Abstract: The mechanical property of interface between geomembrane and sand is a critical problem in stability analysis of landfill liner system. Based on basic theories of elastic mechanics and soil mechanics, the analytical solution of additional stress is given. The additional stress distribution of sandy soil near the interface is analyzed. The results show that there are three kinds of distribution form of additional stress isolines, which are hyperbolic type arch, enlarge shoulder arch type and circular arc arch. The additional stress distribution patterns are only related with the length of reinforcement and the distance from the reinforcement surface. There are no relation to the bearing stress of reinforcement. Under the same conditions, the effect of strip reinforced geomembrane is larger than that of lump reinforced geomembrane. So the strip reinforced geomembrane can improve the interface shear performance more effectively. The farther the sandy soil from the interface, the weaker the additional stress. When the distance from the reinforcement surface is up to 12 mm, the additional stress is close to zero. That is to say, the range of influence of reinforcement is about 12 mm.

Key words: geomembrane, additional stress, Boussinesq solution