Unreinforced Masonry Buildings
By: Erica and
Laura Garcia
Abstract
• The affect of earthquakes on unreinforced masonry buildings and
solutions to reduce the damage of future
earthquakes.
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.
Experiment
• Sugar Cubes (brick)
• Peanut Butter
(mortar)
Failure of Masonry
Structures
•
•
•
•
Typical failures occur in:
Walls
Windows, doors
Unsymmetrical plan of building
Failure Modes
• Shear
• Sliding shear
• Bending
Un-reinforced Masonry
Shear
Examples
• Wall Failure
Shear Failure
Bending
What is retrofit?
• Retrofitting is the way that many buildings are
reinforced to better withstand the shaking of an
earthquake.
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
Retrofitted Sugarhouse
Steel Bolts
Steel Braces
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)
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.
Works Cited
•
•
•
•
http://www.sandiego.gov/developmentservices/industry/urmexamples.shtml
http://www.staff.city.ac.uk/earthquakes/MasonryBrick/PlainBrickMaso
nry.htm
http://images.google.com/imgres?imgurl=http://www.ngdc.noaa.gov/s
eg/hazard/icons/thumb/14/14_288.jpg&imgrefurl=http://www.ngdc.noa
a.gov/seg/hazard/slideset/14/14_thumbs.shtml&h=58&w=87&sz=2&hl
=en&start=11&tbnid=RaCiWVL7Ng2ADM:&tbnh=51&tbnw=77&prev=/i
mages%3Fq%3Dunreinforced%2Band%2Breinforced%2Bmasonry%2
Bbuildings%26svnum%3D10%26hl%3Den%26lr%3D%26sa%3DN
http://pasadena.wr.usgs.gov/office/ganderson/es10/lectures/lecture18
/lecture18.html
ACKNOWLEDGEMENTS
Thanks to
Andreas Stavridis
Jonathan Deck
Professor Benson Shing
Jerry Lederman
Bridget Smith
Allison Jacobs