Laboratory Evaluation of Select Retention Criteria for Cyclic Flow Conditions

A hydromechanical framework, for retention compatibility of soil-geotextile filters in cyclic flow, is developed through laboratory test data. Combinations of eight geotextiles and four cohesionless soils were tested in a cyclic gradient ratio permeameter. Interpretation of the results addresses three test variables namely, filter ratio (AOS/D₈₅), hydraulic gradient (i) and confining stress (σ). The framework is found reasonable to explain filter compatibility, and conditions leading to onset of retention incompatibility. For a uniformly-graded soil, the onset of incompatibility occurs at 2 ≤ AOS/D₈₅ ≤ 2.5. Two select retention criteria involving cyclic or dynamic flow are evaluated and recommended for certain types of base soils.