Significance of Spatial Variability of Deep Cement Mixed Columns on Reliability of Column-Supported Embankments
Publication: International Journal of Geomechanics
Volume 19, Issue 8
Abstract
The spatial variability of mechanical properties of deep cement mixed (DCM) soil leads to uncertainty in performance of DCM column–supported embankments. While adequate safety levels can be achieved using a large factor of safety in a deterministic design, a reliability assessment helps to find an optimum safety level for the design by managing variability parameters. However, only few studies have been conducted on the performance of DCM column–supported embankments considering the variability of mechanical properties of columns. None of these studies have considered the strain-softening behavior of DCM columns along with the strength variability. This study investigates the reliability of a DCM column–supported embankment considering the spatial variability of mechanical properties and strain-softening behavior. Compressive strength, elastic modulus, and cohesion of DCM soil were considered as stochastic parameters in this study. The analysis was carried out using Monte Carlo method assuming three different cases of spatial variability. The reliability response of the embankment to changing coefficient of variation (COV), mean compressive strength, and the spatial correlation length are discussed. Results demonstrate that the reliability performance level of the embankment can be conservatively predicted by considering the variability of mean DCM column strength without considering the spatial variability. Based on the results of this study, a method is proposed to determine the overdesign factor required to achieve a target reliability for the embankment.
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References
Abusharar, S. W., and J. Han. 2011. “Two-dimensional deep-seated slope stability analysis of embankments over stone column-improved soft clay.” Eng. Geol. 120 (1-4): 103–110. https://doi.org/10.1016/j.enggeo.2011.04.002.
Al-Naqshabandy, M. S., N. S. Bergman, and S. Larsson. 2012a. “Strength variability in lime-cement columns based on CPT data.” Proc. Inst. Civ. Eng. Ground Improv. 165 (1): 15–30. https://doi.org/10.1680/grim.2012.165.1.15.
Al-Naqshabandy, S., N. Bergman, and S. Larsson. 2012b. “Effect of spatial variability of the strength properties in lime-cement columns on embankment stability.” In Proc., 4th Int. Conf. on Grouting and Deep Mixing, 231–242. Reston, VA: ASCE.
Al-Naqshabandy, M. S., and S. Larsson. 2013. “Effect of uncertainties of improved soil shear strength on the reliability of embankments.” J. Geotech. Geoenviron. Eng. 139 (4): 619–632. https://doi.org/10.1061/(ASCE)GT.1943-5606.0000798.
Andromalos, K. B., Y. A. Hegazy, and B. H. Jasperse. 2000. “Stabilization of soft soils by soil mixing.” In Proc., Soft Ground Technology Conf. Reston, VA: ASCE.
Ariyarathne, P., D. S. Liyanapathirana, and C. J. Leo. 2013. “Comparison of different two-dimensional idealizations for a geosynthetic-reinforced pile-supported embankment.” Int. J. Geomech. 13 (6): 754–768. https://doi.org/10.1061/(ASCE)GM.1943-5622.0000266.
Babu, G. L. S., A. Srivastava, and P. V. Sivapulliah. 2011. “Reliability analysis of strength of cement treated soils.” Georisk Assess. Manage. Risk Eng. Syst. Geohazards 5 (3-4): 157–162. https://doi.org/10.1080/17499518.2010.490116.
Broms, B. B. 1999. “Keynote lecture: Design of lime, lime/cement and cement columns.” In Proc., Int. Conf. on Dry Mix Methods: Dry Mix Methods for Deep Soil Stabilization, edited by G. H. H. Bredenberg and B. B. Broms, 125–153. Rotterdam, Netherlands: A. A. Balkema.
Bruce, D. A., and M. E. C. Bruce. 2003. “The practitioner's guide to deep mixing.” In Grouting and Ground Treatment, Geotechnical Special Publication No. 120, edited by L. F. Johnsen, D. A. Bruce, and M. J. Byle, 474–488. Reston, VA: ASCE.
