Improvement of embankment dam safety against overflow by downstream face concrete macro-roughness linings

摘要

The study of a macro-roughness lining system for protection of earth embankment dams during overflow is presented. The system consists of pre-cast concrete elements placed on a drainage/separation layer. Their stability concept is based on the self-weight of the blocks. Several types of elements were developed and tested for stability in a physical model for a typical dam slope of 1/3 (V/H). Based on the experimental results, a stability model was developed to compute the design safety factor for the surface protection lining. Synoptic design charts were derived for 1/3 dam slopes, allowing the rapid estimate of the lining characteristics, as dimensions and weight, for a given design unit discharge and various margins of safety. This macro-roughness lining system is envisaged for spillway rehabilitation of existing dams, for the design and construction of dams less than 30 m high, as well as for the protection of cofferdams.