises.
203~041
S DEVICE FOR RAISING AND SUPPORTING
THE FOUNDATIONS OF A BUILDING
BACKGROUND OF THE INVENTION
1. Field of the invention:
The present invention relates to a device
capable of raising the concrete foundations of a
building and of supporting these foundations after
they have been raised. The device according to the
invention is particularly useful to stabilize snagged
concrete foundations.
2. Brief description of the prior art:
Buildings such as houses are usually
constructed on concrete foundations. Such foundations
generally comprise a footing on which is erected a
vertical foundation wall.
After a building has been erected, the
soil conditions may change, causing the foundations to
sag. This may in particular be caused by settling of
the soil. Unless the situation is rapidly corrected,
this may cause major damages such as cracks or
fissures in the concrete footing, in the foundation
wall as well as in the exterior brick covering. Also,
the floors and walls of the building are no longer
horizontal or vertical.
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An example of prior art apparatus for
raising and supporting sagged building foundations is
described in United States patent No. 4,673,315 (SHAW
et al.), granted on June 16, 1987.
This prior art apparatus comprises a
lifting arm assembly for supporting the foundations.
The latter assembly includes an L-shaped bracket with
an horizontal portion applied to the underside of the
footing. The lifting arm assembly also comprises a
vertically oriented sleeve in which a cylindrical
tubular pile is disposed and can slide longitudinally.
The apparatus of United States patent No.
154,673,315 also comprises a clamping assembly including
an outer ring concentric with the pile and surrounding
the same. The clamping assembly is positioned on the
pile above the lifting arm assembly.
20The lifting and clamping assemblies are
interconnected by a pair of diametrically opposed
hydraulic cylinders.
In order to drive the pile into the soil,
three inner arcuate inserts are interposed between the
inner surface of the outer ring and the outer surface
of the pile. These inserts are tapered in a vertical
direction so that upon retraction of the hydraulic
cylinders they will grab, or engage, the pile to drive
it into the soil and, when the lower end of the pile
has reached soil of sufficient hardness, to raise the
lifting assembly and accordingly the foundations. As
the cylinders extend, the inserts slide over the pile.
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One skilled in the art can appreciate that
the ring and inserts of the clamping assembly of
United States patent No. 4, 673,315 operate
satisfactorily only with a pipe having a generally
cylindrical geometry. Piles with other cross
sectional shapes cannot be utilized.
OBJECT OF THE INVENTION
An object of the present invention is
therefore to eliminate the above discussed drawback of
the prior art by replacing the clamping assembly of
United States patent No. 4, 673,315 with an assembly of
articulated jaws suitable for use in particular but
not exclusively with a pile of rectangular cross
section. These jaws pivot to enable the assembly to
slide upwardly on the pile but to grasp that pile when
a downward force is applied to the assembly in order
to drive the pile into the ground.
SUMMARY OF THE INVENTION
More specifically, in accordance with the
present invention, there is provided a device for
raising and supporting the foundations of a building,
comprising:
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an elongated, generally vertical tubular
pile having a generally rectangular cross section and
a lower end;
a lifting assembly secured to the
foundations of the building for supporting these
foundations as they are raised and after they have
been raised, the lifting assembly comprising pile
guiding means for slidably receiving the pile and for
guiding longitudinal movement of the pile;
a jaw assembly comprising (a) a rigid
frame embracing the pile and being longitudinally
slidable on that pile, (b) two jaws disposed on
respective opposite sides of the pile, each jaw having
(i) a proximate end distant from the pile and
pivotally mounted on the rigid frame, and (ii) a
distal end lower than the proximate end and defining
an anti-slip surface contacting the pile, (c) means
for urging the distal ends of the jaws upwardly to
thereby force the anti-slip surfaces against the pile,
and (d) means for limiting upward pivotal movement of
the distal ends of the jaws; and
a plurality of extendible and retractable
hydraulic cylinders interconnecting the lifting
assembly and the rigid frame for (i) applying an
upward force to the rigid frame in order to slide both
the rigid frame and the jaws upwardly on the pile, or
(ii) applying a downward force to the rigid frame
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whereby these jaws grasp the pile to drive the pile
into the soil and, after the lower end of the pile has
reached soil of sufficient hardness, to raise the
lifting assembly and accordingly the foundations.
