Civil Engineering Reference
In-Depth Information
Probability
R
Q
Intensity
Figure 5.3. Load (Q) and resistance (R) curves, shown on the same plot.
ation in which loads exceed the strength limit state and threaten severe
damage. Note that this comparison of the curves on the same plot can be
made only when they fulfill specific mathematical conditions (namely that
they are “normal curves”).
Under the same mathematical conditions, we can create a combined
curve that represents the remainder when load curve is subtracted from
resistance curve. The resulting R-Q curve is shown in figure 5.4. Now the
shaded area to the left of the Y-axis shows where load exceeds resistance—it
Probability
Intensity
0
Figure 5.4. Reliability curve, also known as the
failure probability curve.
Failure prob-
ability is shown in the striped area to the left of the Y-axis.
