Loading...

Seismic Retrofitting of Buried Pipelines in Soil Slopes using Physical Model Shaking Table Tests

Sabbaghi Dehaghi, Saeed | 2014

542 Viewed
  1. Type of Document: M.Sc. Thesis
  2. Language: Farsi
  3. Document No: 48168 (09)
  4. University: Sharif University of Technology
  5. Department: Civil Engineering
  6. Advisor(s): Jafarzadeh, Fardin
  7. Abstract:
  8. The purpose of this research is to study methods of Seismic retrofitting of buried pipelines in soil slopes subjected to landslide due to earthquakes. For this purpose, two methods were considered. The first method is to increase the burial depth of pipes. To check the performance of this method, results of three physical model tests conducted by previous research groups in this project, were used. The second method is to construct flexible retaining walls adjacent to buried pipe in soil slope. Wall was selected of Expanded polystyrene (EPS) geofoam. For this purpose a physical model was built on and excited using shaking table facility of Sharif University of Technology. Simulation laws suggested by Iai 1989 were satisfied in these models. Babolsar coastal sand was used for modeling the slopes. Pipes with the outside diameter of 16 mm and thickness of 1 mm were used to model steel pipelines. Models were made and tested at dry condition. Applied load to the models was sinusoidal harmonic with 5Hz frequency and 0.32g acceleration amplitude.
    The study showed that increasing burial depth in toe and downstream area of slope reduces the bending deformations of the pipe. The situation is reversed for crest and upstream areas of slope. So that, increasing the burial depth is leading to increase pipe strains. Placement of EPS wall behind the pipes reduced pipe bending deformations in all areas of the slope. This reduction in toe and downstream areas of slope was very significant and in crest and upstream areas had slight impact. Comparison between the two seismic retrofitting methods showed that use of flexible EPS walls behind pipelines is much more effective than increase the burial depth of the pipes. This method in all cases, at least twice more reduced bending deformations in pipes. Study of all four physical models showed that slope toe is the safest place to cross pipelines
  9. Keywords:
  10. Physical Model ; Dynamic Loading ; Earthquake Resistance ; Buried Pipline ; Shaking Table Test ; Soil Slope ; Instrumentation

 Digital Object List

 Bookmark

No TOC