|
|
Environment
Lasting
Architecture
by VK
Joshi
 The newly emerged Himalayan Kingdom, Uttarakhand is on a shaky ground.
The term kingdom though a misnomer here, but specifically used because
the era about which we are talking was not an era of democracy, as 1000
years before present democracy was not known to the people. The story
unfolds about 1000 years ago in the kingdom of Uttarkashi (now
Uttarkashi district of Uttarakhand). Rajgarhi area of Uttarkashi
district has several multistoried buildings report Piyoosh Rautela and
G.C. Joshi from Dehradun which have stood the test of time. Rautela and
Joshi engaged in Disaster Management in the Department of Disaster
Management in the Government of Uttarakhand have published in the August
2008 issue of the Current Science about the Koti Banal architecture,
endemic to the region.
I have often written about the killer earthquakes that have shaken the
Himalayan Kingdom. Yet it is worth recording that since 16th century six
major earthquake events have taken place in the region. Except Kumaon
earthquake of 1720 and Garhwal earthquake of 1803 all others that is
1897 Shillong earthquake; 1905 Kangra earthquake; 1934 Bihar-Nepal
earthquake and 1950 Assam earthquake were of magnitude greater than 8 on
Richter Scale say Rautela and Joshi. It must be remembered that
earthquakes of 8 or more than 8 magnitudes are referred as Great
Earthquakes. They cause widespread damage in several hundred kilometer
areas.
It is well known that people do not die of earthquakes; they die because
of the collapse of houses and other buildings or due to landslides etc.
Poorly designed dwellings tumble down like pack of cards during Great
Earthquakes. Earthquakes are natural environmental hazards and have been
a part and parcel of the earth system. Humanity has been facing them
since it came in to existence and several times humans have proved their
ingenuity. Thus populations all around the globe have evolved innovative
practices for survival. Residents of earthquake prone areas, even
without any knowledge of seismology were intelligent enough to design
structures that could withstand the tremors. 'Kath ki Kunii' was one
such earthquake resistant design which is found in some of the old
mansions in Kulu in Himachal Pradesh, that have withstood the impacts of
past earthquakes.
A similar pattern is noticeable in Kumaon region of Uttarakhand where
three to five storied houses were a routine in the past. Author's own
four storied ancestral house is more than 300 years old and has stood
the test of time without even a crack. The basement of these houses,
locally termed 'Goth' was meant to house the cattle. It had dark dingy
interconnected rooms with a single door opening in the courtyard. In
addition they had a single opening with a lid at the roof connected with
a wooden staircase to the fist floor. This lid was used to tend the
cattle during the winters, without going out to the snow-covered
courtyard. In addition, the lid when left slightly ajar carried the heat
generated by the mixture of fodder and cow dung to the higher floors.
Thus it was a way to naturally heat the rest of the house. The higher
floors were made of wooden planks covered with a thick plaster of clay.
Wood again acted as an insulator. These houses have lots of thick wooden
beams and horizontal wooden 'breakers' in the walls to act as a shock
absorber.
Rautela and Joshi surveyed the Kumaon and Garhwal areas to collect data
about the ancient houses. They targeted upon area north of Barkot,
across Yamuna River. This area has witnessed several major earthquakes
in the past. They found a large number of traditional, multistoried
structures at Dakhiyatgaon, Guna, Koti Banal and Dharali. They report,
'The architectural principles and structural details suggest their
possible evolution under a single architectural school referred as Koti
Banal architecture, after the five-stories structures observed in Koti
Banal village. The antiquity of the architecture can be understood from
the fact that a carbon dating of the wood used has give an age of 880�90
years. The area being in earthquake zone V has undergone a number of
powerful shocks and yet the houses stand majestic.
These ornate multi-storied houses use wood in huge quantities. Like the
RCC frame of present day multi-storied construction, the Koti Banal
architecture uses wooden frame for the entire structure. The intervening
voids are filled with rectangular pieces of rocks making 1.5 ft thick
walls. These walls take the vertical load; while the interconnected
wooden joists running in both directions take the horizontal load, say
Rautela and Joshi. On the two sides of the structure, wooden beams
provided from outside were part of a special provision to enhance the
seismic performance. The structure is raised on a platform two to four
meters above ground. The stone-filled solid platform is in continuation
of a filled-in foundation trench. First the filled-in trench and then
the solid platform at the base helps in keeping the centre of gravity
and centre of mass of the building in close proximity and near the
ground. This takes off the overturning effect from the tall structure
during an earthquake.
Koti Banal architecture was developed and followed in an era when the
building codes or earthquake safe designs were unheard of. Even the
concepts of science had not evolved the science of earthquakes and
related matters were beyond the thought process of people. Despite all
these odds the designs of the multistoried houses seem to follow the
present day building codes of earthquake safety, especially in terms of
length to width ratio of the houses and single, small entry of the
houses. The four walls of the house were raised using the wooden logs
and dressed up, flat, rectangular blocks of rocks alternatively. Often
the structure is reinforced with the help of wooden beams fixed
alternately, that run from the middle of the walls on one side to the
other; intersecting at the centre. This arrangement divided the building
in to four parts and provides for joists supporting the floorboards in
each floor of the building, say Rautela and Joshi. The top two floors
had a balcony with a wooden railing running around on all four sides.
Different floors were connected with specially designed ladders. Wooden
framework supported the slates of the roof.
In other words it seems that this was a unique architecture. It still
stands majestically today, unscathed by the ground shaking. In a
personal communication Dr Piyoosh Rautela says, 'Koti Banal type of
buildings can at best be conserved and studied. It would be highly
impractical to try to rebuild these in present times as we neither have
access to stone nor to wood. I have strong conviction that detailed
research into this kind of buildings can lead to some breakthrough in
technology and structures better suited to the ground realities in the
region can ultimately evolve.'
The upcoming state needs to pioneer architecture that can withstand not
only the earthquakes, but also be energy efficient.
September 28, 2008
Image 1: Five storied majestic house constructed 880�90 Before Present
Image 2: Simple, yet majestic ancient houses in the region
(Images Curtsey Editor Current Science, Bangalore, India)
Top |
Environment
|
|
