Challenges of slope design for high cut slopes in jointed rock masses

Abstract

The construction of the 275 m high Yusufeli arch dam and auxiliary structures required the execution of very steep cut slopes with more than 400 m height. Uncertainties regarding the geotechnical conditions imposed a serious challenge for the cut slope design. The design approach evolved from initial back-calculations to a robust methodology, which was constantly revised and updated as excavation proceeded. The article explains the modular design procedure that allowed continuous interaction, adjustments and updates of and between different design and construction activities. It briefly describes the process of geological data collection and parameter determination and elaborates on the calculation tools utilised for the design. Finally, the verification and updating of the design during construction is explained on a selected case study. The excavation of the Yusufeli Dam was completed in 2018, dam concreting and grouting in 2022, and the final impounding level was reached by the end of 2023.