Challenge

Week 4 Challenge

MMd Nizamuddin Mondal22 Jul 2023

1).Design of Foundation of Abutment (as per IRC 6-2017 loads. optimize the design as per IRC: 112-2011):-

Here's a brief introduction to the design of abutment foundations:

An abutment foundation is a critical structural element used to support and distribute the loads from bridge abutments to the ground. Bridge abutments are the supporting structures at the ends of a bridge that connect the deck to the ground, providing stability and transferring the load of the bridge to the foundation. The design of abutment foundations is crucial to ensure the overall safety and long-term performance of the bridge.

These are the following step we have adopted to consider an abutment foundation design:-

Geotechnical Investigation:
Before designing an abutment foundation, a comprehensive geotechnical investigation of the site is conducted. This investigation involves soil and rock testing to understand the subsurface conditions, including the soil type, bearing capacity, groundwater levels, and potential for settlement or lateral movement.
Foundation Types:
Abutment foundations can be designed using various types, depending on the specific site conditions and bridge requirements. Common types of foundations include spread footings, pile foundations, drilled shafts (also known as caissons), and mat foundations. The choice of foundation type depends on factors such as soil conditions, bridge design, and the magnitude of loads to be supported.
Load Analysis:
Engineers analyze the loads that will be transferred from the bridge deck to the abutment foundation. This includes the weight of the bridge structure itself, traffic loads, live loads, and any additional loads due to seismic events or other external forces.
Design Considerations:
The design of the abutment foundation must consider several factors, including the bearing capacity of the soil, settlement limits, lateral stability, and resistance to overturning. It is crucial to ensure that the foundation can safely support the loads without excessive settlement or tilting.
Retaining Walls:
In some cases, abutment foundations may also include retaining walls to support the approach embankments and prevent soil erosion. The design of these walls is also an essential part of the overall abutment foundation design.
Construction Materials:
The materials used for abutment foundations typically include reinforced concrete, steel, and sometimes additional materials for specialized foundations like piles. The choice of materials depends on the specific design requirements and the local construction practices.
Drainage and Waterproofing:
Adequate drainage and waterproofing measures are incorporated into the abutment foundation design to prevent the buildup of water pressure behind the abutment and to protect the foundation from potential water-related issues.
Construction and Quality Control:
During construction, careful monitoring and quality control measures are implemented to ensure that the abutment foundation is built according to the design specifications. This includes conducting load tests on piles and verifying the foundation's performance before the bridge's superstructure is constructed.

Overall, the design of abutment foundations is a complex process that requires collaboration between geotechnical engineers, structural engineers, and bridge designers. By carefully considering the site conditions and applying engineering principles, a well-designed abutment foundation can provide a stable and durable support system for bridges, ensuring their safe and efficient functioning for many years.

General Arrangement Drawing :-

1. Basic Design data: -

1.1. Span and Cross Section Data

1.1.1. C/C of expansion gap

14.40

(Sq.)

1.1.2. C/C of Bearing

13.40

(Sq.)

1.1.3. Distance of bearing to expansion gap

0.50

(Sq.)

1.1.4. Carriage way width

9.00

1.1.5. Total Width

12.00

1.1.6. Footpath width (left Side) or Parapet

0.50

1.1.7. Footpath width (right Side)

1.50

1.1.8. Crash Barrier (Left Side)

0.50

1.1.9. Crash barrier (Right Side)

0.50

1.1.10. Handrail width (Left Side)

1.1.11. Handrail (right Side)

1.1.12. Skew Angle

00.00 radians

1.2. Super-Structure Details:

1.2.1. Depth of superstructure (Min)

1.60

1.2.2. Depth of superstructure (Max)

1.60

1.2.3. Depth of superstructure

0.88

1.2.4. Thickness of wearing coat

0.065

1.2.5. No of Girder

4.00

1.2.6. Distance of FRL from bearing of least height

10.90

1.2.7. Spacing between girder

3.00

1.2.8. Cross-slope

2.5%

1.2.9. Thickness of bearing

0.07

1.2.10. Thickness of pedestal

0.25

1.2.11. Minimum Thickness of wedge

1.2.12. Thickness of bearing +pedestal

0.315

1.3. Material Data:-

1.3.1. Grade of Concrete

f_ck

M 35

1.3.2. Design strength of Concrete

f_cd

15.63

MPa

(Cl.6.4.2.8,IRC:112-2020,Page-38)

1.3.3. Grade of steel

f_yk

Fe 500

1.3.3. Design strength of Steel

f_yd

434.78

1.3.4. Density of concrete

2.50

t/m³

1.3.5. Density of wearing coat

2.20

t/m³

1.3.6. Co-efficient of thermal expansion of concrete

1.20E-05

/^oC

(Cl.215.4,IRC:6-2014)

1.3.7. Shrinkage Strain

2.00E-04

(Cl.217.3,IRC:6-2014)

1.3.8. Modulus of elasticity of steel

E_s

2.00E+05

MPa

1.3.9. Modulus of elasticity of Concrete

E_s

3.20E+04

MPa

1.3.10.Mean Axial Tensile strength of concrete f_tm

f_ctm

2.80

MPa

1.4. Typical Levels:-

1.4.1. Formation Level FRL

234.065

1.4.2. Dirt wall Level

234.065

1.4.3. Bearing Level

232.180

1.4.4. Max.Abutment Cap level

231.850

1.4.5. Stem top level

1.4.6. Front Ground Level -GL

228.000

1.4.7. Scour Level(MSL)

226.580

1.4.8. Footing top level

225.250

1.4.9. Minimum Founding Level required from scour calculations

1.4.10. Founding level(Design) FL, considering and geo-tech. reqd.

224.250

1.4.11. Height Flood Level, HFL

229.500

1.4.12. Height from bearing top to deck top level(excl.WC)

1.820

1.5. Soil Parameters:-

1.5.1. Angle of shear resistance “

1.5.2. Density of dry backfill “

2.00

t/m³

1.5.3. Density of submerged backfill, “

1.00

t/m³

1.5.4. Net Bearing Capacity

25.00

t/m²

1.5.5. Gross Safe bearing capacity (LWL)

33.42

t/m²

1.5.6. Gross Safe bearing capacity (HFL)

27.00

t/m²

1.5.7. Live load surcharge

1.20

1.5.8. Type of soil

Medium Soil

1.5.9. Co-efficient of friction between the. (soil/rock & Concrete)

0.50

1.6. Abutment Dimensions(square): -

1.6.1. Length of abutment cap in L-L Directions at Top

1.64

1.6.2. Length of abutment cap in L-L Directions at Bottom

1.00

1.6.3. Width of abutment(sqr)

12.00

1.6.4. Width of median wall

3.50

1.6.5. Width of footings(sqr)

8.50

1.6.6. Width of heel(sqr)

5.00

1.6.7. Minimum footings thickness

0.30

1.6.8. Heel thickness at root

1.00

1.6.9. Toe thickness at root

1.00

1.6.10.Stem top thickness(straight)

1.00

1.6.11. Stem bottom thickness(straight)

1.00

1.6.12. Dirt wall Thickness

0.30

1.6.13.Depth of Abutment Cap (Constant Portion)

0.30

1.6.14. Depth of Abutment Cap (Varying Portion)

0.30

1.6.15.Thickness of return wall (Avg)

0.50

1.6.16.No of return wall

1.00

1.6.17. Horizontal distance of CG of abutment shaft from vertical face

0.50

1.6.18.Provision of weep holes in abutment wall

Yes

1.6.19 Distance between bearing c/l and shaft c/l in L-L Dimension

1.6.20 Width of toe

2.50

FRL

234.07

Dirt-Wall Top

234.07

1.557

BRG. Top Lvl

232.18

Abt.Cap Top Lvl

231.85

Abt.Shaft Top Lvl

231.25

228.00

MSL

226.58

FLT

225.25

224.25

HFL

229.50

Base Width

8.5

Heel

5.0

Toe

2.5

Stem Btm Width

1.0

Stem Top Width

1.0

Edge Thickness

0.3

Overall Height

1.0

Abt. Shaft H

6.0

1.8 Load Data:-

· Deal Load

o Total Weight of Superstructure

210.00

o Transverse eccentricity of DL from c/l of abutment

· SILD (excluding of wearing course)

o Self- weight of Crash Barrier

19.46

t/m

o Self- weight of Railing/ Parapet(One Side)

