“…The triaxial shear strength test is traditionally performed in the laboratory to evaluate the effects of monotonic and repeated loading on ballast behavior (Indraratna et al, , 2009Suiker et al, 2005;Aursudkij et al, 2009;Lu and McDowell, 2010;Qian et al, 2013Qian et al, , 2014Qian et al, , 2015Mishra et al, 2014a;McDowell and Li, 2016;Ngo et al, 2016).…”