The City of Oakridge needed to expand their water distribution system including construction of a new 1.0 MG water reservoir, a new booster pump station, a new chlorination system, and retrofit of an existing 1.0 MG water reservoir. Cornforth Consultants (CCI) provided geotechnical design parameters for the new structures including seismic design per IBC. CCI drilled six borings at four sites and excavated five test pits at three sites. Two standpipe piezometers were installed.
CCI provided geotechnical design parameters for structures including bearing capacity, settlement, lateral earth pressures, lateral resistance, uplift resistance, and modulus of subgrade reaction. Preliminary design parameters were also provided for tiedown anchors for the new tank, as well as underpinning recommendations to mitigate settlement at an existing reservoir. Underpinning involved grouting compression anchors into basalt bedrock underlying the fill soils.