New General Analytical Solution for Infiltration Structures Design

This paper develops an analytical solution to assist in designing and sizing stormwater infiltration structures. As original elements, our solution allows to estimate the hydraulic head in the infiltration structure as a function of (1) storm temporal dynamics, making use of an appropriate intensity duration frequency (IDF) curve, (2) the model adopted to describe the response of the catchment to a given input rainfall, and (3) the evolution of the wetted front advancing in a homogeneous soil where the infiltration device is located. Our solution allows highlighting the effects of the various simplifications associated with existing formulations employed in the common engineering practice. Our results indicate that typically adopted methodologies based on the assumptions of a uniform infiltration rate and/or negligible flow rate along the lateral surface of the structure may lead to overestimating the key design parameters.