Experimental investigation and analysis for hydrodynamic behaviours and progressive collapse phenomenon of submerged floating tunnel under anchor cables' breakage

The hydrodynamic behaviours and progressive collapse phenomenon of the submerged floating tunnel (SFT) under anchor cable breakage are experimentally investigated in this study. A physical scale segment model of the SFT under wave and current loadings is designed and studied in wave-current flume. A specially designed anchor cable breakage device is presented. The experimental data are observed to conform well to the numerical calculation results. The dynamic performance of the SFT under anchor cable breakage is comprehensively investigated based on varying effect factors. The results from the test indicate that the response variation assessment, transient effect, force redistribution and impact force in different cases are the key factors to determine the probability of instability and progressive collapse of the SFT under cable breakage. The results can provide valuable design and construction recommendations to avoid potential engineering risks and ensure the safety and stability for the SFT under marine environment.