No abstract

No abstract

This paper aims at the two most common methods used for slope stability analysis. An attempt has been made to bring out the differences in results of reinforced slope stability analysis obtained from SLOPE/W (limit equilibrium based) and PLAXIS 2D (finite element based). The analysis is carried out on two slope angles of 45°and 60°, which are reinforced with nails at three different inclinations of 0°, 15°and 30°respectively. Both the slope angles and all nail inclinations are taken from the horizontal. A comparative study on stability parameters such as factor of safety, critical slip surfaces and nail forces has been carried out. The limit equilibrium method is found to yield higher values of factor of safety in comparison to finite element method. The failure surfaces from both methods are found to vary significantly. Large nail forces are observed by limit equilibrium method for 45°slope with all nail inclinations, whereas for 60°slope angle, finite element method shows an increase in the nail forces. The effect of other parameters like bond length in limit equilibrium, soil-nail interaction and bending stiffness in finite element are also studied.

A numerical study of pulsatile hydromagnetic flow and mass transfer of a non-Newtonian biofluid through a porous channel containing a non-Darcian porous material is undertaken. An extensively-validated biofluid dynamics variational finite element code, BIOFLOW, is employed to obtain comprehensive computational solutions for the flow regime which is described using a spatially two-dimensional momentum equation and a spatially one-dimensional mass transport equation, under appropriate boundary conditions. The Nakamura-Sawada rheological model is employed which provides a higher yield stress than the Casson model. A non-Newtonian model is justified on the basis that blood exhibits deviation from Newtonian behavior at low shear rates. The conduit considered is rigid with a pulsatile pressure applied via an appropriate pressure gradient term. One hundred two-noded line elements have been employed in the computations. The influence of magnetic field on the flow is studied via the magnetohydrodynamic body force parameter (Nm), which defines the ratio of magnetic (Lorentz) retarding force to the viscous hydrodynamic force. Blood vessel blockage effects are simulated with a Darcy-Forchheimer nonlinear drag force model incorporating a Darcian linear impedance for low Reynolds numbers and a Forchheimer quadratic drag for higher Reynolds numbers. Transformed velocity and concentration profiles are plotted for the influence of Reynolds number (Re), Darcy parameter (λ), Forchheimer inertial drag parameter (NF), non-Newtonian parameter (β), and Schmidt number (Sc) and at various times (T). Three-dimensional profiles of velocity varying in space and time are also provided. Applications of the model include magnetic therapy, biomagnetic pharmaco-dynamics and the simulation of diseased arteries.

The laminar, fully developed, transient magnetohydrodynamic (MHD) free convection heat and mass transfer of an electrically conducting micropolar fluid between two vertical plates containing a non-Darcy porous medium with heat generation/absorption and asymmetric wall temperature and concentration has been discussed in this article. A similarity transformation is used to render the problem into a system of coupled, partial, differential equations, which are solved using the finite-element method (FEM). The solutions are validated with a robust finite difference method (FDM) solver. The present work examines the effect of Darcian parameter, Forchheimer parameter, heat absorption/generation parameter, vortex viscosity parameter, buoyancy ratio parameter, magnetic parameter, and variable thermal conductivity parameter on velocity, angular velocity, temperature and concentration profiles. Space—time graphs of velocity and microrotation are also plotted to provide a better perspective of the flowfield evolution with respect to time. Applications of the study may arise in, for example, packed-bed chemical reactors, materials processing, magnetic field control of chemical engineering transport processes in filter media, purification of hydrocarbons with electromagnetic fields, etc.