Wide Hollow Dam

Wide Hollow Dam was designed and constructed in the late 1940s with U.S. Soil Conservation technical assistance and financing. Phase II State of Utah Dam Safety studies identified, among other deficiencies, that the homogeneous earth dam would not survive a Maximum Credible Earthquake event because of the presence of a thick liquefiable foundation sand layer; and, therefore, needed to be remediated. We performed final design field/laboratory studies and analyses and concluded that in addition to the liquefiable sands, thicker foundation clay layers were also sensitive to cyclic softening. Further analyses demonstrated that the most cost-effective remediation option involved removing the existing dam, clay and liquefiable foundation layers and replacing them with zoned embankment/foundation materials and an internal drainage system.