Effect of the buffer blocks in attenuating a tsunami-like flow

Abstract

The construction of protective structures along the coast constitutes a crucial component of tsunami mitigation measures. Most commonly adopted tsunami mitigation measures are submerged structures, elevating the crest level of existing coastal defence structures, or soft measures. However, less considered measures to reduce the inundation level are a well-planned group of buffer blocks, which could not only act as a mitigation measure but also can serve as a facility along the shore to sit and relax during normal conditions. The buffer blocks can be constructed without affecting the scenic beauty. This paper presents the influence of the buffer block characteristics in attenuating the flow depth, and flow velocity. To carry out the study, the numerical model, OpenFOAM is adopted to simulate the dam break setup generating tsunami-like flow. The reduction in the flow velocity is governed by its the configuration. It was observed that a single-row configuration can reduce the momentum flux to an extent of 5–40%. Further, the results indicate that an increase in the number of rows in staggered configurations might enhance the percentage reduction in the flow characteristics. In addition, the forces on the buffer blocks for various configurations are computed and analysed from the existing literature.