Factor of Safety Reduction Factors for Accounting for Progressive Failure for Earthen Levees with Underlying Thin Layers of Sensitive Soils

Table 2

Material parameters used in finite element analyses.

Material	Soil model	𝐸ref (kPa)	𝑐ref (kPa)	𝜑 (°)	𝑘ℎ (m/day)	𝑘𝜈 (m/day)
Embankment	Mohr-Coulomb	2215	43.1	0	0.008	0.002
Foundation clay	Mohr-Coulomb	2299	Varied: 35.9–47.8	0	0.08	0.02
Thin layer material	Mohr-Coulomb^a	Varied^b	Varied^b	0	0.08	0.02

aA stepwise strength reduction scheme was used in conjunction with the Mohr-Coulomb model to capture strain-softening behavior. See the description of this method in Section 2.2.
^bThese strengths were varied throughout the parametric analysis. See Table 3 and Figures 3 and 4 for strengths used within range.
Unit weights used in finite element modeling are equal to those used in limit equilibrium modeling. Refer to Table 1 for values.