Numerical analysis of interaction between flow characteristics and dynamic response of interlocked concrete block mattress during sinking process

Abstract

Revetment can provide effective protection against wave overtopping and fluvial erosion along coastlines, estuaries, and rivers. The cost-effectiveness and rapid implementation make Interlocked Concrete Block Mattress (ICB mat) a viable alternative to unit armors. However, the intense hydrodynamic conditions may compromise the structural integrity of ICB mat during sinking construction, posing significant threats to both personnel and engineering safety. This study aimed to investigate the flow characteristics around the flexible mattress and its dynamic response. Recently, the fluid-structure interaction (FSI) method has been extended to multi-physics analysis in engineering applications due to its superior performance. A two-way coupling was employed to simulate the conceptualized cases of sinking process of ICB mat using the k-ω SST turbulence model, the Arbitrary Lagrangian-Eulerian algorithm, and the partitioned method in this study. The results indicated that the upstream surface velocity of the mattress increased exponentially with the growing water depth; meanwhile, the maximum velocity near the head beam was 23.8–31.2% larger than the average velocity. Additionally, the stress distribution on the mattress manifested transverse stripes influenced by the layout of interlocked blocks, with the highest stress primarily observed in the vicinity of the rotating plate and head beam. Furthermore, an estimation formula was proposed for the dynamic response of ICB mat considering the hydrodynamic conditions as well as structural properties. The current study can provide theoretical guidance for the structural design of ICB mat and engineering risk assessment during sinking construction.