5. Column and Footing Design23-11-04.xls

	A	B	C	D	E	F	G	H	I	J	K	L	M	N	O	P	Q	R
1				Braced Column Design						Case 1: Lowest story column
2										Case 2: Intermediate story column
3	Column Identification:			C1		Steel strength:		60,000	psi	Case 3: Cantilever column
4	Column case No.			1		Concrete strength:		4,000	psi	Case 4: Proped Cantilever column
5	Column height (c/c):			14	ft	Concrete Modulus:		3,644	ksi	Case 5: Pinned Ends
6
7	Beam Spacing (c/c):			24	ft	Concrete strength:		4,000	psi
8	Beam width:			48	in	Concrete Modulus:		3,644	ksi
9	Beam depth:			12	in
10
11			Dead load		Live load		Factored load
12	Axial load P:		230		173		616.1	kips
13	Moment M2:		2		108		186.4	ft-kips		No.	Diameter, in
14	Moment M1:		-2		100		167.2	ft-kips		3	0.375
15										4	0.500
16	Step 1 Design as Short Column (Assuming no slenderness effect):									5	0.625
17	Coulmn dimension:		18	in	Clear cover:		1.5	in		6	0.750
18	Size of Ties No.		3		Size of main bar No.		10			7	0.875
19	γ:		0.72							8	1.000
20	Pu/Ag:		1.90	ksi		Mu/Agh:	0.00	ksi		9	1.125
21	From column interaction diagram,					ρ:	0.02			10	1.250
22										11	1.375
23	Step 2 Braced or Unbraced Frame
24	Criterion based on P-Δ analysis
25	Results of First-order analysis:				Results of Second-order analysis:				Increase
26	Mu1:	105	ft-kips		Mu1:	110	ft-kips		4.76%
27	Mu2:	160	ft-kips		Mu2:	165	ft-kips		3.13%
28	Conclusion		Braced Frame
29
30	Criterion based on Stability Index Q
31	ΣPu:	500	kips		Δo:	0.36	in
32	Vu:	20	kips		lc:	168	in
33	Q:	0.05
34	Conclusion		Braced Frame
35
36	Criterion based on Lateral Bracing
37	Total stiffness of story columns:				250	in-kips
38	Total stiffness of bracing element:				1550	in-kips
39	Conclusion		Braced Frame
40
41	Step 3 Check Slenderness and refine k
42	Column height lu:				13	ft
43	with k=1, klu/r:				28.89
44	Upper limit for short column behaviour				#DIV/0!
45	#DIV/0!
46	For columns, E*Ig/lc:			22,315,299		in-kips
47	For beams,, E*Ig/lb:			17,631,841		in-kips
48
49	At top of the column,
50	No. of top columns:			1		Column height (c/c):		14	ft
51	No. of beams:			2		ψtop:		2.17
52	At bottom of the column,
53	No. of columns:			1		Column height (c/c):		14	ft
54	No. of beams:			2		ψtop:		2.17
55
56	From alignment chart,
57	Effective length factor k,			0.87
58	Slenderness ratio klu/r:			25.13
59	#DIV/0!
60
61	Step 4 Minimum Moment Mu2min:										Area, in2
62	Minimum eccentricity, emin:			1.14	in					No.	1	2	3	4	5	6	7	8
63	Minimum Moment Mu2min:			58.53	ft-kips					4	0.20	0.39	0.58	0.78	0.98	1.18	1.37	1.57
64	Minimum moment controls									5	0.31	0.61	0.91	1.23	1.53	1.84	2.15	2.45
65										6	0.44	0.88	1.32	1.77	2.21	2.65	3.09	3.53
66	Step 5 Cm, βd, EI, and Pc:									7	0.60	1.20	1.80	2.41	3.01	3.61	4.21	4.81
67	Cm:			#DIV/0!						8	0.79	1.57	2.35	3.14	3.93	4.71	5.50	6.28
68	βd:			0.52						9	1.00	2.00	3.00	4.00	5.00	6.00	7.00	8.00
69	EI:		8,389,210		in2-kip					10	1.27	2.53	3.79	5.06	6.33	7.59	8.86	10.12
70	Critical buckling load Pc:			4495	kips					11	1.56	3.12	4.68	6.25	7.81	9.37	10.94	12.50
71										14	2.25	4.50	6.75	9.00	11.25	13.50	15.75	18.00
72	Step 6 δns and Me:									18	4.00	8.00	12.00	16.00	20.00	24.00	28.00	32.00
73	δns:			#DIV/0!
74	Me:			#DIV/0!	ft-kips					4	No.	10	Steel area As:
75	Pu/Ag:		1.90	ksi		Mu/Agh:	#DIV/0!	ksi		4	No.	9	9.06
76	From column interaction diagram,
77	ρ:		2.60%
78	As:		8.42	in2
79
80	Design:	Provide	4	No.	10	bars plus
81			4	No.	9	bars
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