The Experimental Evaluation of the Infiltration Capacity of Urban Soils Using a Lab-Scale Model

Abstract

Due to urbanized developments and excessive compaction from construction activities the in-situ infiltration capacity of urban soils has decreased. As a result, soil tends to behave more like a brick rather than a sponge to absorb water, resulting in poor drainage properties which lead to surface ponding, depleted underground water resources and eventually urban flooding. To counter this issue an infiltration-based system i.e., Drywell can be useful to facilitate the process of infiltration. In-situ infiltration capacity for sandy silt (ML) and lean clay (CL) was determined using single-ring infiltrometer test on site. A series of permeability tests at varied moisture content (N.M.C (Natural Moisture Content), OMC (Optimum Moisture Content), dry & wet side of OMC (Optimum Moisture Content) and from 0-50%) compacted at various compactive efforts was performed to make up a total 26 moisture-density scenarios. Full-scale Drywell test was performed to determine the infiltration performance of tested soils against varied initial moisture content and dry unit weight. The results showed increased infiltration capacity when compared to the in-situ infiltration capacities as determined in field. Linear regression revealed that the parameter of initial moisture content had a correlation of (R² = 0.53) and (R² = 0.50) for ML and CL respectively with infiltration capacity, dry unit weight for ML (Sandy Silt) and CL (Lean Clay) had a correlation of (R² = 0.74) and (R² = 0.64) with infiltration capacity.