Abstract:

For the high rockfill dam, whether too low vertical earth pressure or higher pore water pressure exists in the corewall or not has great significance for the security and stability of dam during construction as well as the impounding period. Combined with the construction schedule and procedure information, based on the monitoring data of gravelly soil core wall stress during the construction period, the soil pressure and pore water pressure in gravelly soil corewall during construction period are analyzed in time, space and effect factors respectively, with a view to improve design theory and construction measures of high rockfill soil corewall dam. Soil pressure primarily relates to soil bulk density, soil column thickness and the arching effect and symmetrically distributes along the dam axis. The strongest arching effect site is around the 1/3 height of corewall near the dam axis. At height with arching effect, the soil pressure is hump-shaped distribution and the minimum soil pressure is near the dam axis. Pore water pressures primarily relate to soil pressure and water content. At the dam filling process, to avoid the generation of excessive pore water pressure and reduce the impact of arching effect, the water content of the corewall material and the upper and lower dam shell should be strictly controlled.

Key words: gravelly soil corewall, pore water pressure, soil pressure, arching effect, hydraulic fracturing, monitoring