Download - Unreinforced Masonry Buildings
Unreinforced Masonry Buildings
By: Erica and Laura Garcia
Abstract
• The affect of earthquakes on un-reinforced 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/development-services/industry/urmexamples.shtml
• http://www.staff.city.ac.uk/earthquakes/MasonryBrick/PlainBrickMasonry.htm
• http://images.google.com/imgres?imgurl=http://www.ngdc.noaa.gov/seg/hazard/icons/thumb/14/14_288.jpg&imgrefurl=http://www.ngdc.noaa.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=/images%3Fq%3Dunreinforced%2Band%2Breinforced%2Bmasonry%2Bbuildings%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 DeckProfessor Benson Shing
Jerry LedermanBridget SmithAllison Jacobs