16.20

t/m

o Transverse eccentricity of crash barrier (with footpath case)

6.75

o Transverse eccentricity of crash barrier (without footpath case)

4.75

o Transverse eccentricity of Railing or Parapet

4.75

o Total Weight of footpath/services

8.10

o Transverse eccentricity of footpath/services

5.75

· SILD (including of wearing course)

o Load intensity due to wearing course

0.14

t/m²

Assume, W/C is 100mm thk.

o Transverse eccentricity of wearing course (with footpath case)

o Transverse eccentricity of wearing course (without footpath case)

· FPLL:

o Maximum intensity of footpath live load

500.00

kg/m²

Cl.206.1,IRC:6-2014

· Live Load: - Cl 205, IRC:6-2014

o Load % to be taken after reduction (in case of three Lane)

90%

Cl.205,IRC:6-2014

o Fraction of live load remaining is seismic

o 1 Lane 70R -Wheeled

123.00

Refer LL calcualtion

o CG

§ Load

o 1 Lane Class -A

68.14

Refer LL calcualtion

§ Load

o Load % to be taken after reduction (in case of three Lane)

90%

Cl.205,IRC:6-2014

o Fraction of live load remaining is seismic

1.9 Bearing Data:-

· Type of bearing

Elastomeric

· Elastomeric Bearing: -

o Length (Along traffic dim.)

500.00

o Width (Perpendicular to traffic)

250.00

o Thickness of each elastomer

10.00

o Number of internal elastomer layer

Nos

o Thickness of Outer elastomer layer

o Thickness of steel plate

o Overall thickness of bearing

65.00

o Clear cover to steel plate (Vertical)

6.00

o No of Steel plates

5.00

Nos

o Effective thickness of the elastomeric bearing

heff

50.00

o Shear modulus

1.00

Mpa

o No of bearing over pier on support line

Nos

1.10 Clear Cover:-

· Dirt wall

50.00

· Abutment Cap

50.00

· Abutment Stem

75.00

· Footing

75.00

1.11 Seismic Data;-

· Seismic Zone

III

· Importance factor

1.20

· Response Reduction factor

1.50

Cl219.8,IRC:6

· Temperature Variation

47.50

· Condition of exposure

Moderate

· Factor by which seismic force is increased for design of fnd.

1.35

Cl219.8,IRC:6

1.12 Sign Convention: -

· Resisting moment (about toe)

Positive (+)

· Overturning Moment (about toe)

Negative (-)

· Horizontal Forces away from earth side

Positive (+)

· Horizontal Forces towards earth side

Negative (-)

· Downward force

Positive (+)

· Upward Forces uplift

Negative (-)

· In the transverse direction

o Eccentricity towards footpath

Positive (+)

o Eccentricity away from footpath

Negative (-)

Load Calculation from super-structure

Load calculations from superstructure

2.1

Deal load of superstructure

Total weight of super structure.

210.00

tonne

Reaction.

Total Weight/2

105.00

tonne

Total reaction on abutment

(210/2)

105.00

tonne

Distance between bearing & Cl of Abutment shaft

Longitudinal moment

(105*0)

t-m

Transverse eccentricity of dead load from c/l of abutment

Transverse moment.

(105*0)

t-m

2.2

SIDL(Crash barrier,railing,footpath)-Excluding Wearing Course

Crash barrier Weight

Weight of C/B*Span*2

35.66

Raling weigth

16.20

Footpath/services weight

8.10

Total reaction on abutment (SIDL excludinf W/c)

(59.96/2)

29.98

Longitudinal moment (Crash Barrier)

t-m

Longitudinal moment (Railing)

t-m

Longitudinal moment (footpath/services)

t-m

Total Longitudinal moment(SIDL Excl. W/C)

t-m

Transverse eccentricity of C/B

6.75

Transverse moment of C/B

240.67

t-m

Transverse eccentricity of Railing

4.75

Transverse moment of Railing

76.95

t-m

Transverse eccentricity of footpath/services

5.75

Transverse moment of footpath/services

46.58

t-m

Total Transverse moment(SIDL Excl. W/C)

364.20

t-m

2.3

SIDL(Including Wearing Course

Load Intensity due to wearing course

Weight of wc*span*cw

0.14

t/m²

DL of Wearing Course

18.53

Total reaction on abutment (SIDL excluding W/c)

(18.53/2)

9.27

Longitudinal Moment( wearing Course)

t-m

Transverse eccentricity of wearing Course

Transverse moment( wearing Course)

t-m

2.4

Summary of loads from superstructure

With Footpath Case

At Bearing Level

Load Item

t-m

Deal Load

105.00

SIDL-Excluding W/C

29.98

SIDL-including W/C

9.27

At Abutment shaft bottom level

Load Item

t-m

Deal Load

105.00

SIDL-Excluding W/C

29.98

SIDL-including W/C

9.27

At Foundatiion bottom level

Distance from centre of abutment to toe

toe width+shaft width/2

3.00

P*eccentricity

Load Item

ML(about toe)

MT(about footing c/l

t-m

Deal Load

105.00

315.00

99.5x2.2 with respect to toe

SIDL-Excluding W/C

29.98

89.93

SIDL-including W/C

9.27

27.80

Calcualtion of Active & Passive earth pressure co-efficients.

Earth pressure co-efficient calcualtion

from Geo-technical report

Degree

radians

𝐴𝑙𝑝ℎ𝑎(𝛼)

1.57

alpha( a )

Inclination of the wall with horizontal

𝐵𝑒𝑡𝑎(𝛽)

0.00

Beta(b)

Angle of fill with horizontal

𝐷𝑒𝑙𝑡𝑎(𝛿)

0.35

delta(d)

friction between wall and the soil

𝑃ℎ𝑖(∅)

0.52

Phi(p)

Angle of internal friction of soil

sin(𝛼+∅)

0.866025

sin(𝛼-∅)

0.866025

cos(𝛼+∅)

-0.5

sin(𝛼)

cos(𝛿-𝛼)

0.3420201

sin(𝛼-𝛿)

0.939693

sin(𝛼+𝛿)

0.939693

cos(𝛼)

6.126E-17

cos(𝛼-𝛽)

6.126E-17

sin(∅+𝛿)

0.766044

sin(∅+𝛿)

0.766044

sin(∅-𝛽)

0.5

sin(∅+𝛽)

0.5

sin(𝛼-𝛽)

sin(𝛼+𝛽)

By Coulombs formula

0.290

3.447

On resolving into horizontal & vertical components

Kah

ka*cos(𝛿)

Kph

kp*cos(𝛿)

Kah

0.273

Kph

3.239

Kav

ka*sin(𝛿)

Kpv

kp*sin(𝛿)

Kav

0.099

Kpv

1.179

1 Lane-70R Wheeled Loading:

Live load Reactions
	Ra	(123*(13.4-8.2762)/13.4)		=	47.03	t
	Rb	(123-47.03)		=	75.97	t
Total Load of 70R vehicle				=	100.00	t

Total Load of 70R vehicle according this span				=	100.00	t
Total Load (including Impact)			(100*1.23)	=	123.00	t


total length of 70R vehicle		3.96+1.52+2.13+1.37+3.05+1.37		=	13.4	m
CG Calculation	(80+123.96+125.48+177.61+178.98+1712.03+17*13.4)/100			=	8.276	m
Vertical reaction on abutment				=	75.97	t
Braking Force	(123* of 20%)			=	24.60	t
Change in reaction due to braking force			(24.6*(1.2+0.065+1.82)/13.4)	=	5.66	t
Max. Verical force on Abutment				=	81.63	t
Mini. Vertical force on abutment				=	70.30	t
longitudinal moment				=	-	t-m
Total Horozontal force at bearing level			Fh/2	=	12.30	t
Total Horozontal force (Longitudinal)			HL	=	12.30	t
Total Horozontal force (transverse)			HT	=	-	t

	Transverse Eccentricity	(12/2-(1.2+0.5+2.79/2)			=	2.905	m
	Transverse Moment on abutment			MT	=	237.14	t-m

