SURFACE-SUBSURFACE MODEL FOR TRENCH INFILTRATION BASINS

This study presents a surface-to-subsurface two-dimensional (2D) model for the design of infiltration trench basins. It assists engineers in estimating the size of an infiltration basin and in determining the s ubsurface geometry required for having an adequate hydraulic conductiv ity. The Federal Aviation Administration (FAA) method is revised to pr edict the detention storage volume by maximizing the volume difference between the design storm runoff and the basin infiltration rate. Diff usion of the wetting front beneath the basin is depicted by the stream line-equipotential flow-net model derived in this study with considera tion of nonisotropic permeability. The required subsurface geometry is found to be related to the width of the basin, and the length of the saturation zone is proportional to the ratio of infiltration rate-to-c oefficient of permeability.