Fig. 4

The shear stress-displacement relationships were analyzed under four distinct normal stress conditions: (a) 4 MPa, (b) 8 MPa, (c) 12 MPa, and (d) 16 MPa.

The shear stress-displacement relationships were analyzed under four distinct normal stress conditions: (a) 4 MPa, (b) 8 MPa, (c) 12 MPa, and (d) 16 MPa.