Loading...

An Investigation on Stability of Concrete Gravity Dam Using Nonlinear Dynamic Analysis Compared to Rigid Block Method

Rahbari, Parishad | 2012

833 Viewed
  1. Type of Document: M.Sc. Thesis
  2. Language: Farsi
  3. Document No: 43263 (09)
  4. University: Sharif University of Technology
  5. Department: Civil Engineering
  6. Advisor(s): Ghaemian, Mohsen
  7. Abstract:
  8. Concrete gravity dams are structures of much importance which their failure due to earthquakes results in a catastrophe. Therefore, precise stability analysis of these types of dams against sliding and overturning is essential. The common method of safety assessment of gravity dams is based on limit equilibrium method assuming that dam slides and overturns as a rigid structure. Although providing high safety factors is somehow acceptable to meet the safety requirements of dams, it should be considered that the whole system of dam body and foundation is flexible in reality and its performance should be studied in this case for stability analysis. In this investigation, first, stability safety factors of concrete gravity dam in rigid system and their accuracy is studied using rigid block method. Then stability analysis in flexible system is performed and sliding displacements are evaluated and compared to those of rigid system. Dynamic analysis of flexible system considering dam-foundation joint is performed by a program using finite element method and sliding displacement of dam on foundation can be plotted and compared to the results of rigid block analyses. Therefore 3 earthquake records normalized in 10 PGAs are applied to the dam considering 3 dynamic loading conditions. Finally, studying the results of these two types of systems, i.e. rigid and flexible, the sufficiency and accuracy of stability analysis of rigid system is investigated. It is concluded that although even for small PGAs that rigid block analysis predicts safety factor values greater than 1, finite element analysis results in dam sliding on foundation. Also, the value of earthquake PGA that causes dam sliding and the value of probable sliding mostly depend on the nature of the earthquake.

  9. Keywords:
  10. Concrete Gravity Dam ; Safety Factor ; Dynamic Finite Element Analysis ; Stability Analysis ; Sliding Stability ; Rigid Block Method

 Digital Object List

 Bookmark

No TOC