The soil mechanics laboratory also has equipment for testing soil permeability characteristics. The Constant Head Apparatus is used specifically for soils with high permeability
such as Sands and Gravel. The permeability characteristics of soils is required in many construction projects where drainage is an important feature. These projects include,
landfill site design, earth dam and sheet-pile wall design, contaminated land investigations, and groundwater lowering feasibility studies.
Direct Shear Test
Direct shear test for cohesionless and cohesive soils can conducted using a motorised and manual mode shearbox
equipment. Soil shear strength parameters are important
for stability as every physical structure will impose some load on the soil that supports the foundations. The stress set-up in the soil may cause soil deformation. This
failure mechanism is known as shear failure and occurs when shear stresses set up in the soil mass exceeds the maximum shear resistance that the soil or rock can
Computerised California Bearing Ratio (CBR)
This test was developed in California, USA, for estimating the bearing value of highway subbase and
subgrades, hence its name. The test provides data with respect to the performance
of soil for subsequent use in the civil engineering projects such as road construction.
Using Consolidation Apparatus (Oedometer), evaluation of Consolidation Characteristics of soils of low permeability can be conducted. The data from this test together with
classification data and the knowledge of the soils loading history enable estimates to be made of the behaviour of the foundation under load.
Soil Compaction Test
Most civil engineering projects require the use of soil as filling material. It is necessary for the soil to be compacted to a dense state so that satisfactory engineering
properties can be acquired. The soil mechanics laboratory has equipment for conducting this
The compaction tests will shed light on the following mechanical properties
of a soil: