Conceptual Drawing of the Casino Cornforth Consultants (CCI) was retained by the Confederated Tribes of Warm Springs to perform a geotechnical evaluation for a proposed casino/resort in Cascade Locks.
The objectives of the investigation were to characterize the fill and natural soil and rock material using field and laboratory testing; perform subsurface geotechnical explorations at the site, including the completion of borings and test pits, installation of vibrating wire piezometers, and performing downhole geophysical testing; monitor groundwater levels using dataloggers; and prepare a geotechnical report summarizing our investigation and recommendations.
The subsurface explorations revealed that the site was underlain by 10 to 30 feet of uncontrolled fill. Pockets of the fill contained large pieces of broken concrete surrounded by sandy gravel. Foundation distress from differential settlement of the non-engineered fill was a significant concern for the casino structures. CCI developed recommendations for piling support in the deeper areas of fill, and excavation and recompaction where it is shallow. Cornforth also provided geotechnical design for a new highway overpass on Interstate 84 that would accommodate traffic flow from casino operations.