[This article belongs to Volume - 38, Issue - 06]

Vibration Study Due to Spilling Event at Chute Dam Spillway Using Modal, Harmonic Response and Fluid-Structure Interaction Analysis

The operational efficiency and long-term stability of spillway dam structures are critical for their safety and reliability worldwide. Dam failures can result from environmental conditions, aging, and unforeseen loads. Previous research has emphasized the importance of dam reliability, with numerical simulations playing a key role. Vibration analysis and fluid-structure interaction are integral to dam spillway reliability in this study. This comprehensive case study focuses on the Kenyir Dam spillway in Malaysia. The spillway designed as an uncontrolled chute spillway has experienced water-spilling incidents over time. Vibration and fluid-structure interaction analyses were employed to understand structural behavior and hydraulic performance. This study presents findings from modal, harmonic, and operational deflection shapes and fluid-structure analyses. Four water levels were assessed, revealing significant vibration-induced deformations and stresses. The modal analysis determines the natural frequency of the spillway results at 12.6 Hz. In comparison, the operational deflection shape determines the operational frequencies for 146 m to 152 m at 12.55 Hz with a vibration deflection amplitude increase of 0.005 to 0.031 m. Mode shape and operational deflection shape occurred at different locations and shapes indicating that no resonance phenomena occurred. Thus, the spillway is safe to operate within the water levels.