ETD at Indian Institute of Science
(528 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.
Mostrando recursos 1 - 20 de 31
1.
Numerical Analysis Of Large Size Horizontal Strip Anchors - Krishna, Y S R
Structures like transmission towers, tele-communication masts, dry-docks, tall chimneys, tunnels and burried pipelines under water etc are subjected to considerable uplift forces. The net effect of external loading on the foundations of these structures results in forces that try to pull the foundations out of the ground. Anchors are usually provided to resist such uplift forces.
Earlier theoretical research of anchor behavior has focused on elastic response and ultimate pullout capacity. Many investigators have proposed techniques for determining the collapse load of anchors. Essentially the approaches involve the use of limit equilibrium concepts, with some assumptions regarding the shape of the...
2.
Prediction Of Engineering Properties Of Fine-Grained Soils From Their Index Properties - Nagaraj, H B
Prediction as a tool in engineering has been used in taking right judgement in many of the professional activities. This being the fact, the role and significance of prediction in geotechnical practice needs no emphasis. Bulk of all man made structures are either made of soil or are resting on natural soil, involving large quantities of soil. Thus, it is often necessary for the geotechnical engineer to quickly characterize the soil and determine their engineering properties, so as to assess the suitability of the soil for any specific purpose. Obtaining these properties requires undisturbed samples, which involves time and money,...
3.
Analysis Of Solute Transport In Porous Media For Nonreactive And Sorbing Solutes Using Hybrid FCT Model - Srinivasan, C
The thesis deals with the numerical modeling of nonreactive and nonlinearly sorbing solutes in groundwater and analysis of the effect of heterogeneity resulting from spatial variation of physical and chemical parameters on the transport of solutes. For this purpose, a hybrid flux corrected transport (FCT) and central difference method based on operator-split approach is developed for advection-dispersion solute transport equation. The advective transport is solved using the FCT technique, while the dispersive transport is solved using a conventional, fully implicit, finite difference scheme. Three FCT methods are developed and extension to multidimensional cases are discussed.
The FCT models developed are anlaysed...
4.
Stabilisation Of Black Cotton Soil By Lime Piles - Venkata Swamy, B
Modification of black cotton soils by chemical admixtures is a common method for stabilizing the swell-shrink tendency of expansive soils. Advantages of chemical stabilization are that they reduce the swell-shrink tendency of the expansive soils and also render the soils less plastic. Among the chemical stabilization methods for expansive soils, lime stabilization is most widely adopted method for improving the swell-shrink characteristics of expansive soils.
Lime stabilization of clays in field is achieved by shallow mixing of lime and soil or by deep stabilization technique. Shallow stabilization involves scarifying the soil to the required depth and lime in powder or slurry...
5.
Collapse Behaviour Of Red Soils Of Bangalore District - Revanasiddappa, K
Collapse phenomenon is exhibited by two types of residual soils. The first category of collapsing residual soils is believed to be transported soils that have undergone post-depositional pedogenesis. The second category of collapsing residual soils is highly weathered and leached soils formed by in-situ weathering of parent rock.
Residual red soils occur in Bangalore District of Karnataka State. Physical and chemical weathering of the gneissic parent rock formed the residual soils of Bangalore District. The red soils of Bangalore District are generally moderate to very highly porous (porosity range 35-50%). These soils are also unsaturated owing to presence of alternate wet...
6.
Study And Design Of Two-Thirds Power Weir - Reddy, K Ranga
This thesis is devoted to the study and designs of two important proportional weirs having the discharge-head characteristics of Q ? H 2/3 In the first design a geometrically simple weir in the form of a rectangular weir over a inverted V-notch (Chimney weir) is presented. This weir gives for all flows above a threshold depth a discharge proportional to H 2/3 within a maximum percentage error of ±1.5, (measured above a reference plane) within certain limits of head.
Second design is concerned with the self-basing weir in which a portion of the weir above the crest acts as a base....
7.
Conjunctive And Multipurpose Operation Of Reservoirs Using Genetic Algorithms - Seetha Ram, Katakam V
Optimal operation of reservoir systems is necessary for better utilizing the limited water resources and to justify the high capital investments associated with reservoir projects. However, finding optimal policies for real-life problems of reservoir systems operation (RSO) is a challenging task as the available analytical methods can not handle the arbitrary functions of the problem and almost all methods employed are numerical or iterative type that are computer dependent. Since the computer resources in terms of memory and CPU time are limited, a limit exists for the size of the problem, in terms of arithmetic and memory involved, that can...
