Objective

To determine the transmissivity of a highly permeable soil in an aquifer.

Apparatus used:

Permeameter with its accessories, Standard soil specimen, De-aired water, Balance to weigh up to 1 gm, I.S sieves 4.75 mm and 2 mm, mixing pan, Stop watch, Measuring jar, Meter scale, Thermometer, Container for water.

Description Transmissivity: Transmissivity (or hydraulic conductivity) refers to the ease with which water can flow through a soil. This property is necessary for the calculation of seepage through earth dams or under sheet pile walls.

STEP  1 

Measure the internal diameter of the cylindrical mould.

Diameter of the cylindrical mould is = 7.3 cm.

Diameter of the cylindrical mould is = 9.83 cm.

Diameter of the cylindrical mould is = 10 cm.

STEP  2 

Fill the mould with sample soil and compact it to a density which may be representative of the field conditions.

STEP  3 

Trim the soil which is poured into the mould to the dimensions similar to that of the mould.

STEP  4 

Attach the mould with two filter discs at the top and the bottom.

Filter Disks
(Highly Permeable)

Inlet

Manometers

Outlet

STEP  5 

The inlet of the instrument is connected with a constant head water reservoir and water is released into the soil sample.

Fixed Time Interval = 60 sec

Fixed Time Interval = 132 sec

Fixed Time Interval = 300 sec

Observations:

Length of specimen L = cm

Diameter of specimen = cm

Area of specimen = cm²

Time (t)= sec

Discharge (Q)= cm³

Height of Water (ΔH) = cm³

Temperature (℃) = ℃

Aquifer thickness (D) = cm

Result:

Transmissivity of a highly permeable soil in an aquifer = 0.069 cm²/sec

Transmissivity of a highly permeable soil in an aquifer = 0.07 cm²/sec

Transmissivity of a highly permeable soil in an aquifer = 0.042 cm²/sec