For a falling-head permeability test, the following values are given: ·         Length of specimen = 250 mm. ·         Area of soil specimen = 1200 mm2. ·         Area of standpipe = 50 mm2. ·         Head difference at time t = 0 = 600 mm. ·         Head difference at time t = 200 sec  = 300 mm. Determine the hydraulic conductivity of the soil in cm/sec.

2. Estimate the hydraulic conductivity (in cm/sec) of a poorly graded sand with the following characteristics: d100 = 0.425mm, d50= 0.3mm, d30 = 0.25mm, d10= 0.2mm, and do = 0.1mm. Show your work and circle your answer.

The hydraulic conductivity of a soil sample (3.4 x 10-4 cm/s) has been determined via a permeability test. The water temperature was 28°C at the time of experiment. What is the hydraulic conductivity of the sample at the standard temperature of 20°C?

4. A constant-head permeability test was conducted on a soil sample retained inside a cylindrical mould with a length of 40cm and an inner diameter of 18cm. In the test setup, a total of 55cm³ of water was collected during 3 hours and 15 minutes after reaching a constant-head difference of 60cm. a. Calculate the hydraulic conductivity (cm/s) of the soil sample. b. Estimate the type and permeability class of the soil. (Show all working calculations.)

(a) What is the pore water pressure at point A (kPa), and what is the effective stress at point A (kPa) ? (b) True or False: The effective strength at point A will increase if the groundwater table rises to the ground surface.

In a constant head permeability test in the laboratory as shown in Figure Q2(e), the data is recorded in Table Q2(b). The void ratio of the soil specimen is 0.46. Determine; (i) Hydraulic conductivity, k, of the soil in cm/sec. (ii) Discharge velocity in cm/sec.

Problem (2) The following data are for a variable head permeability test: Area of soil specimen=1200mm? Length of the soil specimen = 150mm Area of the standpipe = 1.3cm² At time t=0, head difference = 750mm At time t=2min, head difference = 500mm 2 %3D a) Find the hydraulic conductivity of the soil in cm/min.