CEPT University | Geotechnical Engineering Laboratory

The CEPT Geotechnical Engineering Laboratory works towards encouraging students towards practical research activities in the field of geotechnical engineering. It helps students in identifying the engineering behavior of geo-materials (soils and rocks) and by-products such as fly ash by determining different physical, chemical and geotechnical properties. The various tests conducted in the laboratory help in solving problems related to the sub-surface, comprising of different types of soils and rocks, which is the ultimate load bearing stratum. The soil tests which can be performed as per Indian Standards in the laboratory are listed below:

1. Geotechnical Engineering Lab Major Instruments

2. California Bearing Ratio Testing Machine The equipment is used for the laboratory determination of California Bearing Ratio (CBR) and Expansion Characteristics of undisturbed soil specimens obtained from the field and also of remoulded specimens of the soil compacted in the laboratory by static or dynamic compaction. It is also used for the selection of material and control of subgrade. The capacity of the unit is 50 kN (5000 kg), and the rate of travel of the lead screw is 1.5, 1.25 & 2.5 mm/min. It operates on 230 volts, 50 Hz and single-phase AC supply.

3. Vane Shear Test Apparatus The Vane Shear Test Apparatus provides a simple and rapid method for determining the undrained shear strength of soft and sensitive clays having shear strength less than 0.5 kgf/cm 2 for which specimens for triaxial or unconfined compression tests cannot be prepared. The test can be carried out both on undisturbed and remoulded specimens.

4. Consolidation Test Apparatus-3 Gang The apparatus is used to determine the consolidation characteristics of soils of low permeability. Consolidation of clay deposits leads to distress in buildings, such as cracks and failures. Consolidation is the reduction of the volume of soil due to the expulsion of water from its pore space caused by sustained loading.

5. Lab Permeability Test Apparatus The equipment is used for laboratory determination of permeability of soils using a constant or variable hydraulic head. It is used for soils with a coefficient of permeability in the range of 10 -3 to 10 -7 cm/s. It consists of a permeability mould, which is a metallic cylinder of volume of 1000ml with 100mm internal diameter and 127.3mm inside height, and a standpipe board.

6. Permeability Test Apparatus for Geotextile This apparatus is used for determining the hydraulic conductivity (water permeability) of Geotextiles in terms of permeability under standard testing conditions, in the uncompressed state. It consists of an overhead and discharge collection tank with a capacity of 100 liters.

7. Direct Shear Test Apparatus The equipment is used to provide information about the ultimate shear resistance and enable the user to compute the angle of shearing resistance and cohesion intercept of soil samples. The apparatus also provides a facility for measuring the residual strength apart from peak shear strength. The result obtained is used to determine the bearing capacity of soils and in stability calculations of earth slopes. The apparatus has a load capacity of 8 kgf/cm 2 when loads are applied through the lever mechanism. The instrument has an arrangement for applying twelve rates of strain from 0.0002mm/min to 1.25mm/min.

8. Soil pH Meter This apparatus is used to measure the pH of different kinds of soils. The range is 3 to 8 pH and resolution is +/- 0.2 pH. The operating temperature is 5-50 °C.

9. Triaxial Test Apparatus This apparatus is used for shear strength testing on soil specimens. It allows control of specimen stresses in perpendicular directions. It can measure the total and effective stress parameters and can be conducted on any type of soil. It consists of triaxial cells, 38mm and 50mm dia.

10. Air Water Constant Pressure This device is a constant air-water pressure system for the tri-axial test apparatus. The apparatus is designed to provide a confining pressure of up to 10.5 kg/cm 2 .

11. Plate Load Testing Apparatus The equipment is used for conducting a load test on soil to evaluate the bearing capacity and the settlement from the data collected. The loading is done by a 500 kN hydraulic jack consisting of a cylinder and a ram of travel 50mm.

12. Soil Sample Extractor The instrument is used for sample preparation. It is specifically designed to overcome the difficulties faced in extracting soil specimens from longer sampling tubes.

13. Standard Cone Penetrometer This apparatus is used to conduct penetration tests of soil. It provides valuable information about granular and cohesive soils. The test is based on the relationship between moisture content and the penetration of the cone into the soil sample.

14. Swelling Pressure Test Apparatus This apparatus is used for measuring the swelling pressure, made by soil specimens to different desired densities at known moisture content. It has one loading unit hand operated 5000 kg capacity with two rates of travel.