Impact of Soil Structure on Rate-Dependent Consolidation of Clayey Soils

Abstract

An engineering framework for soil structure evaluation was devised and developed to extend understanding on soft soil behavior and characterization. This framework strategy was then implemented for the assessment of the impact of the degree of structure on rate dependence of clayey soils' consolidation behavior in an aim to quantitatively predict rate dependent/independent response of consolidation deformation based on a numerical computed parameter called structure number (SN). To this end, for various natural clayey soils tested in the laboratory experimental program using an advanced automated Rowe cell consolidation device, it was detected that a blue clay extracted from shallow and deep depth in North Anatolia possessing a medium high and a moderate degree of structure presented structure numbers, SN = 2.8 and SN = 2.5, respectively. Further, an olive-green clay extracted from shallow and deep depth in Southwestern Anatolia having a high and a medium low degree of structure showed structure numbers, SN = 3.5 and SN = 2.1, respectively. Moreover, a cream-colored clay extracted from shallow depth in Midwest Anatolia possessing a very high degree of structure provided structure number, SN = 4.4. As a result, it was explored that high SN values (> 2.6) are displayed by highly structured clayey soils resulting in a high degree of rate effect. Additionally, medium SN values (2.2 < SN < 2.6) are exhibited by moderately structured clayey soils leading to a medium degree of rate effect. Besides, low SN values (< 2.2) are demonstrated by slightly structured clayey soils resulting in a low degree of rate effect.