Note: Descriptions are shown in the official language in which they were submitted.
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DESCRIPTION
IMPROVEMENTS RELATING TO THE CLOSING OF MINESHAFTS
The present invention relates to a method and
apparatus for use in closing dis-used mineshafts.
A closure for a mineshaft is disclosed in my British
Patent No. 1 596 238. This closure basically comprises a
stabiliser and a minecap. The stabiliser is usually a
basket like framework which fits snugly-in the mineshaft
and which can be filled with rocks or debris, if desired,
the stabiliser plugging the shaft and reducing the
possibility of the shaft caving-in. The minecap is located
over the mouth of the shaft and may be integrall~ connected
with the stabiliser or completely separate therefrom, as required.
The above mineshaft closure has been found to be
perfectly satisfactory in all cases, though ingenuity
has had to be used in certain installations to provide a
satisfactory and stable closing of the shaft. This is
especially the case when the shaft is irregular in shape,
requiring the stabiliser to be deformed to fit the shaft
2~ and/or when the ground surrounding the mouth of the shaft
-~s soft and it is impractical to dig away the soft surround
until hard rock or strata is reached. Up until now, in
such latter cases the stailiser has been sunk down the
shaft until the rocky mouth of the shaft is reached,
and the minecap is located at some distance above the
stabiliser, on the shaft mouth formed by the surrounding
sot a,round~ In certain circumstances this can be a
difficult installation to complete perfectly satisfactorily.
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The aim oE the present invention is to provide a
mineshaft closure method and apparatus which can be
applied to all situations but which is especially
advantageous when used to close a mineshaft which lS
S surrounded by soft earth and~or which has an irregular
cross-section.
- According to the present invention there is
provided a method of closing a mineshaft comprising
the steps of securing a number o~ elongate support
members-at spaced apart locations around a mineshaft
opening with said elongate support members extending
generally radially of said mineshaft opening, and locating
- covering means on said support members to close the
shaft.
~ccording to a further aspect of the present
- invention there is provided apparatus for use in closing
a mineshaf~, said apparatus comprising a number of elongate
. support members which are adapted to each be secured to .
the ground around the mineshaft, generally radially of the
20 mineshaft, and covering means for locating over said support
members to close the mineshaft.
In a preferred embodiment of the present inven-
tion the elongate support members each comprise a main
member having a la-terally projecting stabiliser leg located
towards one end of the main member, which leg carrles a spreader
plate o~ suitable proportions. A stay is preferably
provided between the stabiliser leg and the main member
to strengthen the construction. At the other end of the
main me~ber, an acutely angled gripping section is provided so
. .30 that with the main members located on the top o~ soft flat
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ground surrounding a mineshaft, the gripping section is
embedde~ in the ground and the stabiliser leg projects
down the mineshaft with the spreader plate against the
wall of the mineshaft. Preferably a stabiliser member
is secured to the main member and prevents the main member
from rolling, the stabiliser member extending laterally
to either side of the main member, substantially at ri~ht
angles to the gripplng section and the stabiliser leg.
Each support member preferably extends
substantially to the central region of the mineshaft
and in the case of large dlameter mineshafts, preferably
two or more of the support members are bolted together
in the central region of the mineshaft. Further the
support members-are preferably embedded in concrete to
- 15 sec~re them in position.
- Whilst the support members are preferably
made of steel of any desired transverse cross-section,
the support members may alternatively be made of rein-
forced concrete~or a combination of concrete and steel.
With the support members in position extending
- generally radially of the mineshaft, covering means,
preferably in the form of one or more concrete slabs, are located on
top of the support members to close off the mineshaft.
Ihe weight of the or each concrete slab is supported by the
support members by virtue of the spreader plates
engaging the wall of the mineshaft and the ~ripping
section gripping in the soft surrounding earth. Whilst
the spreader plate may be weldPd to -the stabiliser leg,
` ~ ~ it may alternatively be bolted and/or adjustable on
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the stabiliser leg to allow for adjustment dependent
upon the nature of the shaft wall e.g the spreader plate
position can be adjusted to avoid a projecting stone.
