| dc.description.abstract | Slope stability is of significant importance for sustainable development in mining, civil engineering, and urban planning as slope failures endanger public safety and continue to
result in costly repair work. This study aimed to investigate the geological and geotechnical
parameters for slope stability of a Himalayan road cut slope along National Highway-7 (NH 7), Uttarakhand, India. The study also attempted to characterize the intrinsic mechanical properties of rocks using nanoindentation experiments.
Extensive field investigations and laboratory tests were carried out for each slope. These
include the survey of slope geometry, weathering grade, groundwater condition, soil and rock
mass sampling, geological strength index. Laboratory investigations mainly comprised of
direct shear test, particle size distribution, Atterberg limits, soil classifications, mineralogy
(XRD) analyses, density measurement, rock hardness test, and Brazilian test on the representative soil/rock samples from each slope. Deterministic and probability limit equilibrium methods (LEM) and strength reduction factor (SRF) based on the finite element method (FEM) were used to evaluate the stability condition of the slopes based on the Rocscience Slide v6.0 and Phase2 v7.0 softwares, respectively. The results showed that with all equal conditions, a gentle slope is vulnerable to weathering, hence induce instability. Factor of safety of completely weathered slope is approximately 50% lower than that of moderately weathered with relatively steep angle. However, steep gradient slope favours surface runoff and inhibits the development of secondary clay minerals which could hamper the stability condition of the slopes. Overall slope angle and height experience more gravitational stresses and have greatest effect on the stability conditions of the studied slopes than the activity of swelling clay minerals. Modification of slope geometry, installation of retaining and gabion walls along toe and surface protection are possible stabilization
techniques to increase the stability state of the slopes.
Uniaxial compressive strength (UCS) is one important strength index parameter widely
used for proper design and analysis of many engineering systems including slope stability
analysis. This study evaluates new approaches to assess the UCS using nanoindentation hardness (Hi) and elastic modulus (Ei) from small pieces of rocks since standard experimental specimens in most cases are difficult to obtain. | en_US |
