Design and performance of the Yele asphalt-core rockfill dam

Abstract

The planning, design, and performance of the Yele asphalt-core rockfill dam in Sichuan Province, China, are presented. The dam has a maximum height of 124.5 m, is located in a very seismic region with inclement climate, and is founded on a geologically complex foundation, partly resting on a deep and pervious alluvial overburden and partly on bedrock. With these site conditions only an embankment-type dam was considered feasible, and three different options were considered for the design of the impervious barrier: (i) earth core, (ii) concrete facing, and (iii) asphalt core. The third option was chosen. The design is based on extensive analyses and laboratory tests, and a special model test was performed to study the behavior of the connection between the narrow asphalt core and concrete plinth. An impoundment test was performed when the dam was 73 m high to test the imperviousness of the constructed core and the connections between (i) the core and plinth and (ii) the plinth and foundation cut-off wall. An extensive field monitoring program was implemented. Design predictions are compared with field performance observations of the core and its interaction with the adjacent transition zones.