collapsing soils and improvement techniques by geosynthetic

Collapsible soils-loose, dry, low-density materials that collapse and compact due to the addition of water or excessive loading.
Soils with large void ratio and water content far less than saturation.
Collapsible soils are different from expansive soils.
Expansive soils: swelling & shrinkage due to clay mineral constituent (montmorillonite).
Collapsible soils: mechanism of failure change in volume due to moisture.

1. Graduation project Soil Mechanics And Foundation Engineering The research point     Team Members   Ahmed Ahmed Hamed Mohamed Mahmoud Younes Mohamed Khairy Lotfy Hassan Abdelaal Hassan Supervisors   Prof. Adel Dif Dr. Ahmed Sallam Dr. Ahmed Rabah Eng. Omnia Emara

2. The research point on collapsing soils and improvement techniques by geosynthetic

3. Content

4. Define collapsing soils

5. Type of collapsing soils

6. Where is the collapsing soil in Egypt

7. Properties of Collapsible soil Collapsible soils-loose, dry, low-density materials that collapse and compact due to the addition of water or excessive loading. Soils with large void ratio and water content far less than saturation. Collapsible soils are different from expansive soils. Expansive soils: swelling & shrinkage due to clay mineral constituent (montmorillonite). Collapsible soils: mechanism of failure change in volume due to moisture.

8. Properties of Collapsible soil

9. Factors affecting the Collapsing potential 1) Grain size distribution 2) Water content 3) Determination of density 4) Determination of welding material in collapsiable soil 5) Critical degree of saturation (Sr = 6 → 10% fine gravel) - (Sr=50→60% silty sand) - ( Sr=90-95% silty clay)

10. Calculation of Collapsing potential

11. تعين طاقة الانهيار Collapsing potential Soil collapsibility is determined by: One dimension o e dometer

12. One dimension oedometer

13. Classification of collapsing soil

14. Shape Of failure

15. Shape Of failure

16. Shape Of failure

17. Methods of treating collapsing soils

18. Soil replacement and compaction

19. Soil properties improvement

20. Stone column Cement, lime, or any other chemical additives that can react with soil can be used for collapsible soil treatment. The addition of fly ash to cement or lime would further improve soil stability .

21. Geosynthetics

22. Optimization using geosynthetics

23. Drainage composites

24. Reinforcement composites