Department of Civil Engineering, IIT Guwahati

Geotechnical Engineering

Faculty-In-Charge

Dr. Sreedeep S.

Geotechmical Engineering Laboratory
Department of Civil Engineering
Indian Institute of Technology
Guwahati 781039 (Assam)

Phone : + 91 361 2582414
Fax : + 91 361 2582440
Email : srees@iitg.ernet.in

Facilities

Soil Characterization

::Physical Properties::

Sieve Analysis
Hydrometer
Atterberg Limits
Specific surface area (Give link) to two methods
EGME method
Desiccators method

::Compaction::

Standard Procter Test
Proctor Needle (Manual)
Dial Gauge Penetrometer

::Permeability::

Field Setup (Guelph Permeameter)

It is a constant-head device, which operates on the Mariotte siphon principle and provides a quick and simple method for simultaneously determining field saturated hydraulic conductivity, matric flux potential, the a parameter and soil sorptivity in the field.

Constant and Variable head Lab Set up

It is used for falling permeability test. It provides the k value of soil that is nothing but the permeability of soil. Darcy’s formula is used to calculate permeability of soil.

::Compressibility and swelling::

Consolidation set up

This setup is used to determine the pressure void ratio, the compression index Cc and coefficient of consolidation Cv of soil. It allows only one dimensional consolidation of soil and it obeys Terzaghi’s one dimensional consolidation theory.

::Swell test set up::

It is opposite to consolidation test. It provides the unloading behavior of soil that is mainly over consolidated state of soil.

::Ordinary Tri-axial::

This setup is used to determine the strength parameters (C and Ф) and the deformation nature of soil. It can perform both the drained and undrained test. so this setup is used for CD, CU, UU, UD test.

::Direct Shear::

Big Sample Size

This setup used proved soil strength parameters; it is mainly used for cohesion less soil. This setup is mainly of two types one is big sample size and another one is small sample size. In both the cases the working principles are same. By using Mohr- Coloumb formula the strength parameters (C and Ф) are determined.

Small Sample Size

This is small sample size direct shear test set up. It’s working principle is quite similar to the previous one (Big Sample Size).

::Unconfined Compressive Strength::

This test is quick and it determines the undrained shear strength of soil. Mainly it is used for remoulded cohesive soil. It provides most conservative shear strength of the soil.

::Vane Shear test::

It provides undrained strength of undisturbed soil sample. So it is quite useful for very sensitive clay which is really difficult to collect in undisturbed state from the field. It is a slow test.

::Rock testing (Compression Testing Machine )::

::Rock testing (Brazialian Test Apparatus)::

It measures the tensile strength of rock. The machine consists of two parts a) a loading frame of 100KN capacity and b) One Brazilian Attachment for 'NX' core size specimen with thickness half the diameter. It is made with stainless steel and it can be used with GCTS unconfined, triaxial and point load test frame.

::Rock testing (Point Load Test Apparatus)::

It is used to perform an index test for the strength classification of rock materials. It provides the point load strength index and rock anisotropy index. Rock specimens in the form of either core (the diametrical and axial tests), cut blocks (the block tests), or irregular lump test are broken by the application of load through a pair of conical platens.

::California bearing ratio test::

This test is used to evaluate mainly the subgrade strength of roads and flexible pavements from these test results thickness of pavement are determined. This test may be soaked or unsoaked. The penetration resistance of the test materials are noted when depth of penetrations of metal plunger is 2.5mm and 5mm.

::Block vibration test::

It provides dynamic properties of soil which is used in design of machine foundation. The oscillator and motor assembly can produce both vertical and horizontal vibration. The coefficient of elastic uniform compression Cu is determined from the calculated amplitude of vibration.