COLUMN DESIGN CALCULATIONS
Project Name : Unassigned
Client Name : Unassigned
Engineer Name : Unassigned
Design File : D:\Bentley\Common data\Bentley Communities\AS\Validation Problem\RCDC Files\RCDC-Staad-Demo -with RCC wall_for shear+Torsion-Column-1.rcdx
Analysis File : D:\Bentley\Common data\Bentley Communities\AS\Validation Problem\RCDC Files\RCDC-Staad-Demo -with RCC wall_for shear+Torsion.std
Analysis Last Modified : 1/15/2022 6:38:14 PM

Definitions Of Terms:
All forces in units 'kN' and 'm'
All reinforcement details like area, spacing in 'mm'
Neutral axis angle for resultant design moment is with respect to local major axis.
1 α2 = Constant used for calculation of stress in concrete for rectangular stress block
2 α2 = Constant used for crackwidth calculation based on Hypothetical thickness of section (th)
3 α3 = Coefficient used for creep calculation, 0.7x (k4 x α2)
4 αv = Angle between the inclined shear reinforcement and the longitudinal tensile reinforcement in Degree
5 βd = A factor required for calculation of Moment magnifier for slender column
6 γ = The ratio, under design bending or design combined bending and compression, of the depth of the assumed rectangulat compressive stress block to kud
7 δb = Moment Magnifier for braced column
8 δs = The Moment Magnifier for a un-Braced column
9 εcc = The creep strain in the concrete
10 εx = Longitudinal strain in concrete
11 θ = Angle between the fitment leg and the confinement plane in Degree
12 θv = Angle between the axis of the concrete compression strut and the longitudinal axis of the member in Degree
13 ΣN* = Summation of Axial load for all columns within storey in kN
14 ΣNc = Summation of buckling load for all columns within storey in kN
15 σo = The compressive stress in concrete assuming a cracked section in N/sqmm
16 σo,Perm = Permissible compressive stress in concrete assuming a cracked section in N/sqmm
17 σscr,Perm = Permissible stress in the tensile reinforcement assuming a cracked section in N/sqmm
18 Φ = Capacity reduction factor for design using linear elastic analysis
19 φcc = Design creep coefficient for concrete
20 φcc.b = Basic creep co-efficient
21 A = Area of column cross section in sqmm
22 Ab.fit = Cross sectional area of one leg of the fitment in sqmm
23 Ac = Cross sectional area bounded by the centre line of the outermost fitments in sqmm
24 Acp = Total area enclosed by outside perimeter of concrete section in sqmm
25 Ao = Area enclosed by shear flow path in sqmm
26 Aoh = Area of the centre line of the closed transverse torsion reinforcement
27 Ast required = Area of longitudinal tensile reinforcement required at a cross section in mm
28 Astmin = Minimum cross sectional area of longitudinal tensile reinfocement in sqmm
29 Asv/s = Cross sectional area of shear reinforcement per m length of section in sqmm/m
30 Asv/s min = Cross sectional area of minimum shear reinforcement per m length of section in sqmm/m
31 B/ tw = Width of the section in mm
32 bc = Core dimension measured between the centr lines of the outermost fitments measured across the width of the section in mm
33 bo = Effective depth at tension face
34 bv / dv = Effective width of a web for shear for shear check along D in mm
35 D / Lw = Overall depth/ lengtn of the section in mm
36 dc = Core dimension measured between the centr lines of the outermost fitments measured across the depth of the section in mm
37 do = Distance from the extreme compression fibre of the concrete to the centroid of the outermost later of tensile reinforcement in mm
38 ds = Overall dimension measured between centre lines of the outermot fitments in mm
39 dv = Effective width of a web for shear for shear check along B in mm
40 Ec = Modulus elasticity of concrete due to creep in N/sqmm
41 Es = Modulus of elasticity of steel in N/sqmm
42 f'c = Characteristic compressive (cylinder) strength of concrete at 28 days in N/sqmm
