Deformation and Cracking of Seepage Barriers in Dams due to Changes in the Pore Pressure Regime

Abstract

A procedure is presented for analyzing postconstruction deformation of seepage barriers due to changes in the pore pressure regime after seepage barrier construction. The procedure uses the changes in pore pressures calculated by finite-element seepage analyses to calculate changes in buoyancy and seepage forces that occur as a result of seepage barrier construction. When the buoyancy and seepage forces are applied to a finite-element soil-structure interaction model, the result is an effective-stress analysis that rigorously models seepage effects. This paper discusses application of the procedure to five dams to calculate postconstruction deformation and stresses in seepage barriers. The results of the analyses indicate that deformation due to pore pressure regime changes is a likely mechanism causing cracking in rigid seepage barriers.