2. Direct shear tests were performed on sandy clay samples. The specimen cross section was 60

mm x 60 mm and the proving ring constant is 11.1 N per division. Test results are given in the

following table. Determine graphically the shear strength parameters (ignore the effect of changing

sheared areas during test). Would failure occur on a plane within this soil at a point where the normal

stress is 300 kN/m² and the corresponding shear stress is 115 kN/m²?

Test No. Normal Force Proving Ring Reading at failure

(N)

(N)

360

23.4

720

34.2

1080

46.8

1440

57.6

1234

4