BS EN 1991-1-2 Parametric FireΒΆ
\[ \begin{align}\begin{aligned}\Gamma = \frac{\left(O/b\right)^2}{\left(0.04/1160\right)^2}\\\Gamma = \left(O/b\right)^2 / \left(0.04/1160\right)^2\\FR=Q\left(1-\frac{P_{f,a}}{p_1\cdot A\cdot p_2\cdot p_3\cdot p_4}\right)\end{aligned}\end{align} \]