Hazards created by geologic conditions include damage due to earthquakes, landslides and slope movement, and karst conditions. Our geoscientists have the training, experience, and tools to evaluate the risk potential of these hazards and to provide data that can be used in the design of prevention or remediation to mitigate the risk of these hazards. Our engineering geologists provide guidance in the evaluation of natural hazards and expertise in earthquake hazard assessments.

Our Geologic Hazards services include:

• Landslide Assessment and Mitigation
• Karst Evaluations and Mitigation
• Earthquake Hazard Assessments
• Liquefaction Assessment
• Fault Studies
• International Building Code (IBC) Site Specific Seismic Studies

One example of our services involves the risk of seismic hazards from earthquakes. The potential for seismic hazards has become a widely recognized concern even in areas that have been considered seismically ‘quiet’ historically. Federal, state, and local governments now are requiring detailed seismic hazard evaluations and more stringent seismic design criteria for new construction.  For critical existing structures, this can include review of seismic hazards and design of seismic damping or structural stabilization. Facilities that typically require seismic evaluations include buildings, bridges, landfills, dams, levees, bulkheads, and locks. AASHTO, UBC and IBC (NEHRP) provide basic seismic design criteria for buildings and bridges for selected facilities. However, where poor soil conditions are present on a site and/or if the site is located in an area of historic seismicity, site specific seismic studies may be required or may be desired to reduce construction costs.

A site specific seismic hazard evaluation requires the development of the Maximum Design Earthquake and selection of appropriate ground-motion time histories. These assessments involve review of the geology and historical seismicity of an area to identify the nature and distribution of seismic events within the region. From this, the Maximum Design Earthquake and appropriate time histories are selected from available strong motion data. These time histories are scaled to match the expected peak ground motion parameters for a site. Finally, if a significant soil depth underlies the site, the earthquake ground surface motions are evaluated to characterize their amplification or attenuation through the soil profile using a SHAKE-type analysis. A site specific design response spectrum can then be developed for the design of structures to resist ground motions from the Maximum Design Earthquake