Contrary to what many people believe, a soft story retrofit job is more specific than a general seismic risk assessment. The retrofit evaluation addresses a floor of a building that’s considerably weaker than the other floors.
What is “Soft Story”?
The term refers to one story of a building which is particularly more flexible or fragile in lateral load resistance than the foundation below it and the floors above it. This can happen in any of the dated buildings and is generally associated with an unusually tall floor height compared to the adjoining floors or large openings in the walls.
These weak levels are called soft stories and they present a severe risk in the event of seismic activity – both in terms of human safety and property damage.
Here are the most common sources of seismic vulnerabilities:
- Ground story tuck-under garages underneath wood-framed apartment complexes
- Retail buildings with the store front made of glass
- Tall first story height, common in older high-rise and mid-rise commercial buildings where the first story is usually double the height of a normal story directly above it
- Buildings with glass-store-fronts retail shops on the ground floor and residential apartments on the top
City Ordinance Requiring Mandatory Soft Story Retrofit
A mandatory seismic retrofit ordinance was passed by the City of Los Angeles in 2015. According to this ordinance, retrofitting is crucial for reinforcing two types of vulnerable buildings in LA:
- Non-ductile concrete buildings that were constructed before 1977
- Wood-frame soft story buildings that were constructed before 1978
The Soft-Story Retrofit Options
Weinstein Construction is expert in designing seismic retrofit plans; we combine our 40+ years of structural engineering experience with our client’s business to create the perfect plan. So, some of the most common installations to modify soft-story buildings are:
- Concrete Shear Walls
- Cantilevered Steel Columns
- Plywood Shear Walls
- Continuity Ties
- Braced or Moment-Resisting Steel Frames
- Strengthening Unreinforced Walls
- Foundation, Roof and Wall Anchors
- Foundations and Grade Beams
- Base Isolation
- Collector Detailing
- Jacketing of Columns
Retrofitting not only protects the residents of the building, it also protects you from massive financial liabilities. If an earthquake hits and even one of your tenants is hurt because you didn’t retrofit your soft-story building, you are liable for millions of dollars in damages.
Therefore, protect your interests and call us at 888-609-4876 for a free soft-story retrofitting inspection today. Prefer email? Drop us a line here to know more.