A granular soil possesses saturated density of 20KN-m3- Its effective angle of Internal friction is 35- If the desired factor of safety is 1-5- the safe angle of slope for this soil- when seepage occurs at and parallel to the slope surface- will be

Effective angle of internal friction nbsp; ϕ ' = 35^∘ FOS = γ _sub z cos^2β tanϕγ _sat z cosβ sinβ ⇒ 1.5 = (20 10) z cos^2β tan35^∘20 z cosβ sinβ ⇒ ...

You visited us 1 times! Enjoying our articles? Unlock Full Access!

Byju's Answer

Other

Foundation Engineering

Infinite Slopes -Dry Cohesionless Soil

A granular so...

Question

A granular soil possesses saturated density of $20 K N / m^{3}$ . Its effective angle of Internal friction is $35^{\circ}$ . If the desired factor of safety is 1.5, the safe angle of slope for this soil, when seepage occurs at and parallel to the slope surface, will be

25^{\circ}

No worries! We‘ve got your back. Try BYJU‘S free classes today!

23^{\circ}

No worries! We‘ve got your back. Try BYJU‘S free classes today!

20^{\circ}

No worries! We‘ve got your back. Try BYJU‘S free classes today!

13^{\circ}

Right on! Give the BNAT exam to get a 100% scholarship for BYJUS courses

Open in App

Solution

The correct option is D $13^{\circ}$
Effective angle of internal friction

$ϕ^{'} = 35^{\circ}$

$F O S = \frac{γ_{s u b} z c o s^{2} β t a n ϕ}{γ_{s a t} z c o s β s i n β}$

$\Rightarrow 1.5 = \frac{(20 - 10) z c o s^{2} β t a n 35^{\circ}}{20 z c o s β s i n β}$

$\Rightarrow 1.5 = \frac{1 t a n 35^{\circ}}{2 t a n β}$

$t a n β = \frac{t a n 35^{\circ}}{3}$

$\Rightarrow β = {13.138}^{\circ} = 13^{\circ}$

Suggest Corrections

Similar questions

Q. An infinite slope is to be constructed in a soil. The effective stress strength parameters of the soil are c' = 0 and

ϕ = 30^{\circ}

, the saturated unit weight of the slope is 20

k N / m^{3}

and the unit weight of water is 10

k N / m^{3}

. Assuming that seepage is occurring parallel to the slope, the maximum slope angle for a factor of safety of 1.5 would be

Q. An infinite soil slope with an inclination of

35^{\circ}

is subjected to seepage parallel to its surface. The soil has C' =

100 k N / m^{2}

and

ϕ^{'} = 30^{\circ}

. Using the concept of mobilized cohesion and friction, at a factor of safety of 1.5 with respect to shear strength, the mobilized friction angle is

Q. A fully submerged infinite sandy slope has an inclination of

30^{\circ}

with the horizontal. The saturated unit weight and effective angle of internal friction of sand are

18 K N / m^{3}

and

38^{\circ}

, respectively. The unit weight of water is 10 KN/

m^{3}

. Assume that the seepage is parallel to the slope. Against shear failure of the slope, the factor of safety (round off to two decimal places) is

Q. A long slope is formed in a soil with shear strength parameter: c' = 0,

ϕ^{'} = 34^{\circ}

. Firm stratum lies below the slope and it is assumed that water table may occasionally rise to the surface, with seepage taking place parallel to the slope. Use

γ_{s a t} = 18 K N / m^{3}

and

γ_{w} = 10 K N / m^{3}

. The maximum slope angle (in degree) to ensure the factor of safety 1.5, assuming a potential failure surface parallel to the slope, would be

Q. The factor of safety of an infinite soil slope shown in the figure having the properties

c = 0, ϕ = 35^{\circ}, γ_{d r y} = 16 k N / m^{3} a n d γ_{s a t} = 20 K N / m^{3}

is approximately equal to

Join BYJU'S Learning Program

A granular soil possesses saturated density of 20KN/m3. Its effective angle of Internal friction is 35∘. If the desired factor of safety is 1.5, the safe angle of slope for this soil, when seepage occurs at and parallel to the slope surface, will be

The correct option is D 13∘Effective angle of internal friction ϕ′=35∘ FOS = γsub z cos2β tanϕγsat z cosβ sinβ ⇒1.5=(20−10) z cos2β tan35∘20 z cosβ sinβ ⇒1.5=1 tan35∘2 tanβ tanβ=tan35∘3 ⇒β=13.138∘=13∘

A granular soil possesses saturated density of $20 K N / m^{3}$ . Its effective angle of Internal friction is $35^{\circ}$ . If the desired factor of safety is 1.5, the safe angle of slope for this soil, when seepage occurs at and parallel to the slope surface, will be