Application of Geotextile/Geomembrane Composite Liner for Infiltration Prevention in Xiaolingtou Rock-Fill Dam

The rock-fill dam at the Xiaolingtou Reservoir is 36.4 m high and uses a geotextile/geomembrane composite liner to prevent seepage. The composite consists of geotextiles bonded to both sides of a geomembrane. The seepage prevention properties of the composite are theoretically analysed, and equations to calculate the design strength and geomembrane thickness have been introduced. The transition material on the side slopes of the dam directly effects the selection of a design strength for the composite. The laboratory testing program carried out to optimize the cushion material gradation of for the Xiaolingtou rock-fill dam is described. The horizontal displacement, vertical settlement, maximum and minimum principal stresses in the rock-fill dam during construction and water storage periods have been analysed by the finite element method.