Experimental study on shear behaviors of sand under different stress path

In order to study shear behaviors of sand under different stress path,eight monotonic shearing tests with different stress path were performed.It shows that,under different stress path,shear dilatancy behaviors of sand are obviously different:it has more notable shear dilatancy behaviors under extension than under compression,in the case of compression,more notable shear dilatancy behaviors revealed under decompression compression path,and most unconspicuous shear dilatancy behaviors under pressurized shearing path,and its shear dilatancy behaviors under conventional compression path are between two former conditions.Under deviatoric stress consolidation,it shows more obvious shear dilatancy behaviors.And that,if stress paths are different,internal friction angles of sand are different,which is 3°-4°bigger under triaxial extension than under triaxial compression.Under the same condition of compression or extension,no matter what different stress loaded,all internal friction angles tend to the same stress ratio at the critical state ultimately.