Physical properties of rock masses
of the engineering structures like dams, tunnels, underground power house,
roads etc. involves large volume of rock mass. The rock mass is generally
more heterogeneous than intact rock. The rock mass contains discontinuity
planes in the form of joints and fault planes, bedding plane and foliations.
These discontinuity planes are responsible to give different physical
properties to rock mass compared with intact rock sample from the same
rock mass. These discontinuity planes are responsible to control the
strength and the deformability of the rock mass.
|Three sets of overstressed discontinuities.
by Prof. Kurt Klima, Graz, Austria)
factors of discontinuity planes which influence the properties of the
rock mass are; i) Orientation, ii) Spacing, iii) Continuity, iv)
Surface Characteristics, v) Separation of disco-ntinuity Surface and vi)
Thickness and nature of filling material.
of the disco-ntinuity planes play an important role
in the strength of the rock mass. The rock mass fail along one or more
of orientation of discontinuities becomes most important for rock slope
plane or plunge of line of intersection of two wedge forming planes day
light the slope at less than the slope angle.
the dip of the joint plane or plunge of the line of intersection exceed
the angle of internal friction.
conditions are prevailing the slope is kinematically unstable.
The orientation of discontinuities also
influence the strength of rock
Characteristics of Discontinuities (Hudson 1989)
of discontinuity affect the overall strength of the rock mass. If the
spacing is less the strength will be less and if it is more strength will
of discontinuity planes influence the stability of the rock mass provided
the orientation of discontinuity is kinematically critical. If the continuity
of the discontinuity planes is more the strength of the rock mass will
be less in comparison to case when continuity is less and there are bridges
are involved when the surface characteristics of discontinuities are
The waviness or undulation of the surface, which results in variations
in orientation or attitude along a given discontinuity.
joint roughness assessment though there are many methods but very widely
used method is to compare the roughness profiles provided by Barton and
|Discontinuities due to Cooling of volcanic
(Picture by Prof. Kurt Klima,
R.E., 1989, “Introduction to Rock Mechanics”, John Wiley and Sons, New
E and Bray, J.W., 1997, “Rock Slope Engineering”, E&FN Spon and Imprint
of Chapman and Hall, 2-6 Boundary Row, London SEI 811 N, UK.
R.B and Degraff, J.V, 1991 “Principles of Engineering Geology”, John
Wiley and Sons, New York..
b) The smaller scale roughness of the surface, which
provides friction between two adjacent blocks.
c) The physical properties of the infilled material
between the two surfaces of discontinuity plane.
and roughness are first and second order irregularities based on their
relative magnitudes. The projections in a rough discontinuity surface
are called asperites. Waviness has a greatest influence on the rock mass
strength than roughness. For two adjacent block to move along a wavy surface,
there must be displacement normal to the surface. The amount of displacement
is controlled by roughness angle and the wavelength of the wave.
The waviness angle reduces the dip angle and thus tendency for sliding
is also reduced.
and Filling of Joints:
separation of joint surface and the presence of filling material in between
has a great influence on the strength of jointed rock mass. The separation
width affects the shear strength of the joint. If the joint is tight
the asperites in the joint surface will interlock and will improve the
if the separation is wide the influence of the infilling material will
reduce the shear strength.
|Diwali or Deepavali
In Hindi, Deepavali literally
means a ‘row of lamps’ and Diwali as it is popularly known, means the ‘festival
of light’! We celebrate Diwali in the month of Kartik (October- November)
on the darkest moonless night or Amavasya! It is the main festival of many
Hindus and celebrated with lights, crackers, sweets and feasts throughout
India. Prayers are offered to invoke the blessings of Goddess Lakshmi, the
Hindu Goddess of wealth. It marks the coming of winter and the beginning
of a new year for the people of Gujrat, the Marwaris and businessmen.
Ishika and Phalguni
Celebrations with lights, crackers
Prayers for Goddess Lakshmi-
the Hindu Goddess of wealth
This festival actually starts
from the thirteenth day of the waning moon in Kartik and goes on till the
dooj or the second day of waxing moon. There are five days of Diwali. Each
day has a special significance.
The first day is called Dhanteras. This
day is very important for the business community of India. ‘Dhan’ means wealth
and ‘teras’, the thirteenth day of the Hindu month. According to ancient
Indian medicine science, or Ayurveda, it is the birthday of lord Dhanwantari!
He is the god who grants immortality. On this day, people pray for lots of
money and success in the year. Lord Dhanwantari was the divine physician,
so people worship him as a symbol of good health on this day! People generally
buy new utensils or metal objects as auspicious items, which they believe
will ward off evil and ill health for the rest of the year and bring peace
However, there is another noteworthy reason for
this day! God Yam, the god of Death, is worshipped on this day to provide
prosperity and well being to people. There is a story behind this.
Years ago, King Hima was a worried man. As per horoscope predications, his
16 year old son was doomed to die on the fourth day of his marriage by snakebite!
“The poor prince,” cried everyone, “he is fated to die!” But the prince’s
wife would have none of that! On the fourth day of their marriage, she lit
countless oil diyas all over the place. She also heaped ornaments and gold
and silver coins at the entrance of the prince’s chambers! Then in a lovely
lilting sing song way, the princess went on telling stories to her prince.Meanwhile,
Yam, the God of Death, disguised himself as a snake and slithered to the
prince’s room! But he could not enter the prince’s room! Why? The snake was
blinded by the bright lights of the diyas and the ornaments! The snake halted
in his tracks. Faintly melodious songs floated to him.
