Geomembrane tensions and strains resulting from differential settlement around rigid circular structures

A simplified model is presented that analyzes tensions and strains in a geomembrane. The membrane analysis is applied to circular structures subjected to differential settlement. It was found that wrinkles are induced in the geomembrane around the circular structure and the associated mechanism was investigated. An improved predictive model was developed based on the wrinkled membrane theory. The model introduced the concept of a “variable Poisson's ratio”, and allowed tensions and strains associated with wrinkles in the geomembrane to be considered. Parametric studies and a comparison between the simplified model and the improved model were performed. Limitations associated with the two models are discussed and some practical recommendations are made with regard to the control of geomembrane tensions and strains around circular structures.