SITE-SPECIFIC SEISMIC DESIGN
Recent developments in the building code (ASCE 7-16) favor site-specific hazard and risk analyses. Greenfield Geotechnical can provide site-specific probabilistic seismic hazard analyses to meet a specified performance level, evaluate the effects of soft ground on the intensity of ground shaking, or just optimize your design to meet the building code. The figure below is an example seismic design spectrum from a site near Portland, Oregon with varying depths of bedrock.
PROBABILISTIC seismic HAZARD ANALYSES
Greenfield Geotechnical also specializes in probabilistic seismic hazard analyses (PSHA), which are another tool to understand possible seismic hazards. Recent projects with PSHA evaluations have resulted in a significant reduction in design loads, yielding significant cost savings to building designs and material costs.
Liquefaction analysis and mitigation
Liquefaction and seismic deformation analyses are a staple of Greenfield Geotechnical's design work. Detailed computational models, like the finite element results shown below provide important information about the underground movements and forces during an earthquake. Different mitigation alternatives can be modeled to determine the best, most efficient, and most effective solution.
SEISMIC HAZARD MAPPING
Regional-scale liquefaction hazard analyses are necessary to prioritize seismic upgrades and plan resilient communities. Greenfield Geotechnical has performed regional liquefaction and coseismic landslide hazard studies for clients like the Portland Water Bureau and City of Forest Grove. These studies are more accurate than conventional methods, like HAZUS, and combine subsurface data with the mechanics of liquefiable soils.
