(1)
Buildings designed in accordance with Articles 4.1.8.19. to 4.1.8.22. need not comply with this Article.
(2)
The design of post-disaster buildings in Seismic Category SC2, SC3 or SC4 shall be verified using 5%-damped spectral acceleration values based on a 5% probability of exceedance in 50 years and shall satisfy the following requirements:
(a)
the building shall be shown to behave elastically for a specified lateral earthquake force, V, determined in accordance with Sentence 4.1.8.11.(2) using IE = 1.0 and Rd Ro = 1.3,
(b)
the largest inter storey deflection at any level of the building, as determined in accordance with Sentence 4.1.8.13.(2) using IE = 1.0 and Rd Ro = 1.0, shall not exceed 0.005hs, and
(c)
the connections of elements and components of the building described in Table 4.1.8.18. with Rp > 1.5 shall be shown to behave elastically for a specified lateral earthquake force, Vp, determined in accordance with Sentence 4.1.8.18.(1) using Rp = 1.5.
(3)
The design of High Importance Category buildings in Seismic Category SC3 or SC4 shall be verified using 5%-damped spectral acceleration values based on a 10% probability of exceedance in 50 years and shall satisfy the following requirements:
(a)
the building shall be shown to behave elastically for a specified lateral earthquake force, V, determined in accordance with Sentence 4.1.8.11.(2) using IE = 1.0 and Rd Ro = 1.3,
(b)
the largest inter storey deflection at any level of the building, as determined in accordance with Sentence 4.1.8.13.(2) using IE = 1.0 and Rd Ro = 1.0, shall not exceed 0.005hs, and
(c)
the connections of elements and components of the building described in Table 4.1.8.18. with Rp > 1.3 shall be shown to behave elastically for a specified lateral earthquake force, Vp, determined in accordance with Sentence 4.1.8.18.(1) using Rp = 1.3.
(4)
For Normal Importance Category buildings in Seismic Category SC4 with a height above grade of more than 30 m, the structural framing elements not considered to be part of the SFRS shall be designed to behave elastically for a specified lateral earthquake force, V, determined in accordance with Sentence 4.1.8.11.(2) using spectral acceleration values based on a 10% probability of exceedance in 50 years and Rd Ro = 1.3.
(5)
For the purposes of applying Sentences (2) to (4), torsional moments due to accidental eccentricities need not be considered if B, as determined in accordance with Sentence 4.1.8.11.(10), does not exceed 1.7.
(6)
For the purposes of applying Sentences (2) to (4), elements of the SFRS and structural framing elements not considered to be part of the SFRS, when included in the analysis, shall be modeled in accordance with Sentence 4.1.8.3.(8) using elastic properties.
(7)
All other requirements of Articles 4.1.8.2. to 4.1.8.18. shall be satisfied in meeting the additional requirements of this Article.