As the old saying goes, people’s homes should also be their castles. Not only that, but houses should be places of safety and security, providing protection and shelter for their occupants.
Unfortunately, a shockingly high number of homes that are located in the iconic city of Los Angeles may offer their occupants neither safety nor security. These structures are known as soft story buildings, and these structures have shown a penchant for collapsing on their residents when earthquakes make their periodic appearances.
Members of the Los Angeles County building inspection department have identified nearly 14,000 of these soft story structures around the city. With this many potentially unsafe buildings in existence and the clock ticking on the next devastating earthquake, it is obviously a priority for these buildings to be reinforced in some way before the worst happens.
This posting will take a closer look at this dangerous situation, and will answer some questions that are relevant to the subject along the way. These questions include: What are soft story buildings? Why are these buildings often incapable of withstanding the seismic stresses caused by earthquakes? And, what are some proposed solutions to this pressing problem?
What are Soft Story Buildings?
When the population in the Los Angeles area began to grow many decades ago, the existing stocks of real estate proved inadequate to the task of sheltering the new arrivals. In response to the developing real estate crisis, builders began constructing new housing units that were capable of providing shelters for multiple residents. These new units were framed with wood, had open ground floors for parking space, and often had several stories above these open first floors. Because of the open and largely unreinforced first stories that characterize these structures, they became known as soft story buildings. While these kinds of structures were often popular with residents for various reasons, it eventually became clear that they could turn into death traps under the right–or wrong–circumstances.
Why are Soft Story Buildings Dangerous During Earthquakes?
The Northridge earthquake struck the city of Los Angeles on January 7, 1994. During the course of the Northridge quake, many soft story structures succumbed to the violent shearing forces produced by the tremblor. One such structure was the Northridge Meadows apartment building, which completely collapsed during the earthquake and killed some 16 residents in the process.
Why did this happen? The former Northridge Meadows building had several flaws which can also be found in the majority of Los Angeles based soft story buildings. These buildings contain a lot of open and unreinforced spaces on their ground floors. While this may be convenient for parking vehicles, it also severely reduces the rigidity and strength of these floors.
The majority of these buildings also contain a lot of wood, a cheap construction material. While wood certainly has its place in the construction world, the way that it was used in the ground floor areas of soft story buildings provided inadequate support for the floors located above. This is because earthquakes can produce strong lateral forces when they strike, forces that unreinforced wood has little chance of resisting. The end result usually involves the collapse of the first floors of soft story buildings. When this happens, the floors above will naturally collapse downwards, crushing both the underlying floors and anyone who happens to be on these floors.
What are Some of the Proposed Solutions for This Issue?
Los Angeles city officials have been aware of the potential dangers of soft story buildings for some time, and in recent times have worked to pass a new law that is designed to rectify these dangers. This law requires owners of soft story buildings to retrofit and strengthen their properties within seven years, and also allows property owners to pass on part of the retrofit costs to tenants in the form of slight rent increases.
While the soft story retrofitting project continues to be a work in progress, successful completion of it will doubtless help to save many properties when the next big quake strikes. More importantly, it may also save many lives.