When California was hit by its most recent major earthquake, some buildings stood undeterred while others shifted off their foundations.
Los Angeles has implemented a mandatory retrofit program under Ordinance 183893 and Ordinance 184081 to address structural deficiencies cost-effectively and safely.
Soft Story Retrofit
Soft-story buildings, as you may already be aware, can be particularly susceptible to earthquakes. This is particularly true of older structures built without regard for seismic safety.
Earthquake retrofitting Los Angeles, CA, and other California cities have passed ordinances mandating that soft-story buildings undergo earthquake retrofitting in order to lessen the risks posed by major quakes and reduce any catastrophic damage they might cause. These retrofits aim to reduce catastrophic loss associated with major earthquakes.
Soft story buildings are a type of architecture that typically feature an open bottom floor and upper stories containing apartments or office space, with parking garages that tuck under to provide for easy accessibility.
Under an earthquake, these types of buildings are highly vulnerable to collapse due to a lack of shear walls that provide resistance against shaking. Two years ago in Taiwan, a 17-story apartment building featuring soft stories was completely leveled when its facade gave way and killed more than 100 people.
If your soft-story building has been designated for retrofitting, your city or county may mandate that the necessary measures are completed in a certain period of time. The amount of work necessary and its complexity will ultimately dictate this time frame.
If your building features garages or large windows on the ground level, these openings must be reinforced so they do not collapse during an earthquake. This type of floor reinforcement is known as an “open ground floor”, which can be more challenging in soft-story buildings than reinforcing traditional structural walls.
Retrofitting typically involves installing new sheathing boards and steel reinforcements, in addition to having a dragline installed as a means of transmitting earthquake loads directly onto a steel frame.
Expect your soft story retrofit to take between one to four weeks depending on its scope and the type of building you own. Alpha Structural offers soft-story retrofitting services for residential and commercial soft-story buildings alike – so get in touch now if your soft-story building requires retrofitting!
Raised Foundation Retrofit
Los Angeles offers an astounding variety of housing types. Each style can carry unique risks that warrant earthquake retrofitting to prevent any possible damage to their structures.
Soft-story houses are one of the most common types of home construction, featuring one or more floors above an attached garage. While this style of dwelling may provide additional living space, soft-story homes may be vulnerable to earthquake damage.
Many of these houses feature a crawl space below their first-floor area, known in the industry as an attic space. Without proper bracing and bolting systems in place, such homes may shift off their foundation during an earthquake and cause significant structural damage to both people living inside and the house itself.
Retrofitting older houses for earthquake protection can help them remain standing. Aside from protecting these older structures from structural damage, earthquake retrofits may also help lower insurance premiums and provide substantial cost savings.
Los Angeles soft story contractors specialize in soft story retrofits that include engineered metal connectors and reinforcement materials at key stress points throughout your home’s structure, such as hold downs, anchor bolts, strap ties or framing angles.
When hiring a contractor to perform your soft story retrofit, look for one with extensive experience and recent projects to assess whether they have what it takes to improve the resiliency of your home.
Be sure to ask if they have experience working with multiple clients and the level of communication during the retrofit process; this will give an accurate representation of their professionalism and work ethic.
Not only can hiring an expert Los Angeles soft story retrofit contractor offer you peace of mind against earthquakes, they can also increase the market value of your property and potentially save up to $200k in repair costs after major earthquakes. Research indicates retrofitting can save homeowners between $10,000-200K in repair expenses post-quake.
Post-and-Pier Retrofit
Post and pier construction is an economical and popular method of homebuilding but is particularly vulnerable during an earthquake due to not incorporating an uninterrupted concrete perimeter foundation.
Preventing this from happening requires strengthening and stiffening the first floor of a home using steel bracing systems installed strategically around its perimeter.
Push pier systems from our company are used to stabilize and raise sinking and settling foundations by using heavy-duty round steel tubes connected by load transfer brackets (retrofit foundation repair brackets). Pier sections are hydraulically driven through these foundation brackets into stable soils or bedrock to transfer the weight away from unstable areas of the site, giving a secure foundation on which structures may stand.
Lux Construction Group of Los Angeles can assist in strengthening and protecting your foundation with seismic retrofitting solutions from start to finish. Contact our experienced team for all of your seismic retrofitting needs today.
At each retrofit stage, our expert engineers will carefully assess each component of your home to ascertain the most efficient way to secure it. This includes testing each beam’s strength and weight as well as checking whether four corners load onto the ground floor simultaneously.
Once we have determined the optimal solution for your home, we will begin the installation process. We will excavate around the foundation and mount heavy-duty steel foundation brackets at every pier location.
Once our brackets are secure, we will install our push piers. After placing each section into its respective brackets, they are hydraulically driven through into suitable soil or bedrock for driving.
Time-consuming but well worth your while; at the end of this project your foundation will be permanently stabilized.
Post and pier retrofit not only strengthen and stabilize your foundation, they can also save you from costly earthquake repairs by helping prevent pancaking or collapsing in buildings that frequently experience earthquakes. They are especially beneficial if you live in areas that experience frequent earthquakes.
Hillside Retrofit
Los Angeles is home to an exceptionally complex geography and seismic risk profile, necessitating the need to secure and strengthen hillside properties for their protection from soil movement during heavy rainstorms or earthquakes, which can cause devastating landslides or mudslides that cause serious property damage. To prevent any missteps from this area causing additional issues with hillside structures.
Prior to building on any property, it is crucial that professionals specializing in hillside retrofitting are consulted in order to reduce structural failure risks and quake damages. This can reduce risks significantly.
There are various slope repair and foundation strengthening systems available for buildings of varying types. Steel moment frames, shear walls or diagonal bracing may be added as one method to strengthen slopes or foundations.
Retrofitting may also involve adding new floor levels, which is often required by insurance companies in high-rise buildings to minimize injuries and fatalities caused by earthquakes. Such modifications could help lower injury risks.
Other factors that could hinder a hillside retrofit’s success include age and structural integrity of existing structures as well as local weather conditions. Any building with steep slopes should undergo a retrofitting assessment to ensure it can withstand an earthquake safely.
At all times, it is paramount to consider the safety of anyone living on the property – including elderly individuals and those with physical disabilities – particularly if there is difficulty traversing steep slopes.
Construction crews can combat wet weather erosion through the use of wet weather erosion control plans (C Sheets). These documents outline how grading and other construction activities will be carried out so as to keep soil from washing from their site into surrounding properties, water courses or nearby creeks.
As well as developing a wet weather erosion plan, it is also recommended that sites be landscaped and sloped correctly in order to minimize soil erosion and the threat it presents to residents. Retaining walls and other landscaping techniques may help with this goal.
Hillside stabilization requires working with a reliable company that offers exceptional services. At Ecocentrix Landscape Architecture, our team is focused on helping clients create outdoor environments that are both beautiful and safe, including extensive feasibility studies as well as tailored slope stabilization services such as landscape design and maintenance.