Open AccessRate Effects on Peak and Residual Strengths of Overconsolidated Clay in Ring Shear Tests
Author(s) -
Nguyen Thanh Duong,
Motoyuki Suzuki
Publication year - 2021
Publication title -
periodica polytechnica. civil engineering/periodica polytechnica. civil engineering (online)
Language(s) - English
Resource type - Journals
eISSN - 1587-3773
pISSN - 0553-6626
DOI - 10.3311/ppci.19202
Subject(s) - cohesion (chemistry) , geotechnical engineering , shear (geology) , residual strength , residual , geology , shear rate , landslide , direct shear test , shear strength (soil) , materials science , soil water , composite material , rheology , soil science , chemistry , mathematics , organic chemistry , algorithm
Overconsolidated (OC) clay soil is widely distributed in landslide slopes. This soil is often fissured, jointed, contains slickensides, and is prone to sliding. Thus, the shear strength behavior of OC clayey soil is complicated and has received much attention in the literature and in practice in terms of evaluating and predicting landslide stability. However, the behavior of the shear strength of OC clayey soil at different shear rates, as seen in ring shear tests, is still only understood to a limited extent and should be examined further, especially in terms of the residual strength characteristics. In this study, a number of ring shear tests were conducted on kaolin clay at overconsolidation ratios (OCRs) ranging from 1 to 6 under different shear displacement rates in the wide range of 0.02 mm/min to 20.0 mm/min to investigate the shear behavior and rate dependency of the shear strength of OC clay. Variations in the cohesion and friction angles of OC clay under different shear rates were also examined. The results indicated that the rate effects on the peak strength of OC and normally consolidated (NC) clays are opposite at fast shear displacement rates. At the residual state, as with NC clay, the positive rate effect on the residual strength is also exhibited in OC clay, but at a lower magnitude. Regarding the shear strength parameters, the variations in the cohesion and friction angles of OC clay at different shear rates were found to be different at peak and residual states.