GRI Principal Dwight Hardin, PE, GE, and Associate Scott Schlechter, PE, GE, were guest speakers at the Oregon Department of Transportation Region 4 Brown Bag session on September 1, 2011.  Their presentation entitled, “Addressing Variable Rock Conditions to Minimize Construction Problems,” addressed common types of construction that are impacted by variable rock conditions and how to identify and characterize the variability.  Dwight and Scott presented several case histories that successfully implemented risk mitigation approaches and outlined a cost-effective foundation solution for challenging rock sites.