Design of RCC Drains.pdf

Project Name: Two/Four Lannig of NH 65 Design Title: Design of RCC Drains Without Live Load for 0.9 m Height: Document Number : Satya/2016-17/0001 -R0

Remarks/Rough

Design of RCC Drains Without Live Load for 0.9 m Height: 1.Design Data: Dimesion Details Clear Span of the Drain Height of the Drain Thickness of Topslab Thickness of Wall Thickness of Bottom Slab Over width of Drain Material Properties Grade of Concrete Grade of Steel Clear Cover (Top Slab) Clear Cover (Bottom Slab)

: : : : : :

Density of Concrete Density of Soil

: : : : : :

Intensity of Pedestrians Load Angle of Internal Friction

: :

0.60 0.90 0.10 0.15 0 20 0.20 0.90

m m m m m m

M 25 Fe 500 40 mm 50 mm 3 25 kN/m 3 20 kN/m 2

4 kN/m 30 o

2.Load and Moment Calculations: (Considering 1 m Longitudinal Width of Drain) i) Top Slab: Effective Span 0.75 m : Self-weight of Top Slab 2.50 kN/m : Live Load due to Pedestrians 4.00 kN/m : Total Load on the Top Slab 6 50 kN/m 6.50 : 6.5

0.75 Unfactored Bending Moment: Due to Dead Load Due to Live Load Design D i Bending B di Moment M t (1.35DL+1.5LL) (1 35DL+1 5LL) ii) Side Wall: Coefficient of Earth Pressure (at Rest) Height of the Wall Intensity of load due to EP (At Base) Intensity of Load due to LL surcharge Inetsity of Load due to Min. Fuild Pressure

: : :

0.18 kN-m 0.28 kN-m 0.66 0 66 kN-m kN

: : : : :

0.50 0.75 m 2 7.50 kN/m 2 12.00 kN/m

0.75 m

Min. Fuild Pressure

Unfactored Bending Moment: Due to Earth Presurre Due to Live Load Surcharge Due to Min. Fluid Pressure Design Bending Moment (1.5 EP+1.2 LL)

7.50 EP

: : : :

12.00 LL Surcharge 0.89 kN-m 3.38 kN-m 5.38 kN-m

Page 1 of 7


iii) Bottom Slab: (Service Condition) Unfactored Loads Dead Load due top slab Live load on top slab (Pedestrian Load) Dead Load due to Side Walls Dead Load due to Bottom Slab Total Load on bottom Slab Intensity of Load at base Factored Loads Dead Load due top slab Live load on top slab (Pedestrian Load) Dead Load due to Side Walls Dead Load due to Bottom Slab Total Load on bottom Slab Intensity of Load at base

: : : : : :

: : : : : :

2.25 3.60 6.75 4.50

Remarks/Rough

kN kN kN kN

17.10 kN 19.00 kN/m

3.04 5.40 9.11 6.08

kN kN kN kN

Load Factor 1.35 1.50 1.35 1.35

23.63 kN 26.25 kN/m

11.81

11.81 0.75

5.38

26.25

Calculating Moment about the centre: Calculating Moments at support

: :

22.79 79 kN-m kN m 3.90 kN-m

Bottom Slab: (Construction Stage) Unfactored Loads Dead Load due to Side Walls Dead Load due to Bottom Slab

: :

6.75 kN 4.50 kN

Total Load on bottom Slab Intensityy of Load at base

: :

11.25 kN 12.50 kN/m

Factored Loads Dead Load due to Side Walls Dead Load due to Bottom Slab

: :

9.11 kN 6.08 kN

Total Load on bottom Slab Intensity of Load at base

: :

15.19 kN 16.88 kN/m

4.56

5.38

Load Factor 1.35 1.35

4.56 0.75

5.38

16.88

Calculating Moment about the centre: Calculating Moments at support

: :

4.86 kN-m 6.71 kN-m

Max. Bending Moment (At Centre) M Max. Bending B di Moment M t (At S Support) t)

: :

4.86 kN-m 6 71 kN-m 6.71 kN

5.38

Page 2 of 7


Remarks/Rough

2.1 Summary of Moments: Top Slab Side Wall Bottom Slab (at Centre) Bottom Slab (at Support) 3. Design of Sections: Design Constants Compressive strength of Concrete, fck Yield Strength of Steel, fyk Design Yield Strength of Steel, fyd Tensile Strength of Concrete, fctm Partial Safety Factor For Steel, γs Partial Safety Factor For Concrete, γm Ratio, α Effect Depth factor, λ Efective Strength g Factor,, η Design Compressive Strength of Concrete, fcd Modulus of Elasticity of Steel Modulus of Elasticity of Concrete Max. Compressive Strain in concrete, εcu Max. Tensile Strain in Steel, εs Max. Depth of Neutral Axis, x Ru,lim 33.11 3.1.1

