The SidePlate Story

Following the 1994 Northridge earthquake, experts learned that the standard steel frame connection used in buildings for over 25 years failed to perform. The discovery of damage to structures, in numerous cases exceeding the replacement value of the building, wreaked havoc on the construction industry and sent engineers scrambling for solutions.

Soon after this infamous event, many cities, counties and jurisdictional agencies issued emergency moratoriums on new steel frame designs using what is now referred to as the Pre-Northridge moment connection. The City of Los Angeles created its own task force to address the newly discovered connection vulnerabilities.


One of the committee members, David Houghton, a structural engineer with years of experience in seismic engineering around the world, was pondering all of the issues on his drive home from a meeting in September 1994 when he realized a simple solution to a complex problem. He excitedly sketched out his idea, now patented in the U.S. and abroad and named SidePlate™, and began sharing it with colleagues. One of them, from the County of Los Angeles, strongly urged that he submit it for testing.

Successful testing would make SidePlate a prime candidate for immediate use in stalled Los Angeles County hospital designs. The fabrication of SidePlate and subsequent testing of three full-scale specimens was completed within record time. Ironically, it wasn't until after testing that detailed and rigorous analyses of the connection was done... the exact opposite to the typical sequence researchers use to develop new technology products.

The County of Los Angeles then formed a technical advisory panel (LACO-TAP) to thoroughly scrutinize SidePlate to insure it addressed and resolved every concern that had surfaced after the Northridge earthquake. After 18 months, SidePlate received LACO-TAP's unanimous approval for immediate use in the design and construction of essential facilities owned by the County of Los Angeles. LACO-TAP concluded "...given the refined SidePlate design methodolgy, the design controls, and completeness of the system qualification of the SidePlate one-sided and two-sided connection, no additional testing is required for LACO-TAP acceptance of one and two-sided connections for implementation on County projects."

Since 1995, SidePlate has been implemented in numerous state of the art facilities and has exceeded the expectations of engineers, contractors and building owners for reliability, ease of fabrication/erection and cost. It is the only moment connection system to achieve unlimited pre-qualification for implementation without additional testing by ICBO, the City of Los Angeles, and County of Los Angeles, and is highlighted in FEMA 350 and 351.

In addition to seismic protection, the connection system is ideally suited to shield against terrorist bomb blasts, extreme wind and other natural disasters. SidePlate uniquely provides multiple applications, which include braced dual systems. As more owners, fabricators and engineers become familiar with the advantages of SidePlate, it is rapidly being added to steel frame construction projects worldwide.