Experiment and evaluation on temperature sensitivities and tensile forces of anti-seepage geomembrane of farmland irrigation canal

In order to understand the temperature sensitivity of anti-seepage geomembrane, the experimental study and analysis of the thermal stress and deformation were conducted for anti-seepage geomembrane of farmland irrigation canal. The tensile force at the fixed end of anti-seepage geomembrane was measured by loadcell, thermocouple, and displacement gauge with variation in temperature. Experimental results indicated that the temperature change had significant effect on the tensile force at the fixed end, especially for the HDPE anti-seepage geomembrane; The temperature of anti-seepage geomembrane could be effectively reduced when the non-woven geotextile was used between the anti-seepage geomembrane and the protective layer; The large deformation occured with variations in temperature, the max displacement could reach 60 mm. Based on limit equilibrium theory, evaluation methods on the tensile forces caused by variation in temperature of anti-seepage geomembrane was proposed, the evaluation results considering the relationship between elastic modulus and temperature were in agreement with the experiment. The method proposed can effectively estimates tensile force of anti-seepage geomembrane with temperature variation. The test results can provide a certain reference for the engineering practice.