Finite element analysis of construction stability of Thika Dam

High pore water pressures were measured in the fill material of the Thika D am embankment early in its construction. These caused concern about the sub sequent short term stability. Therefore construction was stopped. Stability reassessment and drainage design was performed using finite element analys es before construction was allowed to continue. Different methods of modell ing the pore water pressure allowed efficient analysis of various drainage options. The analyses highlighted zones of high shear stress and shear stra in, and formation of failure surfaces. They established the necessary level of drainage required to ensure stability, control movement and reduce the risk of residual shear surfaces. Large toe movement was predicted immediate ly after construction recommences. (C) 1999 Elsevier Science Ltd. All right s reserved.