Earthquake Retrofitting Services for Unreinforced Masonry Buildings (URM)
Unreinforced masonry buildings (URM) are more vulnerable to earthquake damage “than any other kind of construction”, according to a Federal Emergency Management Agency report.
In fact, the FEMA report “Unreinforced Masonry Buildings and Earthquakes: Developing Successful Risk Reduction Programs,” states, “More than any other kind of construction, [this type of building] can be singled out as being seismically vulnerable.”
Owners of URM buildings are responsible to ensure damage to their structures, as well as death and injury to tenants, employees and pedestrians is minimized. This can be accomplished by having an earthquake retrofit engineered and constructed by Optimum Seismic to enhance the structural safety of your historic or heritage building.
The Problem With Unreinforced Masonry
URM have masonry lacking reinforcement within. The masonry is made of earthen materials, such as stone, brick, hollow-concrete brick, clay tile or adobe. Many URM buildings also feature heavy timber columns and beams within the interior. Heavy and typically weak walls of these structures contribute to their instability during earthquakes, as they often lack horizontal force resistance. Additionally, many include parapets, chimneys or other heavy ornamentation. Overall, URM buildings provide very little or no ductility – the toughness, flexibility or energy absorption capacity – to withstand a significant earthquake.
Optimum Seismic’s team of structural engineers and construction experts have many years of experience in retrofitting URM style historic and heritage buildings to help prevent collapse and injury in earthquakes.
Preserving a Piece of History
Each historic preservation project is unique and requires extensive knowledge of structural engineering, building codes, and city ordinances. Properly restoring these structures comes with unique challenges, not the least of which is limited access to original documentation and complications arising from the original construction techniques.
Despite the difficulties, protecting these extraordinary buildings with earthquake retrofits helps preserve the legacy and character of our cities and protects the community surrounding them. Earthquake retrofits of these buildings also provide financial and practical benefits for building owners and businesses operating within them. These benefits include:
- Reduced risk of personal injury and death
- Reduced risk of property damage
- Reduced risk of litigation and liability
- Reduced insurance costs
- Improves the value and marketability of the building
Unreinforced masonry buildings suffer from multiple structural weaknesses that become especially problematic during earthquakes. Built long before building codes addressed seismic safety, URM buildings simply weren’t designed to withstand earthquake forces. As many of these historic and heritage buildings are located in densely populated areas, they create significant risk for loss of life in the event of a disaster. Fortunately, Optimum Seismic is expert in the techniques and methods to dramatically enhance the seismic resiliency of URM buildings.
With multiple seismic weaknesses, earthquake retrofitting for unreinforced masonry can involve a number of different approaches and tactics.
Seismic Retrofit Techniques for unreinforced masonry
- Better-securing the structure to its foundation
- Joining building elements together to avoid independent movement
- Installing steel bracing systems
- Strengthening unreinforced masonry with composite materials
Act Now to Protect Your Unreinforced Masonry Building
Buildings and property owners are responsible for reducing threats their URM buildings pose for loss of life and injuries to tenants, employees and pedestrians. You can start to reduce these threats and your potential liability today by arranging a consultation and building assessment by the experienced team members at Optimum Seismic.
Optimum Seismic has completed more than 3,500 structural engineering and seismic retrofit construction projects. One of California’s leading earthquake retrofit experts, Optimum Seismic has been named by the Apartment Association of Greater Los Angeles (AAGLA) as the organization’s Preferred Supplier for earthquake retrofit engineering and construction.