Study on Settling Efficiency of Sedimentation Basin of Coca Codo Sinclair Hydropower Station in Ecuador

Ecuador is located in South America, and sediment of CCS hydropower station is mainly volcanic ash. This paper makes a study on settling efficiency of sedimentation with the quasi-hydrostatic settlement method and unsaturated sediment discharge method. The result shows that settling efficiency of the two methods are close to each other. Further more, the paper makes a study on settling velocity in different calculation methods, including the method of hydraulic engineering design manual, Zhang Ruijin calculation method and method of the United States Army Corps of Engineers. The settling velocity of volcanic ash under the weak alkaline condition and the influences of temperature on settling velocity are studied by testing. It can provide a reference for design of hydropower station in the surrouding area of South America