43 fr = Average confining pressure on the core cross section taken at the level of the fitments in N/sqmm
44 fr.eff = Effective confining pressure applied to the core of the column in N/sqmm
45 fsc = Characteristic compressive strength of reinforcement in N/sqmm
46 fsy.f = Yield stress of the reinforceemnt used as fitment in N/sqmm
47 G = Design axial load component due to permanent action (Dead load)
48 I = Moment of inertia of column cross section in mm4
49 k1 = Coefficient that accounts for bond properties of the bonded reinforcement
50 k2 = Coefficient used for the creep calculation
51 k2 = Coefficient that accounts for the longitudinal strain distribution
52 k3 = Coefficient depend on the age of concrete at loadings used for the creep calculation
53 k4 = Coefficient depend on the enviroment condition used for the creep calculation
54 k5 = A modification factor for high strength concrete used for creep calculation
55 k6 = Coefficient accounts for the non linear creep that develops at sustained stress level of 0.45 fcmi
56 kd = The depth of the neutral axis on the cracked section in mm
57 ke = Average confining factor accounting for the arrangement of the fitments '
58 km = A Coefficient calculated for Moment maginifier for Braced column
59 kv = Constant to calculate concrete section Ultimate shear strength excluding shear reinforcement
60 Le = Effective length of the column in mm
61 Legs = Number Of legs Of the shear reinforcement
62 lu = Unsupported length of a column in mm
63 Lu = Unsupported length of a column taken as the clear distance between the faces of member capable of providing lateral supports to the column in mm
64 m = Number of fitment legs crossing the confinement plane
65 M* = Design Bending Moment at cross section in kNm
66 M*1 = Smaller design bending moment ar the ends of the the column in kNm
67 M*2 = Larger design bending moment ar the ends of the the column in kNm
68 M*x = Design Bending moment about major axis in kNm
69 M*y = Design Bending moment about minor axis in kNm
70 Mc = Moment used in the calculation fo the buckling load (Nc) in kNm
71 Mub = Particular ultimate strength in beding when Kuo = 0.003 / (0.003 + fsy/Es) in kNm
72 n = Number of laterally restrained longitudinal bars
73 N* = Axial compressive or tensile force on a cross section in kN
74 Nc = The buckling load in kN
75 Nu = Ultimate strength in compression, or tension , at a cross section of an eccentrically loaded compression or tension memebr respectively in kN
76 Nuo = Ultimate strength in compression, without bending, of a an axially loaded cross section in kN
77 ΦMux = Strength in bending about Major axis under the design axial force in kNm
78 ΦMuy = Strength in bending about Minor axis under the design axial force in kNm
79 Q = Design axial load component due to imposed action (Live load)
80 r = Radius of gyration of the cross sections in mm
81 s = Centre to centre spacing of fitments along the column in mm
82 Sr,max = Maximum crack spacing in mm
83 Tcr = Torsional cracking moment in kNm
84 uc = The length of outside perimater of concrete cross section in mm
85 uh = Perimeter of the centre line of the closed transverse torsion reinforcement in mm
86 V*eq = Equivalent factored Shear force for co-existing applied shear force and applied torsion in kN
87 Vu,max = Ultimate shear strength limited by web crushing failure in kN
88 Vuc = Ultimate shear strength excluding shear reinforcement in kN
89 Vus = Contribution of shear reinforcement to the ultimate shear strength of a beam or wall in kN
90 w = Calculated maximum crackwidth in the concrete member in mm
91 x' = Centre line distance of the closed transverse torsion reinforcement along width of section in mm
92 y' = Centre line distance of the closed transverse torsion reinforcement along depth of section in mm
93 wk,perm = Calculated maximum crackwidth in the concrete member in mm


