The villagers built a small earth-rock dam on the river. After years of use and operation, many problems and defects have appeared. After investigation, a leak was found at the top of the dam. Therefore, effective anti-leakage measures must be taken in the entire project storage area to ensure its normal storage.
Geomembrane has low cost and fast construction speed. Due to the complex geological and topographical conditions in the engineering area and the development of faults, the cost of vertical anti-seepage measures in the water storage area is relatively high.
However, the geology and drilling data of this area show that there are no large-scale caves or karst fissures, and the water storage area has good stability, so horizontal anti-seepage measures should be taken. According to the characteristics of large area of anti-seepage treatment and complex geological structure, under the premise of ensuring foundation settlement, it must have a certain ability to adapt to foundation settlement, displacement and deformation caused by expansion and contraction, engineering safety and appropriate effect of anti-seepage treatment.
Compared with traditional anti-seepage measures such as anti-seepage or grouting wall construction, geomembrane has the advantages of low cost, fast construction speed, reliable anti-seepage effect, and low investment. Therefore, after economic and technical comparison, it was decided to adopt composite geomembrane as the anti-seepage measure of this project.
According to the leakage characteristics of the water storage area of the project, an overall closed composite geomembrane is used to cover the entire water storage area. Due to the wide range of anti-leakage, groundwater can be recharged. In order to ensure the safe operation of the composite geomembrane, anti-seepage measures for intercepting the seepage in the water storage area of the project are designed and proposed. The top layer of soil has a thickness of 0.7 m. The water slope protection masonry consists of a 10 cm precast concrete slab, a 10 cm gravel cushion and a layer of composite geomembrane from top to bottom.
