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Foundation Engineering

Plate Load Test

Examine the t...

Question

Examine the test arrangement and the soil properties given below

$γ_{s a t}$ = 18 kN/ $m^{3}$
$ϕ$ = $35^{o}$
c = 0 kPa
$γ_{w}$ = 10 kN/ $m^{3}$
$N_{γ}$ = 40
Angle of friction, ( $δ$ ) = $24^{o}$
Earth pressure cofficient, (K) = 1.5

The maximum pressure that can be applied with a factor a safety of 3 through the concrete block, ensuring no bearing capacity failure in soil using Terzaghi's bearing capacity equation without considering the shape factor, depth factor and inclination factor is

26.67 kPa

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60kPa

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90 kPa

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120 kPa

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Solution

The correct option is B 60kPa
Size of concrete block
= 1.5 m $\times$ 1.0 m (L $\times$ B)
Neglecting shape factor, depth factor and inclination factor
$q_{u} = C N_{c} + q N_{q} + \frac{1}{2} γ^{'} B N_{γ}$

Soil is saturated dense and. so,
C = 0
At the surface,
q = 0

$q_{u} = \frac{1}{2} γ_{s u b}^{'} B N_{γ}$

=0.5 $\times$ (18- 10) $\times$ 1 $\times$ 40
= 160 kPa

$q_{s a f e} = \frac{q_{u}}{F O S}$

$= \frac{160}{3} = 53.33 k P a$

Nearby answer is 60 kPa. Hence option is b.

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