Design, Construction and Performance of Sequilé Dam

Sequilé Dam is a 41.5-m earth fill rolled dam with a thin inclined core, located near Bogota, Colombia. Two uncommon features of this dam are the underwater excavation and uncompacted fill for the foundation of the main dam, and the unusual depth (80 m maximum) of the cut-off wall. Design expectations with regard to the as-built density characteristics of the underwater fill were surpassed through the use of strict but practical specifications, and by careful inspection of the dredging and dumping operations and sequences. Provisions to minimize cracking of the concrete cut-off included construction of the wall near the upstream toe after a large part of the fill had been built. No significant cracking of the wall has been detected in the seven years since closure of the dam. Potentially dangerous uplift pressures, have been treated satisfactorily by a relief-well system. Seepage losses through this system are within economically tolerable limits. The performance of Sequilé Dam has been satisfactory.