Bruce, M. E. C., R. R. Berg, J. G. Collin, G. M. Filz, M. Terashi, and D. S. Yang, 2013. Federal Highway Administration design manual: Deep mixing for embankment and foundation support. FHWA-HRT-13-046. McLean, VA: US Dept. of Transportation, Federal Highway Administration.
CEN (European Committee for Standardization). 2002. Basis of structural design. Eurocode EN 1990:2002. Brussels, Belgium: CEN.
Chen, E. J., Y. Liu, and F.-H. Lee. 2016. “A statistical model for the unconfined compressive strength of deep-mixed columns.” Géotechnique 66 (5): 351–365. https://doi.org/10.1680/jgeot.14.P.162.
Cho, S. E. 2007. “Effects of spatial variability of soil properties on slope stability.” Eng. Geol. 92 (3-4): 97–109. https://doi.org/10.1016/j.enggeo.2007.03.006.
Duncan, J. M. 2000. “Factors of safety and reliability in geotechnical engineering.” J. Geotech. Geoenviron. Eng. 126 (4): 307–316. https://doi.org/10.1061/(ASCE)1090-0241(2000)126:4(307).
EuroSoilStab. 2002. Development of design and construction methods to stabilize soft organic solis. Design guide soft soil stabilization. CP 97-0351. Project No. BE 96-3177. European Commission. Brussels. Industrial & Materials Technologies Programme (Brite-EU-Ram III).
Fenton, G. A., and D. V. Griffiths. 2005. “Three-dimensional probabilistic foundation settlement.” J. Geotech. Geoenviron. Eng. 131 (2): 232–239. https://doi.org/10.1061/(ASCE)1090-0241(2005)131:2(232).
Honjo, Y. 1982. “A probabilistic approach to evaluate shear strength of heterogeneous stabilized ground by deep mixing method.” Soils Found. 22 (1): 23–38. https://doi.org/10.3208/sandf1972.22.23.
Huang, J., D. V. Griffiths, and G. A. Fenton. 2010. “System reliability of slopes by RFEM.” Soils Found. 50 (3): 343–353. https://doi.org/10.3208/sandf.50.343.
Huang, J., R. Kelly, and S. W. Sloan. 2015. “Stochastic assessment for the behaviour of systems of dry soil mix columns.” Comput. Geotech. 66: 75–84. https://doi.org/10.1016/j.compgeo.2015.01.016.
Jamsawang, P., P. Voottipruex, P. Boathong, W. Mairaing, and S. Horpibulsuk. 2015. “Three-dimensional numerical investigation on lateral movement and factor of safety of slopes stabilized with deep cement mixing column rows.” Eng. Geol. 188: 159–167. https://doi.org/10.1016/j.enggeo.2015.01.017.
Jiang, S.-H., and J.-S. Huang. 2016. “Efficient slope reliability analysis at low-probability levels in spatially variable soils.” Comput. Geotech. 75: 18–27. https://doi.org/10.1016/j.compgeo.2016.01.016.
Kasama, K., and K. Zen. 2011. “Effects of spatial variability of soil property on slope stability.” In 1st Int. Symp., Uncertainty Modeling and Analysis and Management; and 5th Int. Symp., Uncertainty Modeling and Analysis, 691–698. Reston, VA: ASCE.
Kasama, K., A. J. Whittle, and K. Zen. 2012. “Effect of spatial variability on the bearing capacity of cement-treated ground.” Soils Found. 52 (4): 600–619. https://doi.org/10.1016/j.sandf.2012.07.003.
Larsson, S., and N. Bergman. 2015. “Probabilistic design of dry deep mixing using an observational approach.” Proc. Inst. Civ. Eng. Ground Improv. 168 (4): 300–311. https://doi.org/10.1680/grim.14.00011.
Larsson, S., H. Stille, and L. Olsson. 2005. “On horizontal variability in lime-cement columns in deep mixing.” Géotechnique 55 (1): 33–44. https://doi.org/10.1680/geot.2005.55.1.33.
Li, D.-Q., S.-H. Jiang, Z.-J. Cao, W. Zhou, C.-B. Zhou, and L.-M. Zhang. 2015a. “A multiple response-surface method for slope reliability analysis considering spatial variability of soil properties.” Eng. Geol. 187: 60–72. https://doi.org/10.1016/j.enggeo.2014.12.003.
