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.