Coupled Effect of Suction Stress and Unit Weight on the Active Earth Pressure of Unsaturated Backfills

Acknowledgments

Notation

C′

total effective cohesive force;

c′

effective cohesion;

C_a

tangential adhesive force;

c_a

unit adhesion at the soil–wall interface;

D

constant of integration;

d_w

depth of water table below the toe of wall;

e

void ratio of soils;

$F_{{\sigma }^s}$

force due to suction stress;

f₁, f₂, f₃, f₄

dimensionless functions;

G_s

specific gravity of soils;

H

matric flux potential;

h

point of application of magnitude of active pressure;

K

hydraulic conductivity function;

K_a

total active thrust coefficient;

k_e

horizontal seismic acceleration coefficient;

k_s

saturated hydraulic conductivity;

L

height of the wall;

P_a

magnitude of active pressure;

P_a

maximum magnitude of active pressure;

p_a

active soil pressure;

Q

surcharge pressure on the ground surface;

q

infiltration rate;

R

effective reactive force;

S

degree of saturation;

U_a

pore air force;

u_a

pore air pressure;

v

variable of integration;

W

weight of the soil wedge;

y

distance above water table;

z

depth below ground surface;

z_t

depth of tensile zone;

β and n

fitting parameters;

δ

friction angle at the soil–wall interface;

γ

bulk unit weight of soil;

γ_s

saturated unit weight of soil;

γ_w

unit weight of water;

η

inclination of the slip surface;

λ

inclination of wall surface in contact with soil;

ψ_t

total hydraulic potential (m);

ψ_m

matric potential (m);

ψ_p

pressure potential (m);

ψ_y

gravitational potential;

σ

total stress;

σ′

effective stress;

σ^s

suction stress;

ϕ′

effective angle of internal friction; and

τ

shear strength of soil.

References