Faculty Publications

Permanent URI for this communityhttps://idr.nitk.ac.in/handle/123456789/18736

Publications by NITK Faculty

Browse

Subject: search.filters.subject.Slope stability

Search Results

Now showing 1 - 10 of 27
  • No Thumbnail Available
    Item
    Slope stability studies of excavated slopes in lateritic formations
    (Springer, 2019) Shivashankar, R.; Thomas, B.C.; Krishnanunni, K.T.; Venkat Reddy, D.V.
    The study area for this paper is coastal Karnataka in India, which has laterites and lateritic soils. The soil stratification in this area mainly consists of lithomargic clay, which is a product of laterization, sandwiched between the hard and porous weathered laterite crust at the top and the hard granite or granitic gneiss underneath. This lithomargic clay, locally called as ‘shedi soil’ behaves as dispersive soil and is also highly erosive. In the first stage of this study, laboratory erosion studies are conducted by using the hole erosion test apparatus on controlled shedi soil samples. Erosion observed in the HET is accelerated due to slaking irrespective of dispersive nature of the soil. Erosion problems were also dealt with using a stabilizer, calcium lignosulfonate and resulted in high increase in its erosion resistance. In the second stage of this study, slope stability studies of excavated slopes in lateritic formations are conducted considering intensity of rainfall, ponding and seepage, apart from the usual geotechnical parameters. The slopes steeper than 60° are not stable in the case of shedi soil considered here. © Springer Nature Singapore Pte Ltd 2019.
  • No Thumbnail Available
    Item
    The Need for Unsaturated Soil Mechanics: A Brief Review
    (Springer Science and Business Media Deutschland GmbH, 2021) Ujwala Shenoy, K.; Babu Narayan, K.S.B.; Sunil, B.M.
    Soils exhibit seasonal saturation and desiccation, often resulting in varying degrees of moisture content. In practice, soil is seldom fully saturated. When it is completely dry or wet, it behaves as a two-phase system. Otherwise, the moisture content within the interstices of soil vary, leading to partially saturated conditions. Unsaturated soil condition has significant influence on soil behaviour. This paper presents a brief review of the emergence of unsaturated soil mechanics and its applications. © 2021, Springer Nature Singapore Pte Ltd.
  • No Thumbnail Available
    Item
    Numerical Modelling of Mechanically Stabilized Earth Walls for Slope Protection
    (Springer Science and Business Media Deutschland GmbH, 2022) Reshma, P.R.; Sridhar, S.
    Slope failure also known as ‘mass wasting’ is the downward movement of rock or debris under the influence of gravity as a result of several natural and manmade triggers. Mechanically stabilized earth wall is one of the popular methods for stabilizing unstable slopes using of extensible or inextensible reinforcements. This paper presents the analytical and numerical analysis carried out on a mechanically stabilized earth wall for the protection of unstable natural sloping ground. The analytical modelling was done as per the Federal Highway Administration (FHWA) guidelines. The numerical modelling was carried out using the finite element method (FEM) software, PLAXIS 2D. The major objective of the numerical study was to analyse the most influential parameters to be taken care of during the design of MSE wall for slope stability. The numerical studies of slopes were carried out with and without reinforcement. The effects of variation of parameters, such as length, axial stiffness and spacing of reinforcement, cohesion and angle of internal friction of reinforced fill, were analysed. It is observed that, with increase in cohesion and angle of internal friction of retained soil, slope stability has improved significantly. Also, increase in reinforcement parameters such as length and axial stiffness resulted in improved slope stability. But the increase in reinforcement spacing had a negative effect, which resulted in the decreased factor of safety of soil slopes. © 2022, The Author(s), under exclusive license to Springer Nature Singapore Pte Ltd.
  • No Thumbnail Available
    Item
    Seismic Slope Stability Analysis Using Pseudo-static Approach
    (Springer Science and Business Media Deutschland GmbH, 2024) Mishra, P.; Venkataramana, K.
