Abstract
This case study describes the failure of an interstate connecting-ramp embankment during construction and investigates the failure mechanism, performance of the prefabricated vertical drains (PVDs) installed to accelerate consolidation of the weak embankment foundation soils, embankment shear strength parameters, and design slope stability analyses. The weak, fine-grained foundation soil experienced less drainage, and thus less consolidation and strength gain, than expected via the PVDs because of an overestimate of the design horizontal coefficient of consolidation. As a result, the inverse analyses show the failure was caused by lower than expected shear strength of the foundation soils and an overestimate of the compacted embankment shear strength. The compacted embankment fill strength was characterized using an undrained shear strength, i.e., cohesion, without a tension crack, which inflated the calculated factor of safety. Recommendations to estimate embankment shear strength parameters, depth of embankment tension crack, bearing capacity factor of safety for comparison with limit equilibrium values, and horizontal consolidation properties for PVD design for future embankment projects are presented.
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Acknowledgments
The contents and views in this paper are those of the individual authors and do not necessarily reflect those of any of the represented corporations, contractors, agencies, consultants, organizations, and/or contributors, including ODOT. The authors also gratefully acknowledge the extensive and beneficial comments of Reviewers 2 and 3, which greatly clarified and improved this case study.
References
Asaoka, A. (1978). “Observational procedure of settlement prediction.” Soils Found. J. Jpn. Geotech. Soc., 18(4), 87–101.
ASTM. (2007). “Standard test method for particle-size analysis of soils.” ASTM D422/D422M-07, West Conshohocken, PA.
ASTM. (2009). “Standard practice for description and identification of soils (visual-manual procedure).” ASTM D2488-09, West Conshohocken, PA.
ASTM. (2010a). “Standard test method for liquid limit, plastic limit, and plasticity index of soils.” ASTM D4318/D4318M-10, West Conshohocken, PA.
ASTM. (2010b). “Standard test methods for laboratory determination of water (moisture) content of soil and rock by mass.” ASTM D2216-10, West Conshohocken, PA.
ASTM. (2011a). “Standard test method for consolidated-undrained triaxial compression test for cohesive soils.” ASTM D4767-11, West Conshohocken, PA.
ASTM. (2011b). “Standard test method for one-dimensional consolidation properties of soils using incremental loading.” ASTM D2435/D2435M-11, West Conshohocken, PA.
ASTM. (2013a). “Standard classification of peat samples by laboratory testing.” ASTM D4427–13, West Conshohocken, PA.
ASTM. (2013b). “Standard test method for unconfined compressive strength of cohesive soils.” ASTM D2166/2166M-13, West Conshohocken, PA.
ASTM. (2014a). “Standard test method for moisture, ash, and organic matter of peat and other organic soils.” ASTM D2974-14, West Conshohocken, PA.
ASTM. (2014b). “Standard test method for specific gravity of soli solids by water pycnometer.” ASTM D854-14, West Conshohocken, PA.
Bishop, A. W. (1955). “The use of slip circles in the stability analysis of earth slopes.” Geotechnique, 5(1), 7–17.
Bowles, J. E. (1977). Foundation analysis and design, 1st Ed., McGraw-Hill, New York.
Bowles, J. E. (1996). Foundation analysis and design, 5th Ed., McGraw-Hill, New York.
Chirapuntu, S., and Duncan, J. M. (1976). “The role of fill strength in the stability of embankments on soft clay foundations.”, U.S. Army Engineer, Waterways Experiment Station, Washington, DC.
Duncan, J. M., and Stark, T. D. (1992). “Soil strengths from back-analysis of slope failures.” Proc., Specialty Conf. Stability and Performance of Slopes and Embankments-II, Vol. 1, ASCE, Berkeley, CA, 890–904.
Gamez, J., and Stark, T. D. (2014). “Fully softened shear strength at low stresses for levee and embankment design.” J. Geotech. Geoenviron. Eng., 06014010-1–06014010-6.
