BEAM DESIGN CALCULATION

Project Name

:

Unassigned

Client Name

:

Unassigned

Engineer Name

:

Unassigned

Design File

:

D:\Bentley\Common data\Bentley Communities\ACI\ACI_English_validation Sheet\2019_English\Beam_Coupling\STAAD file\Coupling beam-testing-model-2-Beam-1-49.2125 ft.rcdx

Analysis File

:

D:\Bentley\Common data\Bentley Communities\ACI\ACI_English_validation Sheet\2019_English\Beam_Coupling\STAAD file\Coupling beam-testing-model-2.std

Analysis Last Modified

:

3/3/2023 1:25:18 PM

Level Designed

:

49.2125 ft

 

 

Sr.No.

Symbol

Definitions

1

α

=

Angle formed with horizontal line along length of Beam

2

Ach

=

Cross sectional area of structural member measures to the outside edge of transverse reinforcement in 'in2'

3

Ag

=

Cross sectional area of concrete in 'in2'

4

Ash

=

Total cross sectional area transverse reinforcement (including cross ties) within spacing S in 'in2'

5

Avd

=

Area of diagonal reinforcement in coupler beam in 'in2'

6

As

=

Area of Tension reinforcement required in 'in2'

7

As,min

=

Minimum area of flexural reinforcement in 'in2'

8

As,nominal

=

Nominal area of reinforcement in 'in2'

9

Al

=

Area of longitudinal reinforcement required to resist torsion in 'in2'

10

Al,face

=

Area of longitudinal reinforcement required on each face to resist torsion in 'in2'

11

At Torsion

=

Area of closed stirrups resisting torsion in 'in2'

12

AstPrv

=

Area of longitudinal reinforcement provided at given section in 'in2'

13

Av

=

Area of shear reinforcement required per meter length in 'in2'

14

Av,min

=

Minimum area of shear reinforcement in 'in2'

15

Al,min

=

Minimum area of longitudinal torsional reinforcement in 'in2'

16

Av Total Reqd

=

Total area of shear reinforcement required, including that for torsion in 'in2'

17

Av Total Prv

=

Total area of shear reinforcement provided, including that for torsion in 'in2'

18

Ao

=

Gross area enclosed by shear flow path in 'in2'

19

Aoh

=

Area enclosed by centerline of the outermost closed transverse torsional reinforcement in 'in2'

20

Ast

=

Total area of longitudinal reinforcement calculated at a given section in 'in2'

21

Asr

=

Area of Skin reinforcement calculated for given section in 'in2'

22

Asc

=

Area of Compression reinforcement required for doubly reinforced section or if torsion exists in 'in2'

23

Asv Reqd Sway

=

Area of shear reinforcement required for sway condition in 'in2'

24

b

=

Width of the Beam in 'in'

25

bw

=

Width of Web ( For flanged Beam ) in 'in'

26

b'

=

C/C distance between longitudinal reinforcement along B in 'in'

27

bc

=

Oustside dimension of transverse reinforcement in 'in'

28

Cc

=

Effective Cover to tension reinforcement in 'in'

29

Cmin

=

Clear cover to top and bottom reinforcement in 'in'

30

Cside

=

Clear cover to side reinforcement in 'in'

31

c'

=

Effective cover to reinforcement at compression face in 'in'

32

d

=

Effective depth of Beam in 'in'

33

d'

=

C/C distance between longitudinal reinforcement along D in 'in'

34

D

=

Depth of Beam in 'in'

35

Es

=

Modulus of elasticity of steel in 'ksi'

36

f'c

=

Specified compressive strength of concrete in cylinder in 'ksi'

37

fs

=

Calculated tensile stress in reinforcement at service loads, 'ksi'

38

Hf

=

Thickness of Flange in 'in'

39

hx

=

Maximum C/C horizontal spacing of hoops legs on all faces in 'in'

40

Icr

=

Moment Of Inertia Of concrete crack section

41

l

=

Effective Length Of Beam (Clear Span) in 'in'

42

Legs

=

Number Of legs Of the shear reinforcement

43

Mcr

=

Cracking Moment

44

Mh

=

Hogging moments of resistance of member at the joint faces in 'kip-ft'

45

Mpr1

=

Hogging moments Of resistance Of member at the joint faces in 'kip-ft'

46

Mpr2

=

Sagging moments Of resistance Of member at the joint faces in 'kip-ft'

47

Ms

=

Sagging moments Of resistance Of member at the joint faces in 'kip-ft'

48

Mu

=

Factored Bending Moment at a section in 'kip-ft'

49

Mubal

=

Nominal flexural strength Of Singly Reinforced Section At Balance Neutral Axis in 'kip-ft'

50

Ptmin

=

Minimum percentage steel

51

PtPrv

=

Provided percentage steel

52

Stirrup

=

Bar mark representing shear stirrup

53

S

=

spacing Of confining links in 'in'

54

SCalc

=

Stirrup spacing calculated As per Asv in 'in'

55

Spc-trans

=

Spacing of shear links along width of the beam in 'in'

56

Sprv

=

Stirrup spacing provided in 'in'

