ICJ_TsunamiPreliminaryReport

8/13/2019 ICJ_TsunamiPreliminaryReport

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January 2005 * The Indian Concrete Journal 11

Recent tsunami and earthquakedevastation

The Indian Institute of Technology (IIT),Kanpur organised a reconnaissancestudy of the affected areas of the recentearthquake and the tsunami with a viewto document the scientific, engineeringand disaster management lessons fromthis tragedy. A total of 13 investigatorswere divided into six groups withindependent responsibilities: each of the groups spent about eight days inthe field, during January 1 to January

13, 2005, as per Table 1.

General observationsDue to the subduction of the Indo-Australian plate under the Eurasian

plate, the Andaman and Nicobar Islandsexperienced uplift on the western coastand subsidence on the eastern coast asseen from the field evidence. At PortBlair, located on the east coast, waterlevel has risen by about 1 m, Fig 1.

Western coast of the middle Andamanislands showed emergence of newshallow coral beaches suggesting anuplift.

Damage to buildings and otherstructures were primarily due totsunami (as against due to groundshaking) on the mainland India. In LittleAndaman and other islands south of it;

Table 1: Group investigation

Group Investigators Activity

1 Prof Sudhir K. Jain, IIT, Kanpur Coordination, Areas around Port Blair,Mr Hemant Kaushik, research scholar, IIT Kanpur Meetings with administrators in

Andhra Pradesh in Andaman andNicobar islands

2 Prof C V R Murty, IIT Kanpur Islands south of Port Blair; Meetings

Prof Javed Malik, IIT Kanpur with administrators in Tamil NaduMr Suresh Ranjan Dash, M Tech scholar, IIT Kanpur

3 Prof Durgesh C Rai, IIT Kanpur Areas north of Port BlairMr Gautam Mondal, research scholar, IIT Kanpur

4 Ms Alpa Sheth, seismic advisor, Govt. of Gujarat, Areas along the coast from Cochin toand consulting engineer, Mumbai ChennaiMs Pratibha Gandhi, research scholar, IIT Madras

5 Mr Arvind Jaiswal, consulting engineer, Hyderabad Areas along the coast fromMs Snigdha Sanyal, senior project associate, IIT Kanpur Visakhapatnam to Chennai

6 Lt Col J S Sodhi, M. Tech student, IIT Kanpur Car Nicobar islandLt. Col G Santhosh Kumar, M. Tech student, IIT Kanpur

Fig 1 Sea water level at Port Blair with respect to land has gone has up byabout 1 m. Hence many areas are now flooded during high tide (Photo: Sudhir K Jain)

Preliminary Report


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The Indian Concrete Journal * January 200512

and structural damage in islands north of LittleAndaman were primarily due to ground shaking.

Damages on the Andaman andNicobar islandsTsunami created giant waves as high as 10-12 m; inseveral instances, objects were found on top of thetrees after the tsunami. In the islands of GreatNicobar, Car Nicobar, and Little Andaman, buildingsconstructed on the coast were washed away by thegreat waves, while those located on high groundssurvived. When a number of rows of buildingsexisted on the coast, buildings in the first row fromthe sea suffered extensive damagewhile those in the rear rows did betterdue to the shielding provided by thefront row. In general, constructionsthat were circular in plan (for example,circular water tanks, light house) did be tt er under the onslaugh t of tsunamis as the water could easily flowaround such objects. At Car Nicobarabout 100 personnel of air-force(including the family members) lost lifeor are missing. However, theoperational area and the airstripsurvived enabling rescue and relief operations by the air force after theevent.

Fig 3 Collapse of a stilt plus one-storeyhouse in reinforced concrete near Port Blair(Photo: Sudhir K. Jain)

Fig 2 Severe damage to Passenger TerminalBuilding at Port Blair (Photo: Sudhir K Jain)

Fig 5 Collapse of a reinforcedconcrete scooter stand at Port

Management Board office inPort Blair (Photo: Hemant Kaushik)

Fig 4 Collapse of a stilt plus one-storey house in reinforcedconcrete near Port Blair (Photo: Hemant Kaushik)


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January 2005 * The Indian Concrete Journal 13

Due to the ground shaking, thewooden buildings have performedvery well as compared to the moremodern RC frame and concrete blockmasonry buildings. The latter sustainedlarge damages wherever the seismiccodes were not complied with. Forinstance, the passenger terminal building at the Phoenix Bay in Port Blairwas recently constructed but did notcomply with the seismic codes. Thisrather expensive building has been

irreparably damaged, Fig 2. At least twohouses built by local people usingreinforced concrete but without properengineering supervision and seismicdetailing collapsed, Figs 3 to 5. A three-storey apartment building in Port Blair

on stilt columns, not complying with the codal requirements,collapsed, Fig 6.

