Browse > Article
http://dx.doi.org/10.12989/gae.2016.10.6.827

Rate of softening and sensitivity for weakly cemented sensitive clays  

Park, DongSoon (K-water Institute, Korea Water Resources Corporation)
Publication Information
Geomechanics and Engineering / v.10, no.6, 2016 , pp. 827-836 More about this Journal
Abstract
The rate of softening is an important factor to determine whether the failure occurs along localized shear band or in a more diffused manner. In this paper, strength loss and softening rate effect depending on sensitivity are investigated for weakly cemented clays, for both artificially cemented high plasticity San Francisco Bay Mud and low plasticity Yolo Loam. Destructuration and softening behavior for weakly cemented sensitive clays are demonstrated and discussed through multiple vane shear tests. Artificial sensitive clays are prepared in the laboratory for physical modeling or constitutive modeling using a small amount of cement (2 to 5%) with controlled initial water content and curing period. Through test results, shear band thickness is theoretically computed and the rate of softening is represented as a newly introduced parameter, ${\omega}_{80%}$. Consequently, it is found that the softening rate increases with sensitivity for weakly cemented sensitive clays. Increased softening rate represents faster strength loss to residual state and faster minimizing of shear band thickness. Uncemented clay has very low softening rate to 80% strength drop. Also, it is found that higher brittleness index ($I_b$) relatively shows faster softening rate. The result would be beneficial to study of physical modeling for sensitive clays in that artificially constructed high sensitivity (up to $S_t=23$) clay exhibits faster strain softening, which results in localized shear band failure once it is remolded.
Keywords
sensitive clay; shear band; strain softening; sensitivity; cemented soil; vane shear; strength loss;
Citations & Related Records
연도 인용수 순위
  • Reference
1 Einav, I. and Randolph, M. (2006), "Effect of strain rate on mobilised strength and thickness of curved shear bands", Geotechnique, 56(7), 501-504.   DOI
2 Geertsema, M. and Torrance, J.K. (2005), "Quick clay from the Mink Creek landslide near terrace, British Columbia: Geotechnical properties, mineralogy, and geochemistry", Can. Geotech. J., 42(3), 907-918.   DOI
3 Horpibulsuk, S., Bergado, D.T. and Lorenzo, G.A. (2004), "Compressibility of cement-admixed clays at high water content", Geotechnique, 54(2), 151-154.   DOI
4 Horpibulsuk, S., Liu, M.D., Liyanapathirana, D.S. and Suebsuk, J. (2010), "Behaviour of cemented clay simulated via the theoretical framework of the Structured Cam Clay model", Comput. Geotech., 37(1-2), 1-9.   DOI
5 Hossain, M. and Randolph, M. (2009), "Effect of strain rate and strain softening on the penetration resistance of spudcan foundations on clay", Int. J. Geomech., 9(3), 122-132.   DOI
6 Kamruzzaman, A.H.M., Chew, S.H. and Lee, F.H. (2009), "Structuration and destructuration behavior of cement-treated Singapore marine clay", J. Geotech. Geoenviron. Eng., 135(4), 573-589.   DOI
7 L'Heureux, J.-S., Locat, A., Leroueil, S., Demers, D. and Locat, J. (2014), "Landslides in sensitive clays - from geosciences to risk management", Landslides in Sensitive Clays, Advances in Natural and Technological Hazards Research, 36, 1-12.   DOI
8 Longva, O., Janbu, N., Blikra, L.H. and Boe, R. (2003), "The 1996 Finneidfjord slide; seafloor failure and slide dynamics", EGS - AGU - EUG Joint Assembly Meeting, Nice, France.
9 Meijer, G. and Dijkstra, J. (2013), "A novel methodology to regain sensitivity of quick clay in a geotechnical centrifuge", Can. Geotech. J., 50(9), 995-1000.   DOI
10 Mitchell, J.K. (1976), "The properties of cement-stabilized soils", Proceedings of Residential Workshop on Materials and Methods for Low Cost Road, Leura, Australia, September, pp. 365-401.
11 Mitchell, J.K. and Soga, K. (2005), Fundamentals of Soil Behavior, John Wiley & Sons.
12 Park, D.S. (2012), "Effects of chemical additives on the properties of Young Bay Mud", Int. J. Geo-Eng., 4(3), 29-35.
13 Park, D.S., Kutter, B.L. and DeJong, J. (2010), "Centrifuge modeling of a sensitive clay slope for simulation of strain softening", Proceedings of the 7th International Conference on Physical Modelling in Geotechniques, International Society for Soil Mechanics and Geotechnical Engineering, Zurich, Switzerland, July.
