Some Aspects of the Boundary Value Problems for the Cyclic Deformation of Soil
Some geotechnical installation processes such as vibratory pile driving or vibro-compaction of soils are characterised by a wide strain amplitude range in the soil, from several per cent and higher in the vicinity of the vibration source to vanishingly small amplitudes in the far field. The gradual accumulation of residual stresses and deformations after each small-amplitude cycle plays in such processes as important a role as large-amplitude cyclic deformation. The numerical simulation of such processes faces, among other difficulties, the necessity to model simultaneously large- and small-amplitude cyclic deformation with a large number of cycles. This imposes stringent requirements on the constitutive model. A problem of the large-amplitude vertical vibration of a pile in saturated soil, which belongs to the problems with a wide strain amplitude range, was solved earlier with two constitutive models: an incremental hypoplasticity model and a high-cycle accumulation model. Using this problem as an example, the present paper discusses the solution approaches and numerical and constitutive aspects of the problem, with particular attention to the accumulation effects in hypoplasticity.
KeywordsCyclic deformation Hypoplasticity Pile vibration
- 1.Chrisopoulos, S., Osinov, V.A., Triantafyllidis, T.: Dynamic problem for the deformation of saturated soil in the vicinity of a vibrating pile toe. In: Triantafyllidis, T. (ed.) Holistic Simulation of Geotechnical Installation Processes. LNACM, vol. 80, pp. 53–67. Springer, Heidelberg (2016). doi:10.1007/978-3-319-23159-4_3 CrossRefGoogle Scholar
- 8.Osinov, V.A.: Numerical modelling of the effective-stress evolution in saturated soil around a vibrating pile toe. In: Triantafyllidis, T. (ed.) Holistic Simulation of Geotechnical Installation Processes. LNACM, vol. 77, pp. 133–147. Springer, Heidelberg (2015). doi:10.1007/978-3-319-18170-7_7 CrossRefGoogle Scholar
- 11.Osinov, V.A., Chrisopoulos, S., Grandas-Tavera, C.: Vibration-induced stress changes in saturated soil: a high-cycle problem. In: Triantafyllidis, T. (ed.) Holistic Simulation of Geotechnical Installation Processes. LNACM, vol. 80, pp. 69–84. Springer, Heidelberg (2016). doi:10.1007/978-3-319-23159-4_4 CrossRefGoogle Scholar
- 12.Wichtmann, T.: Explicit accumulation model for non-cohesive soils under cyclic loading. Dissertation, Publications of the Institute of Soil Mechanics and Foundation Engineering, Ruhr-University Bochum, vol. 38 (2005)Google Scholar
- 13.Wichtmann, T., Private communication (2016)Google Scholar