A PHYSICAL HYDRAULIC MODEL TEST TO SOLVE THE PROBLEM ON SPILLWAY DAM

Abstract

This research studies about the hydraulic performance and and the problem solving alternativesof spillway design at Fila Tukutaha Dam, Alor District Indonesia. Flow water passing over the spillway of adam typically has a large amount of energy, must be dissipated safely before the floodwaters rejoin to thenatural river system. Therefore, energy dissipation takes place at the downstream end of the chuteway. Thestilling basin at the end of the chute way is commonly used to dissipate energy from the spillway and slow thewater velocity to protect the downstream river channel from erosion and damage. The methodology ofexperiment consists of physical modeling in the Hydraulic and Coastal Engineering Laboratory of CivilDepartement, Sepuluh Nopember Institute of Technology. The discharge design was analyzed by hydrologicalrouting formula over the spillway. The methods include Bernoulli’s formula equation for the steeply slopedchannel, the standard step formula for calculating the energy equation on the transition channel, and the USBRtype 2 for designing the stilling basin. From the experimental result, cross-flow was reduced by adding thehexagonal baffle block on the transition channel, and the effectiveness of stilling basin was occurred by placingthe abrupt rise in the downstream area.