    Ensuring the stability of slopes under the action of an earthquake is always a challenging problem for geotechnical engineers. As earthquake is one of the major factors responsible for the failure of slopes, it becomes necessary to carry out comprehensive research on the stability analysis of slopes subjected to earthquake-induced loads. Many researchers have developed several methods to analyse the stability behaviour of slope, but till now the failure behaviour has not been understood properly because of the complexity of earthquake loading. With the above background, this study presents a numerical analysis, performed in PLAXIS 3D, to investigate the stability of slopes subjected to earthquake-induced loadings using pseudo-static approach. Also, parametric studies have been carried out to better understand the effects of different parameters (soil properties, slope dimensions, earthquake loadings, etc.) on the Factor of Safety (FOS) and displacement of the slope. The stability of a slope is best assessed in terms of its FOS, which is computed by the strength reduction technique. Analyses’ results show that the slope can sustain a maximum displacement of 442.80 mm, while slope height is varied till the failure point keeping all other parameters constant. © The Author(s), under exclusive license to Springer Nature Singapore Pte Ltd. 2024.
  • No Thumbnail Available
    Item
    Earthquake-Induced Landslides in India—An Overview of Causes, Effects and Mitigation Strategies
    (Springer Science and Business Media Deutschland GmbH, 2025) Ajesh Sankar, M.; Sreevalsa, K.
    This review paper examines the landslides triggered by significant earthquakes in India over the past two decades, focusing on their causes, impacts, and mitigation strategies. The present study examines detailed case histories of earthquake-induced landslides from Kashmir (2005), Sikkim (2011), Gorkha (2015), Uttarakhand (2017), and Assam (2021) earthquakes. It has been observed that landslides are often associated with an earthquake of magnitude four or more. Also, the reported peak ground accelerations (PGA) were more than 0.05 g, sufficiently triggering the landslides. Other common factors contributing to the landslides are fragile geological conditions, steep slopes, hydrological influences, and human activities. The review highlights the distinct topographical and geological vulnerabilities of the Himalayan and northeastern parts of India. The paper also evaluates the effectiveness of various mitigation strategies adopted for effective future risk management. The findings aim to enhance the understanding and preparedness for earthquake-induced landslides, contributing to developing more resilient infrastructure. © The Author(s), under exclusive license to Springer Nature Singapore Pte Ltd. 2025.
  • No Thumbnail Available
    Item
    Numerical Analysis of Geocell Retaining Wall for Slope Stabilization of Netravathi River Bank
    (Springer Science and Business Media Deutschland GmbH, 2025) Anjana, S.; Menon, V.; Kolathayar, S.
    Stability of slopes is a major concern when it comes to construction near hills, excavations, embankments and river banks. Geosynthetics and geotextiles have proven to be extremely efficient in slope stabilization and landslide protection, among which the use of geocells has been drastically increasing. It is made up of geogrid like materials that give it sufficient tensile strength. This paper focuses on the use of geocells to construct a retaining wall to support an existing backfill. The study area is located at a Netravathi River bank which belongs to a temple in South Mangalore city. The aim of the work is to prevent flooding of the temple during heavy rainfall and the erosion of banks. Numerical analyses have been carried out by Limit Equilibrium Method (LEM) using GEO5 software and Finite Element Method (FEM) using PLAXIS 2D software. The results of displacements and factor of safeties have been compared for both methods to determine if the proposed structure is stable. Geocell retaining wall has been developed in PLAXIS 2D using a soil geocell equivalent composite model due to the difficulties of modelling its actual honeycomb like structure. The structure gives sufficient safety for static as well as pseudo static condition for different water levels hence preventing further erosion of existing soil. The design provided for the present work gives a factor of safety of 1.69 in LEM analysis and 1.90 in FEM analysis for the rapid drawdown condition in a psuedo dynamic analysis. © The Author(s), under exclusive license to Springer Nature Singapore Pte Ltd. 2025.
  • No Thumbnail Available
    Item
    Computer aided slope stability analysis
    (2006) Sastry, V.R.; Ram Chandar, K.; Santosh, M.
