A Framework for Evaluating the Effects of Drained Cyclic Preshearing on the Liquefaction Resistance of Ottawa Sand

摘要

A series of cyclic simple shear tests were conducted on reconstituted specimens of clean, finegrained Ottawa C109 sand at three relative densities. Small-amplitude drained cyclic preshearing strains of 0.02-0.3% were applied to the specimens for 30-1000 cycles. After drained cyclic preshearing, the specimens were subjected to higher amplitude cyclic shear strains under constant-volume conditions until liquefaction occurred. The test results are compared with constant-volume cyclic shear tests without preshearing to evaluate the influence that strain amplitude and the number of cycles of drained cyclic preshearing have on the liquefaction resistance of Ottawa C109 sand. Based on this comparison, a framework for understanding drained preshearing is proposed.