Refer to Figure P3.3. Vane shear tests were conducted in the clay layer. The vane (tapered) dimensions were 63.5 mm (d) × 127 mm (h), i_B = i_T = 45° (see Figure 3.23). For the test at A, the torque required to cause failure was 51 N ∙ m.

For the clay, given: liquid limit = 46 and plastic limit = 21.

Estimate the undrained cohesion of the clay for use in the design by using Bjerrum’s λ relationship [Eq. (3.40a)].

Figure P3.3

Eq. (3.40a)

Transcribed Image Text:

Dry sand y = 16.5 kN/m3 1.5 m Groundwater table Sand 1.5 m Ysat = 19 kN/m? 60 5 1.5 m 8 Clay Ysat = 16.8 kN/m3 1.5 m * A •8 1.5 m 9 1.5 m 10 Sand 00