Seismic Retrofit Services

Penhall Retrofit Plans for Seismic Retrofit, Soft Story Seismic Retrofit

Penhall is your top choice for seismic engineering and construction services for every type of seismic retrofitting. Penhall Company is celebrating 60 years of excellent service! Whatever your design build need we are ready assist you with your next seismic retrofitting project.

Penhall has a long history of seismic work. While we possess the resources and capabilities to take on any size contract, we consider no job too specialized, too large or too small. We believe that every project deserves our utmost attention to detail and commitment to client satisfaction. Our clients know they can depend on us to get the job done on time and on target, from start to finish and every step in between. Whatever your needs, wherever you’re located, trust Penhall Seismic retrofit services do it right.

Seismic Retrofitting Service at Penhalll

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Buildings at Risk from Seismic Events

Soft Story

Currently in California the most common type of seismic retrofitting is called soft-story retrofit.  The weak wood frames are often seen in multifamily apartment dwellings with tuck under parking.  This style of  building is a common design in both San Francisco and Los Angeles. Due to multiple seismic retrofit ordinances in the State of California cities like San Francisco and Los Angeles have already begun engineering and construction to become compliant. Other cities are following suit like Santa Monica and West Hollywood.  We expect many more cities to jump in line to become compliant with new seismic safety standards.   Common solutions for soft-story retrofitting are steel special moment frames, cantilevered column solutions, or shear wall paneling.

Non-Ductile Concrete

Another type of seismic retrofitting includes non-ductile concrete buildings. Often seen in multi-story buildings built pre 1978 before seismic codes were tightened. The buildings are considered reinforced concrete in design, but  often don’t have enough steel reinforcement to handle a major seismic event. While there are several combinations of solutions for non-ductile concrete steel beam installations and polymer fiber wrap solutions are often used to retrofit non-ductile concrete buildings.

Unreinforced Masonry (URM)

URM construction is another type of seismic retrofit that Santa Monica is most recently preparing for. This type of construction often seen on older historic buildings has no metal or steel reinforcements at all and is literally often only brick and mortar. A common solution is to center core or drill through the bricks vertically and thread rebar or steel through and pour back concrete to secure hole.

Penhall launched operations nearly 60 years ago supporting southern California with a singular commitment to providing the highest level of services to its clients. Since then, Penhall has expanded its reach, scope and expertise, serving clients across the U.S. and beyond. Today, Penhall encompasses 41 strategic locations and employs more than 1,200 professionals, with current and ongoing expansion into Canada. We’ve dedicated that last 60 years to honing our specialized seismic, scanning and concrete services.

Common Soft Story Retrofit Solutions

What are moment frames?

  • A moment frame is a system of columns and beams that are connected to one another with fully and/or partially restrained connections.
  • A special moment frame is expected to withstand significant inelastic deformation as a result of lateral forces. They are used typically in mid/high-seismic regions and are significantly more expensive than other retrofit options.

What are cantilever columns?

  • A cantilever is a horizontal beam that is unsupported at its end.
  • A cantilever column is the vertical component that supports the horizontal cantilever beams.

What are shear walls?

  • A shear wall is a vertical-oriented wide beam that transfers lateral forces from exterior walls, floors, and roofs to the ground foundation.
    vertical-oriented wide beam also known as a sheer wall

What is destructive testing?

  • Destructive testing is the process of determining design weaknesses.
  • For seismic retrofit projects, the city would like to see the quality and connections of load-bearing beams that are at-risk of failure in the event of an earthquake prior to approving permitting for the project.
  • This type of testing requires exposure of these connections.

ZOOMED IN Destructive testing area to determine design weaknesses. ZOOMED OUT Destructive testing area

What is non-destructive testing?

  • Non-destructive testing is the process of evaluating materials or components for discontinuities or differences in characteristics without causing damage to the structure.
  • Ground penetrating radar uses radio waves to scan concrete.
  • Concrete x-ray uses x-rays or gamma rays to image the interior of a concrete target to identify embedded objects.

Ground penetrating radar being used to locate imbedded hazards GPR Analyst Scanning a concrete slab to locate post tension cable

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Latest News

CoreLogic’s California Earthquake Risk Report

Discussion centered around the topic of the “big one” that is expected to hit California in the next 30 years has been ongoing, as research has been conducted in order to assess risk and prepare as much as possible for its arrival. An 8.0 magnitude or higher earthquake along the San Andreas fault would be devastating to the lives of those in the affected areas.

The data released describes the potential damages that California could experience in the case of a massive earthquake. The report’s data estimates the number of homes that could be damaged as well as the potential reconstruction cost for different earthquake scenarios, dependent upon on the location of the rupture area. CoreLogic’s new earthquake hazard system has identified the startling conclusion that a single large earthquake could actually rupture the entire length of the San Andreas fault line, which extends for about 750 miles through California- running from Mendocino County to Riverside County. Previously, other risk models considered the Northern and Southern regions of the San Andreas fault as “independent” of each other. This understanding significantly increases the probability of losses and damage for both Northern and Southern California.

While it is certainly possible for both the Northern and Southern portion of the San Andreas fault to rupture at once, the chances of that happening in our lifetime are quite slim- a USGS researcher states. However, the intent of the CoreLogic study was to theorize about a worst case scenario situation- including multiple earthquake possibilities (LA TIMES).