1 lane Class - A (Cl.204,IRC:6-2014):-

Total Load of Class A vehicle		2.72+11.42+6.8*4		=	55.40	t
(depending on the span, wheels can be reduced)
Total Load of Class A vehicle according this span			(55.4-2.7*2-11.4)	=	38.60	t
Total Load (including Impact)		(4.5/(6+13.3)+1)		=	47.6	t
total length of Class A vehicle		1.1+3.2+1.2+4.3+3*3		=	18.80	m
Actual length of Class A vehicle		4.3+3*3		=	13.30	m
CG Calculation	(2.70+2.70+11.40+11.45.5+6.89.8+6.812.8+6.815.86.818.8)/38.6			=	6.20	m

Live load Reactions
	Ra	(47.59*(13.3-6.2)/13.3)		=	22.19	t
	Rb	(47.59-22.19)		=	25.40	t

Vertical reaction on abutment				=	25.40	t
Braking Force	(47.59* of 20%)			=	9.52	t
Change in reaction due to braking force			(9.52*(1.2+0.065+1.82)/13.3)	=	2.21	t
Max. Verical force on Abutment				=	27.61	t
Mini. Vertical force on abutment				=	23.20	t
longitudinal moment				=	-	t-m
Total Horozontal force at bearing level			Fh/2	=	4.76	t
Total Horozontal force (Longitudinal)			HL	=	4.76	t
Total Horozontal force (transverse)			HT	=	-	t

Transverse Eccentricity		(12/2-(0.15+0.5+2.3/2)		=	4.20	m
Transverse Moment				=	116.0	t-m

3	3 lane Class - A

Live load Reactions
	Ra	(322.19 of 90%)		=	59.91	t
	Rb	(325.4 of 90%)		=	68.59	t

Vertical reaction on abutment				=	68.59	t
Braking Force	(20% of 47.59+ 5% of 47.59%)*90%			=	10.71	t
Change in reaction due to braking force			(10.71*(1.2+0.065+1.82)/13.3)	=	2.50	t
Max. Verical force on Abutment				=	71.09	t
Mini. Vertical force on abutment				=	66.09	t
longitudinal moment				=	-	t-m
Total Horozontal force at bearing level			Fh/2	=	5.4	t
Total Horozontal force (Longitudinal)			HL	=	5.4	t
Total Horozontal force (transverse)			HT	=	-	t

Transverse Eccentricity		12/2-.5-.15-2.3-1.2-2.3/2		=	0.70	m
Transverse Moment				=	49.8	t-m

1 lane 70R +1 lane Class - A:-

Live load Reactions
	Ra	90% of (47.03+ 22.19)		=	62.30	t
	Rb	90% of (75.97+ 25.4)		=	91.23	t

Vertical reaction on abutment				=	91.23	t
Braking Force		(20% of 123+ 5% of 47.59%)*90%		=	24.28	t
Change in reaction due to braking force				=	6.1	t
(24.28*(1.2+0.065+1.82)/13.3)
Max. Verical force on Abutment				=	97.32	t
Mini. Vertical force on abutment				=	85.14	t
longitudinal moment				=	-	t-m
Total Horozontal force at bearing level			Fh/2	=	12.14	t
Total Horozontal force (Longitudinal)			HL	=	12.14	t
Total Horozontal force (transverse)			HT	=	-	t

Transverse Eccentricity of 70R-W		12/2-(0.5+1.2+2.79/2)		=	2.905	m
Transverse Eccentricity of Class-A			12/2-6.84	=	-0.84	m
Total Transverse Moment			MT	=	192.55	t-m
	(90% of (81.632.905+27.61-0.84)

Summary
Load Cae		Pmax	Pmin	ML	MT	HL	HT
		t	t	t-m	t-m	t	t
1 lane 70R-W		81.63	70.30	0	237.14	12.30	0
1 lane Class-A		27.61	23.20	0	115.97	4.76	0
3 lane Class -A		71.09	66.09	0	49.76	5.4	0
1 lane 70R-W+1 lane Class A		97.32	85.14	0	192.55	12.14	0

LL1	Maximum Reaction Case			97.32	t
LL2	Maximum Moment Case			237.14	t-m
At Bearing level
Longitudinal moment at bearing level,ML=HL*(FRL-bearing level+1.2)

		Pmax	Pmin	ML	MT	HL	HT
		t	t	t-m	t-m	t	t
LL1- Maximum Reaction		97.32	85.14	37.45	192.55	12.14	-
LL2- Max. MT		81.63	70.30	37.95	237.14	12.30	-


At Abutment shaft bottom level
		Pmax	Pmin	ML	MT	HL	HT
		t	t	t-m	t-m	t	t
LL1- Maximum Reaction		97.32	85.14	121.59	192.55	12.14	0
LL2- Max. MT		81.63	70.30	123.18	237.14	12.30	0


At Foundation bottom level
Longitudinal moment atfoundation bottom level,ML due HL =ML at bearing level +HL*(bearing level- founding level)
Longitudinal moment at foundation bottom level,ML due P =Pmax* distance between toe & centre of bearing
	Pmax	Pmin	ML due to HL(about toe)	ML due to P(about toe)	MT (about footing)	HL	HT
	t	t	t-m	t-m	t-m	t	t
LL1- Maximum Reaction	97.32	85.14	-133.73	291.97	192.55	12.14	0
LL2- Max. MT	81.63	70.30	-135.48	244.89	237.14	12.30	0

Calculation of forces due to Earth Pressure
Provision of weep holes in abutment wall	=	Yes
No hydrostatic force needs to be applied	=	0

Horizontal force due to earth pressure on abutment acts in L-L direction

Width of abutment(skew)

Horizontal earth pressure co-efficient

Kah

0.273

Horizontal earth pressure co-efficient

Kav

0.099

Width of median wall(skew)

3.5

Horizontal earth pressure co-efficient

Kah

0.273

Horizontal earth pressure co-efficient

Kav

0.099

Earth Pressure@Foundation bottom Level

Normal Case: LWL

H= Dirt wall top to Founding level

9.815

Horizontal force in long. L-L Dimension

315.16

Lever arm from abutment shaft bottom

0.42*H

4.12

Moment along L-L

-1,299.20

t-m

Abutment Portion

:LWL

Vertical force

114.71

Lever arm from toe

Base width of foundation

7.5

Total Moment along L-L

860.33

t-m

Summary of forces at foundation bottom level

Normal Case

ML due to HL(abouttoe

ML due to P(about toe)

t-m

LWL

114.71

315.16

-1,299.20

860.33

HFL

94.50

266.20

942.88

708.50

Live load surcharge

Abutment shaft Bottom level

Normal Case: Abutment Portion

9.625

Horizontal force

Kah*y*1.2*H*b

77.3388

Lever arm

H/2-rectangualar shape

4.8125

372.192975

t-m

Summary of forcesdue to live load surcharge at abutment shaft bottom level

Normal Case

ML due to HL(abouttoe

t-m

LWL

77.34

372.19

HFL

77.34

372.19

Normal Case: Abutment Portion

LWL

to Foundation bottom

Dirtwall top level- founding level

9.815

Horizontal force

Kah*y*1.2*H*b

77.07

Lever arm

H/2-rectangualar shape

4.91

Anti-clockwise

-378.20

t-m

HFL

Total Horizontal force in long Dimension

77.06500392

-378.196507

Summary of forcesdue to live load surcharge at Foundation bottom level

Normal Case

ML due to HL(abouttoe

t-m

LWL

77.07

-378.20

HFL

77.07

-378.20

Calculation of forces on Abutment and Foundation
Calculation of forces on Abutment and Foundation
Abutment Dimensions (square) as shown below:-

Width of abutment

12.00

Return wall in on

1 side

horizontal distance of CG abutment shaft from vertical face

0.5

Normal case

Component

Weight

Horizontal lever arm from bearing c/l

Horizontal lever arm from toe

ML About toe

t-m

Dirt- wall bracket

4.05

0.953

3.86

3.970

16.08

Dirt- wall

19.935

0.670

13.36

3.670

73.16

Abutment Cap

26.64

0.00

3.000

79.92

Abutment Shaft

180

0.00

3.000

540.00

Total

230.625

17.22

709.160

Hor. Eccentricity of weight of sub-structure from c/l of bearing

0.07

Width of abutment shaft at HFL

Volume of abutment shaft submerged in water

63.00

m³

Bouyancy on abutment shaft

-63

Longitudinal Movement due to bouyancy about toe

-189

t-m

Summary of forces at abutment shaft bottom level

Normal Case

LWL

Component

Pmax

Pmin

t-m

Weigth of sub-structure

230.625

17.22

HFL

Component

Pmax

Pmin

t-m

Weigth of sub-structure

230.625

17.22

Bouyancy

-63

-189

Calcualtion of weight of foundation

Rectangular Part

Volume

30.60

m³

Weight

76.50

Trapezoidal Part

Volume

39.9

m³

Weight

99.75

Total Volume of Foundation

70.50

m³

Total weight of Foundation

176.25

Bouancy force on foundation

-70.50

Lever arm from toe

Base width/2

4.25

Moment due to wt of foundation

749.06

t-m

Moment due to buoyancy force on foundation about toe

-299.63

t-m

Calculation for Return wall

Portion

Weight

Hor. Lever arm from toe in L-L dimension

ML about toe

t-m

51.6

6.16

317.7

2.4

3.66

8.8

0.06

3.71

0.2

2.2

5.90

12.9

Total

56.2

339.6

Hor. Eccentricity of CG of return wall from toe in longitudinal dir.

