Analysis of triaxial test data

ENGINEERING GEOTECHNICAL Assignment 

Please complete questions with all necessary data and graphs required.  Extended answers please provide all calculations required.  image attached Staged Test (analysis of trixial test data) 

 

Analysis of triaxial test data

 

The results of a Consolidated Undrained (CU) triaxial test on clay soil sample are given below. Specific gravity of the soil is 2.60.

 

a) Determine initial sample wet density (𝜌𝑏), water content (w) and void ratio (e).

b) Calculate the elastic modulus of the soil.

c) Determine undrained and effective stress shear strength parameters.

d) Calculate the coefficient of volume change (𝑚𝑣).

 

Extended answers

a) The sample tested above was taken from a depth of 5.5 m from the ground surface. The ground profile consists of a 2.5 m sand (unit weight 18.6 kN/m3) layer underlain by a 4 m thick clay deposit. Water table is located 7 m below the ground surface. What is the in-situ shear strength of the point where sample was located?

 

b) If a fill is placed at the ground surface which exerts a surcharge of 20 kN/m2, what will be the impact on shear strength at the original location of the sample?

Explain giving reasons.

 

c) Why is it important to evaluate total stress shear strength parameters as well as effective stress parameters? How are they applicable to different conditions in the field?