First Soft Story Collapse

Columns and walls collapse 

Topple effect

Imperial College London Library

On the 22nd August I went to a university library to read their books on engineering in earthquakes. This was a daunting idea at first, but i managed to pluck up the courage to go and it turned out to be an extremely useful thing to do. I intend to go again, either to the same library or a different London university Library.

I took notes from three different books which i sourced:

• Introduction to Earthquake Engineering, second edition, Shunzo Okamoto, University of Tokyo Press,copyright 1984
• Design of Earthquake-resistant Buildings,Minoru Wakabayashi, McGraw-Hill Book Company USA, copyright 1986
• Urban Disaster Mitigation- the role of engineering and technology, Elsevier Science Ltd, copyright 1995

These books gave me background knowledge to my project, but now i need to research in depth the two cities i have decided to research for my essay, and then start writing my essay. 

Cambridge Summer School

At the beginning of August I attended a residential Mechanics summer school at Cambridge university in which I learnt new equations and concepts to do with dynamics; harmonic motion, circular motion, rotational dynamics.

This was indirectly relevant to my topic; the motion caused by earthquakes to buildings can often involve these calculations. I will not need to know this knowledge to write my essay, however when researching, I will be able to understand more of the mathematics behind what happened to the structures during the earthquakes as this will no doubt be recorded in studies and in the university books.  

Timeline

July 8th:

- google topic to get overview of people and theories involved in structures in earthquakes and the people involved in the structures of the two cities that I am studying

- make Gantt chart

July 9th- 17th:

 -read my books on why structures fail whilst on holiday

July 18th- 22nd:

- Work experience with Sir Robert McAlpine engineering company

August 1st- 5th:

- spend time in the Imperial library researching structures in earthquakes

- find programmes about Hiroshima earthquake in Japan (2011) and articles on Sumatra earthquake in Andaman Islands (2004) to start my research for essay

End of August:

- hopefully get work experience with Arup around this time

- continue with research

September 1st - 6th:

- begin writing essay, by coallating all research

possible cities to compare

At my residential this week at Imperial I had a lecture on Earth science and was able to pick up some information for my project on Earthquakes. 


The Sumatra earthquake of 2004 is of magnitud 9.3, similar to Japan's Hiroshima of magnitud 9 on the richter scale. They both suffered an earthquake and tsunami and are therefore similar situations. Sumatra however was in 2004 so it might be interesting to discover how/ if buildings have improved over 7 years.

Sources

• http://www.ideers.bris.ac.uk/resistant/isolating_pendulum.html - 30th June 10.30 2011

Introduction to Earthquake Engineering, second edition, Shunzo Okamoto, University of Tokyo Press,copyright 1984

Design of Earthquake-resistant Buildings,Minoru Wakabayashi, McGraw-Hill Book Company USA, copyright 1986

Urban Disaster Mitigation- the role of engineering and technology, Elsevier Science Ltd, copyright 1995

http://www.eeri.org/lfe/clearinghouse/sumatra_tsunami/reports/Boen_Sumatra%20Earthquake%2026%20Dec%202004.pdf

Damping

I have been researching a method of relieving the stresses in a structure when subject to earthquakes. This method is called damping and I found a great source: http://www.taylordevices.eu/pdfs/seismic%20applications.pdf (accessed 30th June 2011, 10.00am )

EP training

Today was really useful in giving us tips on research and management of our projects.

Some key things I need to do:

• buy some books- great sources
• create a preliminary source list
• make a detailed plan
• set myself goals throughout my project
• question my essay and what it is asking of me
• create an overview of theories and people surrounding my project
• always take note on anything relevant, where and when i found it
• choose the two town I wish to research further and compare
• make a Gantt chart

Next Deadline- 15th July- fully detailed plan of summer plans for project!

Possible Work Experience

I am really excited because I have managed to get in contact with an engineer- Jo Da Silva- working at Arup whose expertise is in Structural design, disaster risk reduction and non-linear programme management. http://www.arup.com/News/Feeds/~/link.aspx?_id=6DEE0ADF8FAD47D89E2049313E01B05B&_z=z


I will hopefully be able to get some work experience in this field, and possibly some support for my extended project!