6.04

Hor. Eccentricity of CG of return wall from toe in tranverse dir.

5.75

Total moment in transverse direction

323.22

t-m

Submerged height of return wall in HFL case upto foundation top level

Submerged volume of return wall

m³

longitudinal moment due to buoyancy force on return wall

t-m

transverse moment due to buoyancy force about centre line of footing

t-m

Calculation of Backfill Weight

width oof backfill in transverse direction(skew)

One side consider

11.50

LWL

Portion

Weight

Hor. Lever arm from toe in L-L dimension

ML about toe

t-m

948.85

6.16

5844.9

44.16

3.66

161.6

1.10

3.71

4.1

38.64

6.83

264.0

Total

1032.8

6274.7

HFL

Portion

Weight

Hor. Lever arm from toe in L-L dimension

ML about toe

t-m

689.34

5.26

3625.9

15.64

2.86

44.7

1.10

2.91

3.2

19.32

5.90

114.0

Total

725.4

3787.9

Summary of forces at foundation bottom level

Normal Case: LWL

Components

P_max

P_min

ML due to HL about toe

ML due to P about toe

t-m

Weigth of Sub-structure

230.63

709.16

Weigth of foundation

176.25

749.06

Weight of Return Wall

56.21

339.56

323.22

Weight og Backfill

1,032.75

6,274.66

Load combination( Limit limited )

Overturning and sliding stability.

Ultimate limit state( For Verification of Equilibrium)

Basic Combination

Overturinig stability

Sliding Stability

Legends

LWL( Lower Water Level)

Overturning

1.1

Maximum Reaction case

1.1

Maximum Reaction case

Sliding

1.2

Maximum Moment case

1.2

Maximum Moment case

Uplift

HFL( Height Flood Level)

resisting

2.1

Maximum Reaction case

2.1

Maximum Reaction case

FOS

Factor of Safety

2.2

Maximum Moment case

2.2

Maximum Moment case

F_o

FOS for Overturnung

F_s

FOS for Sliding

Oveturining Stability

Moment along Longitudial

LWL

1.1

Maximum Reaction case

Unfactored ML ( About toe)

Remarks

Partial safety factor

factored ML ( About toe)

factored Overturing ML ( About toe)

factored Resistaing ML ( About toe)

t-m

DL-Sup

315.00

0.95

299.25

SIDL(exclu.W/C)

89.93

0.95

85.44

SIDL(W/C)

27.80

1.00

27.80

LL1

Due to HL

-133.73

1.50

-200.60

Due to P

291.97

EPLL1

1.15

Shearing Rating

-43.1

1.00

-43.10

Earth Pressure

Due to HL

-1,299.20

1.50

-1,948.80

Due to P

860.33

LL Surcharge

Due to HL

-378.20

1.20

-453.84

Weight of Sub-structure

709.16

0.95

673.70

Weight of Foundation

749.06

0.95

711.61

Return Wall Weight

339.56

0.95

322.58

Backfill Weight

6,274.66

0.95

5,960.93

Service Condiation

-1

M_O

-2,646.33

Overturning Moment

M_R

8,081.30

Resisting moment

F_o

3.05

factor of safety

1.2

Maximum Moment case

Unfactored ML ( About toe)

Remarks

Partial safety factor

factored ML ( About toe)

factored Overturing ML ( About toe)

factored Resistaing ML ( About toe)

t-m

DL-Sup

315.00

0.95

299.3

299.25

SIDL(exclu.W/C)

89.93

0.95

85.4

85.44

SIDL(W/C)

27.80

27.8

27.80

LL2

Due to HL

-135.48

1.5

-203.2

-203.23

Due to P

244.89

0.0

EPLL1

1.15

0.0

Shearing Rating

-43.1

-43.10

Earth Pressure

Due to HL

-1,299.20

1.5

-1948.8

-1,948.80

Due to P

860.33

0.0

LL Surcharge

Due to HL

-378.20

1.2

-453.8

-453.84

Weight of Sub-structure

709.16

0.95

673.7

673.70

Weight of Foundation

749.06

0.95

711.6

711.61

Return Wall Weight

339.56

0.95

322.6

322.58

Backfill Weight

6,274.66

0.95

5960.9

5,960.93

Service Condiation

M_O

-2,648.96

Overturning Moment

M_R

8,081.30

Resisting moment

F_o

3.05

factor of safety

HFL

2.1

Maximum Reaction case

Unfactored ML ( About toe)

Remarks

Partial safety factor

factored ML ( About toe)

factored Overturing ML ( About toe)

factored Resistaing ML ( About toe)

t-m

DL-Sup

315.00

0.95

299.3

299.25

SIDL(exclu.W/C)

89.93

0.95

85.4

85.44

SIDL(W/C)

27.80

27.8

27.80

LL1

Due to HL

-133.73

1.5

-200.6

-200.60

Due to P

291.97

0.0

EPLL1

1.15

0.0

Shearing Rating

-43.1

-43.10

Earth Pressure

Due to HL

-1,299.20

1.5

-1948.8

-1,948.80

Due to P

860.33

0.0

LL Surcharge

Due to HL

-378.20

1.2

-453.8

-453.84

Weight of Sub-structure

709.16

0.95

673.7

673.70

Bouyancy on structure

-189

-189.0

-189.00

Weight of Foundation

749.06

0.95

711.6

711.61

Bouyancy on foundation

-299.63

-299.6

-299.63

Return Wall Weight

339.56

0.95

322.6

322.58

Bouyancy on return wall

0.0

Backfill Weight

6,274.66

0.95

5960.9

5,960.93

Service Condiation

M_O

-3134.9575

Overturning Moment

M_R

8081.30259

Resisting moment

F_o

2.58

factor of safety

2.2

Maximum Moment case

Unfactored ML ( About toe)

Remarks

Partial safety factor

factored ML ( About toe)

factored Overturing ML ( About toe)

factored Resistaing ML ( About toe)

t-m

DL-Sup

315.00

0.95

299.3

299.25

SIDL(exclu.W/C)

89.93

0.95

85.4

85.44

SIDL(W/C)

27.80

27.8

27.80

LL2

Due to HL

-135.48

1.5

-203.2

-203.23

Due to P

244.89

0.0

EPLL1

1.15

0.0

Shearing Rating

-43.1

-43.10

Earth Pressure

Due to HL

-1,299.20

1.5

-1948.8

-1,948.80

Due to P

860.33

0.0

LL Surcharge

Due to HL

-378.20

1.2

-453.8

-453.84

Weight of Sub-structure

709.16

0.95

673.7

673.70

Bouyancy on structure

-189

-189.0

-189.00

Weight of Foundation

749.06

0.95

711.6

711.61

Bouyancy on foundation

-299.625

-299.6

-299.63

Return Wall Weight

339.56

0.95

322.6

322.58

Bouyancy on return wall

0.0

Backfill Weight

6,274.66

0.95

5960.9

5,960.93

Service Condiation

M_O

-3137.5869

Overturning Moment

M_R

8081.30259

Resisting moment

F_o

2.58

factor of safety( overturning

Sliding Stability

LWL

1.1

Maximum Reaction case

Unfactored HL

Remarks

Partial safety factor

factored HL

Unfactored P_min

Remarks

Partial safety factor

factored P_min

DL-Sup

0.95

0.0

105.00

0.95

99.8

SIDL(exclu.W/C)

