Analysis Of Double Curvature Arch Dam and Abutment Stability Using Three Dimensional Nonlinear Finite Element Numerical Modeling In MATLAB R2013a Of Budhigandaki Hydroelectric Project

Abstract

As Nepal needs peaking type electric plant to solve the current deficiency during dry season, storage type hydroelectric plant is very promising option for this problem. For construction reservoir of dam is required and in context of Nepal where geology is young and construction of large scale dams are not in practice till date, stability analysis of such large scale dam along with its foundation is important job, so this thesis is dedicated towards the three dimensional finite element analysis of double curvature arch dam, abutment and foundation. This thesis includes preparing the solid deformable model representing the purposed dam for the Budhi Gandaki hydroelectric project in Budhi Gandaki River near Benighat and its foundation, generation of hexahedral elements for continuum portion and interface element for the discontinuity in foundation, developing partial deferential equations representing the three dimensional finite element solution for the model which considers the elastic plastic behaviour of rock mass in foundation through return field method and study of variation in the deformation and stresses in dam and foundation with different foundation rock mass properties . To perform pure mathematical modelling of problem, MATLAB is used as programming language, which gives the understanding of analysis process and numerical techniques that is not achieved by using commercial applications based on finite element analysis. Identification of potential failure plane or surface is performed and factor of safety is evaluated for sliding through plane or wedge formed at abutment or beneath concrete arch dam in foundation rock mass. Evaluation of safety is done at different stages of loading (excluding dynamic loading and seismic loading) which includes hydrostatic loads, gravitational loads and pore pressure as major loadings. Different states of discontinuities (with and without filling material, weathered and unweathered condition) are considered for safety for potential failure. Failure of rock mass is evaluated according to failure criterion and deformation of rock mass is evaluated.