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GATE 2020 CE (CE2) – Question 44

Geotechnical Engineering · Permeability and seepage: flow nets, uplift pressure, piping, capillarity · 2 marks · Multiple choice

Permeability measurements for the two layers are shown. Find equivalent horizontal/vertical permeability ratio.

Diagram for GATE 2020 CE (CE2) question 44
  1. 37.29
  2. 80.20
  3. 68.25
  4. 0.03

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Correct answer: (A) 37.29

Explanation

Horizontal equivalent permeability is the thickness-weighted mean: $k_h=[3(0.0044)+4(0.6)]/7=0.344743$ m/s. Vertical equivalent is harmonic: $k_v=7/[3/0.004+4/0.55]=0.00924370$ m/s. Ratio is **37.29, A**.