Sikkim Visit- Post 18th Sept. 2011 earthquake

My second trip to Sikkim this time was well restricted within the state capital, Gangtok. The priority task was to start rehabilitation activities in a damaged school identified during the last trip. It has been a part of our long term agenda of school safety, where through reconstruction of schools we are looking at Sikkim for:

• Strengthening of existing school building stock
• Introduce and integrating the concepts of safety and accessibility in school buildings
• Conducting dissemination programmes on safe construction to various user groups including the local government

To begin with, we started our work in Lumsey Junior School, which is within Gangtok city limits and has two classrooms damaged. The idea is not only to repair the damage and strengthen the school building, but also utilize this opportunity for hands-on training of masons on retrofitting activities. Me and Rehman (from SEEDS) started with interviews and discussions, and taking necessary information from the site including pictures and measurements.

Rapid visual surveys during my first visit and also by the SEEDS team members on their respective visits had helped us finalize Lumsey then. Lumsey seemed to be the best accessible school as we would want various groups such as engineers from various agencies and government departments, schools, and other groups to visit the school and interact. Currently, we are undergoing the process of finalising on a small team and also look forward to conduct our activities in the Junior High until the end of March 2012. Rakhi has joined us on SEEDS payrolls, and two masons from D.A. soon to join us.

Pictures of Lumsey school can be accessed here .

Lumsey Junior High School (Link to Picasa album)

Other than this, I also tried making a note on post earthquake activities undertaken by other agencies. It appeared from the news reports and discussions with peers that a clearer picture on larger funding from the Prime Minister’s and Chief Minister’s and other grants is still awaited by the administration and the civil society. It is interesting to see the debate at all levels on the mode of earthquake response the State should adopt in the future. Talks about meetings and conferences aiming for improvement in bye laws and infrastructure provisioning can be heard.

With a population of 6,00,000, Sikkim is a closely knit society. One and all are aware of the post earthquake consequences in the state, and have empathy for each other. House owners in towns such as Chungthang had to bear heavy losses. The rehabilitation style of an ex-gratia compensation by the government –as in this case, Rs.50,000 does not seem logical enough for a place like Sikkim.

It is unfortunate that one of the most prosperous States of India has no ready technical help available to its people in terms of safer building awareness and construction technology, and/or and/or counseling that would help them cope with this huge disruption in their lives and livelihoods- it being the need of the hour.

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Written: Chandra Bhakuni

Checks and Reviews: Pratul Ahuja, Shruti Nair, Smriti Saraswat

Engineering Lessons for Sikkim, India Earthquake (Magnitude-6.9)

I recently visited Sikkim, India after the 18th Sept. earthquake. The trip had a few-fold objectives, them being:

1. To understand the damage to buildings and infrastructure in the region

2. Visit the ‘School buildings’ and other institutional setups to understand the impact of this event

3. Observe the Disaster Response mechanism in place

Based on my field experiences and discussions with various people on this trip, I would like to make a few recommendations; as following:

1. Large engineering companies, universities in Gangtok, and individuals have studied Sikkim to a great extent, and their expertise should be utilized for safety and improvement of infrastructure.

2. The earthquake appears an opportunity for overall developmental improvements (access and amenities) in settlements that are urbanizing, such as worst hit Chungthang.

3. Traditional Wattle and Daub (Collq. Ekra) construction has performed well against the earthquake, and has low damage. This construction should be encouraged, and innovation in this area could yield comfortable and safer houses.

4. The damages in Chungthang have caused mental health issues to houseowners (especially who had made large investments) and counseling is an immediate need.

5. Damages in various school buildings have instilled fear/caution in children. Instead of listening to that fear, perhaps it is more prudent that opportunities are created for learning about earthquakes.

6. Sikkim is an opportunity, and can be shown as an example of collective governance, not only from the safety point of view but also development needs of the North East of Indian subcontinent.

