Rajiv Gandhi College Of Engineering, Research & Technology
PRESENTED BY :
SUNIL D. WASADE
Prof. B.K. KHADE
Dr. M.D. Uttarwar
U/G & O/C Comparison
Deepening And Widening Of Shaft
Special Methods Of Shaft Sinking
1. Wood/Steel Piling
2. Open Caisson
3. Cementation Process
4. Freezing Process
Advanced Techniques In Shaft Sinking
1. VSM – Vertical Shaft Sinking Machine
2. Shaft Boring System
3. Shaft Boring
In India, “MINING” industry is the backbone of India’s economy and
energy. After agriculture mining is the second most important industry on
which India’s economy is depend. Which helps in growth of any country
in every aspects, because all existing industries are depend on mining.
There is none of the industry which will replace to mining industry.
Mining remains the most important player in the Indian industry, as well
as Indian economy, Mining industry plays an important role in the
development of nation.
For underground mining working access should be very
precious and reliable. There are many other access but most reliable
option one access to excavate deep seated mineral body, that term is
called as SHAFT. There is no other access existing which can replace
shaft. So we will have to go through shaft. And for better shaft reliability
we have to sink in better ways, that’s why SHINKING is very important.
But there are many things would be considered. Then we can make
Speedy and economical shaft sinking operation depends upon
not only on actual sinking speeds but to a great extent also on the
planning of the number and the size of the shaft of the hoisting
equipment. the shaft sinking with permanent winding equipment offers
some advantages due to the fact that in this case the transition from
shaft sinking to tunneling requires less time and that in case the
transition from shaft sinking to tunneling requires less time and that it is
possible to dispense with the expenditures on the installation and
dismantling of temporary equipment.
Mechanical excavation methods are a step change in
excavation performance and labour safety compared to drill and blast
operations. In hard rock conditions, road headers cannot be used
effectively, so disc cutting is the first
For excavation of declines, tunnel boring machines (TBM) can
be used in many cases. These provide, in certain rock conditions,
considerably higher production rates compared to drill and blast
excavation. Vertical shaft sinking machine (VSM) that allows
excavating shallow shafts in soil a medium soft rock.
OPENCAST AND UNDERGROUND
DEEPENING OF EXISTAING SHAFAT
• A regular coal winding shaft 6.0 m in
diameter has to be deepened to touch the
bottom seam 100 m below without affecting
normal winding operations.
• 1. Electric winding engines 2
• 2. Hoisting sheaves 2
• 3. Sinking buckets 3
• 4. Single tub cage 1
DEEPENING OF EXISTAING SHAFAT
• 5. Tubs
• 6. Jack hammer 6
• 7. Pneumatic picks 4
• 8. Pneumatic face pumps 2
• 9. Electric pump
• 10. Platform with folding doors for shaft top
• 11. Shuttering for concreting
• 12. Pipes, cables, ropes etc.
• Small shaft “A” is sunk near the coal winding pit on the side, away
from main haulage level. Head room is made for installation of
winding sheaves of the hoist “E”. The depth should be enough to
reach beyond the sump of old shaft, cross the safety rock plug “p” and
allow sufficient head room for the installation of the sheaves of
second hoist is driven.
• Level road way “L” to the position on shaft deepening. The place is
widened and heightened for installation of winding engine “H” its
sheaves and other equipment. Additional hoists are installed for
carrying the suspended sinking equipment.
• The shaft center is marked accurately by correlation through the shaft
“A”. The perimeter to be excavated is marked on the rock surface.
• After deepening the shaft to some depths the platform with folding
doors is installed at its mouth.
• Sinking proceeds in the normal manner. The rock from sinking
buckets is dumped into mine tubs and hauled up through shaft A. The
debris can be packed into underground galleries or hoisted to surface
through the main winding shaft for disposal.
• On completion of sinking plug P is removed in sections.
WIDENING A SHAFT
• WIDENING A SHAFT USED FOR COAL WINDING:
In this case entirely different procedure must be
adopted, one of the essential items of equipment being a
strong cylindrical steel shield which fits inside the old shaft and
does not interfere with the travel of the cages.
• PRELIMINARY WORK
Sufficient ground at the surface must first be excavated
behind the old shaft walling down to the depth of say 30 m to
enable a concrete wall 1m thick and 6m internal diameter to be
erected all around the shaft. This wall should be founded on
steel girders and provided with pockets with receives other
girders for the support of existing pit-top frame, receiving
• The next step is to erect a strong platform on
girders at the depth of 3.6m and to widen the
shaft to this depth, the debris being raise to the
crab engine and kibble. The platform then
removed and re-erected at the depth of 6m., the
shaft being widened to this depth in similar way.
