Key Question: How are buildings designed (aseismically) to withstand earthquakes? Key Words: Aseismic Design Retrofitting Land-use planning

Prediction seems unlikely at the moment as seismology is a relatively new science and the earth is more complex than we once thought. 1. ‘Earthquake prediction would be useless anyway.’” Explain why 2. “Aseismic design is the best way to manage the hazard anyway? Explain why

Aseismic Design List 3 things in your book that the LA City Emergency Management Operation Centre Building has to prevent EQ damage ‘Floating Building’ 40 Base Isolators / Friction Pendulum Bearings Slack in cables and pipes to don’t snap Spare Base Isolators

Buildings with one of their dimensions Building Geometry Buildings with one of their dimensions too large don’t perform well during EQ’ as they amplify waves. E.g. skyscrapers / warehouses

Tall Building > Short Building < sway sway Height Towers and Response to EQ’s Tall Building > sway Short Building < sway

‘Pancaking’ of Buildings after Haiti EQ, 2010 Pancaking happens when insufficient steel is used and cheap concrete causes a ‘soft storey’ to collapse

allow the building to float and help absorb the force of shaking by Friction Pendulum Bearings 40 base isolators allow the building to float and help absorb the force of shaking by allowing the foundation to move but the building remains stationary. LA City Emergency Management Operation Centre Building

Base Isolators in Istanbul Airport T4 Rubber shock absorbers can ‘dampen’ vibrations

Base Isolators A ‘base isolated’ building is moved less and shaken comparably less than a fixed one during EQ’s.

Adding cross bracing holds the frame of the X – Cross Bracing Adding cross bracing holds the frame of the building together by increasing strength.

Adding X-cross bracing holds the frame of the building together by increasing lateral strength.

Is another way of reinforcing a buildings frame with bracing K – Cross Bracing (Chevron) Is another way of reinforcing a buildings frame with bracing

Eccentric Cross Bracing Adding eccentric cross bracing makes the building more ductile and twists with the EQ without failure

to actively sway against the building movement Computer Controlled Counter Weights Taipei 101 Tower, Taiwan 508 m tall sways by 60cm Engineers installed a giant pendulum counter weight -which is computer controlled to actively sway against the building movement

Trans-America Building San Francisco Aseismic Stepped Triangular Building Trans-America Building San Francisco Pyramid designs are more stable for tall buildings as their wide base means upper floors shake less

TGC have an array of seismometers to detect EQ’s in progress Smart Meters Tokyo Gas Company TGC have an array of seismometers to detect EQ’s in progress When an EQ occurs the company can cut off the gas supply remotely using a Smart Meter, preventing fires

Aseismically Designed Building

‘Pancaking’ of Buildings after Haiti EQ, 2010 Pancaking happens when insufficient steel is used and cheap concrete causes a ‘soft storey’ to collapse

Retro-fitting corner Cross Bracing after Haiti ‘10 Steel and wood cross bracing can be added to the buildings that survive

Retrofitting Steel shear cores increase a buildings strength

Full Metal Jackets Problem! – You can’t retrofit a full City! Steel jackets can be put around concrete supports on existing bridges to prevent them crumbling

Map faults and unstable geology and avoid! Land-use planning Seismic risk map Map faults and unstable geology and avoid!

Building Regulation Regulations can be put in place and enforced through laws. E.g. in MDC’s like USA, California you can’t build close to faults that are proven to be active. In LDC’s regulations are often in place but they are not strictly policed – due to corruption / mis- Management.

EQ Shake Tables Worlds Largest Test, Japan. Colorado University

Modelling Buildings: Competition Using 10 straws Sellotape 4 pieces of A4 paper Build a 3 storey tower over 15cm high that can take a small load. WE WILL SHAKE TEST THEM TO FIND THE WINNERS

2. As many key words about the topic in a minute The Review Pyramid Write down 1. 1 thing that you now know more about 2. As many key words about the topic in a minute 3. What you want to know more about / find out next 3. This is your homework for next lesson