Predicting Resilient Modulus of Unsaturated Subgrade Soils Considering Effects of Water Content, Temperature, and Hydraulic Hysteresis

Acknowledgments

Notation

a_FX, n_FX, m_FX

Fredlund and Xing (1994) SWRC model’s fitting parameters;

k_h

fitting parameter considering the effect of hydraulic hysteresis [Eq. (23)];

k_m

fitting parameter considering the changes in moisture content [Eq. (2)];

k₁, k₂, k₃

MEPDG model fitting parameters [Eq. (1)];

l₁, l₂

Yang et al. (2005) model fitting parameters [Eq. (3)];

m

SWRC fitting parameters reflecting adsorption strength;

m_M

fitting parameter considering the effect of capillary water content [Eq. (11)];

M_Mc

maximum resilient modulus due to capillary mechanism;

M_Md

maximum resilient modulus at dry state;

M_R

resilient modulus;

(M_R)_D

resilient modulus along the main drying path;

(M_R)_W

resilient modulus along the main wetting path;

M_R,OPT

resilience modulus at optimum moisture content;

M_R,SAT

resilient modulus at saturated condition;

M_w

molar volume of water;

m₁, m₂, m₃

Liang et al. (2008) model fitting parameters [Eq. (4)];

n

SWRC fitting parameters related to soil particle size and distribution;

n₁, n₂, n₃, n₄

Cary and Zapata (2011) model fitting parameters [Eq. (5)];

P_a

atmospheric pressure;

R

universal gas constant;

R²

coefficient of determination;

RH

relative humidity;

RMSE

root mean square error;

S

degree of saturation;

S_OPT

degree of saturation at optimum moisture content;

T

temperature;

Δh_T

enthalpy of immersion per unit area;

$\mathrm{\Delta }{h}_{T_r}$

enthalpy of immersion per unit area at the reference temperature;

Δu_w‐sat

buildup of pore-water pressure under saturated condition;

α

SWRC fitting parameters related to soil air entry value;

α′

soil-water contact angle;

β, ${\beta }_{T_r}$

regression parameters of Eq. (18);

ɛ_r

recoverable strain;

κ

fitting parameter considering the effect of changes in deviatoric stress [Eq. (15)];

θ

volumetric water content;

θ_a,max

maximum adsorption water content;

θ_b

bulk stress;

θ_net

net bulk stress;

θ_s

saturated volumetric water content;

ξ

Han and Vanapalli (2015) model fitting parameter [Eq. (6)];

σ_d

deviatoric stress;

τ_oct

octahedral shear stress;

χ

Bishop’s effective stress parameter;

ψ

suction;

ψ_c

mean cavitation pressure;

ψ_D

suction along main wetting path;

ψ_max

maximum suction;

ψ_OPT

suction at optimum moisture content;

${\psi }_{T_r}$

reference temperature; and

ψ_W

suction along main drying path.

References