Our country
is on a fast track of development. The population pressure demands rapid
strides in housing sector. There has been a tendency to develop housing
colonies as close to city centre as possible. Consequently now there is
a shortage of land. Take Mumbai for example. Land is costlier than life
there. Concept of Navi Mumbai did come, but it seems every one wants a
flat at Colaba only. Naturally buildings have to grow skywards. More
human beings mean more hospitals, more schools and more shopping malls.
Now even these structures are rising more towards the sky than earlier.
Are we aware of possibilities of killer earthquakes in this sprawling
country of ours? Do we have a roadmap to seismic safety? These are some
questions that often haunt the minds of geologists, and earthquake
engineers. We shall try to analyze them and seek answers.
Our
subcontinent is unique, because it is a product of past turmoil. Had
the landmass not broken from Africa, Australia and Antarctica and
moved like a Noah's Arc some 270 million years (m y) ago and started
to collide with stable, Asian landmass some 20 m y, the story today
might have been different! The union of smaller plates and their
collision with the Asian plate did cause gigantic earthquakes,
witnessed today in the form of seismites or evidences of past
earthquakes. Even today, the imperceptible movements of the Indian
plate underneath the Asian plate cause tremors powerful enough to
shake us from the slumber.
Some of the biggest earthquakes in the world have occurred in the
subcontinent and we have learnt some major lessons in the science of
seismology and earthquake engineering. How serious were the British
geologists and engineers about the earthquake problem and safety in
India can be understood by several example. When an earthquake shook
Kutch in 1819 it was first time found and established that the
tremors were due to a subterranean fault. It was then also establish
that the buildings on rocky foundations remain safe while those on
the alluvium shake like a fig leaf.
Necessity is the mother of inventions goes the saying. True to this
after the Baluchistan earthquake 1831, earthquake resistant
buildings were constructed for the first time for the officers of
the Railways at Quetta. The effort paid dividends, as these were the
only houses that remained unruffled during the 1835 earthquake at
Quetta. The 1835 earthquake was quite devastating. It took toll of
nearly 25,000 lives. Taking cue from the earthquake safe houses
built by the Railways, earthquake safety codes were refined and
developed for the army and civil authorities at Quetta.
Professor S.K. Jain of IIT, Kanpur, has drawn attention to 'safe
housing' through his papers published in various national and
international forums. In one of his papers published in April issue
of Current Science he says that collapse of 135 modern, multistory
buildings in Ahmedabad, 245 km from the epicentre clearly shows that
Indian civil construction practices require much to be desired with
respect to seismic safety. Comparing the problem with South America,
he says that earthquake safe houses at Peru which is rocked
frequently by earthquakes are within the reach of only the higher
echelons of society. Unfortunately in India he says no one is safe
with the type of so called earthquake safe houses.
Professor Jain further elaborates damages during the 2001 Bhuj
earthquake and Tsunami of 2004 have left ample scars on the soils of
Gujarat and Andamans. He says that about 6000 school buildings were
constructed in Gujarat between 1999 and 2000. During the earthquake
on 26 January 2001, more than three quarters of these school
buildings either collapsed or were seriously damaged. School
buildings and hospitals are two places where utmost care is taken in
developed countries. Perhaps lives are more precious there than
material costs! Andamans fall in high seismic risk zone. Austin
Creek bridge connecting North Andaman with Middle Andaman was
constructed in 2002. Seismic codes were set aside, this negligence
was pointed out, yet the authorities did not bother. The bridge
became non-functional after the tsunami-genic Sumatran earthquake of
2004.
As per the structural engineers the seismic codes are often flouted,
falls certificates are obtained by greasing the palms of the
authorities and sky-scrappers are built. Immediately after the
earthquakes the state and the central governments announce measures
to be taken to safeguard the future. However, the tall promises are
never kept and a repeat earthquake proves the myth.
