Table 1 Summary of recent studies for numerical modeling of sensitive clay landslides
Name of the researcher | Constitutive model with strain softening | Numerical framework for large deformation | Type of sensitive clay landslide | Triggering factor | Contribution on prediction of landslides | Limitations |
|---|---|---|---|---|---|---|
1. Locat et al. (2013) | NGI-ANISOFT constitutive soil model with linear strain-softening | BIFURC | Spread | Erosion | • Steeper slopes with high Koi, slope with low stiffness, low remolded shear strength, high rate of strain-softening are more susceptible to large progressive failure • Spread occurs in highly over-consolidated clays | • Linear strain-softening • Strain rate effect and depth-wise variation of shear strength not considered • Rheological property of remolded clay not considered • Homogeneous slope • No demonstration for dislocation of soil mass or formation of horst and grabens |
2. Dey et al. (2015) | Von-mises with exponential strain-softening | Coupled Eulerian–Lagrangian | Spread | Erosion | • Illustration for the formation of horst and grabens • Steeper slope, higher sensitivity, lower \({\updelta }_{\mathrm{ld}}\) are more likely to cause large progressive failure • Increase in \({\updelta }_{\mathrm{ld}}\), St, HSt, and decrease in \({\mathrm{s}}_{\mathrm{u}}\) of the crust changes the failure pattern from spread to flow slide | • Strain rate effect and depth-wise variation of shear strength not considered • Rheological property of remolded clay not considered |
Combined | Erosion + surcharge load | • Instantaneous velocity and surcharge load accelerate the propagation of the shear band, causing progressive failure | ||||
Von-mises with linear strain-softening | Implicit & Random material point method | Retrogressive | Gravity load | • Failure surface forms in the weakest soil layer • Shear band propagation is governed by residual strength • For St = 5 the failure is translational forming horst and grabens • Spatial variability alters landslide initiation and propagation | • Linear strain-softening • Strain rate effect and depth-wise variation of shear strength not considered • Rheological property of remolded clay not considered • Homogenous slope • No clarification on the failure mechanism concerning failure type | |
Bingham-Tresca with linear strain-softening | Particle finite element method | Flow slide | Erosion | • Illustration for the multiple rotational slides • Ignoring the viscosity of the remolded clay over-estimates the retrogression and runout • Minimum sensitivity is required to initiate flow slide • Higher sensitivity increases the retrogression and runout • Effect of viscosity is higher for highly sensitive clays • Flow slides can result in horst and grabens | • Linear strain-softening • Depth-wise variation of shear strength not considered • Homogeneous slope | |
6. Tran and Solowski (2019) | Tresca with exponential strain-softening with strain rate effect | Material point method | Spread | Erosion | • Sensitive clay slope with St > 25 and \({\uptau }_{\mathrm{ld}}\)<2 kPa are susceptible to large progressive failure • Strain rate has a significant impact on the propagation of progressive failure | • Rheological property of remolded clay not considered |
7. Islam et al. (2019) | Tresca with exponential strain-softening | Coupled Eulerian–Lagrangian | Flow slide | Seismic loading | • Steeper and inclined slopes have increased retrogression and runout • Upslope surcharge load increases retrogression and runout • Increased thickness of highly sensitive clay changes the failure pattern from spread to flow slide • Increased remolding energy decreases retrogression • A combination of rotational flow slide and translational spread can be possible in a large retrogressive failure | • Strain rate effect and depth-wise variation of shear strength not considered • Rheological property of remolded clay not considered • Assumption of static stress–strain behavior of soil under dynamic loading |
Tresca with exponential strain-softening and rate effect | Coupled Eulerian–Lagrangian | Flow slide and Spread | Erosion | • The occurrence of flow slide or spread depends on the movement of liquified debris, brittleness of soil, lateral earth pressure • Lower strain rate increases the mobility of the debris leading to a large flow slide | • No conclusive relationship between remolding energy and retrogression • Increasing stability number did not result in increasing retrogression • Some estimated input parameters (δ95, β, η) for the constitutive model had high uncertainty | |
Strain-softening Tresca Model | Smoothed particle finite element method (SPFEM) | Retrogressive failure | Erosion | • Suitability of SPFM for retrogressive failure • Increased softening modulus increases retrogression and runout | • Linear strain-softening • Strain rate effect on shear strength not considered • Rheological property of remolded clay not considered • Homogenous slope | |
10. Shan et al. 2021 | Elastoviscoplastic model | Re-meshing and interpolation technique with small strain (RITSS) | Retrogressive failure leading to spread | Decreasing shear strength of soil | • Increased St, decreased \({\uptau }_{\mathrm{ld}}\), decreased viscosity of the remolded clay and increased riverbed width increases the retrogression | • Linear strain-softening • Homogenous slope |