57

Tcr

=

Cracking torque under pure Torsion in 'kip-ft'

58

Tu

=

Factored Torsional Moment at a section in 'kip-ft'

59

VD+L

=

Shear due to Dead and Live load in Simply supported beam in 'kip'

60

Ve

=

Earthquake induced shear in 'kip-ft'

61

φVc

=

Reduced Shear strength provided by concrete in 'kip'

62

φVc sway

=

Reduced Shear strength provided by concrete for sway condition in 'kip'

63

Vu

=

Factored Shear Force at a section in 'kip'

64

Vu-A1(sway Left)

=

VD+Lleft - (Mpr1left + Mpr2right / L ) in 'kip'

65

Vu-A2(sway Left)

=

VD+Lleft + (Mpr2left + Mpr1right / L ) in 'kip'

66

Vu-B1(sway Right)

=

VDLRight - (Mpr1left + Mpr2right / L ) in 'kip'

67

Vu-B2(sway Right)

=

VDLRight + (Mpr2left + Mpr1right / L ) in 'kip'

68

Vud

=

Design Shear Force due to sway in 'kip'

69

Vs

=

Nominal shear strength provided by shear reinforcement in 'kip'

70

Vs Sway

=

Nominal shear strength provided by shear reinforcement for sway condition in 'kip'

71

Vu sway

=

Max (Vu-A1,Vu-A2) & (Vu-B1,Vu-B2) in 'kip'

72

y

=

Neutral axis depth.

73

Φ

=

Strength reduction factor

 

All Forces are in 'kip', 'kip-ft', Stress in 'ksi' & Dimension are in 'in'.

 

Code References

 

Sr.No.

Item

Clause / Table

1.

Ptmax

:

7.3.3.1, 8.3.3.1, 9.3.3.1

2.

As,min (flex) (B)

:

9.6.1.1, 9.6.1.2

3.

As,min

:

9.6.1.3

4.

Vc

:

22.5

5.

Asv

:

22.5.10.5 & 22.6.7

6.

Min Shear Reinf

:

9.6.3.1

7.

Max Stirrup Spacing

:

9.7.62

8.

Shear Reinf - Torsion

:

22.7.3.1

9.

Side Face Reinforcement

:

9.7.2.3

10.

Tcr

:

9.5.4.1

11.

fs,perm

:

10.6.4

12.

fc,perm

:

10.2.7.1

13.

Wcr

:

Eq 4.2(a)

14.

Ptmin

:

18.6.3.1

15.

Asmin

:

18.6.3.1

16.

Sclc

:

18.6.4.1 & 18.6.4.4

17.

Bidirectional one-way shear effects

:

22.5.1.10 & 22.5.1.11


Group

:

G2

 

Beam No

:

B2

 

Analysis Reference (Member)

:

1304 (49.2125 ft)

 

Beam Length

:

39.37

in

Breadth (B)

:

11.81

in

Depth (D)

:

23.62

in

Effective Depth (d)

:

20.94

in

Design Code

:

ACI 318 - 19

Beam Type

:

Coupling Beam

Grade Of Concrete (f'c)

:

C3

ksi

Grade Of Steel (Main)

:

Fy60

ksi

Grade Of Steel (Shear)

:

Fy60

ksi

Grade Of Steel - Flexural Design

:

Fy60

ksi

Grade Of Steel - Shear Design

:

Fy60

ksi

Grade Of Steel - Torsion Design

:

Fy60

ksi

Top/Bottom Clear Cover (Cmin)

:

1.5

in

Side Clear Cover

:

1.5

in

Es

:

29007.55

ksi

Mubal

:

414.36

kip-ft

As,min (flex) (B)

:

0.82

in2

As,nominal (Bn)

:

0.32

in2

As,min(user input)(B')

:

0.32

in2

Strength Reduction Factor φ (Shear)

:

0.6

 

Check for coupling action

 

Design of diagonal reinforcement

 

Clear Span of Beam, Ln

=

39.37

in

Beam Depth, D

=

23.62

in

Effective Depth, deff

=

20.94

in

Angle with horizontal, (α)

=

27.646

deg

Shear for EQ case, Vu

=

104.14

kip

λ

=

1

Φ

=

0.85

Criteria

1.

=

Ln/D

=

39.37/23.62

=

1.67 < 2, Hence coupling beam is applicable

2.   Vc

=

4 x  λ  x sqrt(fck) x B x D

=

61.12

kip

=

Vc  <  Vu

=

Hence, Beam Is coupling beam

Vn

=

10 x sqrt(fck) x B x Deff

=

135.46

kip

Vu

< 

Vn

Hence Ok

Avd

=

(Vu x 1000 / (2 x Fy x sinα)) / Φ

=

2.2

in2

Reinforcement provided

=

4-#5
4-#5 Both diagonals

    

Flexure Design (For Vertical Load Only)

Beam Bottom

Beam Top

Left

Mid

Right

Left

Mid

Right

Critical L/C - Analysis

-

13

-

13

13

13

Critical L/C - RCDC

-

3

-

3

3

3

Mu (kip-ft)

