Civil Engineering April 2022 | Vol 30 No 3

16 April 2022 Civil Engineering to match the assigned design return period event. As before, the behaviour of the mate- rial illustrated via stress paths in p’: q: e space and their proximity to the CSL is used to assess stability during the seismic event. In Figure 8, the effect of dynamic loading is evident in the stress paths, with the grey paths representing stress history up to the onset of the seismic event and the coloured paths the effect during the event. In this scenario, liquefaction and critical state of some of the queried points have been reached. CONCLUSION Realistic assessment of TSF stability be- yond simplified, conservative assumptive analysis is necessary. The triggering assessment methodology presented here is an example of the type of rigorous approach which will be necessary to ac- complish this. This article demonstrates that by utilising CSSM constitutive models and finite element analysis, the stress and strain state of upstream tailings facilities can be realistically analysed and predicted under normal and abnormal loading conditions. Findings indicate that despite the presence of contractive saturated tailings, liquefaction does not necessarily ensue under all plausible trig- gering events. The development and incorporation of complex non-linear constitutive models into FEM analytical tools enables the application of realistic and representative engineering assessment of contractive TSF stability, as opposed to the overly conservative historic as- sumption of residual strength in limit equilibrium analyses.  REFERENCES Graham, J. & Jefferies, M. 1986. Some examples of in situ lateral stress determinations in hydraulic fills using the self-boring pressuremeter . Proceedings of the 39th Canadian Geotechnical Conference. Ottawa, Canada. ICOLD Tailings Dam Safety Bulletin – Preliminary Draft. 2020. Jefferies, M. & Been, K. 2016. Soil Liquefaction – A Critical State Approach, Second Edition. CRC Press. Shuttle, D. & Jefferies, M. 2016. Determining silt state from CPTu . Geotechnical Research Vol. 3 Issue 3, 90-118. Shuttle, D.A. & Cunning, J. 2008. Reply to discussion: Liquefaction potential of silts from CPTu. Canadian Geotechnical Journal, 45(1), 142–145. This article demonstrates that by utilising CSSM constitutive models and finite element analysis, the stress and strain state of upstream tailings facilities can be realistically analysed and predicted under normal and abnormal loading conditions. Findings indicate that despite the presence of contractive saturated tailings, liquefaction does not necessarily ensue under all plausible triggering events. GRLWEAP14 Wave Equation Software • Simulate pile response and hammer performance • Calculate soil resistance, dynamic pile stresses, and estimated capacities • NEW GRLWEAP14 available in professional, offshore, or network versions To learn more about GRLWEAP14, visit www.pile.com.