After the foundations have been raised at
the desired level, the pile guiding means of the
lifting assembly and the pile, advantageously both
made of steel, can be welded together to stabilize the
foundations.
The objects, advantages and other features
of the present invention will become more apparent
upon reading of the following non restrictive
description of a preferred embodiment thereof, given
by way of example only with reference to the
accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
In the appended drawings:
Figure 1 is a perspective view of a
preferred embodiment of a foundations raising and
supporting device in accordance with the invention,
comprising a pile, a lifting assembly, a jaw assembly,
and a pair of hydraulic cylinders;
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Figure 2 is an exploded, perspective view
of the pile of the device of Figure 1;
Figure 3 is a rear, perspective view of
the lifting assembly of the device of Figure 1; and
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Figures 4 and 5 are respectively front
elevational and side elevational views of the jaw
assembly of the device of Figure 1.
DETAILED DESCRIPTION OF l~E PREFERRED EMBODIMENT
As partially illustrated in Figure 1,
conventional foundations of houses and other buildings
are made of concrete and comprise a footing 2, a
foundation wall 3 and a concrete floor 4. The
foundation wall 3 is vertical and erected onto the
footing 2, and the floor 4 covers the entire surface
delimited by the foundations walls 3.
A foundations raising and supporting
device in accordance with the present invention,
generally identified by the reference numeral 1 in the
appended drawings, comprises a lifting assembly 5, a
pile 6, a jaw assembly 7, and a pair of hydraulic
cylinders 8 and 9.
The structure of the pile 6, made of
steel, is illustrated in Figure 2. It comprises pile
sections such as 10 and 11, generally square in cross
section.
A head 12 includes a point 13 in order to
facilitate driving of the pile 6 into the soil, and a
tubular section 14 also square in cross section and
dimensioned to fit in the lower end of pile section
10. When tubular section 14 has been placed into the
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lower end of the pile section 10, the head 12 and pile
section 10 are welded together.
As the pile 6 is driven into the soil,
lengthening of this pile can be required to reach hard
soil. A steel insert 15, square in cross section, is
then used. This insert 15 comprises a first tubular
section 16 dimensioned to fit into the upper end of
the pile section 10, and a second tubular section 17
fitting into the lower end of the pile section 11.
Sections 16 and 17 are separated from each other by an
outer flange 18 on which the corresponding ends of the
pile sections 10 and 11 abuts. When the tubular
sections 16 and 17 have been introduced in the pile
sections 10 and 11, respectively, these sections 10
and 11 are both welded to the flange 18 of the insert
15. If required, other inserts such as 15 and other
pile sections such as 11 can be used to further
lengthen the pile 6.
As can be appreciated by one skilled in
the art, the square cross section of the pile 6
increases its stiffness. The cross section area of
the pile 6 can accordingly be substantially reduced.
Although the preferred embodiment of the
present invention uses a pile 6 with a square cross
section, it is within the scope of the present
invention to use piles having generally a rectangular
cross section.
As illustrated in Figures 1 and 3 of the
appended drawings, the lifting assembly 5, made of
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steel, comprises a vertical and tubular member 19
substantially square in cross section. The pile 6
snugly fits into the tubular member 19 but is free to
slide longitudinally therein.
A pair of angle irons 20 and 21 are welded
to the outside of the tubular member 19 on opposite
sides thereof. These angle irons each comprise a
planar portion 20' and 21' lying into a common plane.
These portions 20' and 21' are provided with holes
such as 22 through which the lifting assembly 5 is
bolted to the concrete on the outside of the
foundation wall 3 and/or footing 2. Figure 1 shows
expansion bolts such as 23 anchored in the concrete to
secure the assembly 5 to the foundation wall 3 and/or
footing 2.
