Effect of stress path circumgyration on shear modulus under small strain and initial stress state

The test object was remolded soil after K 0 consolidation.Using advanced stress path triaxial system,STDTTS+UNSAT(7 kN/1700 kPa) produced by GDS of UK,the effect of stress path circumgyration on shear modulus and the trend of shear modulus along with variation of shear strain under small strain were studied.Some conclusions were drawn.Under the condition of small strain,the initial value of shear modulus increased along with the increment of angle θ between trail stress paths and recent stress history.If the two directions were entirely reverse,the effect of stress path circumgyration on shear modulus was the largest;if they coincided completely,the effect was very feeble.At the same time,under the condition of small strain,firstly,the secant shear modulus was always larger than the tangent shear modulus.Secondly,when the logarithmic coordinates were applied to describe shear strain,the decrease of shear modulus with shear strain could be expressed by reversed S shape curve with two inflexion points,and through analyzing and validating,the deduced equation could perfectly reflect this characteristic.Finally,different stress paths and strain areas would lead to different attenuation trends.