Effect of time on soil-geomembrane interface shear strength

Date of Award


Degree Name

M.S. in Civil Engineering


Department of Civil and Environmental Engineering and Engineering Mechanics


Advisor: Ömer Bilgin


In the past thirty years, geosynthetic materials have been used widely in various civil engineering applications due to their numerous advantages. Geomembranes are one of the most common geosynthetics that are used primarily as an impervious boundary for liquids or gases. High density polyethylene (HDPE), the material used for geomembranes, shows a viscoelastic behavior to the applied loads over a period of time in the form of creep or stress relaxation. Effect of time on soil-geomembrane shear strength is critical factor that should be studied carefully, because soil-geomembrane interfaces usually form weak planes and may cause failures. A series of large direct shear tests were carried out in the laboratory to investigate the effect of time on soil-geomembrane interface shear strength. The geomembrane samples were placed under a sustained load for two weeks then the shear tests were performed. The test results showed that the interface friction angle increases with time due to further penetration of soil particles into the geomembrane, resulting in the increase of soil-geomembrane contact areas. This thesis presents the tests performed, results obtained, discussion of the results, findings, and recommendations for future studies


Civil Engineering

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