http://rulrepository.ru.ac.bd/handle/123456789/228 Tue, 07 Apr 2026 21:40:55 GMT 2026-04-07T21:40:55Z http://rulrepository.ru.ac.bd/handle/123456789/930 Slope Stability Analysis Consid­ering Local Factors of Safety Using Non-vertical Slices within the Limit Equilibrium framework Khan, Younus Ahmed A method for slope stability analysis considering local factor of safety is pro­posed based on a technique of non-vertical slices ,vithin the limit equilibriumf amework, ·which wonk! give an estimate of the stability of a slope that failsprogressively. To accommodate the non-uniform shear stress distribution, the local factors of safety are calculated by defining variable factor of safety instead of conventional single value safety factor along a shear surface. Simplifying as­sumptions about the inter-slice forces and their points of action made this method determinate. In the analysis, the acting points of inter-slice forces and forces at slice base are set to he varied for the complete converged solnti,on .. Strnin softening using Law and Lumb (1978) approach of peak and residual strength, is also included in the analysis. Two loading conditions called as In­stantaneous Load-ing Cond·it-ion(ILC) and Grndual Loading Condition(GLC), a.re introthtced for treating the locally failed zones. An overall factor of safety is introduced for the ultimate stability of a slope. The appropriate boundary conditions are satisfied successfully. A rigorous optimization scheme is intro­duced in order to find out the equilibrium conditions using simplex method. The proposed method can handles both the approaches of non-vertical and vertical slices as well.------- This Thesis is Submitted to the Department of Geology and Mining , University of Rajshahi, Rajshahi, Bangladesh for The Degree of Doctor of Philosophy (PhD) Sat, 01 Jan 2005 00:00:00 GMT http://rulrepository.ru.ac.bd/handle/123456789/930 2005-01-01T00:00:00Z http://rulrepository.ru.ac.bd/handle/123456789/929 Geological Evolution of the Ganges­Brahmaputra Delta During the Holocene time and Hazard Assessment and Zonation Along the Deltaic Coastal plain, Bangladesh Khan, Sirajur Rahman An extensive deltaic plain of Bangladesh has been formed by the sediments of the Ganges-Brahmaputra (GB) river system that carries an annual suspended load of more than a billion tons into Bangladesh. In spite of the huge sediment discharge, the seaward growth of the subaerial delta is insignificant since quite sometime especially for the last two centuries. The coastal part of Bangladesh has more recently been threatened by sea level rise due to much talked global warming. This study investigates stratigraphy, evolution, active processes and coastal hazard in the lower subaerial deltaic part of the GB delta in Bangladesh. The delta plain under investigation can broadly be divided into three geomorphological domains on the basis of it's origin. These are river floodplains, tidal plains and estuarine plains. The landforms under river floodplains are levee or levee complex, abandoned meander belt and beels or depressions. Interdistributary tidal plains, tidal swamp/depression, beach and beach ridge complex and mangrove swamp constitute the landforms of the tidal plain domain. The landforms constituting the estuarine plain are estuarine plain and mud flat. ------ This Thesis is Submitted to the Department of Geology and Mining , University of Rajshahi, Rajshahi, Bangladesh for The Degree of Doctor of Philosophy (PhD) Sun, 01 Jan 2006 00:00:00 GMT http://rulrepository.ru.ac.bd/handle/123456789/929 2006-01-01T00:00:00Z