Recursos de colección

ETD at Indian Institute of Science (2.800 recursos)

Repository of Theses and Dissertations of Indian Institute of Science, Bangalore, India. The repository has been developed to capture, disseminate and preserve research theses of Indian Institute of Science.

Civil Engineering (civil)

Mostrando recursos 1 - 15 de 15

  1. Factors Controlling the Dispersivity of Soils and the Role of Zeta Potential

    Parameswaran, T G
    Most soil particles loses cohesion and split up the soil mass into individual soil grains when they come in contact with water and get saturated. In dispersive soils the particles detach more spontaneously from each other and go into suspension even in quiet water. Thus the phenomenon of dispersion is common to most soils, the degree varying from soil to soil. Dispersive soils are abundantly found in various parts of the world such as Thailand, United States, Australia, Mexico, Brazil, South Africa and Vietnam. Several geotechnical failures such as piping due to internal erosion, erosion and gullying in relatively flat...

  2. Experimental and Analytical Studies on Damage Detection and Failure Analysis of Transmission Towers and Tower like Structures

    Balagopal, R
    The transmission line (TL) tower is an important component in electrical network system. These towers consist of members (angle sections) and connections (bolted connections) plus foundation, which act together to resist externally applied loads. The latticed towers are used to support conductors in transmission network for transmission and distribution of electricity. These towers are constructed in large numbers all over the world. The connections in electric TL classical latticed towers are peculiar compared to other types of bolted connections in buildings and bridges because (i) the angle members are connected directly or through gusset plates with bolts, (ii) the eccentric...

  3. Influence of Chemo-Mechanical Factors on Compression and Undrained Strengths of Soft Kaolinites Prepared using Synthetic Seawater

    Deepak, G B
    Marine clay deposits are characterized by very soft to soft consistencies (undrained strength 1-50 kPa), presence of saline pore solution and low-swelling clays. Besides, loss of metastable structure on disturbance, poor undrained strengths of soft clays is contributed by high water contents. Presence of saline pore solution and low-swelling clays (illite, chlorite, kaolinite) play an important role in developing metastable structure of soil sediments deposited in marine environment. The pore solution salinity regulates the “physico-chemical (A - R) stress” that in turn has significant bearing on development of the metastable structure. Metastable structure refers to edge-face, edge-edge associations in card-house...

  4. Upper Bound Finite Element Limit Analysis for Problems of Reinforced Earth, Unsupported Tunnels and a Group of Anchors

    Sahoo, Jagdish Prasad
    This thesis presents the implementation of the upper bound limit analysis in combination with finite elements and linear optimization for solving different stability problems in geomechanics under plane strain conditions. Although the nonlinear optimization techniques are becoming quite popular, the linear optimization has been adopted due to its simplicity in implementation and ease in attaining the convergence while performing the analysis. The objectives of the present research work are (i) to reduce the computational effort while using an upper bound finite element limit analysis with linear programming in dealing with geotechnical stability problems, and (ii) to obtain solutions for a...

  5. Stochastic Modelling of Flexible Pavement Performance

    Dilip, Deepthi Mary
    Stochastic analysis provides a rationale for the treatment of uncertainties, founded on the principles of probability theory and statistics, and is concerned with a quantifiable measure of the confidence or the reliability associated with any design process. In this thesis, a stochastic approach is employed in the design of flexible pavement structures, to facilitate the development of safe and reliable pavement structures. The important aspects that have been explored in sufficient detail include the system reliability and global sensitivity analysis, and the spatial and temporal uncertainties that pervade the life of pavements. Chapter 1 of the thesis provides an introduction...

  6. Non Motorized Transport Planning for an Indian City

    Rahul, T M
    Indian cities are currently facing various transportation issues like congestion, pollution, urban inequity, high fatality rate due to accidents etc. because of an increase in the ownership of private motor vehicles and their usage. This has prompted many policy makers to search for alternate modal options that are more sustainable than motorized modes. Non Motorized Transport (NMT), which includes mainly walking and cycling in an urban context, do not produce many of the issues associated with motorized modes like congestion, pollution, fatal accidents etc. But, promotion of NMT requires a clear-cut planning strategy, with a lucid understanding of various strategies...

  7. A Hydroclimatological Change Detection and Attribution Study over India using CMIP5 Models

    Pattanayak, Sonali
    As a result of increase in global average surface temperature, abnormalities in different hydroclimatic components such as evapotranspiration, stream flow and precipitation have been experienced. So investigation has to be carried out to assess the hidden abnormality subsisting in the hydroclimatological time series in the form of trend. This thesis broadly consists of following four parts. The first part comprises of a detailed review of various trend detection approaches. Approaches incorporating the effect of serial correlation for trend detection and interesting developments concerning various non parametric approaches are focused explicitly. Recent trends in annual, monthly, and seasonl (winter, pre-monsoon, monsoon...

