Shear rate effect on residual strength of typical clay soils

Autor: Deepak Raj Bhat
Rok vydání: 2021
Předmět:
Zdroj: Innovative Infrastructure Solutions. 7
ISSN: 2364-4184
2364-4176
Popis: Residual strength parameters of clay soils along the slip surface of a slope are important parameters for stability analysis and countermeasure works against the activation and reactivation of landslides. The residual strength of slip surface soil is defined as the minimum constant value attained after a large displacement, which may equivalent to the measured residual strength of such slip clay soils in the ring shear test. However, the previous studies reported that the residual shear strength of clay soils may vary with shearing rates in ring shear tests. Therefore, further investigation is needed to understand the relation between the residual strength and shear rates for various types of clay soils collected from the reactivated landslide sites. Moreover, the effect of shear rate on the residual strength of high- to low-plasticity soils with the presence of different clay minerals has not yet been fully understood. The main objective of this study is to understand the rate dependency of the residual strength of typical clay soils from the soil plasticity and clay mineralogical perspective, and the shear rate effect mechanisms behind it. This paper presents the effect of shear rates on residual strength of various typical clay soils having high-to-low plasticity in its soil natures. The shear rates were fixed in a range of 0.073–0.586 mm/min at different six shear rates (i.e., 0.073 mm/min, 0.162 mm/min, 0.233 mm/min, 0.313 mm/min, 0.398 mm/min, and 0.586 mm/min). A series of tests were performed by means of torsional ring shear apparatus in the fully natural drained condition under an effective stress of 98.1 kN/m2. Shear rates on residual strength of the high-plasticity soils, medium-plasticity soils, and low-plasticity soils having various clay minerals were compared. The results showed the neutral rate effect on the residual shear strength of typical clay soil at shear rates of 0.073 mm/min, 0.162 mm/min. Similarly, the positive rate effect on residual strength of typical clay soils was confirmed at shear rates of 0.233 mm/min, 0.313 mm/min, 0.398 mm/min, and 0.586 mm/min. The relation between residual friction coefficient and shear rate of typical clay soils was also presented. Finally, shear rate mechanism of clay soils was discussed based on the variation of residual friction angles with shearing rates.
Databáze: OpenAIRE
Externí odkaz: