Comparison of Two Mechanics-Based Methods for Simplified Structural Analysis in Vulnerability Assessment

Table 3

Sway potential index calculated using the formula in (15) for the 4-storey building from Figure 3 designed to different proportions of lateral load (c).

Floor	𝑐=12.5%	𝑐=5%	𝑐=5%	(𝜆)%	Δ𝑦%
1st	0.5	0.6	0.5	0.4	0.4
2nd	1.0	0.6	0.5	0.4	0.4
3rd^*	2.6	0.6	0.5	0.4	0.4

^*The storey mechanism for the fourth floor is not calculated as plastic hinges are likely to form in the top of the columns at the roof, even for a global mechanism.