Increased Structural Height Limit per ASCE 7-16 with ideCAD

How does ideCAD control increased structural height limits according to ASCE 7-16?

The software controls the Increased structural height limit automatically according to ASCE 7-16 12.2.5.4.

Design coefficients and factors selected by the user in the analysis settings wizard are checked automatically, and the results are reported.

Structural system selection, Response modification coefficient R, Deflection amplification factor Cd and Overstrength factor Ωo are defined by the user.

SYMBOLS

C_d = Deflection amplification factor
Ω_o = Overstrength factor
R = Response modification coefficient

Increased Structural Height Limit for Steel Eccentrically Braced Frames, Steel Special Concentrically Braced Frames, Steel Buckling-Restrained Braced Frames, Steel Special Plate Shear Walls, and Special Reinforced Concrete Shear Walls

The limits on structural height, h_n, are given in Table 12.2-1, shown below.

It has permitted to be increased from 160 ft (50 m) to 240 ft (75 m) for structures assigned to Seismic Design Categories D or E and from 100 ft (30 m) to 160 ft (50 m) for structures assigned to Seismic Design Category F, on condition that the seismic force-resisting systems are limited to steel eccentrically braced frames, steel special concentrically braced frames, steel buckling restrained braced frames, steel special plate shear walls, or special reinforced concrete cast-in-place shear walls.

Structural System Type	Response Modification Coefficient, R	Overstrengh Factor, Ω_o	Deflection Amplification Factor, C_d	Structural System Limitations Including Structural Height, h_n (ft) Limits
				Seismic Design Category
				B	C	D	E	F
A. Bearing Wall Systems
A1 - Special reinforced concrete shear walls	5	2^1/2	5	NL	NL	160	160	100
A2 - Ordinary reinforced concrete shear walls	4	2^1/2	4	NL	NL	NP	NP	NP
A3 - Detailed plain concrete shear walls	2	2^1/2	2	NL	NP	NP	NP	NP
A4 - Ordinary plain concrete shear walls	1^1/2	2^1/2	1^1/2	NL	NP	NP	NP	NP
B. Building Frame Systems
B1 - Steel eccentrically braced frames	8	2	4	NL	NL	160	160	100
B2 - Steel special concentrically braced frames	6	2	5	NL	NL	160	160	100
B3 - Steel ordinary concentrically braced frames	3^1/4	2	3^1/4	NL	NL	35	35	NP
B4 - Special reinforced concrete shear walls	6	2^1/2	5	NL	NL	160	160	100
B5 - Ordinary reinforced concrete shear walls	5	2^1/2	4^1/2	NL	NL	NP	NP	NP
B6 - Detailed plain concrete shear walls	2	2^1/2	2	NL	NP	NP	NP	NP
B7 - Ordinary plain concrete shear walls	1^1/2	2^1/2	1^1/2	NL	NP	NP	NP	NP
C. Moment-Resisting Frame Systems
C1 - Steel special moment frames	8	3	5^1/2	NL	NL	NL	NL	NL
C2 - Steel special truss moment frames	7	3	5^1/2	NL	NL	160	100	NP
C3 - Steel intermediate moment frames	4^1/2	3	4	NL	NL	35	NP	NP
C4 - Steel ordinary moment frames	3^1/2	3	3	NL	NL	NP	NP	NP
C5 - Special reinforced concrete moment frames	8	3	5^1/2	NL	NL	NL	NL	NL
C6 - Intermediate reinforced concrete moment frames	5	3	4^1/2	NL	NL	NP	NP	NP
C7 - Ordinary reinforced concrete moment frames	3	3	2^1/2	NL	NP	NP	NP	NP
D. Dual Systems with Special Moment Frames Capable of Resisting at Least 25% of Prescribed Seismic Foces
D1 - Steel eccentrically braced frames	8	2^1/2	4	NL	NL	NL	NL	NL
D2 - Steel special concentrically braced frames	7	2^1/2	5^1/2	NL	NL	NL	NL	NL
D3 - Special reinforced concrete shear walls	7	2^1/2	5^1/2	NL	NL	NL	NL	NL
D4 - Ordinary reinforced concrete shear walls	6	2^1/2	5	NL	NL	NP	NP	NP
E. Dual Systems with Intermediate Moment Frames Capable of Resisting at Least 25% of Prescribed Seismic Foces
E1 - Steel special concentrically braced frames	6	2^1/2	5	NL	NL	35	NP	NP
E2 - Special reinforced concrete shear walls	6^1/2	2^1/2	5	NL	NL	160	100	100
E8 - Ordinary reinforced concrete shear walls	5^1/2	2^1/2	4^1/2	NL	NL	NP	NP	NP
F. Shear Wall-Frame Interactive System with Ordinary Reinforced Concrete Moment Frames And Ordinary Reinforced Concrete Shear Walls
F1 - Shear wall-frame interactive system	4^1/2	2^1/2	4	NL	NP	NP	NP	NP
G. Cantilevered Column Systems Detailed to Conform to the Requirement for
G1 - Steel special cantilever column systems	2^1/2	1^1/4	2^1/2	35	35	35	35	35
G2 - Steel ordinary cantilever column systems	1^1/4	1^1/4	1^1/4	35	35	NP	NP	NP
G3 - Special reinforced concrete moment frames	2^1/2	1^1/4	2^1/2	35	35	35	35	35
G4 - Intermediate reinforced concrete moment frames	1^1/2	1^1/4	1^1/2	35	35	NP	NP	NP
G5 - Ordinary reinforced concrete moment frames	1	1^1/4	1	35	NP	NP	NP	NP
H. Steel Systems not Specifically Detailed for Seismic Resistance, Excluding Cantilever Column Systems
H - Steel Systems not Specifically Detailed for Seismic Resistance	3	3	3	NL	NL	NP	NP	NP