Earthquakes can happen at any time. Without warning, seismic forces can severely damage your building’s structural elements. Setting up a retrofit program and reinforcing your property with a sturdy seismic design gives your facility the edge it needs to withstand earthquakes and stand tall for many years.
Learn more about the benefits of seismic reinforcement and how you can build an earthquake-resistant building.
The Difference Between Earthquake-Proof and Earthquake-Resistant Buildings
There is no such thing as an earthquake-proof building. While improvements like reinforced concrete and steel bracings provide a lot of protection against ground shaking, no seismic retrofitting measure can guarantee full immunity. However, buildings can be earthquake resistant, and that’s the goal of an earthquake retrofit—to optimize your property’s seismic protection and maximize its chances against natural disasters.
Even though perfect earthquake defense isn’t possible, property owners need to do all they can to reinforce their buildings. According to the National Earthquake Information Center, there are around 20,000 earthquakes worldwide every year. With 15,700 known faults in California, the state has more than a 99% chance of having one or more magnitude 6.7 or larger earthquakes over the next 30 years.
Without an earthquake-resistant building, you’re at nature’s mercy. Few existing structures located along fault lines are designed to withstand earthquakes. While a worthwhile retrofit program could cost $60,000 to $130,000 in California, there are many retrofitting techniques you can use, and a capable commercial construction service provider can work with you to build a plan that aligns with your short- and long-term business objectives.
Seismic Retrofitting Techniques for Buildings and Their Benefits
The side-to-side ground shaking earthquakes can significantly damage a building that isn’t set up with the right seismic design. The movement vibrates walls, floors, columns, and other structural elements, causing severe stress on the structure. A building’s supporting frame can collapse if the shaking is powerful enough.
There are many ways to withstand an earthquake. While each of the following retrofitting techniques is useful, a comprehensive seismic protection plan includes a combination of upgrades to make sure you get the most resistance. Here are a few ideal seismic reinforcements:
Shear Walls
Shear walls transfer seismic forces. They help buildings keep their shape during ground shaking with their multilayered structure. Shear walls paired with steel braces are exceptionally sturdy, as the beams can counteract seismic pressure through their compression and tension support.
Moment-Resisting Frames
These frames improve flexibility in buildings. Once installed around the structure’s joints, the building can withstand bending in columns and beams without sustaining damage. Because the frames are unintrusive, building managers have free rein to implement other design elements without affecting the seismic design.
Diaphragms
Diaphragms are horizontal frames that distribute seismic forces to the columns and walls. They reduce tension on the floor and withstand horizontal movement in an earthquake.
When building an earthquake retrofit plan, you need an expert touch. RSP Group founder Paula June Bakjajian has over 50 years of experience in commercial and residential construction services and brings all of her skills to bear on your renovation project.
San Francisco’s Soft-Story Ordinance
The Earthquake Safety Implementation Program and Department of Building Inspection introduced the Mandatory Soft Story Retrofit Program (MSSP) in 2013. Under the program, wood-framed buildings of three or more stories or two stories over a basement or underfloor area with a soft-story structure built before January 1, 1978, are required to implement a seismic retrofit plan.
Over 5,000 San Francisco properties must participate in the program, and over 700 building managers have completed their seismic retrofitting. These buildings house over 150,000 residents and are more vulnerable than other structures due to their soft-story build.
What Is a Soft Story Building?
A soft-story property is a wood-frame building with a first story that is a lot weaker than others due to a lack of frames or walls. These buildings often feature large parking areas or commercial spaces on the first floor, leaving the site vulnerable to seismic forces. The side-to-side movement of an earthquake is too intense for these open floors, and when they fail to support the weight of the stories overhead, there’s a chance the whole structure could collapse.
What Buildings Fall Under the Program?
A soft-story building at risk for earthquake damage and eligible for seismic protection has the following characteristics:
- Type V building as defined by the San Francisco Building Code
- Application of permit for original construction obtained before January 1, 1978
- Five or more residential units
- Two or more stories over a basement or underfloor area with a portion extending above grade
- A soft-story condition as determined through a screening process conducted by a licensed design professional
How Much Does a Seismic Retrofit Cost Under the Program?
The cost of seismic retrofitting varies depending on the risk level and protection needed. Building managers must work with a licensed civil or structural engineer or architect specializing in retrofitting techniques and building seismic protection plans. According to the Community Action Plan for Seismic Safety (CAPSS) analysis, the average cost of seismic reinforcement is between $60,000 and $130,000, depending on the building size.
Introduce Effective Seismic Reinforcements With RSP Group
Making sure your property lasts as long as it could is easier when you have a construction expert in your corner. RSP Group offers seismic upgrades to buildings in the San Francisco area. Our steel bracings and shear walls prevent your building from swaying under pressure and offer more protection than a traditional build. Our team is creative and collaborative. We share your vision and strive to make the construction process simple and enjoyable.
Ready to protect your property? Reach out today.
