Engineering Geology

Engineering Geology

Investigation on Experimental Analysis of the Effect of Geocell on the Load-Settlement Behavior of Dredged Sand in Shahid Rajaee Port

Authors
Seyed Taha Tabatabaei Aghda
Ali Ghanbari
Gholamhosein Tavakoli Mehrjardi
10.18869/acadpub.jeg.13.2.237
Abstract
Introduction

In some ports, the dredging and accumulation of a large amount of sedimentary material turned to a serious challenge, because of their sequent environmental and economic effects. These problems clarify the necessity of reusing dredged materials. Often, owing to their poor mechanical properties, they are not applied directly in technically engineering uses, so they require to be improved. Geocell application is one of the methods used for the improvement of soil behavior, which confines the sand mass through itself in the three-dimensional structure. These methods ease the speed of applying emerged it into a perfect option for stabilizing of the granular soil.

In Shahid Rajaee port, by the dredging process for developing new phases, a large amount of calcareous sand is being accumulated near the Persian Gulf coastline. Therefore, in order to provide a solution to reuse these materials, this study attempts to investigate the beneficial influence of reinforcing sand by geocell on its load-beneficial behavior experimented by the plat loading test. For this purpose, a large scale model including circular foundation on reinforced and unreinforced sand has been employed under cyclic loading process.

Material and Methods

Soils

Two types of soils were used in this study. The first type was the sand derived from the dredging process of Shahid Rajaee port which has been used in different layers of the models. The second type of soil was well-graded gravel which has been used only in the cover layer.

Geocell

The geocell in this study were made of heat-bonded non-woven polypropylene geotextiles. Single cells were 110 mm long, 100 mm wide and 100 mm height.

Plate load test

In order to determine the bearing capacity of backfills, repeating plate load test was used with 150 mm diameter. Loading process included four stress levels (250, 500, 750 and 1000 kPa) consisting of 10 cycles each.

Test backfills

Four backfills was made by manually compacting the dredged sand, with tamper up to 350 mm in reinforced cases and 450 mm in unreinforced cases. Then geocells placed and dredged sand filled with accuracy in cells. Finally, a 50 mm thick sand or gravel cover layer, was placed. All lifts were compacted to 70% of relative density with 4% moisture content.

Results and Discussion

PLT results are summarized in Table 1. According to the results, only geocell reinforcement backfills can carry standard truck wheel load (550 kPa). Geocell can increase the ultimate strength of backfills with a sand cover layer by 70% (from 416 kPa to 725 kPa) while in backfill with a gravel cover layer showed 80% increase (from 520 kPa to 960 kPa) in ultimate strength. The gravel cover layer in unreinforced backfills increases the ultimate strength by 25 percent (from 416 kPa to 520 kPa).