0.95

0.0

29.98

0.95

28.5

SIDL(W/C)

0.0

9.27

9.3

LL1

12.14

1.5

18.2

85.1

0.0

EPLL1

0.0

1.15

0.0

Shearing Rating

4.8

0.0

Earth Pressure

315.16

1.5

472.7

114.71

0.0

LL Surcharge

77.07

1.2

92.5

0.0

1.2

0.0

Weight of Sub-structure

0.95

0.0

230.625

0.95

219.1

Weight of Foundation

0.95

0.0

176.25

0.95

167.4

Return Wall Weight

0.95

0.0

56.2115

0.95

53.4

Backfill Weight

0.95

0.0

1032.7506

0.95

981.1

Service Condiation

588.2

1558.5

0.50

F_s

1.32

1.2

Maximum Moment case

Unfactored HL

Remarks

Partial safety factor

factored HL

Unfactored P_min

Remarks

Partial safety factor

factored P_min

DL-Sup

0.95

0.0

105.00

0.95

99.8

SIDL(exclu.W/C)

0.95

0.0

29.98

0.95

28.5

SIDL(W/C)

0.0

9.27

9.3

LL2

12.30

1.5

18.5

85.1

0.0

EPLL1

0.0

1.15

0.0

Shearing Rating

4.80

4.8

0.0

Earth Pressure

315.16

1.5

472.7

114.71

0.0

LL Surcharge

77.07

1.2

92.5

0.0

1.2

0.0

Weight of Sub-structure

0.95

0.0

230.63

0.95

219.1

Weight of Foundation

0.95

0.0

176.25

0.95

167.4

Return Wall Weight

0.95

0.0

56.21

0.95

53.4

Backfill Weight

0.95

0.0

1,032.75

0.95

981.1

Service Condiation

588.5

1558.5

0.50

F_s

1.32

HFL

2.1

Maximum Reaction case

Unfactored HL

Remarks

Partial safety factor

factored HL

Unfactored P_min

Remarks

Partial safety factor

factored P_min

DL-Sup

0.95

0.0

105.00

0.95

99.8

SIDL(exclu.W/C)

0.95

0.0

29.98

0.95

28.5

SIDL(W/C)

0.0

9.27

9.3

LL1

12.14

1.5

18.2

85.1

0.0

EPLL1

0.0

1.15

0.0

Shearing Rating

4.8

0.0

Earth Pressure

315.16

1.5

472.7

114.71

0.0

LL Surcharge

97.32

1.2

116.8

0.0

1.2

0.0

Weight of Sub-structure

0.95

0.0

230.625

0.95

219.1

Bouyancy on structure

0.0

-63

176.3

Weight of Foundation

0.95

0.0

176.25

0.95

53.4

Bouyancy on foundation

0.0

-70.5

-63.0

Return Wall Weight

0.95

0.0

56.2115

0.95

167.4

Bouyancy on return wall

0.0

Backfill Weight

0.95

0.0

1032.7506

0.95

981.1

Service Condiation

612.55

1671.79

0.50

F_s

1.36

HFL

2.2

Maximum Moment case

Unfactored HL

Remarks

Partial safety factor

factored HL

Unfactored P_min

Remarks

Partial safety factor

factored P_min

DL-Sup

0.95

0.0

105.00

0.95

99.8

SIDL(exclu.W/C)

0.95

0.0

29.98

0.95

28.5

SIDL(W/C)

0.0

9.27

9.3

LL2

1.5

0.0

85.1

0.0

EPLL1

0.0

1.15

0.0

Shearing Rating

4.8

0.0

Earth Pressure

266.20

1.5

399.3

114.71

0.0

LL Surcharge

70.30

1.2

84.4

0.0

1.2

0.0

Weight of Sub-structure

0.95

0.0

230.625

0.95

219.1

Bouyancy on structure

0.0

99.75

99.8

Weight of Foundation

0.95

0.0

176.25

0.95

167.4

Bouyancy on foundation

0.0

-70.5

0.0

Return Wall Weight

0.95

0.0

56.2115

0.95

53.4

Bouyancy on return wall

0.0

Backfill Weight

0.95

0.0

1032.7506

0.95

981.1

Service Condiation

488.47

1658.29

0.50

F_s

1.70

Summary

Normal

FOS against Overturing

FOS against Sliding

Service Condition

F_overturning

Check

F_sliding

Check

1.1

3.05

1.32

1.2

3.05

1.32

2.1

2.58

1.36

2.2

2.58

1.70

Combination of Base Pressure( Open Foundation) Annex B,IRC 6:2014

Following Limit states are considered

Ultimate Limit State(For Verification of Equilibrium)

A-1

Basic Combination

Ultimate Limit State(For Verification of structural strength)

B-1

Basic Combination

Serviceability Limit State(SLS)

C-1

Rare combination(For Checking stress limits)

C-2

Quasi-permanent combination(for checking crack width in RCC structure)

Combination for Design of Foundation

D-1

Combination -01

D-2

Combination -02

Overturning & Sliding Stability

Normal case

LWL

1.1

Maximum Reaction case

1.2

Maximum Moment case

HFL

2.1

Maximum Reaction case

2.2

Maximum Moment case

Span present Condition

LWL

1.1

Maximum Reaction case

Load Item

Unfactored

P_max

P_min

ML due to HL about toe

ML due to P about toe

t-m

DL-Sup

105.00

315.00

SIDL(exclu.W/C)

29.98

89.93

SIDL(W/C)

9.27

27.80

LL1

97.32

85.14

-133.73

291.97

192.55

EPLL1

Shearing Rating

-43.10

Earth Pressure

315.16

-1,299.20

860.33

LL Surcharge

-378.20

Weight of Sub-structure

230.63

709.16

Weight of Foundation

176.25

749.06

Return Wall Weight

56.21

339.56

323.22

Backfill Weight

1,032.75

6,274.66

Total

2,052.57

2,040.39

-1,854.23

9,657.47

515.77

Eccentricity of vertical load from c/l of footing

(ML due to P/Load P)-(width of footing/2)

Eccentricity of vertical load from c/l of footing

0.455

Longitudinal Moment about c/l of footing

920.18

t-m

1.2

Maximum Moment case

Load Item

Unfactored

P_max

P_min

ML due to HL about toe

ML due to P about toe

t-m

DL-Sup

105.00

99.50

315.00

SIDL(exclu.W/C)

29.98

13.30

89.93

SIDL(W/C)

9.27

16.10

27.80

LL2

81.63

70.30

-135.48

244.89

237.14

EPLL1

Shearing Rating

-43.10

Earth Pressure

315.16

-1,299.20

1,033.16

LL Surcharge

-378.20

Weight of Sub-structure

230.63

709.16

Weight of Foundation

176.25

749.06

Return Wall Weight

56.21

339.56

323.22

Backfill Weight

1,032.75

6,274.66

Total

2,036.88

2,010.21

-1,855.98

9,783.23

560.36

Eccentricity of vertical load from c/l of footing

(ML due to P/Load P)-(width of footing/2)

Eccentricity of vertical load fron c/l of footing

0.553

Longitudinal Moment about c/l of footing

729.48

t-m

Summary

Service Condition

P_max

P_min

t-m

1.1

2,052.57

2,040.39

920.18

515.77

1.2

2,036.88

2,010.21

729.48

560.36

2.1

1721

1713.1

321.7

488.3

2.2

1701.4

1693.5

291.5

530.4

Base Pressure for Design of Foundation

Area of Base

8.5*12

102.00

m²

Longinitudinal Section Modulus

12*8.5^2/6

Z_L

144.50

m³

Transverse Section Modulus

8.5*12^2/6

Z_T

204.00

m³

Combination of Base pressure for foundation

Span Present Condition

Forces/Moments

For P_max

For P_min

P_max

P_min

P/A+ML/Zl+MT/Zt

P/A+ML/Zl-MT/Zt

P/A-ML/Zl-MT/Zt

P/A-(ML/Zl+MT/Zt)

