Reference no: EM132704849

The purpose of this assignment is to provide context for the models of soil behaviour discussed within the lectures, through the application to actual laboratory data.

Data sets from the laboratory testing of a kaolinite clay accompany this assignment. The laboratory testing conducted on this material include:
• Consolidated Drained (CD) Triaxial Compression tests
Three tests, each with a preconsolidation stress (p0') of 200 kPa, and tested at effective confining stresses (pi') of 50, 100 and 200 kPa. This includes the data recorded during consolidation.
• Consolidated Undrained (CU) Triaxial Compression tests
Four tests, each with a preconsolidation stress (po') of 200 kPa, and tested at effective confining stresses (pi') of 50, 100, 200 and 300 kPa. This includes the data recorded during consolidation.
• Unconsolidated Undrained (UU) Triaxial Compression tests
Two tests, each with a preconsolidation stress (pc,') of 200 kPa (after which it was unloaded), and then tested at total confining stresses (pi) of 100 and 300 kPa.
• Consolidated Drained Direct Shear (DS) tests
Seven tests, three of which had a preconsolidation stress (σ'v0) of 200 kPa, and tested at vertical effective stresses (σ'v) of 50, 100 and 200 kPa; the remaining four had a low preconsolidation stress (σ'v0,), and were tested at vertical effective stresses (σ'v) of 50, 100, 200 and 300 kPa. This includes the data recorded during consolidation.

1. For the CD and CU Triaxial Compression tests:
a) Process the laboratory data to develop the relevant plots in the p-q, v-p', q-ε, μ-ε (CU only), v,-ε (CD only) spaces. (remember to include relevant consolidation portions of tests)
b) Evaluate unload-reload lines (URL) and normal consolidation line(s) (NCL), and the parameter required to describe them.
c) Evaluate yield and critical state within the data sets, and discuss implications for strength. Identify these states in all relevant plots.
d) Estimate relevant moduli and pore pressure parameters for stress states at which it is reasonable to approximate as being elastic. Be explicit in the limits of the data being used to evaluate these parameters, and the rationale for those limits.

2. For the UU Compression tests:
a) Process the laboratory data to develop the relevant plots in the p-q, v-p q-μ , μ-ε spaces.
b) Identify the limitations of the interpretation of these test results compared to those from the CD and CU laboratory tests.

3. For the DS tests:
a) Evaluate unload-reload lines (URL) and normal consolidation line(s) (NCL), and the parameter required to describe them for the consolidation of the specimens
b) Evaluate peak and residual strengths in terms of effective strength parameters, include Mohr's circle plots.
c) Compare the strength results obtained from the DS test to those from the triaxial testing.

Attachment:- CD Triaxial test.rar