Earthquake Engineering

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EarthquakeEngineering
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What is the Damage Quakes can cause?
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Direct Effects

• Ground failures
• Vibration of soil
• Fault rupture
• Liquefaction
• Ground lurching
• Differential settlement
• Lateral spreading

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Indirect Effects

• Tsunamis
• Seiches
• Landslides
• Floods
• Fires
• Release of hazardous material

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What is earthquake engineering?
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Earthquake Engineering

• It is a branch of engineering devoted to prevent
  earthquake hazards and its after effects

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Why is there Earthquake Engineering?

• Quakes demonstrated they destroy cities and
  people faster than Brandon can.

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Basic Goals

• To prevent non-structural damage, structural
  damage and collapsing of buildings in earthquakes

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Quiz

• What is earthquake engineering?
• It is a branch of engineering devoted to prevent
  earthquake hazards and its after effects

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Now do you want earthquake safe buildings?
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Seismic Retrofit!
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Seismic Retrofit brings older buildings/structures
up to more current seismic standards without
having to completely rebuild them.
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Sliding

• Old structures may not be strongly bolted into
  the foundation
• Corrosion weakens attachments
• These structures could be bolted to the
  foundation.

Weak Foundation
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Shock Absorbers

• A device for reducing the effect of a sudden
  shock by the dissipation of the earthquakes
  shock energy

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Base IsolationAllows the ground to move while
the building remains in place.

• This method allows a building to move

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Isolation

• Isolation pads are used to let the ground shake,
  but have the building not move

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Dampers

• Converts the energy of motion in a building into
  heat.
• Are for buildings rigidly attached to the ground
  will protect from resonance vibrations.

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Shear walls

• Wall composed of braced panels
• Flexible
• Counters the effects of swaying on a structure

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Reinforcement

• Shorter buildings can resist seismic forces.
• Instead of adding stories, expand the first floor
  of your home.

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Slosh Tanks

• Water in tank sloshes back and forth during an
  earthquake
• Prevents resonance in buildings
• Extra heat in building is absorbed

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Tuned Mass Dampers

• A device mounted in structures to prevent damage
  or outright structural failure by vibration.

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Masonry

• Stone veneer or cement
• More resistant to earthquakes so crack easily
• Use other lighter materials to replace

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Reinforcement

• Exterior concrete columns
• Infill shear trusses
• Massive exterior structure.
• It is not beautiful but it works.

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Quiz-y!

• 2. What is seismic retrofitting?

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Quiz-y!

• 3. At what college are the dorms reinforced?
• UC BERKELEY!!!

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Time for SEISMIC DESIGN!

• Everyone smile because its so exciting!

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Traditional Seismic Design

• Lower stories are stronger than upper stories,
  meaning it is more prevalent to reinforce taller
  buildings and higher stories.

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Quiz-y!

• 4. What is traditional seismic design?
• Lower stories are stronger than upper stories,
  meaning it is more prevalent to reinforce taller
  buildings and higher stories.

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Floor Diaphragm

• Wooden building floors are made on joints to
  prevent beams from tipping.

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Sliding Off Foundation

• Older homes can be bolted to their foundation to
  prevent major damage in an earthquake.

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BRIDGERetrofits
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Hot Rivet Replacement

• The rivet was replaced with a heat-treated
  high-strength locator bolt and nut

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Lattice Beam Conversion

• Beams were replaced with bolted steel plates.
  Also, face plates were added to the large
  diagonal beams

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Diagonal Reinforcement

• Diagonal box beams are added to the upper and
  lower decks of the bridges

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Expansion Rockers

• allow the bridge expand and contract with
  temperature changes

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Bay Bridge Structure

• During the October 17, 1989 Loma Prieta
  earthquake (7.1 on the Richter Scale). A 50-foot
  section of the bridge collapsed.

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Bay Bridge Retrofit!

• the strengthening of bents and columns on the
  east viaduct and the piers, bents, and trusses

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Fill Overpass

• Elevated roadways are built on sections of
  elevated earth supported with vertical columns

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ROADS!

• Soil is tested to see if it can hold weight, then
  asphalt is added

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Cypress Freeway Viaduct Collapse
During the Loma Pieta Earthquake, the Cypress
Structure collapsed. This roadway was not
properly reinforced. After the quake the
structure was removed and a new roadway was
built.
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Overpasses

• Pillars
• Spiral steel girders support columns and prevent
  bending of steel rods in the highway

Construction of Pillars
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• Add size and weight to bridges footing
• Anchor with metal rods (pilings)
• Jacket of steel around column
• Thick cables help hold together

Top Bridge Components Left Cable System
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OMG! ItsUNDERWATER TUBES!

• It makes you all giddy! ?

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Underwater Tubes Safety

• depend on soil conditions, the materials used,
  and the maximum predicted earthquake expected.

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BART! yay!

• BART trans-bay tube was constructed at the bottom
  of San Francisco Bay

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What does BART have? ?

• two inner tunnels
• a central tunnel
• an outer oval shell encompassing the three inner
  tubes

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Quiz!

• 5. _____ trans-bay tube was constructed at the
  bottom of San Francisco Bay.
• BART! gasp!

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THE END