Pojednání o bezpečnostních faktorech doporučovaných pro svahy malých vodních nádrží

摘要

The design and assessment of the slope stability of small embankment dams is usually not carriedout using slope stability calculations but rather by the comparison of proposed or existing damslopes with those recommended by technical standards or guidelines. Practical experience showsthat in many cases the slopes of small dams are steeper than those recommended. However, mostof such steeper slopes at existing dams do not exhibit any visible signs of instability, defects orsliding. For the dam owner and also for dam stability engineers, the safety of the slope, expressede.g. via a factor of safety, is crucial. The aim of this study is to evaluate the safety margin provided byrecommended slopes. The factor of safety was evaluated for several dam shape and layout variantsvia the shear strength reduction method using PLAXIS software. The study covers various damgeometries, dam core and shoulder positions and parameter values of utilised soils. Three load caseswere considered: one with a steady state seepage condition and two with different reservoir water leveldrawdown velocities – standard and critical. As numerous older small dams lack a drainage system,variants with and without a toe drain were assessed. Calculated factors of safety were compared withrequired values specified by national standards and guidelines.