Owing to the lack of complementary shear stress on vertical boundaries of a direct simple shear (DSS) specimen, the stress/strain distributions in soil specimens are not uniform. Although the previous studies discussed the effect of diameter-to-height ratio (D/H) on the mechanical and dynamic properties of soil, there is a lack of experimental studies that cover the influence of D/H ratio on the liquefaction potential of sand under stress and strain-controlled conditions. In this study, the influence of the D/H ratio on the cyclic behaviour and liquefaction potential of Ottawa sand C-109 and Ottawa sand F-65 specimens is experimentally investigated. Reconstituted soil specimens of Ottawa sands were prepared at four different D/H ratios using the combined triaxial simple shear (T_xSS) and conventional DSS devices. The influence of the D/H ratio on the cyclic behaviour in terms of pore pressure generation and decay …