Abstract: Due to complicated and diverse circumstances and the difficulty in observing blasting process, underwater blasting project is prone to cause landslides and cracks in buildings and roads as quantitative assessment of regional risk in advance is thus challenging. With the underwater reef demolishing project in the Jiulongpo-Chaotianmen segment of upstream Changjiang River as a research background, we assessed the risk levels of blasting-affected regions using a comprehensive method integrating analytic hierarchy process (AHP) and fuzzy mathematics. In line with the three stages of blasting, namely, blasting stage, propagation stage, and vibration resonance stage, we established an assessment model with geological features, blasting parameters, propagation features, and safety control as four assessment indicators. Comparison between the results of model application and on-site monitoring verified that the assessment method is strongly practical with good effect in the assessment of risk level of underwater blasting.

Key words: underwater blasting, risk assessment, analytic hierarchy process, fuzzy mathematics, evaluation indexes