Relations between liquefaction resistance obtained from cyclic triaxial test conducted on various graded sand and direct shear box and hydraulic conductivity test results

In this thesis, relations between liquefaction resistance obtained from cyclictriaxial test conducted on various graded sand and conventional direct shearbox and hydraulic conductivity test results, were studied. In this aspect, at first,a very comprehensive preliminary study was carried out, and specimens ofPaşabahçe silica sand, having various gradation and fines content, were formed.Then, liquefaction resistance of sand specimens, under cyclic loading, wasobtained on stress controlled cyclic triaxial test apparatus. In cyclic triaxial testprogram, while loading pattern was chosen as sinusoidal wave form with 1 Hzfrequency, effective consolidation pressure were chosen as 1 kgf/cm2. Hydraulicconductivity of sand specimens was also obtained from the cyclic triaxialapparatus. Strength characteristics of identical sand specimens were obtainedfrom deformation controlled conventional direct shear box test apparatus.Lastly, relations between cyclic stress ratio (CSR) to reach 0,95 pore pressureratio at 10 cycle with gradation characteristics, maximum and residual internalfriction angle and hydraulic conductivity were obtained.From the test results, it can be concluded that for uniform graded granular soilsamples, as the effective particle size decreases cyclic stress ratio decreases aswell. Furthermore, there is no a definite relation between cyclic stress ratio withuniformity coefficient (Cu) and gradation coefficient (Cc). Moreover, as the finescontent increases, cyclic stress ratio decreases.As the particle size gets smaller, cyclic stress ratio, permeability and internalfriction angle tend to decrease. As the maximum and residual internal frictionangles increases cyclic stress ratio increases as well. Although a relation betweenrelative density and cyclic stress ratio is available, there is not a definite relationbetween cyclic stress ratio or relative density with permeability.Key Words : sand, liquefaction, hydraulic conductivity, direct shear testfines content, cyclic triaxial test