Question

A plate load test is carried out on a 300 mm $\times$ 300 mm plate placed at 2 m below the ground level to determine the bearing capacity of a 2 m $\times$ 2 m footing placed at same depth of 2 m on a homogeneous sand deposit extending 10 m below ground. The ground water table is 3 m below the ground level. Which of the following factors does not require a correction to the bearing capacity determined based on the load test?

• A. Absence of the overburden pressure during the test
• B. Size of the plate is much smaller than the footing size
  
• C. influence of the ground water table
• D. settlement is recorded only over a limited period of one or two days

Answer 1

The correct option is D settlement is recorded only over a limited period of one or two days


In granular soil (sand) bearing capacity increases with the size of foundation.
As the size of plate is smaller than the footing size so correction is required.
Ultimate bearing capacity of footing

$q_{uf}=q_{up}\left(\frac{B_f}{B_p}\right)$

where,

$q_{up}$ = ultimate bearing capacity of plate

$B_f$ = width of foundation

$B_p$ = width of plate

Depth of water table below the foundation is less than 2 times width of foundation.
so, correction for water table is required.
In sand, immediate settlement occurs which take short duration to complete.
Hence no correction is required for settlement recorded only over a limited period of one or two days.