| Dams, in the form of concrete gravity or earth zoned, are important and costly civil engineering structures that provide the essential infrastructure for the development of the civilization. One of the critical aspects of dam design is the analysis of stability and safety of the structure under various operating and environmental conditions. Traditionally, the deterministic approach is used for such analysis. However, determination of variables such as soil strength parameters, pore pressure, and other pertinent material properties involve uncertainties, which can't be handled in the traditional deterministic methods. It is, therefore, highly desirable to develop a reliability based analytical/numerical methodology for stability analysis of dams taking into account of these uncertainties.; Reliability and probability theories, using the first-order reliability method, were used to develop a methodology for analyzing the stability of gravity dams. The computer program AKREL was developed to facilitate the numerical calculations. The program is capable of calculating the reliability of a single mode of failure as well as the reliability of a series system of more than one failure mode. The Tannur concrete gravity dam was selected as a case for detailed analysis to illustrate the implementation of the developed methodology. Four failure modes were considered, including sliding, overturning, bearing capacity, and overall stability. A sensitivity analysis was also performed for the Tannur dam, leading to the development of specific recommendations to improve the reliability of the Tannur dam.; Reliability and probability theories were also developed for assessing the reliability index and corresponding probability of failure of multi-layered embankment dams and slopes. Two definitions were incorporated in the methodology to calculate the reliability index (i.e., the normal distribution and the log-normal distribution definition). Furthermore, the advantages of using the log-normal distribution definition were elucidated. The computer program RESLOP was developed and used to study the King Talal embankment dam. The results were discussed and recommendations were also made. |
