Method and apparatus for implanting screw-in pilings or anchors in the ground

There is provided a new and useful apparatus for use in implanting a screw-in piling or anchor into the subsoil. The apparatus comprises an insertion means mounted to a skid-steer loader combined with a first load bearing measuring device to measure the load required to insert the piling or anchor and a second load bearing measuring device releasably attachable to the anchor to measure the holding strength of the piling or anchor within the subsoil.

FIELD OF THE INVENTION 
This application relates to a method and apparatus for the implanting of 
screw-in pilings or anchors into the subsoil. 
BACKGROUND OF THE INVENTION 
Screw-in pilings or anchors are required to be implanted into the subsoil 
in order to act as anchors to carry load-bearing members such as for 
drilling rigs and building foundations. Such pilings and anchors must be 
implanted into the subsoil in such a manner so as to be confident that 
they will not pull free from the subsoil under heavy load conditions. In 
fact, government regulations require that the pilings or anchors meet 
certain minimum pull-test standards once implanted, before they can be 
used. 
To that end, it is known in the prior art to test the subsoil conditions 
prior to insertion of the piling or anchor in order to estimate the 
density of the subsoil and hence, derive an estimate of the holding 
strength at that location. Reference is made for example to Canadian 
Patent No. 838,379 of Rowe and Dixon, issued Apr. 7, 1970. 
It is further known to the prior art to test the piling or anchor after it 
has been inserted to determine the holding strength of the implanted 
piling or anchor. Such a test typically involves a straight axial pull on 
the piling or anchor until the subsoil holding it gives way and it is 
released or until the force exerted on the anchor meets or exceeds the 
government requirements. Reference is made to Canadian Patent No. 
1,076,835 of Tremblay, issued May 6, 1980. 
However, such apparatus are not adapted to perform both of the above-noted 
testing functions. 
It would thus be advantageous to the art to have a single such apparatus, 
capable of testing the holding conditions of the subsoil while the anchor 
is being implanted as well as confirming that holding strength by means of 
a constant pull test on the anchor once it is implanted. Further, such an 
apparatus ought to be adaptable to operate easily over uneven terrain. 
While it is known to mount a post hole digger on a conventional skid-steer 
loader, see for example Canadian Patent No. 967,145 of Coontz, issued May 
6, 1975, such a device does not provide the testing capabilities thus 
described as desirable. 
SUMMARY OF THE INVENTION 
In one aspect of the invention there is provided an apparatus mountable to 
a skid-steer loader for use in the implanting of screw-in pilings or 
anchors into the subsoil. The apparatus comprises a means for holding the 
anchor in position for inserting into subsoil of the ground, insertion 
means for inserting the anchor into subsoil of the ground, a first load 
bearing measuring device connected to the insertion means to measure the 
load required to overcome the resistive force of the subsoil and a second 
load bearing measuring device releasably attachable to the anchor to test 
and measure the holding strength of the anchor within the subsoil. 
In a preferred embodiment of the invention, the insertion means comprises a 
device which applies an axial force to the anchor sufficient to maintain 
advance of the anchor into the subsoil and sufficient torque to the anchor 
to cause rotation of the anchor upon application of the axial force to 
allow the anchor to be inserted into the subsoil. 
In another preferred embodiment of the invention, the first load bearing 
measuring device comprises a pressure gauge to measure the pressure 
required to insert the anchor into the subsoil, those pressure readings 
then converted to axial force and torque units of measure. 
In still another preferred embodiment of the invention, the second load 
bearing measuring device comprises a hydraulic ram and a connection means 
to connect to the anchor once implanted in the subsoil, and means for 
applying a selectively incremental increasing upwards pull on the anchor 
and a device to measure the pressure being exerted upon the member, the 
pressure reading then converted to axial force units of measure. 
There is thus provided in the present invention an apparatus mountable to a 
skid-steer loader and method for the insertion of a member into the 
subsoil, to test the force required to insert the anchor and to apply a 
selectively incremental increasing force to the member once inserted in 
order to test the holding strength of the member within the subsoil.

