Field Experimental of Eliminating Geomembrane Air Expansion by Vacuumizing for Plain Reservoir

The geomembrane liner has been extensively utilized as a containment system for the construction of reservoirs, ponds, and lagoons. In the reservoirs that are completely lined with geomembranes, a number of factors could cause geomembrane air expansion, including the rising of groundwater level, a rapid decrease in the reservoir water level, and geomembrane defects. Geomembrane air expansion would increase the risk of failure of the geomembrane liner. At present, sand ditch exhaust systems are often employed to eliminate pore air pressure, however, the effect is not obvious. In this article, the method of vacuumizing is proposed to eliminate geomembrane air expansion. A field experiment was performed to verify the validity of the proposed method. Experimental results indicated that: (1) during the storage period of the plain reservoir, leakage water flowed into the sand ditch exhaust system, which would greatly reduce pore air exhaust efficiency of the sand ditch exhaust system; (2) the proposed method could be employed to suck out the pore air under geomembrane liner, and thus, the problem of geomembrane air expansion was solved effectively.