A sand sample of cross-sectional area and 20 cm long was tested in a constant head permeameter. Under a head of 60 cm , the discharge was 120 ml in 6 min . The dry weight of sand used for the test was 1120 g , and Determine the seepage velocity.

Question

Question

This question was previously asked in

JKSSB JE (Civil) Official Paper (Held On: 19 Nov, 2023)

Attempt in App

Answer 1

Concept:

Seepage velocity is related to Darcy’s velocity (discharge velocity, v) and porosity (n):

Calculation:

Given Data:

Cross-sectional area (A) = 35 cm² = 35 × 10⁻⁴ m²
Length of specimen (L) = 20 cm = 0.2 m
Head (h) = 60 cm = 0.6 m
Discharge (Q) = 120 ml in 6 min
→ Q = 120 ml = 120 × 10⁻⁶ m³ in 6 min
→ Time = 6 min = 360 sec
→ Q/sec = (120 × 10⁻⁶) / 360 = 3.33 × 10⁻⁷ m³/sec
Dry weight of sand (Wd) = 1120 g = 1.12 kg
G (specific gravity) = 2.68

Discharge Velocity:

Volume of specimen = A × L =

Volume of voids:

Void volume = Total volume − Volume of solids = 2.821 x 10^-4 m³

Porosity:

Seepage Velocity:

Download Solution PDF