Loading...

Performance Evaluation of Concrete Gravity Dam Using Crest Displacement by Nonlinear Analysis

Enayati, Hamed | 2010

519 Viewed
  1. Type of Document: M.Sc. Thesis
  2. Language: Farsi
  3. Document No: 40999 (09)
  4. University: Sharif University of Technology
  5. Department: Civil Engineering
  6. Advisor(s): Ghaemian, Mohsen
  7. Abstract:
  8. Concrete gravity dams are one of the most important infrastructures therefore their performance under seismic load is an important issue of concern for dam owners. It is necessary that these infrastructures to be able to continue their function after a disaster such as earthquake, as any damage can cause huge cost. For analysis of dams linear and nonlinear analyses are used. Because even operating loads will create cracks in the body of the dam, dam behavior can not always be considered linear. It is remarkable that these surface cracks can join together under seismic loads and this question the safety of dams. It is important to note that nonlinear analysis of concrete gravity dams is strongly depends on boundary conditions, geometry, materials properties, Therefore criterion was defined to consider behavior of dams linear. Due to difficulties of nonlinear analysis, it is tried to use a linear analysis instead of nonlinear analysis in evaluation of gravity dam's performance. The criterion is chosen such that crack at the base is becoming 5% of total cross section area based on the nonlinear dynamic analysis. Bluestone, Folsom and Pine Flat dams are examined for these purposes. Foundation of each dam is assumed to be rigid and massless. In this regard 10 records of earthquake have been used. Each of them are standardized due to foundation soil properties. In this investigation it is tried to devise a range that can consider dam behavior linear based on it. Cumulative time that displacement is more than the maximum displacement multiplied by the desired ratio in crest displacement time history curve was used to define this range. The ratio of displacement to maximum displacement is variable between 0.94 to 1. Corresponding to each ratio and its pertinent time, we can determine desired range that can consider dam behavior linear. This study shows that the cumulative time is frequently greater when foundation is rigid and nonlinear analysis is necessary when peak ground acceleration is more than 0.3g
  9. Keywords:
  10. Concrete Gravity Dam ; Linear Dynamic Analysis ; Nonlinear Dynamic Analysis ; Performance Curve ; Cumulative Inelastic Time ; Crest Displacement

 Digital Object List

 Bookmark