A question thus emerges, what is the way out? If by a magic wand all
the buildings and structures become earthquake resistant the problem
would be over. Is it possible? To some extent it is. Certain
precautions are mandatory in the buildings code. For example, a
hospital building or a school building where there is a larger
congregation of people precise information about past ground motion
and intensity of earthquakes that have occurred within a radius of
300 km has to be collected. In developed countries this is a normal
practice. But in this part of the sub-continent, safety of school
buildings and hospitals is perhaps the last priority. We have recent
examples of 400 plus children perishing in Anjar during Bhuj
earthquake of 2001 and another 400 children were crushed alive in
Muzzaffarabad in Pakistan during 2005 earthquake.
Examples of such earthquake generated tragedies are well recorded in
the annuls of the Geological Survey of India (GSI). The first
semi-scientific record in India is that of Delhi-Agra earthquake of
July 15, 1505. A major earthquake again rocked Delhi on July 15,
1720. It was 22nd Ramzan and people had assembled in mosques to
offer prayers. Many people lost their lives in Shahjenabad (New
Delhi) and Old Delhi. After this Kaifikhan recorded in 'Muntakhabul-Ul-Lulab'
that similar shocks continued to terrorize Delhi for 40 days.
On September 1, 1803, the Mathura-Delhi area was rocked at 3AM.
Mathura suffered the maximum damage. Open fissures were formed on
the ground and water gushed out with force. Delhi was also severely
affected and top portion of famous Kutubminar came tumbling down.
The earthquake on June 16, 1819, in Kutch was no less devastating.
Its intensity was such that eight kilometers north of Sindri, in the
Rann of Kutch a three metre high and 65 km long ridge of clay and
shell was formed. The local population named it 'Allah Bund'. Bhuj a
major town then, had perished in this earthquake. About 2000 people
lost their lives. This earthquake took a toll of 500 lives during a
religious congregation in a mosque at Ahmedabad. So powerful was the
earthquake that shocks were felt in the far north at Sultanpur,
Jaunpur, Mirzapur and Kolkata.
Thomas Oldham of Geological Survey Of India calculated the intensity
of this earthquake on Richter scale as 8.3. The gravity of the
situation can be understood by the fact that an earthquake beyond
the intensity 8 causes total devastation.
Despite such precise information available we have not drawn any
concrete roadmap to safeguard our lives. Immediately after an
earthquake teams after teams of 'experts' visit the affected areas
and describe the devastation like the 'five blind men' describing an
elephant. Each expert has his own notions of safety and plans for
future safety. Naturally there are clash of views and finally the
government accepts some recommendations and does implement some of
them. However, the masses remain deprived of the provisions made by
the government, because there is hardly any awareness amongst the
masses.
The recent two earthquakes of 2001 (Bhuj) and 2005 (Kashmir) have
been an eye opener and the experts have aired their views on what
should be done for future safety. It is a tendency to gather the
expertise from developed countries. No harm as long as it is for the
betterment of our own people. Lorna Prieta in California is prone to
frequent earthquakes. Famous for historical buildings and churches
the government and the society decided to go for large scale
retrofitting after a devastating earthquake in 1989. The technique
saved hundreds of lives and scores of building too. Thereafter the
term retrofitting came to stay for the earthquake safety of
buildings in India. But before going for that one has to think 'is
it really viable', 'where do we need it and where we can avoid it'.
Retrofitting is a specialized technique. Apart from skill it
involves huge costs. Before embarking upon the project one has to
evaluate the cost-benefit ratio. For example for a heritage building
retrofitting may be extremely beneficial, but for comparatively
recent constructions dismantling the present structure and
reconstructing it with earthquake safe designs may work out cheaper,
says Prof Jain.
Construction activity in our country, especially in the urban
housing sector has been following age old techniques. There are vast
areas that have not experienced a severe earthquake in the recent
past. Buyers of apartments in the high rise buildings of Ahmedabad
learnt the hard way about the primitive techniques. Their houses
crumbled like a pack of cards during the Bhuj earthquake of 2001.
People of Gujarat and Kashmir have become quite aware about the
significance of earthquake proofing of houses. But alas, people in
the rest of the country either hoodwink themselves or the government
and avoid the mandatory aseismic designs. Therefore a massive
awareness drive is required to enlighten the masses across the
country. It is time that big builders are brought under a
confederation which keeps updating their knowledge about the
advantages of earthquake resistant houses.
