Modeling of geosynthetics using true Findley and Onaran and Findley models

Geosynthetics are polymeric materials subjected to creep. Creep is an important factor. Studies on creep are few as they are expensive and time consuming. Hence, extrapolation for the design life becomes a necessity. This is achieved by modeling the behavior by means of chain models and superposition techniques. The current study utilizes the True Findley model which is an empirical model and the Onaran and Findley Model which is a multiple integral representation. Isochronous creep data corresponding to SR2 ,a high density polyethylene based uniaxial geogrid and SS2,SS20 which are polypropylene based geogrids and PP0294 which is also polypropylene based found from literature are generated and the feasibility of using the True Findley and Onaran and Findley models are examined. Regression analysis based on Levenberg-Marquardt Algorithm was carried out using IMSL subroutines. The material parameters were evaluated and stiffness - variation with time were generated.