8.
A Study On The Predictive Optimal Active Control Of Civil Engineering Structures - Keyhani, Ali
Uncertainty involved in the safe and comfort design of the structures is a major concern of civil engineers. Traditionally, the uncertainty has been overcome by utilizing various and relatively large safety factors for loads and structural properties. As a result in conventional design of for example tall buildings, the designed structural elements have unnecessary dimensions that sometimes are more than double of the ones needed to resist normal loads. On the other hand the requirements for strength and safety and comfort can be conflicting. Consequently, an alternative approach for design of the structures may be of great interest in design...
9.
Vibration Analysis Of Structures Built Up Of Randomly Inhomogeneous Curved And Straight Beams Using Stochastic Dynamic Stiffness Matrix Method - Gupta, Sayan
Uncertainties in load and system properties play a significant role in reliability analysis of vibrating structural systems. The subject of random vibrations has evolved over the last few decades to deal with uncertainties in external loads. A well developed body of literature now exists which documents the status of this subject. Studies on the influence of system property uncertainties on reliability of vibrating structures is, however, of more recent origin. Currently, the problem of dynamic response characterization of systems with parameter uncertainties has emerged as a subject of intensive research. The motivation for this research activity arises from the need...
10.
Passive Earth Pressure Coefficients And There Applications In The Uplift Capacity Of Anchors - Nayak, Sitaram
The problem of passive earth pressure is one of the important topics in Geotechnical engineering. At attempt is made in this thesis to generate passive earth pressure coefficients for general c-? soils using logarithmic spiral failure surface by limit equilibrium approach. Method of slices for the determination of passive force in c-?soils is presented and the method is extended to a typical problem of two layered soil system. The application of passive earth pressure coefficients has been demonstrated for pullout capacity of inclined strip anchors in sloping ground. A semi-empirical approach for the determination of displacement-related passive earth pressure is...
11.
Two Dimensional Numerical Modelling Of Variably Saturated Flows - Muthineni, Srinivas
The prediction of moisture and contaminant transport through unsaturated soil to ground water is becoming increasingly important in the fields of hydrology, agriculture and environmental engineering. Computer aided simulation techniques enables one to conduct a series of systematic numerical experiments to analyze flow phenomenon in subsurface hydrology under various physical and chemical processes. The flow movement depends upon medium characteristics, initial and boundary conditions, which reflect, physical processes occurring below the ground. To understand the effects of physical process an efficient and accurate model is needed. Thus the model developed must be able to handle varied initial and boundary conditions....
12.
Engineering Behaviour Of Ash-Modified Soils Of Karnataka - Muttharam, M
During a survey of black cotton soil zones of Karnataka, indigenously stabilized black cotton soil deposits were encountered in Belgaum, Bijapur, Bagalkot and Gadag Districts of Karnataka. These modified black cotton soils have low swelling and negligible shrinkage tendencies. Owing to their low volume change potential on moisture content changes, these soils are widely preferred in earth construction activities. The exact origin of these modified black cotton soil deposits is not known. According to anecdotal references, these soils were prepared by mixing unknown proportions of wood ash, organic matter and black cotton soil and allowing them to age for unknown...
13.
Numerical Modeling Of Jointed Rock Mass - Jade, (B) Sridevi
The behavior of jointed rock mass is very complex and is influenced by many factors such as location of joints, joint frequency, joint orientation and joint strength. A thorough review of literature on different aspects of jointed rock mass indicate that the discontinuities or planes of weakness present in rock mass significantly influence its behavior. Numerous experimental tests were conducted to study the behavior of natural as well as artificial joints in rocks. Laboratory tests are time consuming and give results applicable to specific joint fabric and confining pressure. Numerical methods are the best alternative to laboratory tests to study...
14.
Influence Of Joint Compliance On The Behaviour Of Space Structures - Pradyumna, M
Space structures are inevitable while covering large spans. Space structures are skeletal structures, which are lighter for the same stiffness when compared with RCC roofs. Till now, space structures, like any other metal structures have been designed assuming the joints as rigid, although there have been several publications about semi rigid joints. Of course, the publications mostly deal with 2D structures and there are very few reports on 3D structures. Space structures, by their nature fall into the latter category.