A number of jetties collapsed or were severely damaged in anumber of islands, Fig 7. This has severely affected the sea trafficand hence the relief operations.

A new bridge between north and middle Andaman had to beclosed to even the light vehicles. The superstructure has movedon the substructure by a substantial amount. As a result, currentlyone has to cross from one island to the other by foot and leavethe vehicle behind. More interesting part of the story that DrC.V.R. Murty and Dr Durgesh C Rai of IIT Kanpur had visited thisregion two years back after a moderate earthquake onSeptember 14, 2002 and in their published report had expressed

Fig 9 Foundation failure in Kerala dueto scouring of rather shallowfoundation (Photo: Alpa Sheth )

Fig 6 Collapse of three-storey reinforced concreteframe building at Port Blair (Photo: Sudhir K Jain)

Fig 7 Collapse of the 80-m segment of the approach to GreatNicobar island jetty at Cambell Bay. This has adverselyaffected the relief work (Photo: CVR Murty )

Fig 8 Ravaged houses at Nagapattinam due to poorconstruction (Photo: Alpa Sheth)


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The Indian Concrete Journal * January 200514

concerns about this very bridge asfollows:

Inadequate seating of bridge deck over piers and abutments is a serious concern for it s sa fe ly during a st rongerearthquake in future. The bearings aresimple neoprene pads which are far fromsatisfactory for a bridge located inseismic zone V. Bridge deck restrainersare the minimum that need to be provided to ensure that the spans arenot dislodged from the piers in futureearthquakes.

A free copy of the report can be re-quested by sending an e-mail with com-plete postal address to the National In-

formation Centreof Earthquake Engi-neering at IITKanpur [email protected].

Damages onthe mainlandThe fishing commu-nity living along theshore suffered the

maximum damage:to its housing, to its boats and fi sh ingequipment, and interms of loss of life,

Fig 8. Most houses along the coast had been non-engineered. In general, qual-ity of construction had a major influ-ence on the level of damage sustained

by the buildings. Buildings with lowfoundation depth, those with poorer

building materials, poor integrity andpoor workmanship were worst suffer-ers, Fig 9.

Several bridges suffered seriousdamages. The superstructure of all fourspans of a bridge at Melmanakuddicame off the sub structure and two of the spans washed away to largedistances, Fig 10. A good connection

between the superstructure and thesubstructure and the additional

provision of restraining upstands recommended features for seismicdesign would have helped these

bridges. Infrastructure in Nagapattinamdistrict was significantly affected: arailway line on the shore,telecommunication tower and controlpanel room were irreparably damaged.Compound walls upto 300 m inside theshoreline were very extensivelydamaged.

In ports and harbours, majordisturbance was caused by vesselsparting their ropes and becoming looseand hitting other vessels and causingdamage. Small boats and ships weretossed astray onto the land by theincoming wave and thereby damagingthem. Some boats were sunk to the

basin due to the returning giant waves,Fig 11.

Breakwaters generally did well, andhelped reduce the impact of waves.Beaches shielded by landmass or by

rocky cliff sustained less damage. Sea-water intrusion was less in area coveredwith thick vegetation as compared tothose with bare lands. Sand deposits dueto tsunami in delta areas have damagedstanding crops and affected fertility of the land.

NICEE press release

Fig 11 Small mechanised boat sunk into harbour basinbeing pulled out of water at Fishermen's Wharf,Chennai (Photo: Arvind Jaswal)

Fig 10 Complete loss of the four span of a RC bridge at Melmannakudi (Photo: Alpa Sheth)

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ICJ_TsunamiPreliminaryReport