  8. Finite Element Limit Analysis for Solving Different Axisymmetric Stability Problems in Geomechanics : Formulations and Solutions

    Chakraborty, Manash
    Limit analysis is a very powerful tool to find accurate solutions of several geotechnical stability problems. This analysis is based on the theory of the plasticity and it provides two limiting solutions within lower and upper bounds. With the advancement of the finite elements and different robust optimization techniques, the numerical limit analysis approach in association with finite elements is becoming quite popular to assess the stability of various complicated structures. The present thesis deals with the formulations and the implementation of the finite element limit analysis to obtain the solutions of different geotechnical axisymmetric stability problems. The objectives of...

  9. Stochastic Modelling of Vehicle-Structure Interactions : Dynamic State And Parameter Estimation, And Global Response Sensitivity Analysis

    Abhinav, S
    The analysis of vehicle-structure interaction systems plays a significant role in the design and maintenance of bridges. In recent years, the assessment of the health of existing bridges and the design of new ones has gained significance, in part due to the progress made in the development of faster moving locomotives, the desire for lighter bridges, and the imposition of performance criteria against rare events such as occurrence of earthquakes and fire. A probabilistic analysis would address these issues, and also assist in determination of reliability and in estimating the remaining life of the structure. In this thesis, we aim...

  10. Field Investigations And Modeling of Flow in Vadose Zone in a Forested Watershed

    Parate, Harshad Rameshwar
    The vadose zone is the unsaturated zone between the ground surface and water table. This zone is of much importance as it acts as a link between surface water and ground water. Knowledge of soil moisture in this zone is very much essential to understand the meteorologic, hydrologic and agronomic process. Flow and transport in the unsaturated zone are more complex compared to saturated medium, as the pores in unsaturated zone are partly filled by air and partly by water. Most of vadose zone studies are done on agricultural plots where anthropogenic activities govern the vadose zone flows. Vadose zone...

  11. Schemes for Smooth Discretization And Inverse Problems - Case Study on Recovery of Tsunami Source Parameters

    Devaraj, G
    This thesis deals with smooth discretization schemes and inverse problems, the former used in efficient yet accurate numerical solutions to forward models required in turn to solve inverse problems. The aims of the thesis include, (i) development of a stabilization techniques for a class of forward problems plagued by unphysical oscillations in the response due to the presence of jumps/shocks/high gradients, (ii) development of a smooth hybrid discretization scheme that combines certain useful features of Finite Element (FE) and Mesh-Free (MF) methods and alleviates certain destabilizing factors encountered in the construction of shape functions using the polynomial reproduction method and,...

  12. Partial Slip Contacts in Linear Viscoelasticity

    Dayalan, Satish Kumar
    This work analyzes partial slip contact problems in the theory of linear viscoelasticity using both the semi-analytical method and nite element method. Such problems arise in metal-polymer contacts in orthopedic implants and similar applications. The boundary conditions of such problems are inherently mixed and vary with time, thus restricting the use of classical correspondence principle, which have been the basic approach for most of the solved problems in viscoelasticity. In the present semi-analytical approach, the governing equations for the vis-coelastic partial-slip contact are formulated as a pair of coupled Singular Integral Equations (SIEs) for a pin-plate geometry using the viscoelastic...

  13. Experimental Studies on The Mechanical Behaviour of Cohesive Frictional Granular Materials

    Kandasami, Ramesh Kannan
    Thss thesis presents the results of an experimental programme on the static mono-tonic response of cohesive-frictional granular materials. The purpose of this experimental programme was to gain insight into the mechanical behaviour of uncemented sands, and sands with small percentages of cementation. With this objective in sight, the research involved understanding and delineating the e ects of four variables: the intermediate principal stress, stress inclination, cohesion (or cementation), and particle morphology. The hollow cylinder torsion (HCT) apparatus, which allows control over both the magnitude and direction of principal stresses, was used in this study to carry out a series of...

  14. Effect of Cyclic Strain Path And Vibration Cycles on Shear Modulus And Damping of Sand

    Cherian, Achu Catherine
    The soil strata is often subjected to various kinds of vibrations such as that caused by earthquakes, water waves, traffic loads, wind power plants, construction related equipments, pile driving and vibratory machines. The strains induced in a soil mass due to the vibrations generated by these different sources often lie in a range of 0.0001% - 0.1%. The estimation of the shear modulus (G) and damping (D) of soils in this strain range becomes an important aspect for performing the analysis and design of various geotechnical structures subjected to different kinds of vibrations. Strain amplitude, effective confining stress, void ratio/relative...

  15. Regionalization Of Hydrometeorological Variables In India Using Cluster Analysis

    Bharath, R
    Regionalization of hydrometeorological variables such as rainfall and temperature is necessary for various applications related to water resources planning and management. Sampling variability and randomness associated with the variables, as well as non-availability and paucity of data pose a challenge in modelling the variables. This challenge can be addressed by using stochastic models that utilize information from hydrometeorologically similar locations for modelling the variables. A set of locations that are hydrometeorologically similar are referred to as homogeneous region or pooling group and the process of identifying a homogeneous region is referred to as regionalization. The thesis concerns development of new...

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