P/A+ML/Zl+MT/Zt

P/A+ML/Zl-MT/Zt

P/A-ML/Zl-MT/Zt

P/A-(ML/Zl+MT/Zt)

t-m

t/m²

1.1

2,052.57

2,040.39

920.18

515.77

29.0

24.0

11.2

16.3

28.9

23.8

11.1

16.2

1.2

2,036.88

2,010.21

729.48

560.36

27.8

22.3

12.2

17.7

27.5

22.0

11.9

17.4

2.1

1,721.00

1,713.10

321.70

488.30

21.5

16.7

12.3

17.0

21.4

16.6

12.2

17.0

2.2

1,701.40

1,693.50

291.50

530.40

21.3

16.1

12.1

17.3

21.2

16.0

12.0

17.2

LWL

Normal

Maximum Axial Force Condition

Maximum Base Pressure

29.0

t/m2

Maximum Base Pressure

29.0

t/m2

Minimum Base Pressure

11.2

t/m2

Minimum Base Pressure

11.2

t/m2

Maximum Base Pressure

29.0

t/m2

<33.42

t/m²

Gross Pressure

Minimum Base Pressure

11.2

t/m2

t/m²

HFL

Normal

Maximum Axial Force Condition

Maximum Base Pressure

21.5

t/m2

Maximum Base Pressure

21.5

t/m2

Minimum Base Pressure

12.0

t/m2

Minimum Base Pressure

12.0

t/m2

Maximum Base Pressure

21.5

t/m2

Minimum Base Pressure

12.0

t/m2

Combination for Design of Foundation

D-1 Combination-01(ULS)

LWL

1.1

Maximum Reaction case

1.2

Maximum Moment case

HFL

2.1

Maximum Reaction case

2.2

Maximum Moment case

LWL

1.1

Maximum Reaction case

Partial Safety Factor

Unfactored

factored

P_max

P_min

ML due to HL about toe

ML due to P about toe

P_max

P_min

ML due to HL about toe

ML due to P about toe

t-m

DL-Sup

1.35

105.00

315.00

141.75

425.25

SIDL(exclu.W/C)

1.35

29.98

89.93

40.47

121.41

SIDL(W/C)

1.75

9.27

27.80

16.22

48.65

LL1

1.30

97.32

85.14

-133.73

291.97

192.55

126.52

110.69

-173.85

379.57

250.32

EPLL1

1.20

Shearing Rating

0.90

-43.10

-38.79

Earth Pressure

1.50

315.16

-1,299.20

860.33

472.75

-1,948.80

1,290.49

LL Surcharge

1.20

-378.20

-453.84

Weight of Sub-structure

1.35

230.63

709.16

311.34

957.37

Weight of Foundation

1.35

176.25

749.06

237.94

1,011.23

Return Wall Weight

1.35

56.21

339.56

339.40

75.89

458.40

458.19

Backfill Weight

1.35

1,032.75

6,274.66

1,394.21

8,470.79

Total

2817.1

2801.2

-2615.3

13163.2

708.5

Eccentricity of vertical load from c/l of footing

(ML due to P/Load P)-(width of footing/2)

Eccentricity of vertical load fron c/l of footing

0.423

Longitudinal Moment about c/l of footing

1,424.73

t-m

1.2

Maximum Moment case

Unfactored

factored

Partial Safety Factor

P_max

P_min

ML due to HL about toe

ML due to P about toe

P_max

P_min

ML due to HL about toe

ML due to P about toe

t-m

DL-Sup

1.35

105.00

105

315.00

141.8

0.0

425.3

0.0

SIDL(exclu.W/C)

1.35

29.98

29.977632

89.93

40.5

0.0

121.4

0.0

SIDL(W/C)

1.75

9.27

9.2664

27.80

16.2

0.0

48.6

0.0

LL2

1.5

81.63

70.30

-135.48

244.89

237.14

122.4

105.5

-203.2

367.3

355.7

EPLL2

1.2

0.0

Shearing Rating

0.9

-43.1

0.0

-38.8

0.0

Earth Pressure

1.5

315.16

-1,299.20

860.33

0.0

472.7

-1948.8

1290.5

0.0

LL Surcharge

1.2

-453.5

0.0

-544.2

0.0

Weight of Sub-structure

1.35

230.63

230.625

709.16

311.3

0.0

957.4

0.0

Weight of Foundation

1.35

176.25

749.06

237.9

0.0

1011.2

0.0

Return Wall Weight

1.35

56.21

56.2115

339.56

323.22

75.9

0.0

458.4

436.3

Backfill Weight

1.35

1,032.75

1032.7506

6,274.66

1394.2

0.0

8470.8

0.0

Total

2813.0

2796.0

-2735.0

13150.9

792.1

Eccentricity of vertical load from c/l of footing

(ML due to P/Load P)-(width of footing/2)

Eccentricity of vertical load fron c/l of footing

0.425

Longitudinal Moment about c/l of footing

1,539.37

t-m

HFL

2.1

Maximum Reaction case

Unfactored

factored

Partial Safety Factor

P_max

P_min

ML due to HL about toe

ML due to P about toe

P_max

P_min

ML due to HL about toe

ML due to P about toe

t-m

DL-Sup

1.35

99.5

218.9

134.3

0.0

295.5

0.0

SIDL(exclu.W/C)

1.35

13.3

29.3

18.0

0.0

39.5

0.0

SIDL(W/C)

1.75

16.1

25.4

28.2

0.0

62.0

0.0

LL1

1.5

85.4

77.5

-115.6

187.9

148.9

128.1

116.3

-173.5

281.8

223.4

EPLL1

1.2

0.0

Shearing Rating

0.9

-43.1

0.0

-38.8

0.0

Earth Pressure

1.5

94.5

-1686.4

1033.2

0.0

141.8

-1618.2

1062.9

0.0

LL Surcharge

1.2

-453.5

0.0

-544.3

0.0

Weight of Sub-structure

1.35

262.1

577.9

353.8

0.0

780.2

0.0

Buoyancy on sub.str

-89.1

-195.9

-89.1

0.0

-195.9

0.0

Weight of Foundation

1.35

156.8

587.8

211.6

0.0

793.5

0.0

Buoyancy on Foundation

-62.7

-235.1

-62.7

-235.1

Return Wall Weight

1.35

304.6

339.4

79.7

0.0

411.2

458.2

Buoyancy on return wall

0.0

Backfill Weight

1.35

1086.1

5604.1

1466.2

0.0

7566.5

0.0

Total

2409.8

2398.0

-2374.8

10862.1

681.6

Eccentricity of vertical load fron c/l of footing

0.8

Longitudinal Moment about c/l of footing

551.00

t-m

2.2

Maximum Moment case

Unfactored

factored

Partial Safety Factor

P_max

P_min

ML due to HL about toe

ML due to P about toe

P_max

P_min

ML due to HL about toe

ML due to P about toe

t-m

DL-Sup

1.35

99.5

218.9

134.3

0.0

295.5

0.0

SIDL(exclu.W/C)

1.35

13.3

29.3

18.0

0.0

39.5

0.0

SIDL(W/C)

1.75

16.1

25.4

28.2

0.0

62.0

0.0

LL1

1.5

65.8

57.8

-116

144.7

191.0

98.7

86.7

-173.5

217.0

286.5

EPLL1

1.2

0.0

Shearing Rating

0.9

-43.1

0.0

-38.8

0.0

Earth Pressure

1.5

94.5

-1686.4

1033.2

0.0

141.8

-1618.2

1062.9

0.0

LL Surcharge

1.2

-453.5

0.0

-544.3

0.0

Weight of Sub-structure

1.35

262.1

577.9

353.8

0.0

780.2

0.0

Buoyancy on sub.str

-89.1

-195.9

-89.1

0.0

-195.9

0.0

Weight of Foundation

1.35

156.8

587.8

211.6

0.0

793.5

0.0

Buoyancy on Foundation

-62.7

-235.1

-62.7

-235.1

Return Wall Weight

1.35

304.6

339.4

79.7

0.0

411.2

458.2

Buoyancy on return wall

0.0

Backfill Weight

1.35

1086.1

5604.1

1466.2

0.0

7566.5

0.0

Total

2380.4

2368.4

-2374.8

10797.3

744.7

Eccentricity of vertical load fron c/l of footing

0.8

Longitudinal Moment about c/l of footing

505.80

t-m

Summary

Service Condition

P_max

P_min

t-m

1.1

2,817.08

2,801.25

1,424.73

708.51

1.2

2,813.01

2,796.02

1,539.37

792.05

2.1

2,409.83

2,397.98

551.00

681.60

2.2

2,380.43

2,368.43

505.80

744.70

Combination for design of Foundation

D-2 Combination-02(SLS)