Li, J., Y. Tian, and M. J. Cassidy. 2015b. “Failure mechanism and bearing capacity of footings buried at various depths in spatially random soil.” J. Geotech. Geoenviron. Eng. 141 (2): 04014099. https://doi.org/10.1061/(ASCE)GT.1943-5606.0001219.
Liu, L.-L., Y.-M. Cheng, and S.-H. Zhang. 2017a. “Conditional random field reliability analysis of a cohesion-frictional slope.” Comput. Geotech. 82: 173–186. https://doi.org/10.1016/j.compgeo.2016.10.014.
Liu, Y., J. Hu, Y.-P. Li, and L.-H. Li. 2017b. “Statistical evaluation of the overall strength of a soil-cement column under axial compression.” Constr. Build. Mater. 132: 51–60. https://doi.org/10.1016/j.conbuildmat.2016.11.098.
Liu, Y., Y. J. Jiang, H. Xiao, and F. H. Lee. 2017c. “Determination of representative strength of deep cement-mixed clay from core strength data.” Géotechnique 67 (4): 350–364. https://doi.org/10.1680/jgeot.16.P.105.
Liu, Y., F.-H. Lee, S.-T. Quek, E. J. Chen, and J.-T. Yi. 2015. “Effect of spatial variation of strength and modulus on the lateral compression response of cement-admixed clay slab.” Géotechnique 65 (10): 851–865. https://doi.org/10.1680/jgeot.14.P.254.
Möller, N., and S. O. Hansson. 2008. “Principles of engineering safety: Risk and uncertainty reduction.” Reliab. Eng. Syst. Saf. 93 (6): 798–805. https://doi.org/10.1016/j.ress.2007.03.031.
Namikawa, T. 2016. “Conditional probabilistic analysis of cement-treated soil column strength.” Int. J. Geomech. 16 (1): 04015021. https://doi.org/10.1061/(ASCE)GM.1943-5622.0000481.
Namikawa, T., and J. Koseki. 2013. “Effects of spatial correlation on the compression behavior of a cement-treated column.” J. Geotech. Geoenviron. Eng. 139 (8): 1346–1359. https://doi.org/10.1061/(ASCE)GT.1943-5606.0000850.
Navin, M. P. 2005. “Stability of embankments founded on soft soil improved with deep-mixing-method columns.” Doctoral thesis, Dept. of Civil Engineering and Environmental Engineering, Virginia Tech.
Navin, M. P., and G. M. Filz. 2006. “Reliability of deep mixing method columns for embankment support.” In GeoCongress. Reston, VA: ASCE.
Nguyen, L., and B. Fatahi. 2016. “Behaviour of clay treated with cement & fibre while capturing cementation degradation and fibre failure – C3F model.” Int. J. Plast. 81: 168–195. https://doi.org/10.1016/j.ijplas.2016.01.015.
Nguyen, L., B. Fatahi, and H. Khabbaz. 2017. “Development of a constitutive model to predict the behavior of cement-treated clay during cementation degradation: C3 model.” Int. J. Geomech. 17 (7): 04017010. https://doi.org/10.1061/(ASCE)GM.1943-5622.0000863.
Nguyen, L. D., B. Fatahi, and H. Khabbaz. 2014. “A constitutive model for cemented clays capturing cementation degradation.” Int. J. Plast. 56: 1–18. https://doi.org/10.1016/j.ijplas.2014.01.007.
Papaioannou, I., and D. Straub. 2017. “Learning soil parameters and updating geotechnical reliability estimates under spatial variability–theory and application to shallow foundations.” Georisk Assess. Manage. Risk Eng. Syst. Geohazards 11 (1): 116–128. https://doi.org/10.1080/17499518.2016.1250280.
Phoon, K. K. 2004. Towards reliability-based design for geotechnical engineering. Special Lecture for Korean Geotechnical Society, 1–23. Seoul: Korean Geotechnical Society.
