Hydraulic compatibility of nonwoven conical filters with a backfill material

Abstract

Alternative drainage designs are developed due to high failures in retaining walls with missing or inadequate drainage. This study investigates the usage of nonwoven conical filter systems and their hydraulic compatibility with common backfill material using both laboratory and computational modeling. Computational fluid dynamics numerically solved the fluid flow and the discrete element method allowed for the modeling of particle to particle, and those methods were coupled to simulate particle-to-fluid contact. Through a combination of these methods, piping and retention performances of various soil-geotextile systems were studied. Nonwoven geotextiles were numerically modelled, partly by using the Poisson line process to simulate the inherent randomness found in fabricated nonwoven filters. The model results were compared with laboratory tests to corroborate the accuracy of the models. The soil-nonwoven filter systems, either conventional or conical, provided 6% - 87% lower permeability values compared to soil-woven systems and had 10% - 48% higher piping rates than their counterparts. Support-vector-machine algorithm was utilized to classify zones for the performance curves for woven and nonwoven geotextiles, where a clear distinction in zones was shown.