    Primary purpose of slope stability analysis in most of the engineering applications is to provide safe and economic design of slopes that prevent failure. The analysis technique chosen depends on both site conditions and potential mode of failure which depends upon the rock mass characteristics. Various slope stability analysis techniques include physical, numerical and analytical methods. Physical modeling is a time consuming process and a costly affair, while analytical method involves past experiences, it is site specific and depends upon various parameters which are difficult to quantify. Numerical analysis with sophisticated softwares provides an accurate solution within short duration. This paper presents an in-house developed software package called "V-slope" to analyze and interpret the slope with options for suggesting suitable safety measures based on the nature of slope. Slip circle and tension crack techniques were considered for analysis. The slope profile for different factor of safety (FOS) values will be displayed on the screen for easy understanding. In case the FOS is lower than the required, the V-slope gives suggestive measures. In case of temporary slopes the only way by which slope failure can be prevented is by decreasing the slope angle and in such cases the program gives additional volume of material to be excavated and the likely additional cost incurred for various slope angle options. For permanent slopes, option is provided for designing the soil nails, i.e. number of bolts required, length, diameter and spacing of the bolts etc. Finally the V-slope is compared with a comprehensive commercial software package Slide and the results were found very much satisfactory.
  • No Thumbnail Available
    Item
    Stability aspects of nonreshaped berm breakwaters with reduced armor weight
    (2008) Rao, S.; Subrahmanya, K.; Balakrishna Rao, B.K.; Chandramohan, V.R.
    The present work involves the investigation of the influence of wave height, wave period, water depth, and sea-ward slope on the stability, wave runup, and wave rundown of statically stable rubble-mound berm breakwater. The weight of armor stones used in the present study is 20% lighter than the weight that is required for a conventional breakwater, designed using Hudson formula for a wave height of 0.1 m in the model. In the present work models with a berm width of 0.6 m, at constant depth of 0.32 m from the seabed were tested. The damage to the breakwater model with the berm was compared with the results on a model without the berm using different armor weights. The variation of relative runup and rundown was found for different values of wave steepness and water depths in front of the structure. The damage to the breakwater, wave runup, and rundown for the structure with seaward slope 1:2 and 1:1.5 were compared. The investigation was carried out in the Marine Structures Laboratory, Department of Applied Mechanics and Hydraulics, National Institute of Technology Karnataka, Surathkal. © 2008 ASCE.
  • No Thumbnail Available
    Item
    A comparison of limit equilibrium method of slope stability analysis with finite element modelling
    (2009) Mangalpady, M.
    Stability analysis of slopes susceptible to different types of failures can be performed with different techniques. The selection of an appropriate technique is, therefore, very important in a process of slope stability evaluation. In this paper, slopes of a large surface iron ore mine was analyzed by limit equilibrium method and by finite element modelling. GALENA software was used for analysis by limit equilibrium method and ANSYS for finite element modelling (FEM). Factor of safety (FOS) was calculated by both the methods and they are compared for their applicability. Based on the results obtained by the analysis, conclusions were drawn on the application of these methods. It was found that FEM analysis gives factor of safety value which is found to be lesser than the values determined by limit equilibrium method. This is because it considers more parameters and performs a detailed analysis of stress and strain conditions in the strata under consideration.
  • No Thumbnail Available
    Item
    Correlation between Petrographical and engineering properties of Ilkal granites, Karnataka
    (CAFET INNOVA Technical Society 1-2-18/103, Mohini Mansion, Gagan Mahal Road, Domalguda, Hyderabad 500029, 2011) Venkat Reddy, D.; Santosh, H.G.; Priyanka, K.
    Granitic rocks show a variety of engineering properties that may affect quarrying operations, slope stability, mining and the use of rock as a structural as well as architectural material. In present investigation, correlation analysis is carried out for experimental results to study the influence of mineralogical and textural characteristics on physical and strength properties using SPSS software. A variety of granitic rock samples from different parts of Ilkal were subjected to study petrographical and then same samples were tested to determine the specific gravity, bulk and dry density, water absorption, porosity, P-wave velocity, rebound hardness, point load strength index, uniaxial compressive strength and tensile strength. The study revealed that a petrographical characteristic like grain size, mineral composition and the bonding between each mineral of granitic rocks plays a major role in contributing the strength parameters. © 2011 Cafet-Innova Technical Society. All rights reserved.