Assessing the Effect of Damaged and Fractured Concrete Cutoff Wall on the Dynamics of Seawater Intrusion

摘要

The physical cutoff barrier is one of the best known techniques to control seawater intrusion in a coastal aquifer. This method is widely used in many sites worldwide, such as Japan, Brazil, India, Burkina Faso etc. In the current research, we use the FEFLOW code to investigate the effect of a damaged concrete cutoff wall on saltwater dynamics. The damage is modeled as a fracture where three configurations were investigated: horizontal, oblique, and combined fractures. The results show that the fractured cutoff wall loses its effectiveness in reducing the penetration of saltwater wedge at a rate of 63%. Furthermore, to assess the impact of some key variables, a sensitivity analysis was carried out. Results show that the efficiency impairment of the fractured cutoff wall to prevent seawater intrusion is very sensitive to the cutoff wall position, fracture aperture and seawater density.