A back-analysis of Beliche Dam

A back–analysis of the Beliche Dam in southern Portugal is described. This dam was the subject of a 'Class A' prediction which grossly under–predicted the actual settlement at the end of construction. The analysis described here, which incorporated an elasto–plastic critical state model applied in terms of effective stress, simulated the effect of collapse settlement and by so doing reproduced a maximum settlement which was close to that measured. The earlier underprediction is attributed mainly to the fact that that analysis did not include the collapse settlement due to the partial impounding of the reservoir which occurred before construction was complete. The back–analysis described here covers the period from the start of construction in 1984 to approximately four years after the first complete impounding in January 1988. Comparisons are made between the calculated and measured movements and stresses. Apart from the good agreement with the maximum recorded settlement, the measured settlements general...