Study on dam zoning scheme of Yecha Reservoir dam in Chongqing

Abstract

The maximum dam height of the Yecha Reservoir Dam in Fengjie, Chongqing is 90 m. The dam is designed as a concrete face rockfill dam. The material field for the dam is located at the tail end of Jiudongxi Creek, a tributary on the right side of the reservoir. The geological formations in the material field consist of limestone interbedded with breccia, where limestone is classified as hard rock and breccia as soft rock. The zoning and material design of the dam are crucial aspects in designing high concrete face rockfill dams. To optimize the utilization of material resources and reduce the amount of material waste, thereby lowering project costs, finite element stress-strain analysis was employed to study the feasibility and appropriate mixing ratios of hard and soft rock materials in the primary and secondary rockfill zones. The research findings indicate that limestone should be used as the dam material in the primary rockfill zone of the Yecha Reservoir Dam. In the secondary rockfill zone, a mixture of limestone and breccia with a ratio of at least 60% limestone to 40% breccia is recommended. Additionally, excavation material from the weakly weathered sandstone and shale in the core area should be used in the dry upper section of the secondary rockfill zone.

Keywords

concrete face rockfill dam / zoning design of dams / limestone / mixture of limestone and breccia