Folding, Destructuring, and Strength Changes in Overconsolidated Varved Clay under Embankment Loading.

Evidence of the lateral compression of the Earth's crust is apparent from folds and faults observed in rock, and the mechanics describing their development is well established in the fields of structural geology and tectonics. This paper describes similar structures in soils that developed in multilayered varved clay under the side slopes and toe of an embankment due to the nonuniform loading. Using analytical methods derived for the buckling of thin plates of alternating high and low moduli, predictions of wavelengths and the critical stresses to initiate folding were determined, and found to correlate with field and laboratory measurements. When these conditions occur, the resulting fabric changes have implications for slope stability modeling and the interpretation of field monitoring observations. This includes the ability of the clay to sustain large strains as it transitions from a highly anisotropic macrofabric to a relatively homogeneous material, without undergoing shear failure. [ABSTRACT FROM AUTHOR]