Effectiveness of Emergent Coastal Vegetation as a Defense System to Mitigate Debris Load on a Structure During Extreme Events

Recent research has shown the effectiveness of a vegetation patch in reducing the fluid force of an extreme surge. However, research on the loading behavior of debris such as shipping containers, in the presence of this coastal defense system, is limited to the best of this author’s knowledge. This study examines the behavior of impact loading on a column structure due to a modeled shipping container in the presence of rigid staggered vegetation (RSV) and Tilting staggered vegetation (TSV) based on indices such as Reduced Fluid Force Index (RFI) Reduced Momentum Index (RMI) and Transmission coefficient ( \(C_\textrm{T}\) $C_{\text{T}}$ ). The non-linearities and the free surface of the fluid are dealt with in Smoothed Particle Hydrodynamics (SPH), and the dynamics of vegetation tilt are dealt with using Differential Variational Inequality (DVI). Our results demonstrate that integrating coastal vegetation can reduce debris impact forces significantly, with reductions of up to 96% for rigid vegetation and 89% for tilting vegetation. Finally, a relationship between trunk tilting and its corresponding underestimation of peak debris impact load on a column structure for a half-emerged vegetation patch is derived. This study provides a significant understanding on the effect of coastal vegetation in mitigating the impact of peak debris.