Choose the correct answer and justify it with a reasonable explanation. (i) Quic
ID: 1711345 • Letter: C
Question
Choose the correct answer and justify it with a reasonable explanation. (i) Quick sand conditions occur only in sands and not in clays. (ii) The pore-water pressure along the upper-most flow line (i.e., phreatic surface) (see Figure 2) in a homogeneous earth dam is equal to atmospheric pressure (i.e., pore-water pressure is equal to zero.) (iii) The water content of a compacted sample at dry of optimum conditions is lower than the sample compacted at wet of optimum conditions). The coefficient of permeability of a clay sample compacted at dry of optimum conditions is higher than the coefficient of permeability of the same clay compacted at wet of optimum conditions. (iv) When the soil is fully saturated, the water content can be determined using the relationship: w = n/(1 - n)G_sExplanation / Answer
1) T
quick sand condition occurs only in fine sands and silt as the name itself indicates quick sand condition.
2) T
as it is a homogenous earth dam atmospheric pressure is equal to the pore water pressure along the upper most flow line.
3) T
in soil structure , in dry side of optimum permeability is more. in wet side of optimum permeability is less.
soils compacted on wet of optimum will have more pore water pressurethan dry of optimum.
4) F