Acoustic behavior and time prediction method for water inrush of tunnel floor under osmotic water pressure

• Design a tunnel water inrush test bench to obtain the dynamic evolution process of multiple signals during water inrush disasters. • Classify AE event source fracture types based on RA-AF values. • A new method for predicting the time of sudden water disasters has been proposed. To deeply study the instability and water inrush catastrophe law of a tunnel floor under osmotic water pressure, a self-designed tunnel water inrush test system was used to conduct similar simulation experiments of tunnel floor sudden water under osmotic water pressure. It fills the gap in large model three-dimensional similar simulation water inrush experiment. Through the monitoring of multiple physical information during the experimental process, the distribution of AE results in space and time was obtained, and the fracture sources were further categorized by the AF-RA values of the AE data. We predicted the failure time of tunnel floor destabilizing water inrush based on the critical power-law singularity (CPLS) precursor with acoustic emission event rate and tunnel floor water pressure as response variables, the discrete coefficients of the prediction result were 1.098 % and 0.6523 % respectively. It is proved that this prediction method has a small degree of dispersion and high accuracy. The research results provide theoretical reference and experimental guidance for the prediction and prevention of water inrush disasters on tunnel floors.