Construcción de la presa de Lechago

Resum

The construction of Lechago dam has posed an important technical challenge. The size of the dam, that had to reach some 35 m above the river level and the nature of the alluvial soils, highly compressible and with a thickness that is locally greater than 20 m, led the designer to an earth dam with impervious clay core and rock (slate) shoulders that were locally available. The technical problems associated to the foundation have been solved by means of some �in situ� testing (foundation treatment test) and a series of special preventive measures, among them it is opportune to mention the deep foundation of the spillwater stilling basin and the preconsolidation of the foundation of the dam by means of a forced lowering of the water table together with some preloading. It is also included in this paper the studies directed to investigate the dynamic strength of the dam under an eventual seismic loading. Those studies include some laboratory dynamic tests of the foundation soils and the use of a numerical model for dynamic analysis.