Load Transfer and Hydraulic Fracturing in Zoned Dams

Incremental, nonlinear finite element analyses were conducted for 14 representative zoned dams of differing geometries and material properties to assess the load transfer and potential for cracking by hydraulic fracturing and local overstress. The results of these analyses showed that significant load transfer was observed in all cases; the load transfer was from the core onto the transitions and shells over most of the height, but was onto the core near the crest. This may be a possible mechanism for longitudinal core cracking in the crest. All other factors being equal, the dams which would exhibit the least transverse cracking potential would have flatter side slopes, thicker cores, sloping cores, medium dense shells and cores compacted drier than optimum. The effect of variations in the transitions properties and thicknesses, dam height and core slope in sloping core dams was found to be small with regard to cracking potential.