“…The inherent anisotropy on shear strength has been investigated widely in much previous research employed a variety of laboratory tests (Oda et al, 1972; Aurthur and Menzies, 1972; Lam and Tatsuoka, 1986;Guo, 2008;Tong et al, 2014;Razeghi and Romiani, 2015). On the other side, the inherent anisotropy on the shear modulus at small strain was also carried out by means of shear wave velocity Vs determination (Pennington et al, 1997;Jovičić et al, 1998;Gasparre et al, 2007;Escribano and Nash, 2015) and direct measurement of G0 using the local strain measuring instruments incorporated to testing apparatus (Hoque and Tatsuoka, 1998;Yamashita et al, 2003;Yamashita et al, 2005).…”