The financial losses associated with an earthquake of this size are overwhelming. The new estimates put forward by CoreLogic estimate losses of up to $289 billion dollars for an earthquake of 8.3 magnitude, with a larger rupture area than once anticipated. The previous earthquake risk assessment considered the earthquake risk as limited to either areas of Northern California or Southern California, making up two different earthquake scenarios. While the new and revised earthquake risk report considers a full rupture across the entirety of the San Andreas Fault. The previous earthquake risk scenario for a Northern San Andreas rupture estimated the reconstruction cost value at $161 billion. That is more than 100 billion dollars less than the new report estimates for reconstruction cost. As the potential rupture area size increases, so does the number of homes at risk for damage- especially homes in Northern California. The initial risk assessed the number of homes damaged at 1.6 million, while the revised risk estimates more than double that number of homes will be impacted.

San Andreas Fault- Photo Accessed Via NY Daily News

The Shakeout Scenario, published by the USGS in 2008, theorized about a potential 7.8 magnitude earthquake that would strike on the far southern portion of the San Andreas fault. This earthquake risk scenario, like CoreLogic’s, assessed the potential property damage and included estimates of the loss of life that may be experienced during a quake of this magnitude and at that specific location. The study initially estimated that there would be approximately 1,800 deaths overall as a result of this quake. Their explanation for such a number is related to the quality of buildings in the area as well as the high risk for fire following the earthquake. Since this report was published, mandatory seismic retrofit ordinances have been passed in cities throughout California.

With this in mind, it is not unreasonable to infer that this number may lessen as residents continue to make seismic improvements on their properties. In fact, it was stated in the ShakeOut scenario report that the number 1,800 was as low as it was because of the proposed improvements that will continue to be made as the retrofit program deadlines approach. The emphasis on seismic retrofit mandates in California can in part be explained by the overwhelming amount of deaths caused by the collapse of soft-story buildings during the 1994 Northridge earthquake, as noted in the Shakeout Scenario report.

It is reassuring that some of California’s cities are taking such significant strides towards greater seismic safety. In the case of “the big one” to come, safer buildings will hopefully lessen the financial damages that California will face and most importantly- lessen the loss of life.

While CoreLogic’s study allows for risk managers to evaluate risk for the purposes of insurance- the implications of this information are much more far reaching. The information this risk assessment provides allows for, among many other things, better preparation for emergency response and improvement to public safety in an earthquake situation.







October 16, 2017

Santa Monica Seismic Retrofit Updates

As you may already know, the Santa Monica City Council approved a stringent seismic retrofit ordinance on March 28th, 2017. While the retrofit of single family homes is voluntary in the city, there are a list of other building types that require seismic retrofitting. While some must be retrofitted as quickly as 2 years upon receiving notice, others have up to 20 years to comply with the ordinance.

Among the building types that have the quickest timeline are…

  1. Unreinforced Masonry  (Completed Retrofit: 2 years)
  2. Concrete Tilt-Up (Completed Retrofit: 3 years)
  3. Soft-Story Buildings (Completed Retrofit: 6 years)

Now that the ordinance has been passed, the issue of how to deal with the costs associated with seismically vulnerable buildings that are subject to rent control has come up. In other cities, such as Los Angeles and San Francisco, you can pass through a percentage of the retrofit cost to tenants. In Los Angeles, property owners can pass through 50% while in San Francisco property owners can pass through 100% of the seismic retrofit costs to tenants- through incremental increases in rent. There are at least 1200 buildings that fall under this ordinance which are subject to rent control- Santa Monica Daily Press reports.

In their meeting on October 12th, 2017, the Santa Monica Rent Control Board will discuss what percentage of the cost should be allowed to be passed through to Santa Monica’s tenants (if any at all).  The Santa Monica Rent Control Board urges all and any concerned parties, whether tenants or property owners, to come out to voice their opinions on this matter.

The meeting will take place at City Hall on Thursday, October 12th at 7:00 pm.

Updates on the issue of rent increases due to seismic retrofitting to follow as they are released following the meeting.




October 12, 2017

Hurricane Maria Relief

Amidst all of the chaos associated with the multiple natural disasters over the last few months, it is so inspiring to see people reaching out to truly try and help those who have been impacted by these tragic events. Hurricane Maria has left Puerto Rico without power, without adequate resources, and without the ability to sustain the lives and wellbeing of millions of people.

The distribution of aid has proved to be problematic following the aftermath of the Hurricane, due to a lack of transport vehicles and blocked roads- among other reasons. Thousands of containers of supplies holding food, water, and other vital resources have been sitting at the San Juan Port, waiting to be distributed. While often times it can seem hopeless watching these disasters and extreme difficulties unfold, four women decided to take action to try and bring support to the millions of people in Puerto Rico, who we know need it so badly.

Susan Sarrett, Becky Bump, Joy Haycox, and Kathy O’Hara are the four women spearheading what has been referred to as an “informal relief mission”- dedicating their time and resources to bring necessities to the many devastated communities in Puerto Rico. This whole story began when Haycox traveled through San Juan to the Virgin Islands to assist in an animal rescue mission. Through this trip Haycox was introduced to a United Airlines employee named Sonia Morales, who assisted Haycox in getting to the Virgin Islands. Later, Haycox had the opportunity to return the favor by providing Morales with a camping stove (trying to, at least).

Photo Courtesy of The Virginian Pilot Online

This modest request from Morales motivated these women to begin their mission. With the help of a taxi driver named Tony, they distributed their first batch of supplies to Puerto Rico residents.

These women brought along with them everything from tarps and batteries to strawberry jelly and with these simple yet vital items were able to touch the lives of many affected by Hurricane Maria. This team is planning yet another trip back to Puerto Rico to offer more assistance early next week, bringing with them more than 50 water filters from the Water Works program. The Water Works program is team building with a cause.  Penhall Company and Penhall Technologies came together to donate these water filters to help the residents of Puerto Rico who are still struggling for even the most basic necessity; water.  

For more information on the Water Works program and how you can get involved- visit the link below.

October 5, 2017