GATE Civil Engineering (CE) 2019 Shift 1 Solved Paper

Question : 43 of 65

Marks: +1, -0

3 {m} × 3 {m}

square precast reinforced concrete segments to be installed by pushing them through an existing railway embankment for making an underpass as shown in the figure. A reaction arrangement using precast PCC blocks placed on the ground is to be made for the jacks.

At each stage, the jacks are required to apply a force of

1875 {kN}

to push the segment. The jacks will react against the rigid steel plate placed against the reaction arrangement. The footprint area of reaction arrangement on natural ground are:

{c}=17 {kPa} ; φ=25^{∘}

and

γ=18{kN} {/} {m}^{3}

. Assuming that the reaction arrangement has rough interface and has the same properties that of soil, the factor of safety (round off to 1 decimal place) against shear failure is

Your Answer:

Validate

Solution:

FOS against shear failure

=\;{\;\text " Strength "\;}/{\;\text " Applied load "\;}=\;{(c+σ \tan φ) A}/{P}

σ=\;{N}/{A}=\;{4 {k N}/{m^{2}} × 37.5 m^{2} × 7.5 {m}}/{37.5 {m}^{2}}

=24 × 7.5 {kN} {/} {m}^{2}

⇒ \;\; FOS=\;{(c+σ \tan φ) A}/{P}

=\;{(17+24 × 7.5 × \tan 25^{∘}) × 37.5}/{1875}

FOS=2.0187

Go to Question:

Prev Question

Next Question