Question

In case of non-cohesive soils such as sand and gravel ___________ reduction in allowable bearing capacity of the soil should be applied, if the water table is situated below or near the bearing surface of the soil.

(a) 20%

(b) 50%

(c) 80%

(d) 100%

This question was addressed to me in class test.

My query is from Ground Techniques in division Site Investigation and Ground Techniques of Construction & Building Materials

Answer 1

Correct choice is (b) 50%

To explain I would say: However, if water table is situated below the bearing surface of the soil at a depth equal to the width of the foundation trench, no such reduction should be applied. But in this case, 50% reduction is applied. For intermediate depths of the water table, the proportion and percentage reduction should be applied.