The Rion-Antirion Bridge- earthquake proof

I have started writing an essay on the Rion-Antirion bridge, the largest multi-span cable-stayed bridge that spans the Gulf of Corinth in Greece, an area of high seismicity and large rift expansion. I was inspired by the program 'Richard Hammond's Engineering Connections' to find out more. I thought that it tied in nicely with this project, to know about the possibilities of infrastructure other than buildings to withstand earthquakes.

The engineers working on this project were able to overcome the seemingly impossible challenges due to the extreme conditions of the location with innovative solutions. Since its completion in 2004 it has already proven its ability to withstand earthquakes. The bridge has also proven to be a link of great necessity with 10,000 vehicles crossing on a daily basis. [1]

The aim of an earthquake-proof bridge was achieved due to:

• the deck being suspended entirely by cables allowing it to move freely during an earthquake;
• the pylons being built on gravel allowing them to move freely;
•  Fluid viscous dampers prevent the deck from rocking too much.

Other features:

• The weak soil was reinforced using steel piles which transfer the forces to lower soil;
• restraints were connected to the fluid viscous dampers to prevent the deck rocking and thus suffering wind induced oscillation when there is no seismic activity;
• the restraints were built to break under a certain load i.e. in an earthquake allow the fluid viscous dampers to start;

On April 13, 2005, the Rion-Antirion Bridge was given “The Outstanding Civil Engineering Achievement (OCEA)” award by the American Society of Civil Engineers (ASCE). [2] The project set numerous world records including: longest cable-stayed suspended bridge deck and deepest bridge foundations. It was the first time steel pipes were used to reinforce weak soil and to have moving pier bases.

Why Buildings fall down- how structures fail

In this book 'Why Buildings Fall Down' by Matthys Levy and Mario Salvadori I read about the worst earthquakes up to date, something that could influence which cities I choose to study in further depth. 

The San Francisco earthquake of 1906, of magnitude 8.3 on the Richter scale caused a rupture 275 miles long causing major alterations in the landscape- displacements of 9-15 ft. 

Earthquake Missouri 1811 - 8.7 grades- "the ground rose and fell as earth waves". 

The houses here that were made of wood were well suited to survive the earthquake due to their flexible joints and thus sway and also stretch in response to an earthquake. 

Japan is subsequent to many earthquakes every year.

Useful Information: 

• According to this book, ductility is the most important measure of resistance to seismic forces. 
• a building needs to be high in compression and tension to resist the sway motion caused by an earthquake. 
• each whole number on the Richter scale represents approx. a 32 times energy increase; it is a logarithmic scale. 
• Liquefaction- sandy soils in water turn to liquid with movement; this is therefore very dangerous to build houses on in seismic areas. 
• soft soils magnify intensity of shock
• each building has a natural frequency (a natural way of swaying) 

Engineering Lecture, Cambridge

At a maths day in May I was able to experience a typical engineering lecture in which the topic was earthquake proof buildings, very appropriate for my area of interest. 

We discussed the different types of sway that a building may face eg. only top floor sways; a snake-like sway, whole building sways, only bottom floor sways. 

I learnt that no building, unless extremely expensive, is earthquake proof but there are ways to reduce the impact, minimise damage to the building and save lives. One way suggested was to design a building in which the first floor fails easily, thus the top floors fall, but (hopefully) stay intact, and are safe.

I also learnt that it is necessary that buildings have a natural frequency less than, and different to, the frequency loads it may have to sustain. 

My Proposal

For my extended project I intend to do a comparative study on the way in which two different cities have dealt with an earthquake. I will carry out research on two cities, one will be the recent earthquake in Japan and I haven't decided the other- I will have to do some prior research in the best example to compare to Japan. I will research how the buildings survived- or did not survive, and then how the city resolved it's devastation. Firstly I will research earthquake resistant buildings in order to have a better understanding of how and why the buildings survived and/or failed structurally. There are many sources I can use for my research; books, a specialist engineer from Arup, the Internet.

I intend mainly to learn about how earthquake resistant buildings work structurally, and how to improve those that don't. I am hoping that by comparing two different cities i will learn the most effective structures for earthquake resistance and how to overcome the unexpected magnitudes of earthquakes and their aftermath- something I hope i will be able to be involved in one day.

I intend to write an essay on the comparison between the two cities, this will help me develop my essay writing skills, a weakness of mine. Furthermore I want to develop my research skills, and my ability to work independently. These will be important skills to develop before starting university.