Category Archives: Training

Cal State Northridge Parking Structure

Cal State Northridge Parking Structure

This past week marked the 20th anniversary of the M6.7 Northridge earthquake.  In addition to 57 fatalities, over 40,000 buildings sustained damage amounting to an estimated $25 billion in losses, making it the most costly earthquake in the United States.

Good friend and extraordinary structural engineer Gene Trahern shared with us an update on changes in earthquake engineering during the intervening years. Although I had not yet met Gene in 1994, I worked in a support role on the Northridge response effort, a big project for Gene and a pivotal time in my career. Since then Gene has further developed his expertise in evaluating seismic vulnerability of existing structures and founded Cascade Crest Consulting Engineers.  More information about Gene’s practice is here:

IBC replaces UBC, BOCA, and SBC

Three semi-regional codes were combined into one uniform document, the International Building Code, causing engineers nationwide finally to use the same design procedures. As part of that change, design ground motions changed from the 475-yr earthquake to two-thirds of the 2500-yr earthquake.  The change elevated design forces in areas with large but infrequent earthquakes like some parts of the Midwest, Salt Lake City, and the Carolinas.  Design forces increased in Seattle and slightly decreased in  Sacramento and Portland.

ASTM Seismic Loss Estimation Standards

Two new standards,  E2026 and E2557, now define a uniform method for assessing potential earthquake damage to existing buildings.  The standards define several terms that used to have various meanings, eliminating conflicts in insurance and valuation procedures. They also establish four discrete levels of analysis, improving quality and reliability of seismic loss estimation studies.

Improved Seismic Evaluation and Upgrade Methods

At the time of the Northridge Earthquake, seismic evaluations of existing buildings used basic ground motions similar to the outdated UBC seismic zone system.  ASCE-31 (2003) improved evaluation methods by changing to the current USGS seismic hazard maps.  ASCE-41 followed 3 years later and carried the evaluation method improvements forward into seismic upgrade of existing buildings. 

Gene Trahern can be reached at (541) 549-1331 and






I had a really excellent time last week attending the Dispute Resolution Board Foundation conference and training in Seattle. The DRBF ( is a small, sincere organization  that promotes dispute avoidance and resolution on construction projects using the proven Dispute Resolution Board (DRB) method. Having participated in much larger, formal, and bureaucratic standards organizations, the DRBF conference was refreshing in their pragmatic approach to accomplishing the group’s mission. Training was provided by founding members, the attendee were a veritable “who’s who” of construction in the Pacific Northwest, and the excellent interactive format made the training quite effective.

At 47 years old, and with 24 years professional experience, I was the second-youngest person attending the meeting (one of the founding members brought his son,. an accomplished construction manager.) The group has recognized a need for younger members and is in the early stages, it seems, of taking action toa ssure that the organization manes a successful transition when the founding members are ready to reduce their involvement.

As an added bonus, a neighbor of ours back in Lake Oswego was there for part of the conference. Two goals for our move back to the Mainland were to reconnect with a broader professional community, so I could attend events like the DRBF conference, and to reconnect with old friends. It was particularly satisfying that both happened at the same event.