PLANNING AND DESIGN THE OPERATION OF FLOOD GATE SPILLWAY BAGONG DAM

Abstract

This study plans and designs the operation of the flood gate on the spillway of the Bagong Dam for flood control and structural stability. The main objectives of this research include analyzing the design flood discharge, determining the optimal elevation of the sluice gate, and assessing the stability of the spillway structure under maximum water surface conditions (MAB) with the gate closed and without seismic activity. The methodology employed involves the collection of secondary data, including hydrological, topographical, and technical data of the dam. The results of the hydrological analysis indicate a design flood discharge of 266.68 m³/s (Gumbel, 1000-year return period). A radial sluice gate is planned at the crest elevation of the spillway at 325.00 m. Flood routing simulations with the gate closed indicate the occurrence of overtopping, prompting the implementation of an operational strategy for gate openings. The opening of one gate at a height of 3 meters begins at hour 4 (elevation 328.21 m) and is closed at hour 18 (elevation 325.51 m). This strategy effectively maintains the water elevation below 328.50 m. The stability of the spillway structure under MAB conditions is deemed safe, with a factor of safety against overturning of 11.58 and sliding of 11.92, as well as soil stress within permissible limits.