Limit resistive forces from ice frozen to concrete-revetment interface of an inclined dam wall

摘要

To estimate ice loads on concrete panel revetments of inclined dam walls, a series of simple shear tests were conducted to investigate adfreezing (freezing adhesion) behaviors of freshwater ice to concrete panel. Experimental results indicated that the adfreezing strength increases generally as the temperature decreases from -2 degrees C to -10 degrees C, and is impacted insignificantly by the loading/displacement rate. The adfreezing strength for coarse interface (surface roughness (SR) = 4.2 mm) is greater by 30%-40% than that for smooth interface (SR = 0.3 mm). Field investigations in a reservoir in northeastern China and theoretical discussions on ice-dam interactions indicated that the ice-dam bond is the strongest restraint on ice cover movement for a sloped dam wall. The adfreezing strength of ice-dam bond limits the restraining force during ice-push events, usually damaging dam walls or shoreline revetments. Limiting ice loads are estimated using the present adfreezing strengths under various ice failure scenarios induced by typical patterns of water level changes. The highest loads are generated when the water level keeps constant or drops quite slowly especially after large drops and/or ice push events. The estimates of ice loads are in the range of values derived from previous field observations.