Code References:
AS 3600 : 2018
Sr.No Element Clause / table
1 Minimum Bending Moment : 10.1.2
2 Design of Slender column : 10.4
3 Design for Biaxial bending and compression : 10.6.4
4 Confinement to the core : 10.7.3
5 IMRF column detailing : 14.5.4
6 Restraint of longitudinal reinforcement : 10.7.4
7 V*eq : 8.2.1.2
8 Asw min : 8.2.5.5
9 Vus : 8.2.3.1
10 Vuc : 8.2.4.1
11 Max Stirrup Spacing : 8.3.2.2
12 Asv.min : 8.2.1.7
13 Vu,max : 8.2.3.3
14 Tcr : 8.2.1.2
15 Column design procedure : 10.2
16 Slenderness calculation : 10.5
17 Strength of column in combined bending and compression : 10.6
18 Intermediate Moment Resisting Frame : 14.5
19 Ductile Structural wall : 14.6



General Data
Column No. : C1
Level : 0 m To 4.2 m
Frame Type = Non-Ductile
Design Code = AS 3600 : 2018
Grade Of Concrete (f'c) = N25 N/sqmm
Grade Of Steel (fy) = 500N N/sqmm
Column B = 400 mm
Column D = 600 mm
Clear Cover, Cc = 50 mm
Clear Floor Height @ lux = 3400 mm
Clear Floor Height @ luy = 3400 mm
No Of Floors = 1
No Of Columns In Group = 1
Column Type : Braced
Minimum eccentricity check = Simultaneously (Both Axis)
Code defined D/B ratio : 4
D/B Ratio : 1.5 <= 4 Hence, Design as Column


Flexural Design (Analysis Forces)
Analysis Reference No. = 1
Load Combination = [5] : (LOAD 1: LOAD CASE 1) +0.6 (LOAD 2: LOAD CASE 2) +(LOAD 3: LOAD CASE 3 EQ-X)
Critical Location = Bottom Joint
N*t = 380.55 kN
M*xt = -25.85 kNm
M*yt = -8.82 kNm
V*xt = -24.07 kN
V*yt = 10.49 kN
N*b = 432.02 kN
M*xb = 3.21 kNm
M*yb = 117.24 kNm
V*xb = -274.17 kN
V*yb = -139.57 kN



Minimum Eccentricity Check
Since Axial Force is compressive, Min. Eccentricity check to be performed
Minimum Eccentricity Along D:
Minimum Eccentricity = D x 0.05
= 30 mm
Mminx = N* x Minimum Eccentricity
= 12.96 kNm
Minimum Eccentricity Along B :
Minimum Eccentricity = B x 0.05
= 20 mm
Mminy = N* x Minimum Eccentricity
= 8.64 kNm
Effective Length Calculation
Calculation Along Major Axis Of Column
Joint Column Stiffness Beam Sizes Beam Stiffness Y
Beam 1
(Length x Width x Depth)
Beam 2
(Length x Width x Depth)
Beam 1 Beam 2
N-m x 10^6 mm mm N-m x 10^6 N-m x 10^6
Bottom 183.45 No Beam No Beam - - 1
Top 183.45 No Beam 5710 x 400 x 800 - 298.89 1.157
Sway Condition (as per Stability Index) = Braced (Non Sway)
Effective Length Factor along Major Axis = 0.87

Calculation Along Minor Axis Of Column
Joint Column Stiffness
Beam Sizes
Beam Stiffness
Y
Beam 1
(Length x Width x Depth)
Beam 2
(Length x Width x Depth)
Beam 1 Beam 2
N-m x 10^6 mm mm N-m x 10^6 N-m x 10^6
Bottom 81.53 No Beam No Beam - - 1
Top 81.53 8000 x 400 x 800 No Beam 213.33 - 0.721
User Defined Effective Length Factor = 0.76

Calculation Of Slenderness Check
Φ = 0.65
Nuo = 6363.38 kN
α1 = 0.85
αc = 1.654
Along D Along B
Crtical Load Combination [5] : (LOAD 1: LOAD CASE 1) +0.6 (LOAD 2: LOAD CASE 2) +(LOAD 3: LOAD CASE 3 EQ-X) [5] : (LOAD 1: LOAD CASE 1) +0.6 (LOAD 2: LOAD CASE 2) +(LOAD 3: LOAD CASE 3 EQ-X)
N* (kN) 432.02 432.02
M*1 (kNm) 3.21 8.82
M*2 (kNm) 25.85 117.24
Ratio of M*1/M*2 -0.124 -0.075
le (lu x effective length factor) (mm) 2958 2584
Radius of Gyration (r) (mm) 173.21 115.47
Slenderness ratio ( le/r ) 17.078 22.378
Permissible Limits (le/r perm) 52.631 55.571
Hence, Column is not Slender Hence, Column is not Slender


