Overtopping Failure Process and Core Wall Fracture Mechanism of a New Concrete Core Wall Dam

• Published in: KSCE journal of civil engineering Vol. 28; no. 5; pp. 1753 - 1766
• Main Authors: Zuo, You-ming, Zhou, Jia-wen, Li, Hai-bo, Zhang, Jie-yuan, Tan, Chang, Wang, Xiao-dong, Wang, Yu-shan, Zhou, Yue
• Format: Journal Article
• Language: English
• Published: Seoul Korean Society of Civil Engineers 01.05.2024; Springer Nature B.V; 대한토목학회
• Subjects: Bending moments; Civil Engineering; Concrete; Concrete dams; Dams; Deformation; Engineering; Failure modes; Fracture mechanics; Geotechnical Engineering; Geotechnical Engineering & Applied Earth Sciences; Industrial Pollution Prevention; Mechanical analysis; Mechanical properties; Overtopping; Rockfill dams; Scour; Scouring; Two dimensional analysis; Wall thickness; 토목공학; Overtopping failure process; Concrete core wall dam; Core wall fracture mechanism; Overload brittle fracture; Scour pit failure mode; Dam reconstruction
• ISSN: 1226-7988; 1976-3808
• DOI: 10.1007/s12205-024-0951-5

Concrete core wall dams have emerged as a cost-effective alternative to the reconstruction of old dams. However, the flooding mechanism and flood line of these dams differ significantly from traditional earth and rockfill dams due to the concrete core wall functioning as reinforcement. This study presents model tests that simulate the overtopping failure of earth and rockfill dams with concrete core walls of various thicknesses. The hydrologic curve and two-dimensional evolution of the breach are analyzed, and mechanical analysis examines the relationship between core wall thickness and free face during core wall failure. Results indicate that the presence of the concrete core wall shifts the overtopping failure mode to the scour pit failure mode. The scour pit failure mode occurs when upstream water scours the downstream core wall to form scour holes and free faces. Continuous scouring increases the depth of the free face, ultimately causing the moment between the two sides of the core wall to exceed the bending moment of the core wall, resulting in fracture. The study provides a theoretical basis for the design of core walls for this new type of dam.