Seismic Evaluations/Risk Assessments
We provide accurate, building -specific information about earthquake risk.
Retrofitting involves fitting new seismic systems into existing spaces, often with restrictions. The engineering is often challenging, requiring good vision and intuition at the start along with sound analytical thinking throughout the design.
We apply our engineering experience and knowledge of earthquake vulnerabilities with the appropriate analytical standard. In most cases, ASCE 41 is followed, but other standards may be appropriate. Ask us about how to get a USRC seismic rating for your building!
We’ve developed expertise in engineering retrofits for URM (unreinforced masonry/ brick) buildings, soft story buildings, and hillside homes- 3 of the most dangerous building types in earthquakes.
Many older buildings have multiple seismic deficiencies, and it’s often not feasible to improve all of them. In many cases, improving one or two of the main deficiencies can significantly reduce risk of injury or economic loss. We understand real world limitations and support partial retrofitting when it makes sense. Our goal is to accurately communicate seismic risk and let you make the decisions based on your budget and risk tolerance.
Homeowners
The Threat of a Cascadia Earthquake Looms Off the Coast of the Pacific Northwest
Every house is unique, and “textbook” retrofit techniques
often don’t apply
In older homes, the wood-framed house is not anchored to the foundation. It is common for houses to slip off their foundations in earthquakes. While this usually doesn’t result in severe injury, it can result in a complete economic loss of the house and render it unusable after the earthquake. Retrofitting can be inexpensive insurance. For simple homes, engineering is not required. A seismic retrofit contractor is recommended. We’re happy to recommend a contractor or give some guidance to committed DIY homeowners.
Many houses have cripple walls: a short, wood-framed wall between the first floor and the foundation. These can be a significant seismic vulnerability, sometimes even in houses as new as the ‘80’s and ‘90’s. During an earthquake, a house with a weak cripple wall can smash the cripple wall and shift off the foundation. Retrofitting is strongly recommended; this type of work should only be done by an experienced seismic retrofit contractor. Engineering may or may not be required depending on the configuration.
This demographic of homes is by far the most dangerous of all single-family dwellings in earthquakes. The seismic risk varies significantly from house to house, from low to extremely high risk. A seismic assessment by a structural engineer is strongly recommended for homeowners or potential buyers. We specialize in assessing and retrofitting these complex structures; please contact us!
In many older homes, the concrete foundations have deteriorated significantly and it’s questionable, or sometimes obviously useless, to retrofit by anchoring to these foundations. In addition, in houses with concrete basement walls, deterioration could lead to an inward basement wall failure. While these are long term structural concerns in general, an earthquake could cause a sudden failure. Replacing the foundation with new steel-reinforced concrete is the most thorough solution, but there are many intermediate solutions worth considering.
Seismic vulnerability of any building is a combination of the structural and geologic vulnerabilities at that site. Two primary geologic hazards are of biggest concern in the Pacific Northwest: soil liquefaction and earthquake-induced landslide. Our assessments always consider basic geology, both mapped risk and observations at the site. Geotechnical assistance is recommended in some cases. Soil liquefaction potential generally strengthens the case for seismic retrofitting, as it would likely increase stresses on the house during an earthquake.
This condition is considered a significant seismic vulnerability when it occurs in any type of structure, and it has resulted in catastrophic damage and fatalities in many cases. For a house, a “soft story” often occurs at a living space over a garage, or any situation where an upper story sits above a lower story that lacks stability below. This condition varies in severity and risk. Mitigation can be done in many ways and requires engineering.
Split-level houses, additions, and miscellaneous complexities often increase seismic risk. We specialize in complex homes and would be happy to help you assess and or mitigate your seismic risk for these unique conditions.
Brick chimneys are notoriously bad in earthquakes. Chimneys that extend far above the roof line are particularly vulnerable and likely to collapse near the roof line even in moderate earthquakes. Exterior chimneys often peel away from the house. Brick veneer and stone veneer can also collapse away from a wood-framed house. Brick houses and brick basement walls are also vulnerable, as are similar brittle materials such as clay tile. We have expertise with URM buildings and can assess seismic risk and engineer retrofits for these conditions.
Decks and porches extending from a house can collapse in earthquakes. Often, they are tacked onto the side of a house without strong connections. Large decks with complex configurations can be vulnerable.
In houses without significant earthquake vulnerabilities, like newer or retrofitted homes, the contents are likely to cause the most damage and injury in an earthquake. Because the contents of every home are different, homeowners should spend some time going on a “home hazard hunt” to identify the most vulnerable contents. Correctly installed seismic straps on the hot water heater are important. Heavy shelving, china cabinets, and wall-mounted paintings are examples of contents that may need stabilizing.
About The Company
We are a structural and earthquake engineering business dedicated to improving the seismic resiliency of our existing buildings in the Pacific Northwest.
I am a structural engineer with 22 years of experience designing and assessing the condition of various buildings and structures in the residential, commercial, and industrial sectors. I am a registered engineer in Oregon, Washington, and Arizona.
I am also a member of the Structural Engineers Association of Oregon (SEAO), the Earthquake Engineering Research Institute (EERI), and I’m trained in various earthquake assessment methodologies such as FEMA P-50, P-58, P-154, ASCE 41, and ATC-20/ Cal OES post-earthquake inspection.
I am a structural engineer with 22 years of experience designing and assessing the condition of various buildings and structures in the residential, commercial, and industrial sectors. I am a registered engineer in Oregon, Washington, and Arizona.
I am also a member of the Structural Engineers Association of Oregon (SEAO), the Earthquake Engineering Research Institute (EERI), and I’m trained in various earthquake assessment methodologies such as FEMA P-50, P-58, P-154, ASCE 41, and ATC-20/ Cal OES post-earthquake inspection.
Our Customers Love Us
Don’t Just Take Our Word For It, Read It From Them
Kit Homeowner - SE Portland
“BJ’s involvement in our seismic retrofit was very helpful, from his initial risk assessment to the engineered design to his engagement during the construction. He is very creative and thinks outside the box to solve complex seismic issues while thinking about the cost. He worked closely and had a great relationship with our contractor, crew members and me. He was very responsive, personable and professional. And he was quick to respond to any issue that surfaced during the project. I highly recommend him if you are looking for a competent engineer for a seismic upgrade.”
Michael Wieber Owner – NW Seismic
“I appreciate BJ’s collaborative approach to design. Rather than simply handing over a completed set of drawings, in which case I’ll likely need to submit multiple RFI’s to substitute more appropriate hardware based on my many years of experience in the field, BJ will contact me to discuss his thoughts on the project and solicit my input. His openness to working with contractors on the design end, and his availability makes for a smoother and speedier project and schedule.”
Ryan Deckert Former President, Oregon Business Association
“BJ came to our house and performed a thorough initial inspection, as I have read the same news as other Oregonians, and want to ensure we are protecting our house living in the Cascadia Subduction Zone. The good news was: we are in pretty good shape. He did recommend two improvements and we are now pursuing the first with the firm he provided; bolting our 1947 house to its foundation.”
Alex homeowner - NE Portland
“BJ took the time to evaluate our house carefully, and he patiently answered all our questions. He ended up identifying several seismic hazards that our house faced, which had been missed by earlier contractors. For any homeowner who takes seismic safety seriously, I would unhesitatingly recommend calling BJ to get a thorough and rigorous evaluation of your house’s seismic vulnerabilities and what can be done to mitigate them.”