The Failure and the Remedial Containment Dike on a Lacustrine Clay

A compacted silty clay containment dike for a waste slurry holding pond, with a design height of 44 ft. above the pond bottom experienced distress when the construction had reached heights ranging from only 16 to 21.5 ft. The rapid construction rate generated large excess pore water pressure in the saturated lacustrine clay subgrade, the fissured nature of which could not be discerned by the standard sampling and laboratory testing procedures. Lateral transmission of the excess pore pressure caused toe heave and cracking of the dike. Construction was halted and resumed next year. Construction was completed with monitoring of the piezometric levels in the lacustrine clay subgrade and the movement of the dike toe. Several construction pauses were necessary due to the buildup of high piezometric levels