Tendencies in developing structural designs of non-soil seepage-control structures of embankment dams

Гидротехническое строительство

Introduction. The urgent scientific and practical problem in hydraulic engineering is refinement of structural designs of embankment dams with seepage-control elements (SCE) made of artificial materials. They should conform with the requirements of effectiveness and safety. Different authors make proposals on refinement of structural designs of embankment dams with SCE to be made of materials based on cement and on widening the sphere of their application. Materials and methods. Analyses were made of the spheres of application in hydraulic engineering of the materials based on cement: concrete, clay-cement concrete, soil-cement concrete, soil-cement mixes. With this consideration the analysis was made of SCE structure alternatives. Their classification permitted revealing the main tendencies in development of embankment dam structural designs. Results. The sphere of possible application of SCE different types depends on the dam height. For low-head and medium-head dams the most applicable design solution refers to dams with diaphragms made of clay-cement concrete bore piles. It was already tested in practice. For high-head and ultra-high-head dams the effective and safe solution has not been found yet. Four conceptual ways may be considered, but all of the men visage using structures made of cement-containing materials. The first way is refinement of a concrete face rockfill dam structural design. It may be realized by doubling the seepage control facility with use of geo-synthetic materials. The second way is elaboration of a principally new massive seepage-control structure to be made of material based on cement. The third way is use of combined dams, where the dam safety is enhanced by replacement of a part of an embankment dam by concrete. The fourth way is combination of different types of SCE each of which is arranged at different by height dam sections. Conclusions. Materials based on cement propose wide possibilities for refinement of embankment dam structural designs. Nevertheless, the main tendency in development of high-head embankment dam structural designs is application of SCE complicated structures with use of materials based on cement. By their structure they may be either double (multi-layered) or compound (SCE combination).