The emphasis on the earthquake engineering profession grew significantly following the seismic events that occurred in the San Francisco Bay Area in 1989 and in Northridge, California in 1994. In a race against time, there has been an emphasis placed on building owners & managers to ensure the safety of occupants in the event of a catastrophic earthquake. Many jurisdictions have already mandated that a structural engineer evaluate existing buildings to ensure it meets seismic building codes. In cases where the structure does not meet or exceed the adopted performance and safety standards, these buildings must be retrofitted.
Structural seismic evaluation helps to determine if a seismic retrofit is required to mitigate a variety of potential hazards. Structural system types that often require retrofit include unreinforced masonry, concrete shear walls, steel moment frames, steel braced frames, and light framed wood construction among others. In certain instances, standards such as the California Accidental Release Prevention Program (CalARP) have been specifically instituted to protect the public from hazardous materials in the event of an earthquake. DHG earthquake engineers help owners & managers to comply with all of the latest seismic building codes applicable to their property.
With sophisticated structural analysis software, our engineers can model and determine a building’s expected behavior during a seismic event. The strength of the elements within the lateral force resisting system is compared to the seismic forces that are generated within them during an earthquake. When an element is found to be incapable of handling the load that it is required to resist, then retrofit may be required. While many deficiencies can only be identified through complex engineering calculation and analysis, some conditions that require retrofit can be identified through visual observation and investigation.