Porbaha, A. 2002. “State of the art in quality assessment of deep mixing technology.” Proc. Inst. Civ. Eng. Ground Improv. 6 (3): 95–120. https://doi.org/10.1680/grim.2002.6.3.95.
Porbaha, A., T. Tsuchida, and T. Kishida. 1999. “Technology of air-transported stabilized dredged fill. Part 2: quality assessment.” Proc. Inst. Civ. Eng. Ground Improv. 3 (2): 59–66. https://doi.org/10.1680/gi.1999.030202.
Qi, X.-H., and D.-Q. Li. 2018. “Effect of spatial variability of shear strength parameters on critical slip surfaces of slopes.” Eng. Geol. 239: 41–49. https://doi.org/10.1016/j.enggeo.2018.03.007.
Tang, Y. X., Y. Miyazaki, and T. Tsuchida. 2001. “Practices of reused dredgings by cement treatment.” Soils Found. 41 (5): 129–143. https://doi.org/10.3208/sandf.41.5_129.
Terashi, M. 2003. “The state of practice in deep mixing methods.” In 3rd Int. Conf., Grouting and Ground Treatment, 10–12. Reston, VA: ASCE.
USACE. 1995. Introduction to probability and reliability methods for use in geotechnical engineering. Eng. Tech. Letter No 1110-2-547. Washington, DC: USACE, CECW-ED.
Wijerathna, M., and D. S. Liyanapathirana. 2018. “Simplified modelling approaches for DCM column-supported embankments.” Int. J. Geotech. Eng. 1–10. https://doi.org/10.1080/19386362.2018.1462023.
Yapage, N. N. S. 2013. “Numerical modeling of geosynthetic reinforced embankments over soft ground improved with deep cement mixed columns.” Doctoral thesis, School of Computing, Engineering and Mathematics, Univ. of Western Sydney.
Yapage, N. N. S., and D. S. Liyanapathirana. 2014. “A parametric study of geosynthetic-reinforced column-supported embankments.” Geosynthetics Int. 21 (3): 213–232. https://doi.org/10.1680/gein.14.00010.
Yapage, N. N. S., D. S. Liyanapathirana, R. B. Kelly, H. G. Poulos, and C. J. Leo. 2014. “Numerical modeling of an embankment over soft ground improved with deep cement mixed columns: Case history.” J. Geotech. Geoenviron. Eng. 140 (11): 04014062. https://doi.org/10.1061/(ASCE)GT.1943-5606.0001165.
Yapage, N. N. S., D. S. Liyanapathirana, H. G. Poulos, R. B. Kelly, and C. J. Leo. 2015. “Numerical modeling of geotextile-reinforced embankments over deep cement mixed columns incorporating strain-softening behavior of columns.” Int. J. Geomech. 15 (2): 04014047. https://doi.org/10.1061/(ASCE)GM.1943-5622.0000341.
Yu, Y., and R. J. Bathurst. 2017. “Modelling of geosynthetic-reinforced column-supported embankments using 2D full-width model and modified unit cell approach.” Geotext. Geomembr. 45 (2): 103–120. https://doi.org/10.1016/j.geotexmem.2017.01.002.
Zhang, R.-J., M. S. M. S., Hasan, J.-J. Zheng, and Y.-S. Cheng. 2017. “Effect of spatial variability of engineering properties on stability of a CSMC embankment.” Mar. Georesour. Geotechnol. 36 (1): 91–99. https://doi.org/10.1080/1064119X.2017.1290168.
Zhuang, Y., and K. Wang. 2016. “Numerical simulation of high-speed railway foundation improved by PVD-DCM method and compared with field measurements.” Eur. J. Environ. Civ. Eng. 21 (11): 1363–1383. https://doi.org/10.1080/19648189.2016.1170728.
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Published In
International Journal of Geomechanics
Volume 19 • Issue 8 • August 2019
Copyright
© 2019 American Society of Civil Engineers.
History
Received: Mar 27, 2018
Accepted: Mar 14, 2019
Published online: May 17, 2019
Published in print: Aug 1, 2019
Discussion open until: Oct 17, 2019
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