o^= 109.8 kPa (15.93 psi) 

 ef= 2.12 

 tube 4 



increment 0-100 mm 

 0-4 in. 



e^<r^-^^ 



a^ = 37.9 kPa (5.49 psi) 

 ef= 2.21 

 tube 1 



increment 50-150 mm 

 2.6 in. 



o^ = 6.5 kPa (0.94 psi) 

 Cf = 2.28 

 tube 5 



increment 50-150 mm 

 2-6 in. 



Axial Strain in Percent 



Figure 14. Principal stress difference versus axial strain for 

 specimens consolidated isotropically to different 

 pressures and then sheared undrained by increasing 

 the axial stress, a^. Specimens from Box Core 4. 



25 