ULS-Basic 0.66 5.38 4.86 6.71

: : : : : : : : : : : : : : : :

25 500 400 2.2 1.15 1.5 0.67 0.8 1 11.17 200000 30000 0.0035 0.0022

SLS-Rare 0.46 3.59 4.86 6.71

QPC 0.18 0.89 4.86 6.71

MPa MPa MPa MPa

MPa MPa MPa

0.617 d 0.166 fck

εs = fy/Eγs xu,max /d = εcu/(εcu+εs)

Design for Flexure: Top Slab Design Bending Moment : 0.66 kN-m Effective depth Required : 13 mm Effective Depth Provided : 56 mm Depth of Neutral Axis 0.66 mm : Max. depth of Neutral Axis 34.5 mm : Depth of Neutral Axis is less than Max. Depth of Neutral Axis, Hence Ok 2 : 27 mm Area of Steel Required, Ast,req Ast,min1

:

2 64.064 64 064 mm

Ast,min2

:

2 72.8 mm

Minimum Area of Steel

:

2 72.8 mm

Maximum Area of Steel

:

2 2500 mm

Area of Steel Required Diameter of the bar, φ Spacing of reinforcement, s

: : :

2 72.8 mm 8 mm 200 mm

2 Area of Steel Provided : 251 mm Area of Steel Provided is greater than Required Area of Steel, Steel Hence Safe Distribution Steel

Area of Steel required Diameter of the bar, φ Spacing of reinforcement, s

: : :

2 50 mm 8 mm 250 mm

Area of Steel Provided

:

2 201 mm

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3.1.2

Side Wall Design Bending Moment Effective depth Required Effective Depth Provided Depth of Neutral Axis Max. depth of Neutral Axis

: : : : :

5.38 36 105 2.90 64.8

Remarks/Rough

kN-m mm mm mm mm

Depth of Neutral Axis is less than Max. Depth of Neutral Axis, Hence Ok Area of Steel Required, Ast,req

:

2 119 mm

Ast,min1

:

2 120.1 mm

Ast,min2

:

2 136.5 mm


:

2 136.5 mm


:

2 3750 mm


: : :

2 137 mm 10 mm 200 mm

2 Area of Steel Provided : 393 mm Area of Steel Provided is greater than Required Area of Steel, Hence Safe Distribution Steel


: : :

2 79 mm 8 mm 250 mm


:

2 201 mm

3.1.2 Bottom Slab i) At Centre Design Bending Moment Effective depth Required Effective Depth Provided Depth of Neutral Axis Max. depth of Neutral Axis

: : : : :

4.86 34 145 1.88 89.4

kN-m mm mm mm mm


:

2 77 mm

Ast,min1

:

2 166 mm

Ast,min2

:

2 189 mm


:

2 189 mm


:

2 3750 mm


: : :

2 189 mm 10 mm 200 mm



: : :

2 79 mm 8 mm 250 mm


:

2 201 mm

Page 4 of 7

Project Name: Two/Four Lannig of NH 65 Design Title: Design of RCC Drains Without Live Load for 0.9 m Height: Document Number : Satya/2016-17/0001 -R0 ii) At Support Design Bending Moment Effective depth Required Effective Depth Provided Depth of Neutral Axis Max. depth of Neutral Axis

: : : : :

6.71 40 146 2.59 90.1

Remarks/Rough

kN-m mm mm mm mm


:

2 106 mm

Ast,min1

:

2 167 mm

Ast,min2

:

2 190 mm


:

2 190 mm


:

2 5000 mm


: : :

2 190 mm 8 mm 150 mm


3.2 3.2.1


: : :

2 67 mm 8 mm 250 mm


:

2 201 mm

Check for Shear: Top Slab Design Shear Force Effective Depth Provided

: :

3.5 kN 56 mm

Area of Steel Provided Percent of Steel K σcp ρ1 Vmin i Vr,dc Vr,dc min Max. Shear Load without Shear Reinforcement

: : : : : : : : :

251 1.79 2.00 0 0.0045 0.438 0 438 27.7 24.6 27.7

mm2 % Eq. 10.2 in Cl: 10.3.2 of IRC 112 -2011 Cl: 10.3.2 of IRC 112 -2011

<=0.02

Cl: 10.3.2 of IRC 112 -2011 Eq. Eq 10.3 10 3 in Cl: 10.3.2 10 3 2 of IRC 112 -2011

kN kN kN

Eq. 10.1 in Cl: 10.3.2 of IRC 112 -2011 Eq. 10.1 in Cl: 10.3.2 of IRC 112 -2011

The Provided Section is safe in Shear, No additional Shear Reinforcement is provided