Table 1. Results of PLT and performance ratings




Backfill name
UR-S
GR-S
UR-W
GR-W


Maximum stress (kPa)
416
725
520
960


Settlement at failure (mm)
4.6
9.0
15.5
14.9


Plastic settlement (mm)
3.5
7.0
12.5
12.0


Number of load cycles
10
20
20
30


Bearing capacity ratio (BCR)
1
1.74
1.25
2.32


Performance rating
4
2
3
1



Base on Table 1, bearing capacity ratio (BCR) has been increased up to 2.3 and has best when geocell reinforcement and gravel cover layer were used together. Geocell utilization as reinforcement for sand backfills, improves the stress-settlement behavior. Dredged sand can be used as backfill material for yards and access roads when reinforced with geocell and covered with a layer of well-graded gravel../files/site1/files/132/3Extended_Abstracts.pdf
Keywords
Geocell
Plate loading test
dredged sand
load-settlement behavior
1. Maher A., Douglas W. S., Jafari F., Pecchioli J., "The processing and beneficial use of fine-grained dredged material, a manual for engineers", Centre for Advance Infrastructure and Transportation (2013). ## 2. Siham K., Fabrice B., Edine A. N., Patrick D., "Marine dredged sediments as new materials resource for road construction", Waste Manag, 28 (5) (2008) 919-28. ## 3. Dubois V., Abriak N. E., Zentar R., Ballivy G., "The use of marine sediments as a pavement base material", Waste Manag. (2009) 29 (2) 774-82. ## 4. Huang Y., Zhu W., Qian X., Zhang N., Zhou X., "Change of mechanical behavior between solidified and remolded solidified dredged materials", Eng Geol. 119 (3) (2011) 112-9. ## 5. Wang D., Abriak N. E., Zentar R., "Strength and deformation properties of Dunkirk marine sediments solidified with cement, lime and fly ash", Vol. 166, Engineering Geology (2013). ## 6. Tavakoli Mehrjardi G., Ghanbari A., Mehdizadeh H., "Experimental study on the behaviour of geogrid-reinforced slopes with respect to aggregate size", Geotext Geomembranes, 44 (6) (2016) 862-71. ## 7. Kondo J. R., Roodi G. H., Zornberg J. G., "Evaluation of the Interaction between dredged materials and geosynthetic reinforcements", In: 3rd Pan-American Conference on Geosynthetics, Miami, Florida (2016) 1187-202. ## 8. Cantré S., Saathoff F., "Investigation of dredged materials in combination with geosynthetics used in dike construction". Procedia Eng., 57 (2013) 213-21. ## 9. Pokharel S. K., Han J., Leshchinsky D., Parsons R. L., Halahmi I., "Investigation of factors influencing behavior of single geocell-reinforced bases under static loading", Geotext Geomembranes, 28 (6) (2010) 570-8. ## 10. De Garidel R., Morel G., "New soil strengthening techniques by textile elements for low volume roads", In: Proc of 3rd International Conference on Geotextiles (1986) 1027-32. ##11. Dash S. K., Krishnaswamy N. R., Rajagopal K., "Bearing capacity of strip footings supported on geocell-reinforced sand", Geotext Geomembranes,19 (4) (2001) 235-56. ## 12. Rea C., Mitchell J. K., "Sand Reinforcement using Paper Grid Cells". In: Symposium on Earth Reinforcement. ASCE (2006) 644-63. ## 13. Bathurst R. J., Jarret P. M., "Large-scale model tests of geocomposite mattresses over peat subgrades", Transp Res Rec., (1188) (1988) 28-36. ## 14. Mir Mohammad Hosseini S. M., Mohammadi M., Kargar M., "Experimental study on the cyclic behavior of footings on sand reinforced with geocell and tire shreds". In: 7th International Conference on Seismology & Earthquake Engineering. Tehran (2015). ## 15. Thallak S. G., Saride S., Dash S. K., "Performance of surface footing on geocell-reinforced soft clay beds". Geotech Geol Eng., 25 (5) (2007 Aug) 509-24. ## 16. Moghaddas Tafreshi S. N., Dawson A. R., "Comparison of bearing capacity of a strip footing on sand with geocell and with planar forms of geotextile reinforcement". Geotext Geomembranes, 28 (1) (2010) 72-84. ## 17. Pincus H., Bathurst R., Karpurapu R., "Large-Scale triaxial compression testing of geocell-reinforced granular soils", Geotech Test J.,16 (3) (1993) 296. ## 18. Ling Zhang, Minghua Zhao, Caijun Shi H. Z., "Bearing capacity of geocell reinforcement in embankment engineering". Geotext Geomembranes, 28 (5) (2010) 475-82. ## 19. Dash S. K., Sireesh S., Sitharam T. G., "Model studies on circular footing supported on geocell reinforced sand underlain by soft clay". Geotext Geomembranes, 21 (4) (2003)197-219. ## 20. Datta M., Gulhati S. K., Rao G. V,. "Crushing of calcareous sands during shear". In: Offshore Technology Conference (1979). ## 21. Shahnazari H., Tutunchian M. A., Rezvani R., Valizadeh F., "Evolutionary-based approaches for determining the deviatoric stress of calcareous sands". Comput Geosci, 50 (2013) 84-94. ## 22. Moghaddas Tafreshi S. N., Dawson A. R., "Behaviour of footings on reinforced sand subjected to repeated loading-Comparing use of 3D and planar geotextile". Geotext Geomembranes, 28 (5) (2010) 434-47. ## 23. Tavakoli Mehrjardi G., Moghaddas Tafreshi S. N., Dawson A. R., "Pipe response in a geocell-reinforced trench and compaction considerations". Geosynth Int., 20 (2) (2013 Apr) 105-18. ## 24. Tavakoli Mehrjardi G., Moghaddas Tafreshi S. N., Dawson A. R., "Combined use of geocell reinforcement and rubber–soil mixtures to improve performance of buried pipes", Geotext Geomembranes, 34 (2012)116-30. ## 25. Tavakoli Mehrjardi G., Tafreshi S. N. M., Dawson A. R., "Pipe response in a geocell-reinforced trench and compaction considerations", Geosynth Int. (2) (2013). ## 26. Mitchell J. K., Kao T-C., Kavazanjian E., J., "Analysis of grid cell reinforced pavement bases" (1979). ## 27. Attarzadeh A., Ghanbari A., Hamidi A., "A study of searing capacity of shallow foundations next to sand slope with experimental models", J. Eng. Geol., 9 (1) (2015) 2695-710. ## 28. Das B., Omar M., "The effects of foundation width on model tests for the bearing capacity of sand with geogrid reinforcement", Geotech Geol Eng., 12 (2) (1994)133-41. ## 29. Hsieh C., Mao H-L., "A bench-scale performance test for evaluation the geosynthetic reinforcement effects on granular base courses", In: Geo-Frontiers Congress (2005). ## 30. Arnold G. K., "Rutting of granular pavements", PHD thesis, University of Nottingham (2004). ## 31. Tavakoli Mehrjardi G., Moghaddas Tafreshi S. N., Dawson A. R., "Numerical analysis on Buried pipes protected by combination of geocell reinforcement and rubber-soil mixture", Int J Civ Eng., 13 (2) (2015) 90-104. ## 32. Khalaj O., Moghaddas Tafreshi S. N., Masek B., Dawson A. R., "Improvement of pavement foundation response with multi-layers of geocell reinforcement: Cyclic plate load test", Geomech Eng., 9 (3) (2015) 373-95. ## 33. Moghaddas Tafreshi S. N., Dawson A. R., "A comparison of static and cyclic loading responses of foundations on geocell-reinforced sand", Geotext Geomembranes, 32 (2012) 55-68. ## 34. Yadu L., Tripathi R. K., "Effect of the Length of Geogrid Layers in the Bearing Capacity Ratio of Geogrid Reinforced Granular Fill-soft Subgrade Soil System", Procedia-Soc Behav Sci.,104 (2013 Dec) 225-34. ## 35. Terzaghi K., Peck R. B., "Soil mechanics in engineering pratice" (1967). ## 36. Tavakoli Mehrjardi G., "Influence of Geocell Reinforcement on Damping Properties of Trench with Pipe", 15th World Conf Earthq Eng. (2012). ## 37. Moghaddas Tafreshi S. N., Dawson A. R., "Behaviour of footings on reinforced sand subjected to repeated loading-Comparing use of 3D and planar geotextile". Geotext Geomembranes, 28 (5) (2010) 434-47. ##