Rules for earthquake safe housing have been implemented, but down
the ladder slackness is always there. Issuing fake certificates for
earthquake safe houses has to be made a cognizable offence wherein
the builder and the municipal authority both should be made parties.
Commonly an Indian house builder avoids engaging an architect what
to think of a structural engineer. For him all in one is the mason.
There is a strong need for creating a force of technicians and
skilled hands guided by structural engineers so that the civil
constructions are made earthquake proof.
Prof Jain says that in the field of medicine it is criminal offense
for any one without degrees of medicine to practice it. Same applies
to law as well. However, in case of civil construction there are no
restrictions and there are several 'self styled' experts in the
field. Such practice has to be stopped. The best way is to educate
the masses. Like literate people generally avoid quacks for
treatment, same way they will stop going to engineer quacks.
Implementation of regulations is very necessary. A person without a
valid driving license if caught is penalized heavily. Whereas a
person hoodwinking the rules or the other keeping his eyes shut
while the rules are not followed go scot free.
These days we are reading a lot about seismic micro-zonation. Well
that is a long drawn process and it is very much needed especially
in the metros or the cities where high rise buildings are coming up
in bulk. But unless precise details of anticipated ground shaking
are available at a given spot and measures taken in the construction
to counter that, a mere map will be of any use. Thus seismic
zonation studies need to be implemented in letter and spirit.
In a nut shell a tighter control and monitoring is required on part
of the government in the civil constructions Vis a Vis earthquakes
and a closer cooperation is needed from the builders and the like.
J.A. Dunn of GSI wrote in Memoir 73 of GSI in 1939, after completion
of the Nepal-Bihar earthquake of 1934:
"Leprosy is not a common disease, but the medical profession has
done its utmost to eradicate it for the sake of humanity. Great
earthquakes are not part of the earth's crust, but it should be our
duty to do all that we can to reduce its effects. Unless this matter
is looked upon in a broad way, posterity may yet look back upon our
short-sightedness with regret".
What Dunn wrote 68 years ago holds true even now. The science of
seismology and structural engineering has grown in leaps and bounds
in these years. Now at least let us have a road map to seismic
safety.
Image 1- Bhuj Earthquake: 2001-
Apollo Apartment, Ahmadabad, ground floor gave way and building was
tilted.
Image 2- Bhuj Earthquake: 2001- Debris of collapsed Hari House, a
five story newly constructed building in Ahmabadabad.
Image 3- Bhuj Earthquake: 2001- Debris Srinathji Apartments in
Ahmadabad, 23 people died in this building collapse.
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Professor S.K. Jain of IIT, Kanpur, has drawn attention to 'safe
housing' through his papers published in various national and
international forums. In one of his papers published in April issue
of Current Science he says that collapse of 135 modern, multistory
buildings in Ahmedabad, 245 km from the epicentre clearly shows that
Indian civil construction practices require much to be desired with
respect to seismic safety. Comparing the problem with South America,
he says that earthquake safe houses at Peru which is rocked
frequently by earthquakes are within the reach of only the higher
echelons of society. Unfortunately in India he says no one is safe
with the type of so called earthquake safe houses. 
Professor Jain further elaborates damages during the 2001 Bhuj
earthquake and Tsunami of 2004 have left ample scars on the soils of
Gujarat and Andamans. He says that about 6000 school buildings were
constructed in Gujarat between 1999 and 2000. During the earthquake
on 26 January 2001, more than three quarters of these school
buildings either collapsed or were seriously damaged. School
buildings and hospitals are two places where utmost care is taken in
developed countries. Perhaps lives are more precious there than
material costs! Andamans fall in high seismic risk zone. Austin
Creek bridge connecting North Andaman with Middle Andaman was
constructed in 2002. Seismic codes were set aside, this negligence
was pointed out, yet the authorities did not bother. The bridge
became non-functional after the tsunami-genic Sumatran earthquake of
2004.
As per the structural engineers the seismic codes are often flouted,
falls certificates are obtained by greasing the palms of the
authorities and sky-scrappers are built. Immediately after the
earthquakes the state and the central governments announce measures
to be taken to safeguard the future. However, the tall promises are
never kept and a repeat earthquake proves the myth. 