3.2.2

Side Wall Design Shear Force Effective Depth Provided

: :

Area of Steel Provided Percent of Steel K σcp ρ1 Vmin Vr,dc Vr,dc min Max. Shear Load without Shear Reinforcement

: : : : : : : : :

8.2 kN 105 mm 393 00.95 95 2.00 0 0.0037 0.438 49.0 46.0 49.0

mm2 % < 0.2fcd <=0.02 kN kN kN


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Project Name: Two/Four Lannig of NH 65 Design Title: Design of RCC Drains Without Live Load for 0.9 m Height: Document Number : Satya/2016-17/0001 -R0 3.2.3

Bottom Slab Design Shear Force Effective Depth Provided

: :

Area of Steel Provided Percent of Steel K σcp ρ1 Vmin i Vr,dc Vr,dc min Max. Shear Load without Shear Reinforcement

: : : : : : : : :

Remarks/Rough

11.8 kN 146 mm 335 0.68 2.00 0 0.0023 0 438 0.438 57.9 64.0 64.0

mm2 % < 0.2fcd <=0.02 kN kN kN


3.4 Check for Stress (SLS-Rare Case): Age of the Loading Relative Humidity, RH

: :

Sectional Area of Concrete, Ac Member u Perimeter of Member, Notional Size of the Member, ho Design Life of the Darin Calculation of Creep Co-oeficient:

: : : :

φ (t,t0) = φ0 x βc (t,t0) φ0 = φRH x β (fcm) β(t0)

: :

1 1

φRH

/100 / 0.1

_0

:

7 Days 50 % 2 100000 mm 2200 mm 90.9 mm 10 Years 4.128 4.255

:

2.112 3 174 3.174

:

0.635

βc (t,t0)

:

0.970

βH = 1.5 [1 + (1.2 x RH/100)18] x ho +250 Ec,eff = Ecm/(1+φ (t,t0)) Allowable Stress in Concrete Allowable Stress in Steel Modulus Elasticity Steel, Es M d l off El i i off S l E Long Term, Ec,eff Short Term, Ec Modular Ratio (long term) Modular Ratio (Short Term)

: : : : : : : : :

386.38 5850.4 12

Long Term Bending Moment Overall depth Effective Depth Area of Steel Depth of Neutral Axis Cracked Moment of Inertia Stress in Concrete Stress in Steel

Top Slab 0.46 100 56 251 12.14 17123635 0.324 40

β(fcm) = 18 18.78/√f 78/√fcm 0.2

β(t0) = 1/(0.1+t0 ) (( − _0))/(β_ +( − _0)) ^0.3

200000 5850.4 30000 34.2 6.7 Side Wall 3.59 150 105 393 18.97 101632248 0.669 104

Bottom Slab 6.71 200 146 335 16.19 194455524 0.558 153

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Short Term Bending Moment Overall depth Effective Depth Area of Steel Depth of Neutral Axis Cracked Moment of Inertia Stress in Concrete Stress in Steel

Remarks/Rough

Top Slab 0.46 100 56 251 12.14 3819586 1.453 35

Side Wall 3.59 150 105 393 18.97 21651626 3.142 95

Bottom Slab 6.71 200 146 335 16.19 39059693 2.780 149

Top Slab 40 0.18 100 56 251 12 1 12.1 0.0086 294 2.39 -0.000666 0.000007 0.002 Ok

Side Wall 40 0.89 150 105 393 19 0 19.0 0.0090 325 3.52 -0.000631 0.000011 0.003 Ok

Bottom Slab 50 6.71 200 146 335 16 2 16.2 0.0055 419 22.29 -0.000931 0.000067 0.028 Ok

3.5 Check for Crack Width: Clear Cover Bending Moment Overall Depth Effective Depth Area of Reinforcement D th off Neutral N t l Axis A i Depth ρρ,eff = As/Ac,eff Max. Crack Spacing, Sr,max Mean Stress Acting on the Section, σsc (εsm - εcm) 0.6σcp/Es Crack Width, Wk= Sr,max(εsm - εcm) Check 3.6 Calculation of Maximum Base pressure: Load due to Pedestrian Load due to Top Slab Load due to Side Wall Load due to bottom Slab Total Load

: : : : :

3.60 2.25 3.38 4.50 13.73

kN kN kN kN kN

Base Area of the Drain

:

Max. Base Pressure

:

2 0.90 m 2 15.25 kN/m

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Design of RCC Drains.pdf

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