UU gives undrained parameters on the other hand, CU and Direct shear give drained parameters (cohesion and Angle of internal friction). I think, Direct shear is not needed if CU conducted.
For my research, it is necessary to find the width (in the figure, BE) of the failure wedge in Terzaghi, Vesic, or Prandtl bearing capacity theories for shallow foundations. I searched the literature but could not find any equations or calculations. I tried the trigonometric method, but the...