Holtz, R. D., and Kovacs, W. D. (1981). An introduction to geotechnical engineering, Prentice-Hall, Englewood Cliffs, NJ, 733.
Holtz, R. D., Kovacs, W. D., and Sheahan, T. C. (2011). An introduction to geotechnical engineering, Prentice-Hall, Englewood Cliffs, NJ, 653.
Jamiolkowski, M., Ladd, C. C., Germaine, J. T., and Lancellotta, R. (1985). “New developments in field and laboratory testing of soils.” Proc., 11th Int. Conf. on Soil Mechanics and Geotechnical Engineering, Vol. 1, A.A. Balkema, Rotterdam, Netherlands, 57–153.
Kayyal, M. K., and Wright, S. G. (1991). “Investigation of long-term strength properties of Paris and Beaumont clays in earth embankments.”, Center for Transportation Research, Univ. of Texas, Austin, TX.
Lo, D. O. K. (1991). “Soil improvement by vertical drains.” Ph.D. thesis, Univ. of Illinois at Urbana-Champaign, Champaign, IL.
Mesri, G., and Huvaj, N. (2009). “The Asaoka method revisited.” Proc., 17th Int. Conf. in Soil Mechanics and Geotechnical Engineering, Vol. 1, IsoPress, Amsterdam, Netherlands, 131–134.
Mesri, G., and Lo, D. O. K. (1991). “Field performance of prefabricated vertical drains.” Proc., Int. Conf. on Geotechnical Engineering For Coastal Development—Theory to Practice, Vol. 1, Coastal Development Institute of Technology, Tokyo, 231–236.
Morgenstern, N. R., and Price, V. E. (1965). “The analysis of the stability of general slip surface.” Geotechnique, 15(1), 79–93.
ODOT (Ohio Department of Transportation). (1995). Construction and material specifications, Columbus, OH.
ODOT (Ohio Department of Transportation). (2010). GB-6: Geotechnical Bulletin No. 6—Shear strength of proposed embankments, Division of Production Management Office of Geotechnical Engineering, Columbus, OH, 7.
PCSTABL6 [Computer software]. Dept. of Civil Engineering, Purdue Univ., West Lafayette, IN.
Peck, R. B. (1969). “Advantages and limitations of the observational method in applied soil mechanics.” Geotechnique, 19(2), 171–187.
Peck, R. B., Hanson, W. E., and Thornburn, T. H. (1974). Foundation engineering practice, 3rd Ed., Wiley, New York, 514.
Saleh, A. A., and Wright, S. G. (1997). Shear strength correlations and remedial measure guidelines for long-term stability of slopes constructed of highly plastic clay soils, Center for Transportation Research, Univ. of Texas, Austin, TX, 156.
Slope/W [Computer software]. Geo-Slope International, Calgary, Canada.
Stark, T. D., and Hussain, M. (2013). “Drained shear strength correlations for slope stability analyses.” J. Geotech. Geoenviron. Eng., 853–862.
Terzaghi, K., Peck, R. B., and Mesri, G. (1996). Soil mechanics in engineering practice, 3rd Ed., Wiley, New York, 549.
Urzua, A., Ladd, C. C., and Christian, J. T. (2016). “New approach to analysis of consolidation data at early times.” J. Geotech. Geoenviron. Eng., 06016009-1–06016009-6.
Wright, S. G. (2013). “Slope stability computations.” ⟨https://www.youtube.com/watch?v=Q_6aOU7msBM⟩ (Mar. 3, 2013).
Wright, S. G., Zornberg, J. G., and Aguettant, J. E. (2007). The fully softened shear strength of high plasticity clays, Center for Transportation Research, Univ. of Texas, Austin, TX, 132.
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©2017 American Society of Civil Engineers.
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Received: Feb 9, 2016
Accepted: May 25, 2017
Published online: Nov 17, 2017
Published in print: Feb 1, 2018
Discussion open until: Apr 17, 2018
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