Engineering Rock Mechanics

The complete stress-strain curve in uniaxial compression 87

-_

__

= Young’s modulus

b

Residual

strength

do

Zero at peak strength

b

-Negative in

E

post-peak region

Reducing secant modulus

illustrated in figure 6.4

Secant

modulus

&

Figure 6.3 Variation in the tangent and secant moduli throughout the complete
stress-strain curve.