Unreinforced Masonry Buildings

1
Unreinforced Masonry Buildings

• By Erica and
• Laura Garcia

2
Abstract

• The affect of earthquakes on un-reinforced
  masonry buildings and solutions to reduce the
  damage of future earthquakes.

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What is an Un-reinforced Masonry Building?

• Brick and mortar
• No Reinforcement (steel re-bars)
• An earthquake will Push and Pull on the bricks
  and so it causes the bricks to crack.

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Experiment

• Sugar Cubes (brick)
• Peanut Butter (mortar)

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Failure of Masonry Structures

• Typical failures occur in
• Walls
• Windows, doors
• Unsymmetrical plan of building

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Failure Modes

• Shear
• Sliding shear
• Bending

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Un-reinforced Masonry
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Shear
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Examples

• Wall Failure
• Shear
  Failure

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Bending
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What is retrofit?

• Retrofitting is the way that many buildings are
  reinforced to better withstand the shaking of an
  earthquake.

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Ways to retrofit

• Fiber reinforced polymers
• Steel reinforcement
• Dampers (shock absorbers)
• Connection of walls properly to roof and floor,
  windows and doors
• Increasing shear strength

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Retrofitted Sugarhouse
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Steel Bolts

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Steel Braces
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Laws Passed

• After each major earthquake the state of
  California has established new laws to improve
  seismic safety
• The Field Act (1933) and Garrison Act (1939)
• Hospital Seismic Safety Act (1972)
• The Hospital Facilities Seismic Safety Act (1994)
  
• Un-reinforced Masonry Building Law (1986)

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Conclusion

• After experimenting with our model and
  researching the topic of masonry buildings we
  conclude that the un-reinforced masonry
  structures are more vulnerable to damage than the
  reinforced structure during an earthquake. The
  reinforced structure can withstand greater
  magnitudes of earthquakes and more earthquakes
  than the un-reinforced structures.

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Works Cited

• http//www.sandiego.gov/development-services/indus
  try/urmexamples.shtml
• http//www.staff.city.ac.uk/earthquakes/MasonryBri
  ck/PlainBrickMasonry.htm
• http//images.google.com/imgres?imgurlhttp//www.
  ngdc.noaa.gov/seg/hazard/icons/thumb/14/14_288.jpg
  imgrefurlhttp//www.ngdc.noaa.gov/seg/hazard/sli
  deset/14/14_thumbs.shtmlh58w87sz2hlenstar
  t11tbnidRaCiWVL7Ng2ADMtbnh51tbnw77prev/i
  mages3Fq3Dunreinforced2Band2Breinforced2Bmaso
  nry2Bbuildings26svnum3D1026hl3Den26lr3D26s
  a3DN
• http//pasadena.wr.usgs.gov/office/ganderson/es10/
  lectures/lecture18/lecture18.html

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• ACKNOWLEDGEMENTS
• Thanks to
• Andreas Stavridis
• Jonathan Deck
• Professor Benson Shing
• Jerry Lederman
• Bridget Smith
• Allison Jacobs