The lifting assembly 5 further comprises
two horizontally extending steel bars 24 and 25. The
bar 24 has a proximate end welded on the same outer
face of the tubular member 19 as angle iron 20, while
bar 25 has its proximate end welded on the outer face
of the tubular member 19 on which iron angle 21 is
itself welded. As can be seen, the distal end of the
steel bars 24 and 25 are beveled to facilitate
insertion of the lifting assembly under the footing 2.
The lifting assembly finally comprises an
horizontal and rectangular steel plate 27 welded onto
the top edge surface of the bars 24 and 25.
As illustrated in Figure 1 of the appended
drawings, the angle irons 20 and 21 are secured to the
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outside of foundation wall 3 and/or footing 2 through
the bolts 23, with the plate 27 applied against the
underside of the footing 2 in order to support the
foundations upon and after raising thereof. Grout can
be added to closely fit the lifting assembly on the
foundations. Better stabilization of the foundations
is thereby obtained.
As illustrated in Figures 1, 4 and 5, the
jaw assembly 7 comprises a pair of parallel and
rectangular steel plates, namely a front plate 28 and
a rear plate 29. The spacing between the plates 28
and 29 is adequate to enable sliding of the pile 6
between them. The plates 28 and 29 are also secured
to each other by means of lower steel shafts 30 and 31
welded to the plate 29 but bolted to the plate 28 (see
the axial bolts 56 and 57 in Figures 4 and 5). The
corresponding end of the shafts 30 and 31 are reduced
in diameter and received in a cylindrical cavity
formed in the inner face of the plate 28 (see 60 in
Figure 5). The bolts 56 and 57 each traverse a hole
in the plate 28 and are each screwed into a threaded,
axial bore in the end of the corresponding shaft 30
and 31 (see 61 in Figure 5). This type of assemblage
is well known in the art and accordingly will not be
further described. Again the spacing between the
shafts 30 and 31 is adequate to enable sliding of the
pile 6 between them.
Welded to the top edge surface of the
plates 28 and 29 are transversely and horizontally
extending steel bars 32 and 33, respectively. The
bars 32 and 33 are interconnected by means of a pair
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of end steel shafts 36 and 37 perpendicular to these
bars. The shafts 36 and 37 are welded to the rear bar
33 but traverse respective holes in the front bar 32
and are attached to this front bar 32 by means of pins
58 and 59, respectively. The pile 6 is of course
capable of sliding between the steel bars 32 and 33.
As can be appreciated, the bolts 56 and
57 and the pins 58 and 59 enable dismantlement of the
jaw assembly 7.
A first jaw 34 comprises a pair of
parallel flat steel arms 38 and 39 having a proximate
end pivotally mounted on the shaft 36. The jaw 34
also comprises a distal end comprising a steel plate
40 welded to the arms 38 and 39 and provided with a
anti-slip convex surface 41. The surface 41 prevents
downward slippage of the jaw 34 over the outer surface
of the pile 6. A pair of aligned cylindrical members
such as 42, respectively welded to the inside of the
bars 32 and 33, extend between these two bars and
limit pivoting of the jaw 34 in the direction 43. A
coil spring 45 however forces the surface 41 of the
jaw 34 on the pile 6.
A second jaw 35 comprises a pair of
parallel flat steel arms 46 and 47 having a proximate
end pivotally mounted on the shaft 37. The jaw 35
also comprises a distal end comprising a steel plate
48 welded to the arms 46 and 47 and provided with a
anti-slip convex surface 49. The surface 49 prevents
downward slippage of the jaw 35 over the outer surface
of the pile 6. A pair of aligned cylindrical members
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such as 50, respectively welded to the inside of the
bars 32 and 33, extend between these two bars and
limit pivoting of the jaw 35 in the direction 51. A
coil spring 52 however forces the surface 49 of the
jaw 35 on the pile 6.
The lifting assembly 5 also comprises a
bracket 54 welded on the face of the tubular member 19
on which the angle iron 20 and the steel bar 24 are
themselves welded. The lifting assembly 5 further
comprises a bracket 55 welded on the face of the
tubular member 19 on which the angle iron 21 and the
steel bar 25 are themselves welded.
