» Soil Triaxial Shear Test
Soil Triaxial Shear Test
A triaxial shear test is a method to
measure the Engineering properties of many deformable solids, soil, sand,
The principle behind a triaxial shear test is that the stress applied in
the vertical direction can be different than the stress applied in the
horizontal directions. This produces a non-hydrostatic stress state, which
contains shear stress. The triaxial testing apparatus is designed to measure
that limit. The stress on the platens is increased until the material in the
cylinder fails and forms sliding regions within itself, known as shear
bands. A motion where a material is deformed under shear stress is known as
- Triaxial test can be used for obtaining Angle of repose
- Effective stress
- Pore water pressure
- Shear strength
- Overburden pressure
- Soil classification
- Shear wave
- Lateral earth pressure.
- CD - Consolidated Drained Test
- CU-BAR - Consolidated Undrained Test with pore water pressure
- UU - Unconsolidated Undrained test
- In CD Test : (Consolidated Drained Test), we measure the
change in volume of sample at the each stage of shearing.
- In CU -Bar Test : (consolidated Undrained test), we measure
the pore water pressure of sample at the each stage of shearing.
- In UU Test : (Unconsolidated Undrained test), we measure only
load and deformation of sample at the each stage of shearing.
In case of consolidated test, the test is then carried out by a first stage
of applying confining pressure in the pressure chamber and allowing drainage
of the sample. This stage corresponds to the consolidation of the sample.
The deviatoric load is then applied through the vertical axis. The
deviatoric stress is indeed the difference between the vertical stress and
the confining stress. During the deviatoric compression, the drainage valves
can be open (CD) or closed (CU & UU).
Triaxial test data, in general, include evolution of axial and volumetric
strain, deviatoric and isotropic stress, and pore pressure evolution. From
the triaxial test results, it is possible to deduce the shear strength
parameters, namely friction angle, cohesion, dilatancy angle and the other
A thirty different speed motorized load frame with
capacity 50 kn.
A complete source of calculations of UU, CD, CU Bar
triaxial test. Has option for manual as well as automatic recording of data.
Consolidation curves and evaluates t100 and calculates strain rates
depending upon the drainage condition. Stress strain curves after every
curves.Plots pore water pressure and volumetric strain vs. effective stress
ratio vs. axial strain. p-q plot, Mohr columb graph.