Near-Fault Response and Loading Protocols of Box Columns in Steel Frames with Self-Centering Braces to Provide Recentering Capability

Table 1

Base shear and element dimensions.

		Floor	SCBF	BRBF [1]
3-Story design base shear: 184 kN	Col.	1F–3F	C1: BOX 185 × 185 × 8	C1: BOX 185 × 185 × 8
			C2: BOX 225 × 225 × 10	C2: BOX 225 × 225 × 10
			C3: BOX 185 ×185× 8	C3: BOX 185 × 185 × 8
	Beam	2F-RF	H 257 × 102 × 6 × 9	H 257 × 102 × 6 × 8
	Brace	1F	Ac = 900 mm^2 (Py = 331 kN)	Ac = 900 mm^2 (Py = 300 kN)
		2F	Ac = 800 mm^2 (Py = 294 kN)	Ac = 800 mm^2 (Py = 260 kN)
		3F	Ac = 420 mm^2 (Py = 155 kN)	Ac = 400 mm^2 (Py = 130 kN)
7-Story design base shear: 3,125 kN	Col.	1F−3F	BOX 500×500×28	BOX 500 × 500 × 28
		4F−7F	BOX 500 × 500 × 20	BOX 500 × 500 × 20
	Beam	2F−5F	H 500 × 200 × 12 × 25	H 500 × 200 × 12 × 22
		6F-RF	H 500 × 200 × 12 × 22	H 500 × 200 × 12 × 20
	Brace	1F−3F	Ac = 3,640 mm^2 (Py = 1,338 kN)	Ac = 3,640 mm^2 (Py = 1,200 kN)
		4F−5F	Ac = 2,880 mm^2 (Py = 1,059 kN)	Ac = 2,880 mm^2 (Py = 950 kN)
		6F−7F	Ac = 1,760 mm^2 (Py = 647 kN)	Ac = 1,760 mm^2 (Py = 580 kN)
15-Story design base shear: 3,814 kN	Col.	1F−3F	BOX 600 × 600 × 40	BOX 600 × 600 × 35
		4F−6F	BOX 550 × 550 × 40	BOX 550 × 550 × 32
		7F−9F	BOX 550 × 550 × 28	BOX 550 × 550 × 22
		10F−15F	BOX 500 × 500 × 25	BOX 500 × 500 × 22
	Beam	2F−3F	H 600 × 300 × 12 × 25	H 600 × 250 × 13 × 22
		4F−8F	H 600 × 250 × 16 × 28	H 600 × 250 × 12 × 20
	Brace	9F-RF	H 600 × 250 × 16 × 28	H 600 × 200 × 12 × 20
		1F−5F	Ac = 4,600 mm^2 (Py = 1,693 kN)	Ac = 4,550 mm^2 (Py = 1,500 kN)
		6F−9F	Ac = 3,900 mm^2 (Py = 1,435 kN)	Ac = 3,940 mm^2 (Py = 1,300 kN)
		10F−13F	Ac = 3,200 mm^2 (Py = 1,178 kN)	Ac = 3,030 mm^2 (Py = 1,000 kN)
		14F−15F	Ac = 1,820 mm^2 (Py = 670 kN)	Ac = 1,820 mm^2 (Py = 600 kN)
25-Story design base shear: 5,379 kN	Col.	1F−3F	BOX 800 × 800 × 40	BOX 800 × 800 × 36
		4F−6F	BOX 750 × 750 × 36	BOX 750 × 750 × 36
		7F−9F	BOX 700 × 700 × 32	BOX 700 × 700 × 32
		10F−25F	BOX 700 × 700 × 28	BOX 700 × 700 × 28
	Beam	2F−4F	H 700 × 300 × 18 × 25	H 650 × 300 × 18 × 25
		5F−18F	H 650 × 300 × 16 × 25	H 650 × 300 × 15 × 25
		19F-RF	H 600 × 300 × 13 × 22	H 600 × 300 × 13 × 22
	Brace	1F−3F	Ac = 6,000 mm^2 (Py = 2,208 kN)	Ac = 6,060 mm^2 (Py = 2,000 kN)
		4F−10F	Ac = 6,000 mm^2 (Py = 2,208 kN)	Ac = 5,430 mm^2 (Py = 1,800 kN)
		11F−19F	Ac = 5,800 mm^2 (Py = 2,134 kN)	Ac = 4,550 mm^2 (Py = 1,500 kN)
		20F−22F	Ac = 5,800 mm^2 (Py = 2,134 kN)	Ac = 3,030 mm^2 (Py = 1,000 kN)
		23F−25F	Ac = 2,120 mm^2 (Py = 780 kN)	Ac = 2,120 mm^2 (Py = 700 kN)
	3-Story	7-Story	15-Story	25-Story
SCBF	0.36	0.83	1.56	2.47
BRBF	0.44	1.01	1.94	2.77

Note: first mode periods (s)