LWL

1.1

Maximum Reaction case

1.2

Maximum Moment case

HFL

2.1

Maximum Reaction case

2.2

Maximum Moment case

LWL

1.1

Maximum Reaction case

Unfactored

factored

Partial Safety Factor

P_max

P_min

ML due to HL about toe

ML due to P about toe

P_max

P_min

ML due to HL about toe

ML due to P about toe

t-m

DL-Sup

105.00

315.00

105.00

315.00

SIDL(exclu.W/C)

29.98

89.93

29.98

89.93

SIDL(W/C)

9.27

27.80

9.27

27.80

LL1

1.3

97.32

85.14

-133.73

291.97

192.55

126.52

110.69

-173.85

379.57

250.32

EPLL1

Shearing Rating

0.8

-43.10

-34.48

Earth Pressure

1.3

315.16

-1,299.20

860.33

409.71

-1,688.96

1,118.42

LL Surcharge

372.19

Weight of Sub-structure

230.63

709.16

230.63

709.16

Weight of Foundation

176.25

749.06

176.25

749.06

Return Wall Weight

56.21

339.56

339.40

56.21

339.56

339.40

Backfill Weight

1,032.75

6,274.66

1,032.75

6,274.66

Total

2176.3

2160.5

-1525.1

10003.2

589.7

Eccentricity of vertical load from c/l of footing

(ML due to P/Load P)-(width of footing/2)

Eccentricity of vertical load fron c/l of footing

0.346

Longitudinal Moment about c/l of footing

771.28

t-m

1.2

Maximum Moment case

Unfactored

factored

Partial Safety Factor

P_max

P_min

ML due to HL about toe

ML due to P about toe

P_max

P_min

ML due to HL about toe

ML due to P about toe

t-m

DL-Sup

105.00

315.00

105.00

315.00

SIDL(exclu.W/C)

29.98

89.93

29.98

89.93

SIDL(W/C)

9.27

27.80

9.27

27.80

LL2

1.3

81.63

70.30

-135.48

244.89

237.14

106.12

91.40

-176.13

318.36

308.28

EPLL2

Shearing Rating

0.8

-43.10

-34.48

Earth Pressure

1.3

315.16

-1,299.20

860.33

409.71

-1,688.96

1,118.42

LL Surcharge

372.19

Weight of Sub-structure

230.63

709.16

230.63

709.16

Weight of Foundation

176.25

749.06

176.25

749.06

Return Wall Weight

56.21

339.56

339.40

56.21

339.56

339.40

Backfill Weight

1,032.75

6,274.66

1,032.75

6,274.66

Total

2155.9

2141.2

-1527.4

9942.0

647.7

Eccentricity of vertical load from c/l of footing

(ML due to P/Load P)-(width of footing/2)

Eccentricity of vertical load fron c/l of footing

0.361

Longitudinal Moment about c/l of footing

748.06

t-m

HFL

2.1

Maximum Reaction case

Unfactored

factored

Partial Safety Factor

P_max

P_min

ML due to HL about toe

ML due to P about toe

P_max

P_min

ML due to HL about toe

ML due to P about toe

t-m

DL-Sup

105.00

105

218.9

105.0

0.0

218.9

0.0

SIDL(exclu.W/C)

29.98

29.977632

29.3

30.0

0.0

29.3

0.0

SIDL(W/C)

9.27

9.2664

25.4

9.3

0.0

25.4

0.0

LL1

1.3

97.32

77.5

-115.6

187.9

148.9

126.5

100.8

-150.3

244.3

193.6

EPLL1

0.0

Shearing Rating

0.8

-43.1

0.0

-34.5

0.0

Earth Pressure

1.3

315.16

-1,299.20

860.33

409.7

-1689.0

1118.4

0.0

LL Surcharge

-453.5

0.0

-453.5

0.0

Weight of Sub-structure

230.63

230.625

709.2

230.6

0.0

709.2

0.0

Buoyancy on sub.str

-63

-189.0

-63.0

0.0

-189.0

0.0

Weight of Foundation

176.25

749.1

156.8

0.0

749.1

0.0

Buoyancy on Foundation

-70.5

-235.1

-70.5

0.0

-235.1

0.0

Return Wall Weight

56.21

56.2115

339.6

339.4

56.2

0.0

339.6

339.4

Buoyancy on return wall

0.0

Backfill Weight

1,032.75

1032.7506

6274.7

1032.8

0.0

6274.7

0.0

Total

2023.4

1997.6

-2327.2

9284.6

533.0

Eccentricity of vertical load from c/l of footing

(ML due to P/Load P)-(width of footing/2)

Eccentricity of vertical load fron c/l of footing

0.339

Longitudinal Moment about c/l of footing

1,641.89

t-m

HFL Case

2.2

Maximum Moment case

Unfactored

factored

Partial Safety Factor

P_max

P_min

ML due to HL about toe

ML due to P about toe

P_max

P_min

ML due to HL about toe

ML due to P about toe

t-m

DL-Sup

105.00

105

218.9

105.0

0.0

218.9

0.0

SIDL(exclu.W/C)

29.98

29.977632

29.3

30.0

0.0

29.3

0.0

SIDL(W/C)

9.27

9.2664

25.4

9.3

0.0

25.4

0.0

LL2

1.3

81.63

70.30

-135.48

244.89

237.14

85.4

75.2

-176.1

318.4

308.3

EPLL1

0.0

Shearing Rating

0.8

-43.1

0.0

-34.5

0.0

Earth Pressure

1.3

315.16

-1,299.20

860.33

409.7

-1689.0

1118.4

0.0

LL Surcharge

-453.5

0.0

-453.5

0.0

Weight of Sub-structure

230.63

230.625

709.2

230.6

0.0

709.2

0.0

Buoyancy on sub.str

-63

-189.0

-63.0

0.0

-189.0

0.0

Weight of Foundation

176.25

749.1

156.8

0.0

749.1

0.0

Buoyancy on Foundation

-70.5

-235.1

-70.5

0.0

-235.1

0.0

Return Wall Weight

56.21

56.2115

339.6

339.4

56.2

0.0

339.6

339.4

Buoyancy on return wall

0.0

Backfill Weight

1,032.75

1032.7506

6274.7

1032.8

0.0

6274.7

0.0

Total

1982.2

1972.0

-2353.1

9358.7

647.7

Eccentricity of vertical load from c/l of footing

(ML due to P/Load P)-(width of footing/2)

Eccentricity of vertical load fron c/l of footing

0.471

Longitudinal Moment about c/l of footing

1,418.88

t-m

-2353+934.0750211663

Summary Comb-1

Service Condition

P_max

P_min

t-m

LWL

1.1

2,817.08

2,801.25

1,424.73

708.51

1.2

2,813.01

2,796.02

1,539.37

792.05

HFL

2.1

2,023.37

1,997.59

1,641.89

532.97

2.2

1,982.24

1,972.04

1,418.88

647.68

Base Pressure for Design of Foundation

Area of Base

102.00

m²

Corner-01

P/A+ML/Zl+MT/Zt

Longinitudinal Section Modulus

Z_L

144.50

m³

Corner-02

P/A+(ML/Zl-MT/Zt)

Transverse Section Modulus

Z_T

204.00

m³

Corner-03

P/A-ML/Zl-MT/Zt

-,-

Corner-04

P/A-ML/Zl+MT/Zt

-,+

Combination of Base pressure for foundation_ Ultimate Limit state (ULS)

D-1 Combination-01

Service Condition

Forces/Moments

For P_max

For P_min

P_max

P_min

P/A+ML/Zl+MT/Zt

P/A+ML/Zl-MT/Zt

P/A-ML/Zl-MT/Zt

P/A-(ML/Zl+MT/Zt)

P/A+ML/Zl+MT/Zt

P/A+ML/Zl-MT/Zt

P/A-ML/Zl-MT/Zt

P/A-(ML/Zl+MT/Zt)

t-m

t/m²

1.1

2,817.08

2,801.25

1,424.73

708.51

41.0

34.0

14.3

21.2

40.8

33.8

14.1

21.1

1.2

2,813.01

2,796.02

1,539.37

792.05

42.1

34.3

13.0

20.8

41.9

34.2

12.9

20.6

2.1

2,409.83

2,397.98

551.00

681.60

30.8

24.1

16.5

23.2

30.7

24.0

16.4

23.0

2.2

2,380.43

2,368.43

505.80

744.70

30.5

23.2

16.2

23.5

30.4

23.1

16.1

23.4

Combination-01

Critical Case for Design

Ultimate Limit state (ULS)

