Overtopping-Induced breaching process of concrete-faced rockfill dam: A case study of Upper Taum Sauk dam. (February 2023)

• Record Type: Journal Article
• Authors: Mei, Shengyao; Zhong, Qiming; Yang, Meng; Chen, Shengshui; Shan, Yibo; Zhang, Lucheng
• Is Part Of: Engineering failure analysis. Volume 144(2023)
• Publication Date: 2023-02
• Subjects: Concrete-faced rockfill dam -- Failure analysis -- Detailed physically-based model -- Case study; System failures (Engineering) -- Periodicals; Fracture mechanics -- Periodicals; Reliability (Engineering) -- Periodicals; Pannes -- Périodiques; Rupture, Mécanique de la -- Périodiques; Fiabilité -- Périodiques; Fracture mechanics; Reliability (Engineering); System failures (Engineering); Periodicals; Electronic journals; 620.112
• DOI: 10.1016/j.engfailanal.2022.106982
• Languages: English
• ISSNs: 1350-6307

Abstract

Highlights: The breach process of the Upper Taum Sauk Dam has been clarified based on the field investigations. A detailed physically-based model has been developed to simulate the breach process of the concrete-faced rockfill dam. The advantage of the proposed numerical model has been verified by the comparison with the existing dam breach models. Abstract: The back analysis of the dam breaching process based on reported failure case data is of great significance for understanding dam breaching mechanisms and the ability to predict breach flow hydrograph during emergencies. According to the essential information and post-failure investigation report of the Upper Taum Sauk dam, the first pumped storage power station in the United States, the most probable failure mechanism for dam breach is studied. Furthermore, a detailed physically-based numerical model is developed to simulate the overtopping-induced breach process of the concrete-faced rockfill dam (CFRD). Highlights of the model include the establishment of a simulation method of the dam-break flow based on the actual three-dimensional terrain considering the water-retaining characteristics of concrete face slabs, and the times and lengths of failure for each concrete face slab under water load and self-weight, as well as the adoption of different transportation modes for the widely graded rockfill materials. The breach side slope sliding mechanism is considered during the dam breach process. It is worth noting that the hydraulic features of dam-break flow and breach morphology can be well described with a combination of renormalization group (RNG) k - ε turbulence model and volume of fluid (VOF) method. The calculated results of the Upper Taum Sauk dam breaching parameters agree with the measured values, which testify to the rationality of the proposed model. The obtained time-varying dynamic dam breach process of CFRD can be divided into three stages. Moreover, the sensitivity analysis indicated that, the presence and absence of concrete face slabs affect the breach process of the Upper Taum Sauk dam significantly. The performance comparison with the existing dam breach models also verifies the advancement of the detailed physically-based model. Hence, the addressed numerical method can be used as an effective tool for simulating the CFRD breach process.