Answer:
Step-by-step explanation:
The difference between Consolidated Undrained (CU) triaxial test, Consolidated drained (CD) triaxial test and Unconsolidated Undrained (UU) triaxial test is as follows;
Consolidated Undrained (CU) Triaxial Test:
In a Consolidated Undrained (CU) triaxial test, the soil specimen is first consolidated under an applied vertical stress before shearing is initiated.
During the test, no drainage is allowed to occur, meaning the pore water pressure is not measured or controlled.
The test is performed under undrained conditions, where the soil is not allowed to drain or dissipate excess pore water pressure.
CU triaxial tests are typically used to determine the undrained shear strength and stress-strain behavior of cohesive soils.
The test provides information about the soil's shear strength and its behavior under rapid loading conditions.
Consolidated Drained (CD) Triaxial Test:
In a Consolidated Drained (CD) triaxial test, the soil specimen is first consolidated under an applied vertical stress before shearing is initiated.
During the test, drainage is allowed to occur, meaning the pore water pressure is measured and controlled.
The test is performed under drained conditions, where the excess pore water pressure is allowed to dissipate during the test.
CD triaxial tests are typically used to determine the drained shear strength and stress-strain behavior of soils.
The test provides information about the soil's shear strength and its behavior under slow or gradual loading conditions.
Unconsolidated Undrained (UU) Triaxial Test:
In an Unconsolidated Undrained (UU) triaxial test, the soil specimen is not consolidated before shearing is initiated.
During the test, no drainage is allowed to occur, meaning the pore water pressure is not measured or controlled.
The test is performed under undrained conditions, where the soil is not allowed to drain or dissipate excess pore water pressure.
UU triaxial tests are typically used to determine the undrained shear strength and stress-strain behavior of cohesionless soils.
The test provides information about the soil's shear strength and its behavior under rapid loading conditions.
In summary, the key differences between CU, CD, and UU triaxial tests lie in the consolidation process and the drainage conditions during the test. CU and CD tests involve consolidation before shearing, but differ in whether drainage is allowed or not, while UU tests are performed without prior consolidation.