Note: Descriptions are shown in the official language in which they were submitted.
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The present inventi.on relates essentially to a ground-
injection or grouting closing or stopper device adapted to temp-
orarily close or plug in substantially sealing relationship a
bore-hole or drilling hole to enable a forced injection of a
fluid under pressure and in particular injection of a plugging,
choking, clogging, blocking, blinding or like grouting liquid
capable of .setting or to hardening into the lower or bottom
portion of said bore-hole.
In the field of civil engineering the issue of stability
of the ground on which it is desired to erect a building or like
construction and more particularly the problem of reinforcing
or stiffening some underground areas exhibiting a number of rifts,
rents or like clefts or cracks is often raised. Reinforcing of
such cracked areas is achieved by carrying out one or several
borings or drillings into the ground down to said area and by
injecting thereinto a settable or hardenable grouting or plugging
li~uid or like clogging or.choking fluid. It is however necessary
to inject such a plugging or grouting liquid under pressure so
that the latter may flow into and close or seal all and any
cracks communicating with the lower portion of the bore-hole.
Such a forced injection therefore requires the provision at some
level located slightly above:the.cracked area of a temporary
closing or sealing means through which the grouting or plugging
liquid under pressure will flow longitudinally and preventing
the latter from rising up to .the ground surface instead of flowing
int~ the cracks.
The present invention provides an injection closing
device adapted to be secured at the end of a main injection pipe
which comprises a substantially straight pipe section or element
through which a fluid to be injec.ted may be caused to flow, a
single-acting annular power ram-like linear actuator the movable
part of which is axially slidable along the outside wall of said
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pipe section and at least one sidewise deformable or expandable
ring-shaped sealing or packing member fitted in coaxial relation-
ship about and along the outer wall of said pipe section between
said movable part and a stationary stop or like abutment fixedly
attached to or integral with said pipe section.
The annular actuator is connected to a source or supply
of pressure fluid located at the ground surface through a separate
pipe-line or duct and said pressure source for operating or feeding
said actuator may be of hydraulic or pneumatic character.
The present invention will be further illustrated by
way of the accompanying diagrammatic drawings in which:
- Figure 1 illustrates the use of an injection closing
means according to one embodiment of the invention during the
operating step of injecting a plugging or grouting settable liquid
into a cracked subsoil or like substratum;
- Figure 2 is a sectional view showing the injection
closure device proper drawn on a larger scale, the annular power
ram-like actuator being not operated; and
- Figure 3 shows the same closure device when the
operating pressure fluid is filling the working chamber of said
actuator.
In the accompanying drawings, the injection closure
device 11 is adapted to be secured at the end of a main rigid
or flexible injection pipe 12 through which the settable or
hardenable plugging or grouting liquid 13 is fed into the lower
portion or bottom of a bore-or like drilling hole 14. The
injection closure device 11 comprises at its top or upper end a
screw-threaded portion 15 to enable the connection with the pipe
12 so that said injection closure device 11 forms the terminal
nipple or nozzle end of the main pipe 12. The closure device 11
comprises of a substantially straight pipe section or element 16
provided in extension of the main pipe 12 in substantially aligned
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registering relationship therewi.th and inside of which the
settable li~uid may flow, an annular power ram-like linear act-
uator 17 and three ring-shaped sealing or packing members 18, 19
and 20. The actuator 17 is of single acting type and its movable
part 2I is according to this embodiment provided by the actuator
casing or body which is sl.idable in substantially coaxial relation-
ship along the outside wall 22 of the pipe element 16 whereas the
piston 23 of said actuator is stationary with.respect to that
pipe element due to the~provisi:on of a ring-shaped abu:tment or
stop means 24 thereof whi:ch co-operates with.an inner shoulder
25 of the piston 23. The movable part 21 extends downwardly
beIow the working chamber 26 of the actuator in the form of a
sleeve promoting the sliding motion along the outer wall 22.
Two sliding sealing joints or li~e grummets or gaskets 27. and 28
are provided between the movable part 21 and the pipe element 16
whereas another sealing joint or ring 29 provides for the fluid-
tightness between the movable part 21 and the piston 23. Longit-
udinally extending through the latter is a duct or passage-way 30
providing communication between the working chamber 28 of the
actuator and a second pipe-line 31 connected at the ground sur-
face to a pressure source 32.: The:three annular sealing or pack-
ing members 18, 19 and 20 are mounted in coaxial relationship
along the outer wall 22:or.the pipe element 16 between said
movable part 21 and a stationary stop or abutment member 33
screwed onto the bottom portion of the pipe element 16. TheSe
sealing or packing members which are sidewardly deformable or
expandable under the action of the actuator 17 in the manner
shown in Figure 3 are separated or spaced from each other by
spacing washers 34 and 35, respectively. As clearly appearing
from the drawings the various:components of the closure device 11
are.sized and designed so that its general shape at rest be
substanti:ally cylindrical, and in particular the movable part 21,
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the sealing members 18, 19 and 20.at rest and th~ washers or
spacers 34 and 35 have the'same diameter, and they may be inserted
without any difficulty into. the:b~re'hole 14. The:sealing
packing members 18, 19 and 20 consist of a prefer:ably resiliently
deformable homogeneous stuffing material such as rubber for
instance.
The operation of the injection closure device 11 is
as follows.
. The closure dev.ice 11 is secured to the end of the main
pipe 12 and the pressure source'32 is connec.ted to .the ram-like
actuator 17 through a pipe-l:ine'3I. The closure'.devi.ce 11 is then
inserted into the'bore-hole'14 and'moved down to a level posit-
ioned slightly above the cracked area. At that time:the fluid
for operating the actuator 17 is fed into the working chamber
26 and the closure device 11 as:sumes the shape shown in Figures
1 and 3. The resistance of the sealing packing members 18, 19
and 20 and.the press-ure for operating the actuator 17 are such
that a perfect fluid-tightness is obtained betwe,en the closure
devi.ce ll and the wall of the'drilling hole 14. The settable
or hardenable'plugging li~uid 13 is then injec.ted under pressure
into the cracked area through:the pipe 12 and the pipe element
16. At the end of the pro.cess, the pressure is reIeased within
the actuator 17 and the closing device 11 ass'umes again its
initial shape. It is then withdrawn or removed from the bore-
ho.le 14. As clearly appearing from Figure 3 the provision of
sereral sealing packing members separated by spacer washers
between the actuator 17 and the abutment 33 enables to achieve
a certain distribution of the contact areas between the closing
device and the inner wall of the bore-hole 14 thereby improving
the~adhesion and resistance of the closing device undergoing the
thrust of the injection li~uid.
