Monotonic Preloading Effect on the Liquefaction Resistance of Chlef Silty Sand: a Laboratory Study

This paper presents a laboratory study on the influence of monotonic preloading on the liquefaction resistance of Chlef soil using the triaxial apparatus. The study is carried out via a multiple drained monotonic and undrained cyclic tests. The samples were subjected to a static drained loading until an axial strain of 2.25 % (contraction phase), 4.5 % (end of contraction phase) and 9 % (dilatancy phase). For each preloading, cyclic tests have been conducted with different loading amplitudes. The obtained results are highly dependent on preloading amplitude: the liquefaction resistance increases with the application of a preloading during the contraction phase with an axial strain ε 1 = 2.25 % , decreases when the preloading increases to ε 1 = 4.5 % and reaches a lower resistance than the intact soil when ε 1 = 9 % (dilatancy phase).