Geomembrane is used to prevent seepage at the bottom of the reservoir and the slope of the dam. The geomembrane is provided with 200g/m2 geotextile on the upper and lower layers, and the PE membrane is 0.5mm thick. The bottom of the reservoir anti-seepage dimple drainage board manufacturers adopts membrane cloth separation scheme, and the dam slope geomembrane adopts composite geomembrane scheme.
To deal with the problem of large laying area, deep groundwater burial, and the rise of the groundwater level after reservoir storage, it is easy to produce gas inflation, and combined measures of exhaust blind ditch and ballast are adopted. The spacing of the exhaust blind trenches under the composite LDPE geomembrane manufacturers at the bottom of the reservoir is arranged at 50. 0m, and an annular blind trench at 20. 0m from the dam foot communicates with the blind trench at the bottom of the reservoir; The ditch leads to the bottom of the anti-wave wall, and a φ50PPR pipe is installed at the anti-wave wall to discharge the gas under the membrane. The size of the blind ditch is 30cm×30cm. A soft permeable pipe of φ100 is arranged in the blind ditch. The circumference of the pipe is backfilled with 0.5~1.0 cm gravel. The gravel is covered with a layer of 300g/m2 short silk geotextile.
The groundwater level of the LDPE geomembrane for sale groundwater funnel area is relatively large, and the difference between the water level of the reservoir and the groundwater level after the storage of the reservoir is large. The leakage of the reservoir is mainly vertical leakage. If there is no continuous deep water barrier in the reservoir area, the reservoir adopts vertical prevention The effect of infiltration scheme is not obvious.
In the early stage of reservoir impoundment, when the geomembrane has defects, the reservoir water will seep into the unsaturated soil under the membrane along the high quality environmental geomembrane defect, and continuous leakage will produce the following two negative effects: ① water leakage is easy to enter The sand ditch exhaust system composed of permeable medium and coarse sand flows along the sand ditch and invades the pore space of the medium and coarse sand. The exhaust channel of the sand trench under the membrane is closed to produce water resistance, so that the gas under the membrane cannot pass through the sand under the membrane The exhaust system of the groove and check valve is normally discharged. ② Leakage continues to infiltrate along the unsaturated soil. When the infiltrated water contacts the groundwater, the infiltrated water, geomembrane and groundwater divide the unified unsaturated soil space under the membrane in the original reservoir area into several relatively closed gas spaces.