What do you mean by soft story building?
The term “soft-story” refers to one level of a building that is significantly more flexible or weak in lateral load resistance than the stories above it and the floors or the foundation below it (70% or greater reduction from one floor to the next according to the modern, International Building Code (IBC) definition).
Is my building a soft story building?
A typical soft story building is an apartment building of three or more stories located over a ground-level that has large openings, like tuck-in parking garages, or any other large openings. The first floor is considered weak because it is missing adequate shear walls.
What is a soft first story building?
Technically, the definition of a soft story building is one in which the first story has 70% or less stiffness than the second story or 80% less stiffness than the average stiffness of the three stories above it.
Are soft-story buildings safe?
Any soft-story apartment building in Los Angeles, West Los Angeles, and the San Fernando Valley that were built prior to 1980 are considered at risk of collapse during an earthquake. The risk is even higher for soft-story buildings built along fault lines, like the new earthquake faults identified in West Los Angeles.
What is a soft structure building?
A soft-story building is a structure which has a weaker first floor and is unable to carry the weight of the stories above during an earthquake. The first floor generally would have large openings in the perimeter walls such as garages, tuck under parking or even large windows.
Does liquefaction cause earthquake?
Liquefaction takes place when loosely packed, water-logged sediments at or near the ground surface lose their strength in response to strong ground shaking. Liquefaction occurring beneath buildings and other structures can cause major damage during earthquakes.
What is a non ductile concrete building?
Most concrete buildings built prior to 1977 are non-ductile concrete. “Non-ductile” means inflexible or brittle. Due to a lack of reinforcing steel in buildings designed before the implementation of the 1976 building code, these older buildings may not safely resist forces caused by earthquakes.
How do I know if my building has been retrofitted?
Using the Department of Building and Safety website, you can easily check to see if your building is on that list. Just enter your address into the search tool and click on the “Soft-story Retrofit Program Information” button once your building’s information appears.
What is soft storey and weak storey?
SUMMARY: “Soft story” and “weak story” are irregular building configurations that are a significant source of serious earthquake damage. These configurations that are essentially originated due to architectural decisions have long been recognized by earthquake engineering as seismically vulnerable.
Would buildings collapse in an earthquake?
This type of apartment building design is prone to structural failure and collapse during earthquakes if not built to modern building code. Such buildings collapsed in the 1989 Loma Prieta earthquake and the 1994 Northridge earthquake, including one apartment building where 16 people died.
What does tuck under parking mean?
Tuck-Under Parking means parking spaces that are covered by the upper floor of a building, but are otherwise open.
What is soft-story retrofitting?
What is a soft-story retrofit? A soft-story retrofit simply adds to and reinforces the structure of the building so it can hold up much better in an earthquake. The main goal is to make sure the building is still standing after an earthquake hits and ensure the safety of everyone in and around the building.