DETAILED DESCRIPTION OF THE INVENTION 
In the following description, similar features in the drawings have been 
given similar reference numerals. 
Turning to the drawings, FIG. 1 illustrates an apparatus 10 mounted to a 
conventional skid-steer loader 12, such as a Bobcat.TM., for implanting a 
screw-in piling or anchor 14 into the subsoil of the ground 16 at a 
desired location without the necessity of pre-drilling a hole for the 
anchor 14. 
The apparatus 10 comprises a hydraulic motor 18 and a gear reduction box 20 
connected by a U-joint 22 to a drive shaft 24 which operates a hydraulic 
ram 26. The apparatus is in turn mounted on a main support frame 28, as 
generally shown at 29 and in turn mountable on to the skid-steer loader 12 
by quick-connect mounting flanges 30. 
The U-joint 22 permits rotative movement while the drive shaft 24 is 
interconnectably mounted with a pillow bearing box 32 through which the 
ram 26 passes to reduce the friction of the ram 26 within the shaft 24 
during axial movement. The pillow bearing box 32 is also connected to the 
main support frame 28 as generally shown at 33. 
The apparatus 10 is connected to the anchor 14 by connection means 34 
located at a bottom end 36 of the drive shaft 24 to attach a first end 38 
of the anchor 14 to the apparatus 10. The connection means 34 comprises 
adapter sleeve 40 mounted to the bottom end 36 of shaft 24 by means of 
bolt 41 and aperture 42. The adapter 44 fits within adapter sleeve 40 and 
is connected thereto by bolt 45 and aperture 46. The adapter 44 then 
connects to the first end 38 of anchor 14 by bolt 47 and aperture 48. The 
adapter 44 may be of different size in diameter at 50 so as to fit snugly 
within differing sizes of anchor 14. 
In use, the apparatus 10 transfers sufficient axial force from the 
hydraulic motor 18 to the anchor 14 to maintain advancement of the anchor 
14 into the subsoil of the ground 16 and sufficient torque to the anchor 
14 to cause rotation of the anchor 14 upon application of the axial force 
to allow the anchor 14 to be inserted into the subsoil of the ground 16. 
As best illustrated in FIG. 2, connected to the main support frame 28 there 
is provided an enclosure 52 for holding spare anchors (not shown). The 
enclosure 52 comprises a bottom member 54 extending normal from the main 
support frame 52 and having a pair of upstanding members 56 at an outer 
extremity 58 of said bottom member 54 and connected by a pair of cross 
members 60 extending normal thereto. There is further provided a support 
member 62 extending upwardly from said bottom member 54. A plurality of 
cross-members 64 running substantially parallel and co-planar with said 
bottom member 54 connect said upstanding members 56 with said main support 
frame 28. There is further provided a downwardly extending member 66 from 
a bottom surface 68 of said bottom member 54. For the convenience of the 
operator, there is a tool box 70 attached to the enclosure 52. 
In order to determine the axial load and torque required to implant the 
anchor 14 into the subsoil of the ground 16, there is provided a first 
load bearing measuring device 72. Said first device 72 is comprised of a 
two way pressure valve 74 connected by pressure hoses 76 to a pressure 
gauge 78 and a control valve 80. The first device is then connected by 
pressure hose 82 to an input/output valve 84 on the hydraulic motor 18. 
Thus, the pressure required to implant the anchor 14 into the subsoil of 
the ground 16 may be measured thereby allowing the operator to determine 
if the density of the subsoil of the ground 16 at that location is 
sufficient to hold the anchor 14 in place during its load bearing use. 
In use, the operator will have a target holding strength for the anchor 14 
within the subsoil of the ground 16 based on the intended load-bearing 
application of the anchor 14. That holding strength will be converted to a 
target pressure, in appropriate pressure units of measure. The anchor 14 
will be implanted into the subsoil of the ground 16 to a depth such that 
the density of the subsoil requires the target pressure be exerted on the 
anchor 14, as measured on the gauge 78, in order to meet the target 
holding strength for the intended load-bearing application. Once the gauge 
78 reaches a pre-determined amount, the operator will be confident that 
the anchor 14 is implanted to a sufficient depth within the subsoil of the 
ground 16. 
Once the anchor 14 is in place in the subsoil of the ground 16, it is a 
government requirement to ensure that holding strength of the anchor 14 
within the subsoil of the ground 16 meets or exceeds a pre-determined 
limit to confirm that the anchor 14 will be able to withstand the load 
placed upon it in use, without pulling free from the subsoil of the ground 
16. There is thus provided a second load bearing measuring device 86 on 
the apparatus 10 as best illustrated in FIG. 4. 
The second load bearing measuring device 86 comprises a hydraulic ram 88 
within a sleeve 90 having a downwardly oriented extension 92. Said 
extension 92 is connected by bolts 94 to a chain 96 having hook 98 
connected to a bottom portion 100 thereof for releasable engagement with 
the first end 38 of anchor 14. 
The ram 88 is connected by hoses 102 from an input/output valve 104 on the 
ram 88 to the pressure gauge 78 and to pressure recorder 106 and pressure 
control valve 108. 
In use, the skid-steer loader 12 lowers the main support frame 28 of the 
apparatus 10 to a position whereby the bottom platform 110 of the frame 28 
comes in contact with the ground 16 so that the surface area of said 
bottom platform 110 evenly distributes the load being exerted during the 
selectively incremental increasing upwards force on the anchor 14. There 
is provided in said bottom platform 110 an aperture 112 through which the 
anchor 14 is pulled during testing. 
In order to measure the holding force of the anchor 14 within the subsoil 
of the ground 16, the operator selectively incrementally increases the 
pressure that is applied to the anchor 14 by varying the fluid pressure 
delivered to the ram 88 by means of the control valve 108. The pressure 
being exerted is measured on gauge 78 and recorded on recorder 106 until 
such time as the anchor 14 pulls free from the subsoil of the ground 16 or 
the pressure reaches a pre-determined limit based on the known 
requirements of that load-bearing application in axial force units of 
measure, converted to pressure units of measure. The recorder 106 can be 
used to produce a chart (not shown) of pressures exerted during the pull, 
which pressures can then be converted to axial force units of measure to 
satisfy the government requirement for holding strength of the anchor 14 
within the subsoil of the ground 16 for the given application. 
The apparatus thus described and the method of using the apparatus, 
mountable to a conventional skid-steer loader, to implant a screw-in 
piling or anchor while measuring the torque necessary to do so and then 
measuring the holding force of the anchor within the subsoil of the ground 
therefore overcome many of the disadvantages of the prior art by providing 
a single apparatus which can perform all three desired functions while 
adapted to be used on rough or uneven terrain. 
Thus, it is apparent that there has been provided in accordance with the 
invention an apparatus for use in implanting screw-in pilings or anchors 
into the subsoil of the ground that fully satisfies the objects, aims and 
advantages set forth above. While the invention has been described in 
conjunction with example embodiments thereof, it is evident that many 
alternatives, modifications and variations will be apparent to those 
skilled in the art in light of the foregoing description. Accordingly, it 
is intended to embrace all such alternatives, modifications and variations 
as fall within the spirit and broad scope of the invention.