“What are those
sounds coming from the chambers?” thought the snake. That was actually the
princess singing to her prince. Yam was curious. He went closer. Drawn to
the wonderful musician notes, he slithered atop the stack of ornaments. Soon,
Yam was lost to the mesmerizing tunes! He sat there through out the night
and quietly left in the morning; without harming the prince! Since then,
Dhan-teras came to be known as the day of ‘Yamadeepan’! Lamps are kept lit
throughout the night in respect to Yam, the God of Death, to prevent untimely
The second day of Diwali is called Naraka Chaturdashi
or chhoti Diwali! The legend goes that on this day lord Krishna destroyed
the demon Narakasur and made the world free from his terror! Narakasur was
the son of Goddess Earth and had a demonic bent of mind.
He liked to live in filth and was destructive by nature. He harassed the
gods living in the heaven as well as the saints praying on earth! One day,
he overthrew the king of Suraloka called Aditi. More over, he carried away
16,000 women and imprisoned them in his palace! Aditi was the relative of
satyabhama, lord Krishna’s wife!
Satyabhama Killing Narakasura
“This is outrageous!” cried the Gods!
“Shame on Narakasura!” “Yes sir, this is terrible indeed!” agreed lord Krishna’s
wife Satyabhama. Satyabhama pleaded to her husband Krishna, “please, dear
husband, give me a chance to vanquish this evil demon!” Krishna thought deeply
and then replied, “All right, dear wife. You may vanquish Narakasura. But,
on the battle ground, I shall be your charioteer!”
as the charioteer, Satyabhama entered the battle-field. During the war, Krishna
pretended to faint thus giving his wife a chance to behead the monster! Narakasura
was killed and once again, good prevailed over evil. This event is celebrated
with much rejoicing especially in southern India and Assam. Lamps are lit
as a mark of celebration. On this day, houses are washed, painted and decorated;
all filth is discarded. Children light crackers, eat sweets and generally
have fun on this day.
The third day is considered actual Diwali! It
is on this day that Lord Ram, Lord vishnu’s seventh incarnation, returned
to his city Ayodhya with his wife Sita, after killing the lankan ruler Ravan.
Lord Ram has been exiled for fourteen years and the people of Ayodhya welcomed
him with lights and flowers. It is also an important day because this is
the only day of the year, when Goddess Lakshmi comes down to earth. People
perform Lakshmi puja (worship of Goddess Lakshmi) on Diwali, seeking wealth
and prosperity for the whole year. People are even expected to take a traditional
oil bath and be very, very clean!
Lord Rama Returns to Ayodhya
Many of you have not submitted your details for the students section.
Let me remind you again that it is in your interest. For this I wish that
all of you furnish the following information/ material at the earliest;
Date of Birth:
Mobile No.: (optional)
Past working experience:
Please also provide Recent coloured passport size photograph
(digital or hardcopy, if hardcopy please write your name at back
of the photograh.
You may send this information through my E-mail: email@example.com
or may handover it in my office.
People visit each other and give gifts.
Diwali is bonanza time for business people, because it is the maximum time
for giving gifts and making maximum purchases. New account books or bahis
are also inaugurated on this day. In Bengal, Diwali is celebrated as the
people perform the Lakshmi puja seeking wealth and prosperity for the whole
year. People firmly believe that the Goddess Lakshmi would visit their homes
and bestow their prosperity and good fortune on them on Diwali days! Also,
since Diwali falls during a dark period of the year, it is advised that the
best way to drive out damaging influences of darkness is to light candles,
diyas etc! So on all the five days of Diwali, homes glitter with electric
light bulbs and even oil lamps sometimes!
‘patakas’ or fire works are
an integral part of Deepavali. Children especially, burst crackers celebrating
the victory of good over evil! It is also said that crackers represent the
fiery weapons used by lord Krishna to defeat Narakasura! Diwali dispels the
darkness of evil with the brightness of lights in our present age.
Narakasura being killed by Satyabhama
Prior to Diwali, homes are painted,
white washed, spring cleaned and made sparkling clean. For Deepavali day,
new clothes and gifts are purchased for near and dear ones! Markets are well
lit and are full of festivities!
The day after Diwali (Fourth Day) is known as Annakoot. On this
day, Govardhan mountain or the mountain of food is worshipped. According
to legend , when lord Krishna was a young boy, he asked the people of Gokul
to worship Govardhan mountain instead of Lord Indra to Govardhan, Indra flew
into a rage. 'How dare they do this' thundered indra. With one mighty
spell, he sent a deluge of rain and storm for seven days to drown Gokul.
Krishna saved Gokulby lifting and holding the Govardhan mountain over the
peoplelike an umbrella. He lifted the mountain on his little finger so that
the people and cattle could come beneath it to seek refuge from the rains.
Govardhan provided them with food and water for these seven days. Thus, the
day after Diwali is celebrated as Govardhan Puja (or Prayer). Workers celebrated
this day as Vishwakarma Puja also and worship their tools and machinery.
The Fifth and Final day of Diwali festival
is known by the name of Bhai Dooj. This day is observed as a symbol of love
between sisters and brothers. It is believed that on this day, yamraj, the
god of death visted his sister river Yamuna and she put 'Tilak' on
his forehead! Tilak is a holy dot put on the forehead with flower petals
milk, saffron, Turmeric and vermilion!. On this day sister apply Tika on
there brothers forehead and get gifts and blessings in return.