14 Penner, E. (1963), "Sensitivity in Leda Clay", Nature, 197(486).
15 Randolph, M.F. (2012), "Offshore geotechnics - The challenges of deepwater soft sediments", Geotechnical Engineering State of the Art and Practice, 241-271. DOI: 10.1061/9780784412138.0010   DOI
16 Randolph, M.F. (2004), "Characterisation of soft sediments for offshore applications", Proceedings ISC-2 on Geotechnical and Geophysical Site Characterization, (V.d.F. Mayne Ed.), Porto, Portugal, September, pp. 209-232.
17 Sasanian, S. (2011), "The behaviour of cement stabilized clay at high water contents", Ph.D. Dissertation; The University of Western Ontario, London, ON, Canada.
18 Suebsuk, J., Horpibulsuk, S., Chinkulkijniwat, A. and Liu, M.D. (2009), "Modeling the behavior of artificially structured clays by the Modified Structured Cam Clay model", International Symposium on Prediction and Simulation Methods for Geohazard Mitigation, (M.K. Oka Ed.), Taylor & Francis Group, London, Kyoto, Japan, pp. 313-318.
19 Verastegui Flores, R.D. and Van Impe, W.F. (2009), "Stress-strain behavior of artificially cemented Kaolin clay", Proceedings of the 17th International Conference on Soil Mechanics and Geotechnical Engineering, (M. Hamza, M. Shahien and Y. El-Mossallamy Eds.), Alexandria, Egypt, October, pp. 283-286.
20 Tappin, D.R., Watts, P. and Matsumoto, T. (2003), "Architecture and failure mechanism of the offshore slump responsible for the 1998 Papua New Guinea tsunami", Submarine Mass Movements and Their Consequences, Kluwer, the Netherlands, pp. 383-389.
21 Yafrate, N., DeJong, J., DeGroot, D. and Randolph, M. (2009), "Evaluation of remolded shear strength and sensitivity of soft clay using full-flow penetrometers", J. Geotech. Geoenviron. Eng., 135(9), 1179-1189.   DOI
22 Zhou, H. and Randolph, M.F. (2009), "Resistance of full-flow penetrometers in rate-dependent and strainsoftening clay", Geotechnique, 59(2), 79-86.   DOI
23 Biscontin, G. and Pestana, J.M. (2001), "Influence of peripheral velocity on vane shear strength of an artificial clay", Geotech. Test. J., 24(4), 423-429.   DOI
24 Abramson, L.W., Lee, T.S., Sharma, S. and Boyce, G.M. (2002), Slope Stability and Stabilization Methods, John Wiley & Sons.
25 Andersson-Skold, Y., Torrance, J.K., Lind, B., Oden, K., Stevens, R.L. and Rankka, K. (2005), "Quick clay - A case study of chemical perspective in Southwest Sweden", Eng. Geol., 82, 107-118.   DOI
26 Azizian, A. and Popescu, R. (2005), "Finite element simulation of seismically induced retrogressive failure of submarine slopes", Can. Geotech. J., 42(6), 1532-1547.   DOI
27 Bishop, A.W. (1967), "Progressive failure-with special reference to the mechanism causing it", Panel Discussion, Proceedings of the Geotechnical Conference, Norwegian Geotechnical Institute, Oslo, Norway, pp. 142-150.
28 Bushra, I. and Robinson, R.G. (2012), "Shear strength behavior of cement treated marine clay", Int. J. Geotech. Eng., 6(4).
29 Crawford, C.B. (1968), "Quick clays of eastern Canada", Eng. Geol., 2(4), 239-265.   DOI
30 Chew, S.H., Kamruzzaman, A.H.M. and Lee, F.H. (2004), "Physicochemical and engineering behavior of cement treated clays", J. Geotech. Geoenviron. Eng., 130(7), 696-706.   DOI
31 DeJong, J., Yafrate, N. and DeGroot, D. (2011), "Evaluation of undrained shear strength using full-flow penetrometers", J. Geotech. Geoenviron. Eng., 137(1), 14-26.   DOI