There are many wonderful benefits of living in California. The constant sunshine, warm temperatures, and gorgeous beaches are just a few of our favorite things about The Golden State. While people from all over the world flock to California, they often forget about the natural disasters that occur quite frequently there.
Each year, the southern California area experiences roughly 10,000 earthquakes!
At Consulting Engineers Corp., many of our customers come to us with questions regarding seismic retrofitting. Also known as earthquake retrofitting, seismic retrofitting’s primary purpose is to keep your home from being displaced from its concrete foundation during the event of an earthquake. This will leave the structure of your home much safer and less prone to major damages during a natural disaster. In this blog, we’re going to look at some common questions surrounding earthquake retrofitting.
If you live in California and you believe your home may benefit from seismic retrofitting, contact the engineers at Consulting Engineers Corp. today. Our engineers are registered in the states of California, Oregon, Mississippi, and Washington, and they are nationally certified by the Structural Engineering Certification Board (SECB). From commercial buildings to industrial spaces and multi-unit housing developments, we can handle all of your retrofitting needs.
Why Should I Earthquake Retrofit My Home or Business?
There are many reasons to consider retrofitting your home or business. In the state of California, the earth is constantly moving as a result if seismic activity. This means that at virtually any moment, your home or business could be one earthquake away from serious damage, and in some cases, a complete collapse. When you work with a engineer to retrofit your building, they will modify the existing structures of your property so they are more resistant to seismic movement. Some of the main reasons to earthquake retrofit your property, include:
- Keeping your family or employees safe. A large earthquake can wreak havoc on the structure of your building, and it can even bring it to the ground. When you invest in seismic retrofitting for your structure, you can ensure the safety of your family members in your home and the staff or customers in your business.
- Retrofitting can help restore the value of your property. In the event of a big earthquake, the probable maximum loss (PML) is lower on a seismic retrofit property. This means that if you retrofit your home, buyers will regard your property as a more valuable asset, and lenders will view it as a secure investment.
- Abiding to city code requirements. Most popular cities in California, including Los Angeles, have new ordinances that mandate property owners to retrofit their homes or commercial buildings. If you fail to comply to these rules, it can result in serious penalties like fines and even a shutdown of your business.
- Did you know that you can actually save money in insurance premiums by retrofitting your structure? Since an earthquake retrofit can substantially reduce the cost of damages accrued from an earthquake, insurance company’s may reward you with lower premiums.
If you are the owner or facility manager of a building in California that still needs to become compliant with the current seismic preparedness codes for structures, reach out to Consulting Engineers Corp. today.
How Do I Know If I Need To Retrofit My Building?
If you’re unsure whether or not your home needs seismic retrofitting, you can obtain some information about it by simply knowing when it was built. Practically every house built before the 1980s can be improved to reduce the risk of damage during an earthquake. Seismic failures often occur when a house is displaced from its concrete foundation, or when the walls below the main floor of the house collapse. In the first instance, some earthquake retrofitting improvements may consist of strengthening the connections between the house and its foundation. If the walls before the main floor are weak, improvements can be made by supplementing any existing connections to the foundation and strengthening the supporting walls.
There are many things that can help you determine whether or not your home is due for improvements. The existing strength of your structure, as well as its earthquake vulnerabilities, can be determined by a engineer.
What Are Common Types of Seismic Retrofitting?
If your home or business could benefit from seismic retrofitting, it’s important to remember that there is no such thing as a “standard” retrofit. When you reach out to a engineer to conduct a thorough inspection of your structure, they will be able to help you determine the best retrofitting solutions for your building. Let’s take a look at some popular methods of earthquake retrofitting below.
Foundation bolting is pretty much what it sounds like. This kind of seismic retrofit usually means that bolts are added to the foundation of the building to improve its internal connections. These bolts are often used with wooden framing members that are attached to the concrete foundation of the building. Your home may have existing bolts, and if that’s the case, your engineer will work to ensure they are strong enough to withstand earthquake movements.
When it comes to successfully retrofitting the foundation of your building, careful planning and installation is a necessity. It’s important for your engineer to use the best kind of bolt for your home’s condition. The two main kinds of foundation bolts used in foundation bolting are:
Expansion Foundation Bolts
Expansion foundation bolts, also known as mechanical foundation anchor bolts, are a common type of bolt used in earthquake retrofitting. They are normally utilized to anchor the mudsill to the foundation, and they tend to be relatively inexpensive to install. It’s important to note that they do require excellent concrete strength to work well. You’ll find these bolts in houses with newer foundations.
Epoxy-Set Foundation Bolts
If you have an older home with a weak foundation, there’s a good chance your engineer will use epoxy-set foundation bolts on your home. These bolts tend to work better than mechanical anchor bolts where the concrete can be weaker than the actual home. These bolts are also known to perform well when the earthquake force is expected to cause an uplift. When an uplift occurs, the force from the earthquake expels energy upward, which can loosen the bolts in your home.
Cripple Wall Bracing
In the state of California, hundreds of homes have been devastated by the effects of an earthquake due to a cripple wall collapse. But what is a cripple wall? Many homes throughout the state have a short wood-framed wall in the sub-area of their crawl space. Depending on the construction of the home, this wall can be anywhere between a few inches to several feet in height, and it usually runs from the top of your concrete foundation to the bottom of the main floor. The collapse of this wall may result in the main floor of your home dropping to the ground.
Engineers have found unique ways to help strengthen the cripple wall of structures so they are not damaged or devastated by an earthquake. Stiffening or bracing the cripple wall to keep it from collapsing is a very prominent part of earthquake retrofitting. Bracing can be accomplished by attaching high-grade plywood tightly to the cripple wall’s framing. In engineering terms, this stiffened wall is known as a “shear wall.”
Foundation Holdown Brackets
If your engineer feels that your shear wall isn’t strong enough to withstand the movements of an earthquake, they may install additional holdown brackets to anchor the shear walls. Holdown brackets are specially made, right-angle brackets that connect the cripple wall framing to the foundation of the home. These brackets are designed to prevent a shear wall from lifting or rolling in the event of an earthquake.
Why Is A Seismic Contractor Qualified To Make These Recommendations?
Due to the recent major earthquakes that have struck California, several governmental agencies and private engineers have made extensive examinations on the structures of damaged buildings. They have used past earthquakes to help identify failure points in homes and businesses, and other areas of improvement when it comes to seismic construction. Many of their suggestions have been adopted into revisions of the Uniform Building Code, and they have been incorporated into new construction projects since that 1989.
The California Seismic Safety Commission, along with the Association of Bay Area Governments and the International Conference of Building officials, have all come together to sponsor training programs for contractors across California. During these training programs, contractors are encouraged to learn more about the benefits of seismic improvements for their properties.
Consulting Engineers, Corp: Your Partner In Seismic Retrofitting
If you live in California and you believe your home or commercial building could benefit from seismic retrofitting, schedule a consultation with our engineers today. We’re proud to be recognized as leaders in the design and engineering industry, and we can help ensure that your structure is safe from seismic movements. With more than 47 years of experience under our belts, we can assist you with commercial, industrial, and multi-unit residential projects.