16.4. STRESS ANALYSIS OF GRAVITY DAMS
Stress analyses of gravity dams can be carried out using one of the following methods depending upon the configuration of the dam, continuity between the blocks, and the degree of refinement required.
(i) The gravity method,
(ii) The trial-load method, and (iii) The finite element method
The gravity method of analysis is used for designing straight gravity dams in which the transverse contraction joints of a gravity dam are neither keyed nor grouted. When the transverse contraction joints of a gravity dam are keyed, irrespective of their grouting, it becomes a three-dimensional problem and one should use the trial load method. This method assumes that the dam consists of three systems, viz., the vertical cantilevers, the horizontal beams, and the twisted elements. Each of these systems is assumed to occupy the entire volume of the structure and is independent of the others. The loads on the dam are divided among these systems in such a manner as to cause equal deflections and rotations at conjugate points (1). This is achieved by trial process. The gravity method may, however, be used for a preliminary analysis of keyed and grouted dams. The finite element method, developed in recent years, can be used for both two-dimensional as well as three-dimensional problems. In this book, only the gravity method has been discussed.
Dostları ilə paylaş: |
