Experimental Study On The Tensile Force In The Geomembrane Due To Compaction Work And Temperature Variation

The waste landfill should be designed that no leachate that may include hazardous materials flowing into surrounding groundwater over long period of years. A liner system is installed on the bottom and the side slope of a waste landfill to prevent the leachate from infiltrating into surrounding ground and polluting groundwater. The liner system is considered to experience the tensile force due to various factors, such as tensile force induced by settlement of base ground, thermal stress due to decrease of temperature, lifting force by the wind, the tensile force by compaction work of disposed waste. Such high stress condition may result in the failure of the geomembrane and the liner system which resulted in environment contaminated, so it is very important for the design of the lifetime of liner system to determine the tensile force induced in components of liner system. In this paper, the tensile force in the geomembrane due to compaction work and temperature variation was studied.In this paper, the tensile force in the geomembrane induced by compaction work and temperature variation were experimentally investigated with self-designed testing device, evaluation methods of the tensile force in the geomembrane are proposed due to compaction work and temperature variation.The conclusions can be drawn as follow, (1) Testing device adopted in this paper could simulate filling process. (2) The tensile force in the geomembrane by compaction work increased with the increase of height. In a certain height in the landfill, the tensile force in HDPE geomembrane due to compaction work is 4-5 times than the tensile force in EPDM geomembrane. (3)The temperature stress in the geomembrane occurred with decrease of circumstantial temperature. The temperature stress decreased with increase in height at the circumstantial temperature. (4)The evaluation method of the temperature stress was modified, and a comparison showed that calculation results are fairly close to experiment value, the modified evaluation methods is applicable. (5)The experiment value of the tensile force in the geomembrane due to compaction work and temperature variation showed that: the temperature stress in the HDPE geomembrane occurred with decrease of circumstantial temperature; the tensile force in HDPE geomembrane is mainly temperature stress when the height is low; the tensile force in the HDPE geomembrane by compaction work increased with increase of height; the temperature stress decreased with increase in height. The tensile force in the HDPE geomembrane due to compaction work are analyzed by finite element method, the temperature stress are analyzed by modified evaluation method, and a comparison showed that the calculation results are fairly close to experiment value.