Impact of floating debris on houses during floods and vegetation-based mitigation
Debris generated by the destruction of houses in a floodplain can cause damage to the structure in the way of floodwater by the impact of different hydraulic forces. In the present study, the impact of different hydraulic forces including impact force, hydrostatic force, hydrodynamic force, fluid force index, and moment index on the house model of different porosity were examined and also the impact of these hydraulic forces on a house model for different types of debris including rectangular and cylindrical debris was investigated. The results showed that cylindrical debris of type D5 has a greater specific gravity of 0.206 compared to the other types of debris which is why it results higher magnitude of impact force (40%) for the double porous house model. D3 type of cylindrical debris showed the highest values of hydrostatic force (40%) as D3 has a greater length (26.5cm) and diameter (1.5cm). The higher velocity of flow causes a greater magnitude of fluid force index (60%) on the impermeable house model that reduces with the porosity of the house model. The highest moment index (97% ) acts on the impermeable house model because of greater flow velocity and water depth on the upstream side. Vegetation provided as a countermeasure on the upstream side of the house model reduced impact force from 10% to 22% for the double porous house model compared to the single house model (1-12%) and hydrostatic force reduced from 12-59% for different types of debris. Hydrodynamic force reduction was observed to be 30% when vegetation was provided on the upstream side of the house model of different porosity. Providing vegetation as countermeasures reduced the fluid force index and moment index up to 70% and 63.39% for the impermeable house model respectively.
