Stress–Strain Strength Characteristics of Undisturbed Granite Residual Soil Considering Different Patterns of Variation of Mean Effective Stress
Open Access
- 20 February 2021
- journal article
- research article
- Published by MDPI AG in Applied Sciences
- Vol. 11 (4), 1874
- https://doi.org/10.3390/app11041874
Abstract
Granite residual soil is one of the most frequently encountered problem soils in tropical regions, whose mechanical behavior heavily depends on the pattern of variation of mean effective stress (p’) during shearing, which can be classified into three categories: increasing-p’, constant-p’, and decreasing-p’. Unfortunately, so far, the stress–strain strength characteristics of granite residual soils have been studied mainly under increasing-p’ stress paths, although it is very likely to encounter stress paths with decreasing p’ in practice, especially in excavation engineering. Moreover, most pertinent research has focused on remolded granite residual soils, whereas undisturbed specimens have not yet received enough attention. In this paper, stress path triaxial tests considering different patterns of variation of mean effective stress were conducted on an undisturbed granite residual soil. Subsequently, a variable termed loading angle was introduced to quantitatively represent stress path. The influences of stress path on the Mohr–Coulomb strength parameters, deformation characteristics, ductility, and shearing stiffness were analyzed, with an emphasis on the role of pattern of variation of mean effective stress. The experimental results show that friction angle of the soil increases while cohesion decreases with the increase in loading angle. The increase in loading angle leads to less volume contraction and smaller failure strain. During shearing, the soil exhibited a less brittle response under stress paths with smaller loading angles. The initial secant shear modulus first decreased and then increased as the loading angle increased, with the minimum shearing stiffness occurring at a certain loading angle lying between 90° and 123.7°.Funding Information
- National Natural Science Foundation of China (11672320)
This publication has 48 references indexed in Scilit:
- Mechanical response of a medium-fine-grained decomposed granite in Hong KongEngineering Geology, 2012
- Shear strength and dilative characteristics of an unsaturated compacted completely decomposed granite soilCanadian Geotechnical Journal, 2010
- Behaviour of recompacted residual soils in a constant shear stress pathCanadian Geotechnical Journal, 2010
- Influence of the microstructure in the collapse of a residual clayey tropical soilBulletin of Engineering Geology and the Environment, 2008
- Shear strength of a compacted residual soil from consolidated drained and constant water content triaxial testsCanadian Geotechnical Journal, 2004
- Field and Laboratory Measurements of Small Strain Stiffness of Decomposed GranitesSoils and Foundations, 2001
- The intrinsic behaviour of a decomposed granite soilGéotechnique, 1995
- Shear-strength characteristics of a residual soilCanadian Geotechnical Journal, 1995
- A Grading Equation for Decomposed Granite SoilSoils and Foundations, 1990
- The Residual Soils of Hong KongGéotechnique, 1965