THE DESIGN OF ANTI-SEEPAGE SYSTEM OF THE UPPER RESERVOIR IN SHISANLING PUMPED STORAGE STATION

摘要

The Upper Reservoir of Shisanling Pumped Storage Station is the first project in China which adopts all-covered concrete lining for anti-seepage, and the similar project is seldom found in the world. The total area of the lining is 175,000m~2. The Upper Reservoir is built by excavating for storage and filling for rockfill dam. The complicated geological conditions under the lining and adverse climate to operation bring the design some problems, and they also drive to form some features: the connecting slab directly on the drainage cushion, the 65.4-m-long concrete face slab on rock base without horizontal joint, the large-amount usage of GB packing in joint, the once-shaped connector of the copper waterstop. The lining's cracks are mostly fine cracks less than 0.2mm in width, and show the regularity relative to constraint, that is, the parts with slight constraint and careful concrete curing possess fewer and finer cracks, otherwise, more and wider ones. Since the water filling in August 1995, the operation of the Upper Reservoir has been normal, and endured the severe winter. The maximum observed leakage discharge reached 14.2 liter/s, and now the discharge fluctuates between 0.02～1 liter/s (in summer) and 7～8 liter/s (in winter).