Case study behavior of soft soil improved with prefabricated vertical drains
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The document presents a study on soft soil behavior improved with prefabricated vertical drains at a site near the new Suez Canal in East Port Said. It discusses extensive soil investigations, monitoring, and numerical modeling to predict settlement and consolidation over time. The results indicate that using a combination of vertical drains and surcharge can effectively enhance soil strength and manage settlement efficiently.
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0.4 cm/day2 to 1 cm/day
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Settlement rate after 9 months preloading is about 0.6mm/day (0.4 cm/week)](https://image.slidesharecdn.com/casestudybehaviorofsoftsoilimprovedwithprefabricatedverticaldrains-181107100628/85/Case-study-behavior-of-soft-soil-improved-with-prefabricated-vertical-drains-7-320.jpg)
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FEA- II - V2](https://image.slidesharecdn.com/casestudybehaviorofsoftsoilimprovedwithprefabricatedverticaldrains-181107100628/85/Case-study-behavior-of-soft-soil-improved-with-prefabricated-vertical-drains-11-320.jpg)
Case study behavior of soft soil improved with prefabricated vertical drains
- 1. Studying the behavior of soft soil improved with prefabricated vertical drains. Case study Mohamed AYELDEEN Keller Grundbau GmbH Robert THURNER Keller Grundbau GmbH
- 2. Location • The Project is part of the development of East Port Said along parts of the newly extended Suez Canal. The site is located east of Port Said on the east shore of the Suez Canal extension. • Light-weight structures and broad roads in between the structures shall be built over an area of great dimensions (km).
- 3. Within this zone, 8 CPTu test s were carried out to investi gate the underground situati on in more detail. Soil Profile Clayey Silt Silty Clay ImprovementDepth
- 4. Trial Zone Inclinometer Settlement Points Pre and post investigation including: - Boreholes - CPTu - Vane shear - Stand Pipe Piezometer
- 5. Instrumentation Measurements Settlement and Pore pressure Primary Consolidation Stage Secondary Compression Stage
- 6. Average Settlement after 6 month preloading 105 cm 115 cm 185 cm
- 7. 0.0 0.5 1.0 1.5 2.0 2.5 0 2 4 6 8 10 12 14 16 18 20 SettlementRate[cm/day] Time [week] After Embankment Construction 0.4 cm/day2 to 1 cm/day During Embankment Construction Settlement Rate Settlement rate after 9 months preloading is about 0.6mm/day (0.4 cm/week)
- 8. Normal settlement prediction Asaoka Method Point GMP6 GMP7 GMP8 GMP9 GMP10 Expected Settlement, cm 152 134 145 147 152 Settlement Prediction
- 9. Point GMP6 GMP7 GMP8 GMP9 GMP10 Expected Settlement, cm 237 237 238 246 242 Sherif Method Settlement Prediction
- 10. Numerical Model Back calculation Initial Soil models, Soil parameters & Soil profile Numerical Model Long term prediction Boreholes & CPTu results Adjusting the soil parameters General Model Calibration with measured settlement Verification with other measurements Literature Adjusting the model
- 11. Modelling Verification 0 20 40 60 80 100 120 140 160 180 200 0 50 100 150 200 250 300 350 Settlement[cm] Time [days] GMP 6 GMP 7 GMP 8 GMP 9 GMP 10 GMP 18 GMP 19 FEA - I - V1 FEA - II - V1 0 0.2 0.4 0.6 0.8 1 1.2 1.4 1.6 0 50 100 150 200 250 Settlement[m] Time [days] GMP 438 GMP 439 FEA-I - V2 FEA- II - V2
- 12. Generalized Model Results Settlement after 9 months preloading Long term settlement
- 13. 0.0 0.2 0.4 0.6 0.8 1.0 1.2 1.4 1.6 0-10 10-15 15-25 25-50 TipResistance,MPa Depth, m Before Preloading After 1 month After 3 month After 5 months 0.000 0.005 0.010 0.015 0.020 0.025 0.030 0.035 0-10 10-15 15-25 25-50 SleeveFriction,MPa Depth, m Before Preloading After 1 month After 3 month After 5 months Post Investigation 0 5 10 15 20 25 30 35 40 0 3 6 9 12 Depth(m) Ch (m2/year) Before preloading After 3 months
- 14. • Constructing a trial zone in mega project and being monitored well is essential and can give a clear idea about the system behaviour. • The combination between intensive soil investigation work and data from monitoring the trial zone can be used in an efficient way to build up a trustable numerical model which can simulate the behaviour in high accuracy. • The improvement in the soil parameters can be noticed by the CPTu results which is related in somehow to the degree of consolidation. However caution should be taken in analyzing the data which can be misleading as effect of the preloading. • The combination between PVD and surcharge can improve the soil strength and reduce the settlement with high efficiency and as ecofriendly technique. Conclusion and Recommendations
- 15. Thanks for your attention… Mohamed AYELDEEN Keller Grundbau GmbH Robert THURNER Keller Grundbau GmbH