The widened shaft should be supported
temporarily by steel ring and backing deals, the
first ring being hung from the girders at the base
of the concrete walling is built up and the platform
removed all together.
• All this preliminary work is necessary to enable
the protecting shield walling platform to be
installed in the shaft.
SPECIAL METHODS OF SHAFT
1. Wood/Steel Piling
2. Open Caisson
3. Cementation Process
4. Freezing Process
This method is known as simply PILLING or SHEET
PILLING and is suited sinking through loose deposit of sand
, mud,or alluvium near the surface upto a depth of 20 m.
Interlocking steel pile, 6m to 10m long,are used and they
are practically water-tight. Additional length may be
available by welding or riveting2 or 3 lengths of pile.
The surface, the piles are setup to from a ring and then they
are hammered down in rotation, each member being driven
a few meter at a time by adirect acting state piling hammer.
As the pile descent in the lose ground, the latter,enclosed
by the piles is excavated and cleared up, but it should be
remembered that the bottom ends of the piles are kept
sufficiently ahead of the excavation to prevent.
Inrush of water are loose sand. When the excavation
reaches strong rock, permanent lining is constructed and
the sinking then proceeds in the manner describe for normal
a) Wood/Steel Piling
b) Open Caisson
In this method the
shaft is started by
excavation and placing
a cutting shoe on the
bottom of the pit. The
ground inside and just
under the shoe is
excavated and the
lining is built up as the
c) Cementation Process
Cavities and fissures
are filled with quick-
setting cement under
high pressure then
allowed to set. Cement
pumps are designed
for pressure as high as
6kgf to 300kgf.
This method is use in
d) Freezing Process
This method was first used in 1883. The wet round is artificially frozen
and then blasted and excavated as though it were solid rock. From 20 to
50 holes are drilled on the circumference of a circle. Circulating pipes are
placed in the holes and a calcium or magnesium chloride solution is
pumped through the pipes to freeze the ground.
RECENT/NEW METHODS OF SHAFT
There are different methods of shaft sinking/construction. Actually three
possible methods allowing a shaft to me sunk through highly weathered
over burden on the basis of Excavation and Wall support.
1. VSM – Vertical Shaft sinking Machine
2. SHAFT BORING SYSTEM
3. SHAFT BORING
VSM – Vertical Shaft
Shaft installation in difficult
ground conditions – especially
under ground water – requires
Till today, with the help of
several Vertical Shaft Boring
Machines (VSM) dozens of
shafts have been sunken in a
variety of ground conditions.
They have a drill diameter of
5 to 10 meters and built shafts
with a maximum depth of 65
VSM Technique is an
application for Offshore Mining
Shaft Sinking Machine
consists of two main
1.shaft boring machine
2.the lowering units
The shaft boring machine is
lowered into the launch shaft
structure and attached firmly
to the shaft with its three
A rotating cutting drum
equipped with chisel tools is
attached to a telescopic
This road header excavates
All operational processes are controlled and monitored from the
surface. In addition to the separation plant, lowering units and
recovery winches, the jobsite equipment includes a control
container and power supply units.
All information available about the excavation is collected and
visualized in the control container.
There, the operator has a full overview of the situation at hand
and can respond accordingly at all times.
After completing excavation or when changing excavation tools,
the shaft boring machine is retrieved using the recovery winches.
The advantages of the modular design of the overall system
become particularly apparent in inner-city projects.
The equipment can be arranged as needed. For example, the
separation plant can be installed in a street next to the jobsite if
there is not enough space for it next to the shaft.
SHAFT BORING SYSTEM
The SBS is a development for the mechanized
excavation of deep vertical blind shafts in hard
The semi full-face sequential excavation
process is based on the use of a rotating cutting
wheel excavating the full shaft diameter in a two
stage process for one complete stroke.
The excavation process is divided into two steps:
trench excavation to a depth of one stroke with
the cutting wheel rotating around its horizontal
axis and being pushed downward in the shaft
excavation of the entire bench (face) area by
slewing the rotating cutting wheel 180° around
the shaft vertical axis.
The SBS machinery consists of three
major areas of equipment and
operation which are (starting from the
excavation chamber with cutting wheel, cutting
wheel drive assembly, mechanical machine
support structure, shotcrete and probe drilling
adjustable front support with slew
bearing/drive assembly cutting wheel support
and dust shield (Figure (2))
regular rock support area for rock bolts
SBS mainframe with gripper carrier, gripper
system and thrust cylinders (Figure (4))
rear alignment system (secondary gripper)
muck handling system (Figure 3(5)).
High sinking rates.
High level of safety.
Integrated system for excavation, mucking and rock
Fully accessible bench.
