HYDRAULIC DESIGN AND STABILITY ANALYSIS OF THE MAIN DAM OF ASAHAN IV DAM

• Main Author: Irsyad Yusufa J, M
• Format: Final Project
• Language: Indonesia
• Online Access: https://digilib.itb.ac.id/gdl/view/54310
• Institution: Institut Teknologi Bandung

The cost of electricity supply (BPP) in Indonesia has exceeded the economic limit due to the use of petroleum while it's limited. Strategic efforts are needed to conserve fossil fuels along with the development of other energy sources. The potential hydropower energy in Indonesia of 74.9 GW has been utilized only at 5.3%. The Asahan River in North Sumatera is estimated to have a hydroelectric potential of more than 1,000 MW. Therefore, PT Berkat Bina Karya planned Asahan-IV Hydroelectric Power (PLTA Asahan-IV) as the solution. To obtain the needed electrical energy, a concrete gravity dam is planned to raise the river water level, that is Asahan IV Dam. The focus of this final project is to design the main dam resistant to cavitation and structurally stable. Initial studies of hydrologic, topographic, and geological analysis are needed to determine the design flood hydrograph. The design includes an initial concept design for the ogee spillway and outlet works, followed by initial structural design and structural stability verification. The hydrologicad analysis results the low flow with probability of 80% is 114,35 m3/s and with probability of 95% is 108,06 m3/s, the design flood is 447,875 m3/s, and the maximum flood is 2371,619 m3/s. The design of main dam results in a dam height of 69,3 m, with 3 service spillways, 1 emergency spillway, and 1 auxilliary spillway, provide the controlled release of maximum probable flood, terminal structure using theflip bucket type of energy dissipators, and the outlet works using the circular conduit at +60.5 m, provide the controlled release more than the low flow with probability of 95%. The stability analysis of the design structures results that the structures stable from sliding and overturning.