Seismic activity has the potential of impacting your project. At Moran Construction Consultants, we are focused on mitigating the risk of seismic impacts for lenders, syndicators, and investors. Per U.S. Geological Survey’s National Seismic Hazard Map (Figure 1), the country is zoned based on the likelihood of earthquakes within the next 10,000 years. With these seismic activities, the Seismic Class can be gathered.
Figure 1. Frequency of Damaging Earthquakes Shaking Around the U.S., retrieved from USGS. https://www.usgs.gov/natural-hazards/earthquake-hazards/science/introduction-national-seismic-hazard-maps?qt-science_center_objects=0#qt-science_center_objects.
Ranging from “A-F”, a Seismic Class considers the design category of a structure, the occupancy, and potential earthquake ground acceleration. Just like the Seismic Hazard Map, the Seismic Class ranks areas on a scale from minor ground shaking (A) to major active faults (F). Once the Seismic Class is defined for the area, we can begin to understand the potential risk involved and determine if a seismic analysis should be performed.
If an analysis has been done, we will review the completed documentation to ensure it is project-specific and in line with similar structures we are accustomed to seeing in that region. If an analysis is required, we will work closely with the industry leaders in seismic analysis to make sure an inspection is done, preferably, before the final design. As we work alongside these seismic firms, our goal is to make sure all documentation is analyzed, and the design meets the criteria for development and construction in active seismic areas.
By Russ Mabry (West Region Consultant)