... by a confining pressure of 0.5 to 0.6 MPa under room temperature. This condition was maintained for about 30 minutes. The small differential axial stress was applied to ensure the end caps remained in contact with the actuator piston. Next confining pressure was increased to approximately 1.5 MPa while...

... of 3 MPa, and the differential axial stress was stepped at 9 MPa from its initial value of 4MPa. Fig. 8 shows how the pore pressure Pp changed with changing confining pressure in the presence of differential axial loading. Note that here the value of B is increasing for each confining pressure level...

... strength tuff stress-strain curve MPa differential axial stress triaxial test strain gage power law ARMA/USRMS 06-978 Stress Rate Dependent Strength of a Welded Tuff in Triaxial Tests Ma, L. Vector Engineering, Inc., Grass Valley, CA 95945, USA Zhao, G. School of Civil Engineering, Jinan...