-

0.17

-

3.61

0.8

3.61

As (flex) (in2) (C)

-

0

-

0.04

0.01

0.04

Asc (flex) (in2) (A)

-

-

-

-

-

-

Tu (kip-ft)

-

-

-

-

-

-

Tcr/4 (kip-ft)

-

-

-

-

-

-

Al, min(in2)(Tor.) (D)

-

-

-

-

-

-

Al (in2) (Tor.) (E)

-

-

-

-

-

-

Al (Dist) (in2) (D)

-

-

-

-

-

-

Ast (in2)

0.32

0.32

0.32

0.32

0.32

0.32

AstPrv (in2)

0.33

0.33

0.33

0.33

0.33

0.33

Reinforcement Provided

3-#3

3-#3

3-#3

3-#3

3-#3

3-#3

 

Note: Calculation of Ast

 

  

 

Ast

=

Max {B, C+D, A+D} (for Mu > 0 and C x 1.33 > B)

Ast

=

Max{B', C x 1.33 + D, A+D} (for Mu > 0 and C x 1.33 < B)

Ast

=

Bn (for Mu = 0)

Where,

A

=

Asc (flex)

=

Compression reinforcement required for bending moment

B

=

As,min (flex)

=

Min area of flexural reinforcement

Bn

=

As,nominal

=

Nominal area of reinforcement

C

=

As (flex)

=

Total area of longitudinal reinforcement calculated at a given section

D

=

Al (Dist)

=

Distributed longitudinal torsional reinforcement at section considered

E

=

A s,reqd Crack

=

Area of reinforcement required for Crack Width

Ast (Dist) (in2)

=

Max(Al,min (Tor), Al (Tor)) x ((2B) / (2B + 2D))

 

Shear Design (For Vertical Load Only)

Left

Mid

Right

Critical L/C - RCDC

3

3

3

PtPrv (%)

0.133

0.133

0.133

Vu (kip)

4.52

1.66

4.52

Mu-Sect (kip-ft)

3.61

0.26

3.61

Φ Vc (kip)

20.32

20.32

20.32

Vs (kip)

-

-

-

Aoh (in2)

-

-

-

At (in2/ft)

-

-

-

Av (in2/ft)

0.12

0.12

0.12

Tu (kip-ft)

0

0

0

At Torsion (in2/ft)

-

-

-

Av Total Reqd (in2/ft)

0.12

0.12

0.12

Asv Reqd (in2/ft)

0.12

0.12

0.12

Legs

2

2

2

Stirrup Rebar

3

3

3

SCalc (in)

10

10

10

SPrv (in)

10

10

10

Av Total Prv (in2/ft)

0.26

0.26

0.26

Hoop link for diagonal bars as per ACI 318 - 19

 

Spacing Criteria:

Effective Width, (B")

=

8

in

Effective Depth, (D")

=

16

in

6 X diameter of longitudinal bar (db)

=

3.76

in

Maximum Spacing

=

6

in

Minimum Spacing

=

2

in

Hence Link spacing, S

=

Maximum (Minimum Spacing, Minimum (6db, Maximum Spacing))

=

3

in

Hoop dimension, bc

=

5.6

in

Gross area of column, Ag

=

B" x D"

=

119.16

in2

Core area of column, Ach

=

(B" - 2 x Cside + 2 x Outer Link Rebar) x (D" - 2 x Cmin + 2 x Outer Link Rebar)

=

76.66

in2

Hoop Link Criteria:

Ash1

=

0.3 x S x bc x (Fck/Fy) x (Ag/Ach-1)

=

0.14

in2

Ash2

=

0.09 x S x bc x (Fck/Fy)

=

0.08

in2

Ash

=

Maximum (Ash1, Ash2)

=

0.14

in2

Link Rebar (Outer)

=

4

Link Rebar (Internal)

=

3

 

 

 

Maximum Spacing Criteria

 

    

 

       Basic                               

                4 Sqrt(f'c)Bd

=

54.18

kip

Left

Mid

Right

Vs (kip)

0

0

0

Check

Vs <= 4 Sqrt(f'c)Bd

Vs <= 4 Sqrt(f'c)Bd

Vs <= 4 Sqrt(f'c)Bd

Spc1 (in)

d/2=10.47

d/2=10.47

d/2=10.47

Spc2 (in)

24

24

24

 

Maximum Spacing Criteria Along Beam Width

 

                4 Sqrt(f'c)Bd

=

54.18

kip

Left

Mid

Right

Vs (kip)

0

0

0

Check

Vs <= 4 Sqrt(f'c)Bd

Vs <= 4 Sqrt(f'c)Bd

Vs <= 4 Sqrt(f'c)Bd

Spc-trans 1 (in)

d = 20.94

d = 20.94

d = 20.94

Spc- trans 2 (in)

24

24

24

Spc-trans actual (in)

9.19

9.19

9.19

Skin reinforcement

 

  

 

Beam Width

=

11.81

in

Beam Depth

=

23.62

in

Depth

=

23.62 <= 36,     Hence Skin Reinforcement is not required.