Any alternative suitable covering means can
of course be used and to improve the construction, a
minecap, preferably in the form disclosed in my British
Patent Specification No. 1 586 238, can be installed in
the mouth of the mineshaft under the support members,
the minecap being carried on adjustable feet carried by
1~ the stabiliser legs. The minecap, when used, is covered
with an expanded steel mesh, concreted over, which thus ~orms a
dome-shaped plug which further st~hi~ s the mouth of the
shaft, reducing the possibility of a cave-in.
: To allow for subsequent access to the shaft
the covering means and minecap can easily be provided
with a manhole.
The present invention will now be further
described, by way of example, with reference to the
- accompanying drawings, in which:-
Fig.~l is a perspective view of a preferred
- embodiment of a support member for use in the present
invention;
Fig. 2 is a vertical cross-sectional view of
part of a mineshaft illustrating the support member
of Fig. 1 in the installed position;
Fig. 3 is a plan view of a minesha~t with a
single support member in position in accord with the present
invention; and
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Fig. 4 lS a similar view to Fig. 2 with a
minecap in position in the mouth of the shaft.
A support member 1 for use in the present
invention is illustrated in the accompanying drawings.
The support member 1 comprises an elongate main member 3
from one end of which depends a gripping section S which
i5 angled acutely to the main member 3. Towàrds said
o~e end of the main member is a stabiliser member 7
which extends laterally to each side of the main member
3 and at right angles to said gripping section 5.
Towards the other end of the main member 3, a stabiliser
leg 9 depends and carries a spreader plate 11. The
spreader pla~e 11 may be welded to the stablliser leg 9,
bolted thereto or attached thereto in some other way.
Further, the spreader plate ll can be adjustable on the
stabiliser leg 9. A stay 13 extends between the stabiliser
leg 9 and the main member 3 to strengthen the construction.
Whilst the illustrated support member 1 is
made of steel of channel cross-section, the support member
can alternatively be made of steel of any other suitable
transverse cross-section, or reinforced concrete, or
a combination of steel and concrete.
In use, as shown in Figs. 2 and 3 of the
accompanying drawings, the support members 1 are each
arranged generally radially of the mineshaft M with the
spreader plate 11 engaging against the mineshaft wall W
and the gripping section 5 embedded in the soft ground
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surrounding the mineshaft M. In this position, the stab-
iliser member 7 lies flat on the ground and prevents the
support mem~er from twisting. If required, the surrounding
ground can be dug away and filled with concrete to thus
embed the support member in concrete. Further, if the
spreader plate 11 is adjustable on the stabiliser leg 9,
the position of the spreader plate can be adjusted to
select the best part of the mineshaft wall W, against
which it will en~age e.g. projecting stones can be
avoided.
As shown in Fig. 3, the support members 1 each
extend to approximately the central region of the mineshaEt
and in the case of a large diameter mineshaft, the free
- end regions of two or more support members can be
connected together e.g. they can be bolted to an
interconnecting plate (not shown).
With the support members 1 in position like
the spokes of a wheel, the ~.ineshaft M can be closed by
placing covering means thereover i.e. ~y locating a slab or slabs
15 of concrete on the support members 1. The support
members 1 take the weight of the concrete slabs 1 as the
spreader plates 11 press against the mineshaft wall W
and the acutely an~led gripping sections5 grip the
surrounding earth.
To further enhance the mineshaft closure
a minecap 17 ~see Fig. 4) preferably constructed as
per my British Patent Specification No. 1 586 238,
is located on adjustable feet 19 on the stabiliser
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legs 9, within the mouth of the mineshaft M. The
minecap 17 is then covered with expanding steel mesh
forming a dome shaped plug covered with concrete, which
further stabilises the mineshaft reducing the likelihood
of a cave-in.
To allow for future access to the mineshaft M~
manholes can be simply provided in the covering means
e,g. concrete slabs 15.
The pres~nt invention thus provides a slmple
method and apparatus for closing a mineshaft. Whereas
the mineshaft closure as disclosed in my British Patent
Specification No. 1 586 238 has to be custom built
to the shape of a particular mineshaft, and is best
suited to regular shaped e.g. circular, rectangular
etc, mineshafts, it makes no difference with the present
invention, what the shape the mineshaft takes. The
mineshaft can be as irregularly shaped in horizontal
cross-section, as is conce~vable and the present
invention will satisfactorily close off the shaft. Also
~ e present invention is especially advantageous on
soft ground areas.
