Region - Water Conservancy

Dams are structures designed to retain and accumulate water, and the art of designing a dam is linked to the art of controlling the flow of water through the dam-foundation assembly (Cruz, 2004). Studies show that the process of internal erosion is one of the main causes of dam failure worldwide. According to a publication by the U.S. Department of the Interior Bureau of Reclamation (2007), the total number of dam failures related to internal erosion is 49.60%. One of the methods used to control flow is the introduction of internal drainage devices in the dam and foundation which, if properly dimensioned, fulfills the purpose of controlling flow within the massif. In drainage system projects, the assumptions and procedures adopted for sizing must be highlighted, as this system is closely linked to the safety of the structure. Filters must be designed to meet the basic criteria of retention and permeability, which at first appear to be antagonistic criteria. However, these conditions assume that the dimensions of the voids in the filter material must be small enough to retain the larger particles of the protected material and, at the same time, the material must have sufficient permeability to prevent the induction of high percolation forces and hydrostatic pressures applied to the filters.