For the detailed report refer www.quakeschool.org/files/110922SikkimEarthquake.html

By [With Acknowledgements]

Mr. Chandra Bhakuni, Structural Engineer, Quakeschool Consulting

[With sincere thanks to Manu and his SEEDS Delhi team, Mrs. Rinkoo Wadhera from local DOU unit, Mr. Prashant Pradhan and his team at Architects of Sikkim , Tshering (School Teacher), Sohel da (Faculty, Sikkim University), Col. Wadhera, Col. Vishal, and Quakeschool team and many others I could meet during this trip.]



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Magnitude 6.9 Sikkim Earthquake

Source: Maps Of India

Visit link (click) for updates.

Source: Assorted

Some earthquake feelers by Structural Engineers

Photos. Typical Reinforced Masonry buildings in India

The earth’s surface is under continuous movement, in other words is always vibrating. However, these vibrations are so low in magnitude that they are not felt by us humans at all; unless they are large in size, which happen during events such as earthquakes.

One of the methods which earthquake experts apply to understand earthquakes and these vibrations is by classifying these in the form of waves. These waves which are generated inside the earth’s crust during an earthquake have their movement in all directions. Known as seismic waves, these waves can be categorized in to two types- 1. Body, and 2. Surface. While the Body wave would move through the body of the earth; the surface wave would take a little longer route because it has to make its way to the nearest earth’s surface first, and thereafter travels as a surface wave. See some simple educational websites Website 1, Website 2 which provide simplified understanding of these earthquake waves.

The science of structural engineering is concerned how these waves travel and when they hit, have an impact on the building.

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In recent last one year history has seen two unfortunate earthquake events, with some significant aftershocks. New Zealand and Japan, faraway places were in news. Last year significant damage was noted in other places such as Chile as well. See what the Structural Engineers have to say about what they felt:

New Zealand (22^nd Feb 2011)

Roberto T. Leon, president of the Structural Engineering Institute, ASCE has an interesting blog on being present in Christchurch, New Zealand when the 2nd earthquake had unexpectedly stuck there. The whole blog is an interesting read, where in a portion he summarizes a comparison with the Chilean event.

It was eerily different for me because my most recent recollections are from the large Chilean earthquakes that I experienced last year. The Chilean ones “build up” slowly and last a very long time. This one seemed to be three or four very sudden, violent jerks, with a strong vertical feel, and lasting probably no more than 15 seconds or so.

Japan (11^th March 2011)

Balaji, a friend and a structural engineer, was in the fourth floor his ten storey office building in Tokyo when the earthquake stuck. Pretty much inland where the Tsunami could not reach, a few days later he told me over Skype [http://skype.com] how he first felt the body wave which came stinging in no time and took him off ground, and then he waited for the surface waves to arrive. While he prepared himself for a floor dance, for the surface wave would arrive in no time, next moment he saw his colleague flying away and his back curved hitting the wall. It was a nasty bump but thankfully both are safe. The buildings their colleagues designed ensured they are.

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Ten years back, I personally felt the Gujarat, India earthquake (26^th Jan 2001), because it lasted for approximately two minutes. Halfway, it woke me up from my sleep; and the ground plus two building I was in, a typical Reinforced Cement Concrete (RCC) confined structure [See pictures] took the shaking well. One can contend such buildings, which are a typical design for institutional buildings across India, therefore take building movements and uncertainties into consideration when designing/constructing one. Otherwise, many buildings which are built keeping only enclosure in mind were not that lucky. Many had collapsed. A structural engineer colleague of mine, when we were students, in all this chaos, was wise in saying,

… either you design the building so stiff that nothing happens to it, or make it so flexible that you can bend or twist it endlessly anywhere, or you make the joint so ductile that no matter what the earthquake force or duration is, let it be endless, the joint shall never ever snap out.

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Website 1: http://www.matter.org.uk/schools/content/seismology/pandswaves.html

Website 2: http://earthquake.usgs.gov/learn/topics/?topicID=63

ASCE President blog: http://www.asce.org/PPLContent.aspx?id=12884904978

Skype: http://skype.com

Pictures of Typical Reinforced Cement Concrete (RCC) confined structure