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CASE HISTORIES OF WATER INUNDATION IN INDIAN MINES.pptx
1. TERM PAPER PRESENTATION
CASE HISTORIES OF WATERINUNDATION
SUBMITTED BY-
NITESH KUMAR SHAH
23152021
SUBMITTED TO -
Dr. C.S. SINGH
DEPARTMENT OF MINING ENGINEERING
3. INTRODUCTION
Water can flood underground mines, making work
impossible and putting people in danger.
Sometimes it comes in slowly, and we can pump it out,
but if it rushes in suddenly, it can be very dangerous.
Mining companies work hard to manage this problem,
but it's always a risk they have to deal with, including
advanced monitoring systems, reinforced barriers,
improved drainage systems, and emergency response
protocols
4. CAUSES & sources WATER INUNDATION
Danger from surface water: The sources of surface
water may be :
Rivers and "nallahs”
Tanks and reservoirs
Accumulated water in old opencast workings or in low-
lying areas.
Water from these sources can get into the
underground workings through :
Shafts and inclines
Broken ground over caved goaves
Boreholes or geological disturbances like faults
5. Danger from underground water: The sources of
underground water may be
Old water-logged workings either in the same seam or in
another seam
A sump either in the same seam or another seam
Water-logged workings in the adjoining mine
Highly water-bearing strata overlying the working seam
Water from these sources may inundate the active
workings bacause of
Accidental connection
Development of cracks, fissures and fractures
Failure of barrier pillar or parting
Failure of dams
7. What Happened?
– On July 11, 1912, heavy rain caused a problem at the
colliery.
– The embankment of a water tank broke.
– Water rushed into the underground coal mine.
The Details:
– The water tank was 75 meters long and 45 meters wide.
– The break in the embankment was about 1 meter deep.
– The mine was located in low-lying ground.
– The whole of the workings got filled in about 25 minutes.
– 15 people were working nearby.
8. Rescue Efforts:
– 12 people managed to walk out against the strong
current using a hauling rope tied to a tree.
– Unfortunately, most people working nearby drowned.
– 2 people were trapped but survived and came out
after 8 days.
10. What Happened?
– On June 28, 1913, there was an incident at Jotejanaki
Colliery.
– The problem was related to flood water from a “nallah”
(a type of stream or watercourse).
The Details:
– The flood water flowed close to the inclines (the sloping
pathways in the mine).
– The water went higher than the slopes and filled up all the
tunnels and passages inside the mine
– Tragically, 13 persons who were working in the mine got
drowned.
11. Why Did It Happen?
– Interestingly, this “nallah” had never risen to such
heights in the past 40 years.
– However, four years prior to this accident, a tramway
bridge had been built downstream from the mine.
– This bridge and its embankments obstructed the free
flow of flood waters, causing the water to back up and
flood the mine.
13. Mining Method: The mining method being used is
the Vertical Retreat Method.
Stope Filling: In this method, stopes (underground
chambers) are mined and then filled with consolidated
fill containing 5% cement.
Accident: During the filling process, something went
wrong in stope T-17.
Slurry Flow: The barrier made of cement that was holding
back water broke, causing 8000 m³ of slurry (a mixture of
water and broken material) to flow:
– Downward: It flowed to lower levels.
– Main Shaft: It also flowed into the main shaft.
14. Main Shaft Damage: The impact of the flowing
material was so great that it severely damaged the 6-meter
diameter main shaft. The shaft had been deepened using a
plug made of girders and a steel plate, but this plug got
sheared off due to the force of the slurry.
Trapped Individuals: As a result, twelve people who
were at the bottom of the shaft (engaged in deepening
operations) and one person at the drawal level were
trapped in the slurry.
16. Heavy Rainfall: On September 25th and 26th, 1956,
there was an abnormally heavy rainfall in the area.
Surface Water Accumulation: Due to the heavy
rain, surface water started accumulating in the region.
Pothole Subsidence: The roof over an underground
gallery in an old coal mine collapsed. This collapse created
a hole about 5 meters wide and 1.6 meters deep.
Water Rushing In: The collapsed hole allowed water to
rush into the underground workings of the mine. Within
minutes, all the deep workings were flooded.
Trapped Miners: 28 miners got trapped in the dip area
of the mine due to the sudden flooding.
17. Miraculous Survival: These trapped miners survived
for 19 days underground in the dark. Eventually, they
managed to escape through the rise area (using one shaft
and one incline).
Previous Incidents: Interestingly, similar subsidence
incidents had occurred in the mine’s outcrop area in 1941
and 1943, but fortunately, there were no casualties on
those occasions.
Safety Measures: Given the mine’s history, the mine
manager should have withdrawn the miners from the mine
as a precaution.
19. TYPES OF COOLING TOWER
Cooling tower
Mechanical Draft
Natural Draft
Design of Cooling
tower is such that cold
air of the bottom of
tower push the
warmer air out from
top.
Forced Draft
Air is pushed
in the tower
with a fan
from the side.
Induced Draft
Air is pulled from cooling
tower by a fan at the top
Counter flow Cross flow