Model to Design QA/QC Programs for Geomembrane Liner Seams

Abstract

Geomembrane liners are a common component in waste containment systems. Their performance is directly related to the quality of seams in the liner. The objective of this paper is to develop a probabilistic model of geomembrane seams to design and analyze destructive testing programs for quality assurance and quality control (QA/QC). Case study data from field installations are used to validate and apply the model. Statistics for the fraction of defective seam remaining after repair are derived as a function of the sampling interval and sampling method. Fixed interval sampling is shown to be more effective than random or stratified random sampling. The effects of nonperfect detectability on the required sampling interval are also investigated. Parameters in the seam model are estimated from QA/QC data using a Bayesian approach. Application of this model to case study data indicates that typical sampling intervals are not very effective at eliminating defective seams and improvements are needed in QA/QC for geomembrane seams.