Internationally recognized for solid engineering solutions and making seismic compliance straightforward and affordable.


Petra Seismic Design, LLC was created to provide seismic restraint design services. We have expanded our services to keep up with the ever expanding seismic industry growth and to address every aspect seismic design in the construction industry.


Robert E. Simmons – President
James A. Carlson – Principal


Our goal is to provide cost effective designs for the commercial, institutional, and industrial facilities. Basically to be the best. Our staff has extensive experience in all areas of construction from schools and hospitals to nuclear facilities. With over 28 years of experience in seismic restraint design, research oversight, and evaluating shake table testing of equipment performance; we offer clients confidence in our ability to address every issue.

We provide resources to industry and organizations in order to improve the effectiveness of seismic design applications. These activities include proposals for code changes to reduce the fog factor and address real construction issues; development of industry standards (Specifically ASCE 7, ASHRAE, VISCMA, and AHRI standards); and oversight of research projects to ensure the results are meaningful and accessible to the public.


We believe that seismic compliance for non-structural components can be uncomplicated and cost effective. By providing solid solutions to the building community we can save significant costs for compliance and reduce the risk of failures caused by earthquakes. When the cost of implementing seismic restraint is reasonable, the construction community has greater incentive to install an affective seismic restraint system instead of assuming liability associated with “value engineering” out the code required seismic restraint. This results in a building that provides better life safety and reduced risk of costly economic losses associated with post earthquake repair and building down time. We believe that the best way to accomplish this is to begin the seismic design early in the building design process. To achieve code compliance at the lowest cost, it is better to obtain the services of a seismic engineer for all non-structural components during engineering design phase or through the general contractor instead of pushing it down to various subcontractors toward the end of the job. Having a single engineer in responsible charge of all the non-structural seismic provides a coordinated system resulting in significant savings. When the seismic design is relegated to various subcontractors, costs escalate due to mark-ups and numerous change orders due to in field coordination problems caused by incomplete seismic information on plans and specs. In addition, a uniform quality assurance can be maintained from design to installation and final inspection.


PETRA…. Derived from the Greek word meaning stone/rock. In the sometimes “shaky” world of seismic design, we at Petra Seismic Design build on a rock solid foundation of engineering experience, integrity, dedication, fairness, and reliability that guides our decisions and actions, providing excellence in seismic, shock, vibration isolation, and wind design service to our customers.