Addis Ababa University Design and Analysis of Appurtenant

Addis Ababa University Design and Analysis of Appurtenant Structures (FRM: Hydraulic Structure I) Instructor: Dr. Yilma Seleshi, Associate Professor in Water Resources Engineering yilma. seleshi@gmail. com 2019/2020 Academic Year 17/01/2022 1

Design and Analysis of Appurtenant Structures Learning Objective: To teach design concepts, principles, method and procedures of hydraulic structures appurtenances in dams. Topics: 1. Spillway design – General • Approach for locating spillway • Economic size of spillway • PMF 2. Design and analysis of flood overflow control structures (ogee): • Discharge capacity, • Surcharge • Water surface profile • Velocity distribution • Pressure distribution & cavitations issues 17/01/2022 2

Design and Analysis of Appurtenant Structures 3. Design of Side channel spillway • Trough sizing • Spillway capacity determination • D/s control structure determination 4. Chute design Design and analysis of spillway chute, aeration design and anchorage with the abutment and foundation. 5. Crest gates design and analysis • Hydraulic design • Gate rating 6. Intake structure and outlet works hydraulic design • reservoir intake structure; conveyances; Gates and valves 17/01/2022 3

Design and Analysis of Appurtenant Structures 7. Design and analysis of diversion tunnel, coffer dams sizing. 8. Terminal structures and scour protections • Energy dissipaters (USBR), hydraulic jump, stilling basin • Outlet channel and connections with river • Scour protections 17/01/2022 4

References Materials : USBR (1987) Design of small dams. USACE (1992) Hydraulic Design of spillways EM (1100 -2 -1603) USACE(2003) Structural Design and evaluation of outlet works. Novak (2001) Hydraulic Structures. Spon Press. Rober BJ (1988) Advanced Dam Engineering for design, construction and rehabilitation Huat Sentuk (1994) Hydraulic of dams and reservoirs, WRP. Vischer & Hager (1998) Dam Hydraulics 17/01/2022 5

Assignments: Project with incremental development. Megech- dam is taken as case study (1) Spillway design, (2) Chute design, (4) Intake structure design, (3) Energy dissipater design, Grading system: 40% Assignment - Evaluated through presentation and assignment corrections 60% - Final exam – workout- open book 17/01/2022 6