Critical Review on Stress-Sensitivity and Other Behavioral Aspects of Arch Dams

Abstract

Dams have an important role in the economic and social development of a nation. As per ICOLD statistics, there are not less than 59,071 registered large dams in the world of which 2332 are arch dams. Some of the existing dams have deficiencies w.r.t. design and some of them may not meet the present design standards. Further, apprehensions on the health of some of the dams have been raised on account of aging. Safety of dams is of paramount importance and warrants utmost priority as the water stored is a potential source of threat to the life and property of the stakeholders downstream of the structure. Safety inspections and safety evaluations of existing dams would cast light on whether the dam has any structural, hydrological, and operational deficiencies and if there is any deterioration. Periodical structural evaluation using advanced technological interventions are indeed essential. The behavior of arch dams differs unpredictably vis-à-vis that of other types of dams due to its shape, the mechanism of transfer of loads, and the response of the dam body against such loads. Identification of the nature and magnitude of loads acting on the arch and consideration of all possible combinations of loads is an important part of engineering analysis. Safety evaluation of an arch dam shall highlight the issues of strength, stability, and vibrations, as well as special problems of arches and arched structures when subjected to the anticipated loads. Modern-day engineering has solutions for problems related to the strength and stability of arches, and vibrations encountered in its life period. Galleries and other openings are integral parts of arch dams too. Stress contours and intensities of stresses at various salient locations, cantilever motions/periodic movements of an arch dam vis-à-vis fluctuating impoundment levels, the effect of stress reversals due to temperature variations, dynamic behavior due to seismic loads, etc., are to be computed and analyzed to understand the behavior of the dam. Computational models using the finite element method (FEM) are capable of modeling and simulating the dam structure as well as the dam–fluid–foundation interaction, In this paper, a brief review of literature pertaining to structural analyses of arch dams and case studies on its behavioral aspects under various loading scenarios is presented. Some of the issues that require further investigation will be highlighted.