Dedicated drill rigs for probing and pre-excavation grouting.
Semi-partial face excavation system with industry standard
CONVENTIONAL PILOT DRILLING
A tri-cone pilot bit is normally used varying from 9
inches (229mm) to 15 inches (381mm). The 15 inches
(381mm) bit is normally used on long holes with a 12 7/8
inches (327mm) integral drill steel string with a 10 1/8-inch
DI 42 tool joints. During drilling a fluid is pumped through
the center of the drill string to the cutting face, where the
rock cuttings are flushed and raised from the bottom of the
hole through the annulus around the drill string to the collar
of the hole. The drilling fluid is settled in a closed loop via a
series of settling dams so that the drilling water can be re-
used. See figure.
CONVENTIONAL UP-REAMING OF PILOT HOLES:
On completion of pilot drilling and at such time that the
pilot hole breaks through into the lower excavation, a reaming
head is fitted to the end of the drillstring. The size of the
reaming heads range between 1, 2 meters and 6, 1 meters in
diameter. The head is rotated by the machine and is pulled
back against the rock face at the same time. Tungsten
Carbide insert cutters are fitted to the head and these cut
grooves in the rock in a rotary crushing mode. The ‘kerfs’ of
rock in between the grooves ‘spall’ out and rock failure occurs
in a tensile mode. The rock cuttings fall to the bottom of the
hole where it is mucked out by a mechanical loader.
It is a safe, efficient and cost-effective method of
making holes through different geological formations with the
use of powerful machines, high strength drill string and
reliable heads. The maximum loading capacity of the drill
string limits the diameter as well as the length of the shaft.
The loading is dynamic and only approximately calculable
because tensile, torsional and bending stresses are
overlapping. See figure.
In this case an oversize pilot hole is drilled.
The cutting head is installed at the top of
the pilot hole and drilling takes place in the
downward mode. Rock cuttings are
flushed down the oversize pilot hole to the
bottom of the hole where it is removed. In
the case of smaller holes, the machine
provides cutter thrust and in the case of
large diameter shafts the cutter head is
weighted through the addition of steel
collars. The down boring method is not
used often as the risk of blocking the pilot
hole and creating mud rushes at the
In day to day life, demands of mineral is increasing and for fulfillment
of this we would extracted more minerals by increasing production
and productivity of Indian mines working. The production of opencast
mining is greater than underground mines but shallow depth reserves
are being depleted, for what mineral have to extracted from
underground by underground method. . But most of the mineral
reserves are situated at great depth. For minerals extraction from
underground drives access through shaft. And to drives shaft, sinking
is most important aspect. So we have to adopt best sinking methods
so that cost of sinking will be reduce and sinking work will be done at
faster rate to achieve the targeted production.
For better sinking methods we studied the various Shaft
Sinking methods. After studying, found that, the advanced
mechanical excavations systems can have significant advantages
over conventional drill and blast methods for sinking of shafts in many
different aspects. Advanced mechanical excavation systems allow
for a significantly enhanced level of productivity and safety due to the
high degree of mechanization and industrialization. Due to high
After studying case studies of two mines i.e Mansar and
Balaghat mine in India where the shaft sinking was carried out
recently by conventional shaft sinking methods techniques for the
purpose of shaft sinking . The shaft of Mansar and Balaghat mines
have made by Conventional Shaft sinking method but if this shaft
would have been sunk with the advanced technologies like VSM and
Shaft borer the production rate would have been raised to 30 %
(Marks, 2002) with the sophisticated usage of manpower, increasing
safety and reducing cost of capital on shaft sinking with less time
required for sinking same length of shaft.
Most reliable we can call that the advance sinking methods
eliminates the usage of tedious method of Drilling and Blasting which
is most critical to accidents with respect to safetyin mines. This
mechanized method can also be applied for widening and deepening
of existing shafts.
But there are some natural and technical problems, of using
advanced techniques in India, regarding with natural and technical
condition in India such as geology, ground condition, required capital
cost, operating cost, environment, suitability of techniques with
Indian mining atmosphere, lack of knowledge about techniques, lack
of worker’s experience, other training arrangement.
So we will have to make several modification in
technique’s construction and its working parameters
according to suitability of techniques with Indian mining
working and geological aspects. So that, it will work as
better as possible and as per mentioned above, it will help
to enhance production, productivity and safety measures
of Indian mining industry. Really it will help to achieve
India’s mineral target production.
In this thesis an attempt has been made to study
the advanced shaft sinking techniques which are not
practiced in Indian condition but in future those may be
practiced in our condition and it will help to improve the
production, productivity and safety measures. By
application of the advanced techniques India can achieve
their goals in production and economy.
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