Earthquake Retrofitting Services for Unreinforced Masonry Buildings (URM)
Unreinforced masonry buildings are especially vulnerable to earthquakes. 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.”
It is the responsibility of URM building owners to ensure that damage to their structure, as well as death and injury to tenants, employees and pedestrians is minimized. This can be accomplished by having an earthquake retrofit of your historic or heritage building performed by Optimum Seismic.
The Reality of Unreinforced Masonry.
URM is generally defined as 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. The heavy and typically weak walls of these structures contribute to their instability during earthquakes, and they often lack significant horizontal force resistance. Additionally, many include parapets, chimneys or other heavy ornamentation. Overall, URM buildings are said to provide very little or no ductility – the toughness, deformability or energy absorption capacity – to withstand a significant earthquake.
Optimum Seismic’s team of engineers and construction experts have many years of experience in retrofitting historic and heritage buildings to help prevent collapse and injury in earthquakes.
Preserving a Piece of History
Each historic 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 difficulty, protecting these extraordinary buildings from earthquakes is essential to preserving the legacy and character of our cities and protecting the community surrounding them. Earthquake retrofits of these buildings provides financial and practical benefits for building owners and businesses operating within them:
- Limits the risk of personal injury and death
- Limits the risk of property damage
- Limits the risk of litigation and liability
- Reduces insurance costs
- Improves the value and marketability of the building
Unreinforced masonry buildings suffer from multiple seismic weaknesses. Most were built long before building codes were in place to address seismic safety, and simply weren’t designed to withstand the forces of an earthquake. Furthermore, many of these historic and heritage buildings are located in densely populated areas, creating significant risk for loss of life in the event of a disaster. Fortunately, there are tools 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 retrofitting for unreinforced masonry includes:
- 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
Making Civic Decisions that Keep Our Cities Safe.
Buildings and property owners are responsible for making certain that damage to URM buildings and injury or loss of life for tenants, employees and pedestrians is minimized. Start today by scheduling a consultation and analysis from one of our experienced team members. Optimum Seismic has completed thousands of seismic retrofit projects, and is Southern California’s leading 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.
Optimum Seismic is a recognized expert in steel fabrication and construction in the state of California. Our team has decades of experience working with clients to customize programs that match their goals and needs. Let us engineer an optimal retrofit solution for your building.