Geomembrane is a flexible geosynthetic impermeable material, and the stability of its underlying support layer is one of the keys to the safety of geomembrane. If the underlying support layer has obvious uneven deformation and local erosion, the geomembrane will be partially torn, forming a leakage channel, threatening the safety of the project. Therefore, it is necessary to analyze the stress and deformation of the geomembrane and its underlying support layer to determine the safety of the geomembrane. Geomembrane is the flexible material of the reservoir, and the entire reservoir basin penetrates into the deep horizon. The geomembrane is generally in a relaxed state during the construction and laying process, and the geomembrane and the soil can deform and coordinate during the operation of the reservoir.
The geomembrane structure is flexible and deforms with the deformation of the reservoir basin soil. The soil in the reservoir basin deforms into the middle of the reservoir basin under the action of water pressure, and the geomembrane on both sides of the reservoir basin is in an extended state, but the geomembrane in the middle of the reservoir basin is in a compressed state, which conforms to the general deformation law of the reservoir basin. Under the action of water pressure, the soil deformation in the Xianrenshan Reservoir basin is dominated by settlement deformation, with the largest settlement occurring in the center of the reservoir bottom with the largest thickness of the prospective layer and greater water depth. Affected by the U-shaped boundary of the rock and soil in the lower part of the reservoir basin, the soil on both sides of the reservoir basin deforms into the central part of the reservoir basin. The soil deformation contours in the reservoir watershed are uniformly and continuously distributed, and there is no uneven deformation that is obviously harmful to the geomembrane.
The distribution of tension and strain of the composite geomembrane in the reservoir is basically consistent with the deformation of the soil in the reservoir basin. The geomembrane on both sides of the reservoir basin is in a stretched state, and the geomembrane at the center of the reservoir basin is in a compressed state. The maximum tensile strain per unit width appears in the middle and lower part of the left bank slope, but the width is not large. The safety factor of tensile and strain of geomembrane is greater than 5.0. The geomembrane can cope with the deformation of the underlying soil with a certain safety margin.