The hydraulic cylinder 8 has a lower end
formed with a pair of clevises such as 65 and 65 " for
pivotally connecting this lower end to the bracket 54
through a pin, and an upper end pivotally mounted on
the shaft 36 between the arms 38 and 39. The
hydraulic cylinder 9 also has a lower end formed with
a pair of clevises for pivotally connecting this lower
end to the bracket 55 through a pin, and an upper end
pivotally mounted on the shaft 37 between the arms 46
and 47.
In order to install the device according
to the invention, the area close to the foundations
which corresponds to the position of this device is
first excavated to evacuate the soil and enable the
installers to access the foundation wall 3 and the
underside of the footing 2. The upper face of the
steel plate 27 of the lifting assembly 5 is then
applied against the underside of the footing 2 and the
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iron angles 20 and 21 are secured to the foundation
wall 3 and/or footing 2 by means of the expansion
bolts 23 mounted into holes drilled in the concrete.
It may be required to trim or cut the outside and
5 underside of the footing 2 so that this footing
defines with the foundation wall 3 a right angle
adequate to receive the lifting assembly 5 as
illustrated in Figure 1. As mentioned in the
foregoing description, grout can be added to closely
10 fit the lifting assembly 5 on the footing 2 and
foundation wall 3.
After the lifting assembly has been
positioned as described above, the pile 6 is slid into
15 the tubular member 19 until its point 13 reaches the
soil. The jaw assembly 7 is then assembled onto the
pile 6 above the lifting assembly 5 by means of the
bolts 56 and 57 and the pins 58 and 59, while the said
lifting 5 and jaw 7 assemblies are interconnected by
20 means of the cylinders 8 and 9. These hydraulic
cylinders are of course supplied with pressurized
fluid by means of a pump (not shown) in accordance
with conventional techniques.
With the pump, the cylinders 8 and 9 are
simultaneously operated, that is both alternately
extended and retracted. As the two cylinders extend,
an upward force is applied to the jaw assembly 7 and
the surfaces 41 and 49 of the jaws 34 and 35 slide
upwardly over the pile 6. On the contrary, as the
cylinders 8 and 9 retract, the springs 45 and 52 urge
the distal ends of the jaws 34 and 35 upwardly to
force the anti-slip surfaces 41 and 49 on the pile 6
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13
whereby these jaws grasp the latter pile to drive the
pile in the soil. The members 42 and 50 prevent
excessive upward pivotal movement of the distal end of
the two jaws.
By alternately extending and retracting
the hydraulic cylinders 8 and 9, one can easily drive
the pile 6 into the soil until its point 13 reaches
hard soil. After the point 13 has reached soil of
sufficient hardness, further retraction of the
hydraulic cylinders raises the lifting assembly and
accordingly the foundations. After stabilization of
the pile 6, that is after the pile 6 can support the
foundations at the desired level without being further
driven into the soil, the pile 6 is welded to the
tubular member 19 whereby the foundations are
supported and stabilized by the driven pile and
lifting assembly. In order to reach stabilization,
the point 13 of the pile 6 should obviously reach a
soil of adequate hardness. The cylinders 8 and 9 and
the jaw assembly are then disassembled and can
subsequently be used to raise other foundations. The
section of pile remaining above the tubular member 19
can of course be cut if desired or required.
By distributing foundations raising and
supporting devices as illustrated in Figures 1-5 in
the periphery of sagged building foundations, such
foundations can be easily and adequately raised and
supported and therefore stabilized. It should however
be kept in mind that the different devices must be so
operated as to raise and support the entire
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14
foundations or the entire portion thereof that must be
raised and supported.
When the foundations have been raised, are
supported by the devices in accordance with the
invention and are stabilized, the space between the
soil and the so raised concrete footing and floor such
as 2 and 4 in Figures 1 is filled with concrete.
The excavated area around each device can
then be filled with soil to complete the procedure.
Although the present invention has been
described hereinabove by way of a preferred embodiment
thereof, such an embodiment can be modified at will,
within the scope of the appended claims, without
departing from the spirit and nature of the subject
invention.
