Evaluation of slope reliability considering the rotation of the correlation structure of soil properties

Abstract

At present, research on the spatial variability of soil parameters mostly considers isotropy and transverse anisotropy correlation structures; by comparison, little research on other general correlation structures is available. To address this issue, the present study generates a general rotated anisotropy correlation structure random field considering stratum rotation by using random field theory and the matrix decomposition method. FLAC3D and strength reduction theory are used to analyze the influence of the rotation angle of the correlation structure and the angle between the principal axes of the correlation structure on slope reliability. Thereafter, the influences of the coefficient of variation (COV) and shear strength cross-correlation on slope reliability are revealed. Results show that slope stability first increases and then decreases with increasing rotation angle of the correlation spindle. Slope stability is related to the rotation angle of the correlation spindles. In the two-parameter random field of shear strength, slopes in which the dip direction of the strata is against the dip direction of the slope demonstrate higher reliability than slopes in which the dip direction of the strata is along the dip direction of the slope. This effect is more obvious when the COV is small. Compared with the slope reliability analysis results obtained when considering the cross-correlation of shear strength parameters, the results obtained when cross-correlation is ignored demonstrate underestimation of the probability of failure.