Civil Engineering - Soil Mechanics and Foundation Engineering - Discussion

Stability no is defined as the ration of cohesive force to the (product of Factor of saftey*safe hight of retaining wall*unit weight of soil: mathematically it can be expressed as:

Sn=C/F*H*Y.

where
Sn= stability no,
C= cohesive force,
F= Factor of safety,
Y= unit weight.

Pluging values given in question in the above formula.

Sn = 0.05
C = 1.5 T/m^3
Y = 2 t/m^3
F = FOS=1.5
Safe Hight = ?.

H = 1.5/(0.05*2*1.5)
H = 10m is the safe height.

H = (cohesive force)/(density of soil*factor of safety*stability factor).

Safe Height of a slope,

H = (density of the soil* Factor of safety (F) * stability factor)/ Cohesive force (c).

Sn = (Cm)/(yH).

Safe height = (Sn*y)/(Cm).

H = c/Sn*y*f.

Stability factor (Sn) = Mobilized cohesive force/(Density of soil x Safe height of slope).

Sn = Cm/(γ*H) = C/(Fc*γ*H).

therefore H = C/(Fc*γ*Sn) = 1.5/(1.5*2*0.05) = 10 m.

Sn = Cm/yH = C/FyH,
H = C/FySn = 1.5/(1.5 * 2 * .05) = 10m.

Taylor's stability number Sn is given by which one of the following expressions? ( c is the cohesion; Fc is the factor of safety with respect to cohesion; γ is the unit weight of the soil; H is the height of the slope)

Sn = C/(FdH) or H= C/(FdSn).
H=1.5/(1.5*2*0.05) = 100/10 = 10 m.
WHERE Sn= Stability factor =0.05,
C= Cohesive force =1.5,
F= factor of safety= 1.5,
d= soil unit weight = 2.
H= height of embankment= ? required.