The joints in a space structure are popularly called as "nodes". Generally, nodes, which ensure concentricity of member axes, are either...
15.
Structural Analysis And Forecasting Of Annual Rainfall Series In India - Sreenivasan, K R
The objective of the present study is to forecast annual rainfall taking into account the periodicities and structure of the stochastic component.
This study has six Chapters. Chapter 1 presents introduction to the problem and objectives of the study. Chapter 2 consists of review of literature. Chapter 3 deals with the model formulation and development. Chapter 4 gives an account of the application of the model. Chapter 5 presents results and discussions. Chapter 6 gives the conclusions drawn from the study.
In this thesis the following model formulations are presented in order to achieve the objective.
Fourier analysis model is used to identify...
16.
Stability Numbers For Slopes With Associated And Non-Associated Flow Rule And Shake Table Liquefaction Studies - Samui, Pijush
Based upon the upper bound limit analysis, the stability numbers have been developed for a two-layered soil slope both for an associated flow rule material and for a homogeneous slope with non-associated flow rule material. The failure surface was assumed to be an arc of logarithmic spiral and it automatically ensures the kinematics admissibility of the failure mechanism with respect to the rigid rotation of the soil mass about the focus of the logarithmic spiral. The effect of the pore water pressure and horizontal earthquake body forces was also included m the analysis. For a non-associated flow rule material, the...
17.
Geotechnical Behaviour Of Soil Containing Mixed Layered Illite-Smectite Contaminated With Caustic Alkali - Sankara, Gullapalli
The aim of the thesis has been to evaluate and understand the effect of caustic alkali solution of varying composition on the behaviour of expansive soil containing mixed layered minerals. Mixed layered minerals are formed of two or more kinds of inter grown layers, not physical mixtures. Illite - smectite is the most abundant and wide spread of the mixed layered clay minerals in sedimentary rocks and soils and also more common than either discrete illite or smectite. In geotechnical engineering much attention has not been paid to the behaviour of soils containing mixed layered minerals. Much less is known...
18.
Swarm Intelligence And Evolutionary Computation For Single And Multiobjective Optimization In Water Resource Systems - Reddy, Manne Janga
Most of the real world problems in water resources involve nonlinear formulations in
their solution construction. Obtaining optimal solutions for large scale nonlinear
optimization problems is always a challenging task. The conventional methods, such as linear programming (LP), dynamic programming (DP) and nonlinear programming
(NLP) may often face problems in solving them. Recently, there has been an increasing
interest in biologically motivated adaptive systems for solving real world optimization
problems. The multi-member, stochastic approach followed in Evolutionary Algorithms
(EA) makes them less susceptible to getting trapped at local optimal solutions, and they
can search easier for global optimal solutions.
In this thesis, efficient optimization techniques based...
19.
Influence Of Osmotic Suction On The Swell And Compression Behaviour Of Compacted Expansive Clays - Thyagaraj, T
Total suction of unsaturated soils is contributed by matric and osmotic suctions.
Matric suction arises from capillary actions in the soil structure and varies with changes in moisture content of the soil. Pore fluid osmotic suction is related to the dissolved salt content in soil water (soil water salinity) and increases with pore water salinity. Exposure of clay soils to chemical solutions (example landfill leachate, brine pond solutions) induces osmotic suction difference between soil water and the chemical reservoir. Soil
water refers to the aqueous solution residing in soil pores that is chemically composed of H2O molecules and dissolved salt molecules. Osmotic...
20.
Stochastic Analysis Of Flow And Solute Transport In Heterogeneous Porous Media Using Perturbation Approach - Chaudhuri, Abhijit
Analysis of flow and solute transport problem in porous media are affected by uncertainty inbuilt both in boundary conditions and spatial variability in system parameters. The experimental investigation reveals that the parameters may vary in various scales by several orders. These affect the solute plume characteristics in field-scale problem and cause uncertainty in the prediction of concentration.
The main focus of the present thesis is to analyze the probabilistic behavior of solute concentration in three dimensional(3-D) heterogeneous porous media. The framework for the probabilistic analysis has been developed using perturbation approach for both spectral based analytical and finite element based...
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