Calculation of Design Moment
Direction M*analysis Mmin (Abs) Mdesign Mslndx (Abs) Mdesign-final
A B C D E
Top Node
Major Axis - M*x -25.85 11.42 -25.85 0 -25.85
Minor Axis - M*y -8.82 7.61 -8.82 0 -8.82
Bottom Node
Major Axis - M*x 3.21 12.96 12.96 0 12.96
Minor Axis - M*y 117.24 8.64 117.24 0 117.24

Where
A = Moments from analysis
B = Moments due to minimum eccentricity
C = Maximum of analysis moment and min. eccentricity = Max (A,B)
D = Moment due to slenderness effect
E = Final design Moment = Max(C, D)

Final Critical Design Forces
N* = 432.02 kN
M*x = 12.96 kNm
M*y = 117.24 kNm

Moment Capacity Check
Pt Calculated = 1.1
Reinforcement Provided = 12-N16 + 2-N12
Φ = 0.65
ΦMux = 289.95 kNm
ΦMuy = 183.89 kNm
N* = 432.02 kN
ΦNuo = 4136.2 kN
αn = 1
Capacity Ratio = 0.68
= 0.68 < 1

Design Of Shear
Aoh 158100 sqmm
uc 2000 mm
uh 1640 mm
Asv/s.min 320 sqmm/m
Tcr 47.52 kNm
0.25ΦTcr 8.91 kNm
Asw/s min (torsion) 204 sqmm/m
For Transverse Reinf
Along D Along B
Critical L/C - RCDC [2] : 1.2 (LOAD 1: LOAD CASE 1) +1.5 (LOAD 2: LOAD CASE 2) [2] : 1.2 (LOAD 1: LOAD CASE 1) +1.5 (LOAD 2: LOAD CASE 2)
PtPrv (%) 0.55 0.55
V* (kN) -168.05 -283.14
M*-Sect (kNm) 1.75 1.82
T* (kNm) 63.01 63.01
0.9 x T* x uh / 2Ao (N) 294119.21 294119.21
V*eq (kN) 338.74 408.26
εx x 10^-3 0.71 0.97
kv 0.19 0.16
cot θv 1.48 1.39
v* (stress due to V* + T*) (N/sqmm) 2.62 2.93
Φ Vu,max / (bv x dv) (N/sqmm) 4.78 4.89
Φ Vuc (kN) 125.56 105.39
Vus (kN) 284.24 403.83
Asw/s (T*) (sqmm/m) 421.15 451.06
Asw /s (Tcr) (sqmm/m) 238.22 255.14
Asw /s (torsion) (sqmm/m) 421.15 451.06
Asv/s Reqd (sqmm/m) 886.52 2023.4
Fitment Outer 2 - 10
Fitment Inner 2 - 10 3 - 10
Scalc (mm) 175 175
Sprv (mm) 175 175
Asv/s Total Prv (sqmm/m) 1795.2 2243.99


Design Of Fitments
Normal Fitments
Minimum diameter of fitment = 6 mm
Diameter of fitment = 10 mm
> Minimum diameter of fitment
Check for Confinement Zone
f'c = 25 N/sqmm
< 50 N/sqmm
End Confinement Zone not applicable
Check for additional Spacing Criteria
Lu = 3400 mm
5 x D = 3000 mm
Lu >= 5 x D
Criterion for spacing
Bundled longitudinal reinforcement Single
Min. dimension of column = 400 mm
Min. Longitudinal Bar dia X 15 = 180 mm
Provided Spacing = 175 mm




Table For Fitments
Required Provided
Normal Design Shear Design Ductile Design Normal Zone End Zone
Fitment 10 --- --- 10 ---
Spacing 175 --- --- 175 ---