SAFETY SURVEILLANCE OF AN ARCH DAM UNDER CONSTRUCTION DURING SECONDARY COOLING AND GROUTING BY ACOUSTIC EMISSION

Abstract

Acoustic Emission (AE) was applied in order to ensure the safety of an arch dam under construction. AE was monitored during secondary cooling and grouting between dam blocks. Quantitative AE waveform analysis based on the moment tensor analysis was performed as well as conventional AE parameter measurement. Low frequency AE sensors (15kHz resonant) were employed to detect AE signals generated in the dam concrete. Twelve sensors were installed at the dam surface and four of them were mounted on the floor of an inspection gallery inside the dam blocks. Neither critical AE activity nor intense AE cluster was found during the AE monitoring. It was concluded that the dam was safe during the secondary cooling and the grouting.