Analysis of Low-frequency Noise and Vibration Effects during Overflow on a Sediment Control Dam

The sediment control dam located in Yeongju-si is an artificial structure designed to capture and treat sediment inflow, thereby reducing reservoir sedimentation and maintaining a stable storage capacity. Unlike typical sediment control dams, it features a gallery-type internal passage that facilitates limited public access. However, during the monsoon season, higher levels of rainfall cause significant overflow, thereby generating a waterfall-like curtain wall that encloses the passage and forms a narrow cavity. Within this cavity, pressure fluctuations attributable to the flowing water and impact noise from falling water interact, generating periodic low-frequency noise. These sound waves resonate within the cavity and can propagate over a distance of approximately 700 m, causing windows and doors in nearby homes to vibrate, leading to complaints from local residents. In this study, we conducted noise and vibration measurements within the dam, its surroundings, and nearby residential areas. A dominant resonant frequency of approximately 3 Hz was identified, and as a potential mitigation measure, we evaluated the efficacy of four spoiler structures installed at the top of the sediment control dam.