Maximum pressure at toe corresponding pressure at heel

Manimum pressure at heel corresponding pressure at toe

Corner1,2

Toe End

Corner 3,4

Heel End

LWL

HFL

LWL

HFL

Corner

Gross Pressure

Corner

Gross Pressure

Corner

Gross Pressure

Corner

Gross Pressure

t/m2

42.1

30.8

40.8

30.4

34.3

24.1

33.8

23.1

14.3

16.5

12.9

16.1

21.2

23.5

20.6

23.0

Combination of Base pressure for foundation

D-2 Combination-02

Summary Comb 2 Serviceability Limit state (SLS)

Service Condition

P_max

P_min

t-m

LWL

1.1

2,176.32

2,160.48

771.28

589.72

1.2

2,155.92

2,141.19

748.06

647.68

Service Condition

Forces/Moments

For P_max

For P_min

P_max

P_min

P/A+ML/Zl+MT/Zt

P/A+ML/Zl-MT/Zt

P/A-ML/Zl-MT/Zt

P/A-(ML/Zl+MT/Zt)

P/A+ML/Zl+MT/Zt

P/A+ML/Zl-MT/Zt

P/A-ML/Zl-MT/Zt

P/A-(ML/Zl+MT/Zt)

t-m

t/m²

1.1

2,176.32

2,160.48

771.28

589.72

29.6

23.8

13.1

18.9

29.4

23.6

13.0

18.7

1.2

2,155.92

2,141.19

748.06

647.68

29.5

23.1

12.8

19.1

29.3

23.0

12.6

19.0

2.1

2,023.37

1,997.59

1,641.89

532.97

33.8

28.6

5.9

11.1

33.6

28.3

5.6

10.8

2.2

1,982.24

1,972.04

1,418.88

647.68

32.4

26.1

6.4

12.8

32.3

26.0

6.3

12.7

Combination-02

Serviceability Limit state (SLS)

Maximum pressure at toe corresponding pressure at heel

Manimum pressure at heel corresponding pressure at toe

LWL

HFL

LWL

HFL

Corner

Gross Pressure

Corner

Gross Pressure

Corner

Gross Pressure

Corner

Gross Pressure

t/m2

29.6

33.8

29.3

32.3

23.8

28.6

23.0

26.0

13.1

6.4

12.6

5.6

19.1

12.8

18.7

10.83

Moment of Resistane of rectangular concrete section (as per IRC:112-2011)

Properties of Concrete

Grade of Concrete

From IRC 112,Table 6.5

M 35

Characteristic Strength of Concrete

f_ck

Mpa=N/mm²

Design compressive Strength of Concrete

f_cd

15.63

Mpa

f_cd

α*fck/𝛾𝑚

Tensile Strength of Concrete

f_ctm

2.80

Mpa

Table 6.5

Momulus of Elasticity of Concrete

E_cm

3.20E+04

Mpa

Partial Materials Safety Factor for Concrete

𝛾𝑚

1.5

Ultimate Compressive strain in the concrete

0.0035

Constant

0.67

Properties of Steel

Grade of Steel

Fe 500

Characteristic Strength of Steel

f_yk

500

Mpa=N/mm²

Momulus of Elasticity of Steel

E_s

2.00E+05

Mpa

Refer Cl.6.2.2 & 6.3.5,IRC:112-2011

Partial Materials Safety Factor for Steel

𝛾s

1.15

Ultimate Compressive strain in the Steel

2.17E-03

fyk/Es*𝛾s

Design Yield Strength

f_yd

434.78

Mpa

fyd

fyk/𝛾s

ULS

Grade of Concrete

f_ck

M 35

N/mm²

As per Clause6.4.2.8,IRC:112-2020,Page No-39

f_cd

15.63

N/mm²

𝛼

0.67

for basic & Seismic combination

𝛾𝑠

1.5

Grade of Concrete

f_y

500

N/mm²

1.15

f_yd

434.78

Refer Fig. 6.2 of IRC 112-2011

For Steel reinforcement, simplified bilinear diagram is used

Minimum strain in steel reinforcement

0.87fy/Es+0.002

Modulus of Elasticity of steel

2.00E+05

Mpa

Compressive force

0.36*fck*b*x_ulim

17/21*fcd*b*xu,lim

0.80952*fcd*b*xu,lim

CG of compression block from top fibre

0.42X_u,lim

Tensile force

.87*fy*Ast

So, Limiting Resistance is equal to limiting moment

R_lim

M_u,lim/bd²

0.36*f_ck*X_u,lim/d(1-.429X_u,lim/d)

5.86

For Fe500, Xu,lim/d

0.633

Calculation of Reinforcement

Tensile reinforcment caan be calculated from the follwing formalu

pt/100=Ast/bd=.973f_cd/f_yd[1-sqrt(1-2.005*M_ulim/f_cd)

Where

R=M_u/bd²

p_t,lim

Where

R_lim=M_u,lim/bd²

1.81957562

Design of Heel and Toe Slab (LWL Case)

Case:01	Max.Pressure at toe and corresponding pressure at heel
Case:02	Max.Pressure at heel and corresponding pressure at toe
	Corner1,2	Toe End
	Corner 3,4	Heel End
1	Max.Pressure at toe(Corner -1) and corresponding pressure at heel @Ultimate Limit state (ULS)
	Corner	Gross Pressure
	Corner	t/m2
	1	42.1
	2	34.3
	3	14.3
	4	21.2


	Ultimate Limit state (ULS) combo-1
Using interpolation of triangles, the pressure at face to the support & at "d" distance from the support is determined

	Heel End		21.23/2+14.29/2	=	17.76	t/m²
	A-A		17.76+5/8.5*(38.23-17.76)	=	29.80	t/m²
Gross	Toe End		34.35/2+42.11/2	=	38.23	t/m²
	B-B		17.76+(8.5-2.5)/8.5*(38.23-17.76)	=	32.21	t/m²
	at deff from A-A		29.8-0.9125/5*(29.8-17.76)	=	26.07	t/m²
	at deff from B-B		38.23-0.9125/2.5*(38.23-32.21)	=	36.03	t/m²

	Heel End		17.76-((9.82-0.3)2-0.32.5)*1.35	=	-6.92	t/m²
	A-A		29.8-((9.82-1)2-12.5)*1.35	=	9.38	t/m²
Net	Toe End		38.23-((226.58-224.25)2+0.32.5)*1.35	=	30.93	t/m²
	B-B		32.21-(12.5)1.35	=	28.84	t/m²
	at deff from A-A		26.07-((9.82-0.872)2-0.8722.5)*1.35	=	4.84	t/m²
	at deff from B-B		36.03-(0.7452.5)1.35	=	33.52	t/m²

	Overall depth	at A-A	((1-0.3)*(5-0.9125)/5)+0.3	=	0.872	mm
	Overall depth	at B-B	((1-0.3)*(2.5-0.9125)/2.5)+0.3	=	0.745	mm

2	Min.Pressure at heel(Corner -3) and corresponding pressure at toe@Ultimate Limit state (ULS)
	Corner	Gross Pressure		Corner1,2	Toe End
	Corner	t/m2		Corner 3,4	Heel End
	1	40.8
	2	33.8
	3	12.9
	4	20.6

	Ultimate Limit state (ULS) combo-1
	Using interpolation of triangles, the pressure at face to the support & at "d" distance from the support is determined

	Heel End		(20.64+12.88)/2			=	16.76	t/m²
	A-A		16.76+5/8.5*(37.32-16.76)			=	28.86	t/m²
Gross	Toe End		(33.85+40.8)/2			=	37.32	t/m²
	B-B		16.76+(8.5-2.5)/8.5*(37.32-16.76)			=	31.27	t/m²
	at deff from A-A		28.86-0.9125/5*(28.86-16.76)			=	25.10	t/m²
	at deff from B-B		37.32-0.9125/2.5*(37.32-31.27)			=	35.12	t/m²

	Heel End		16.76-((9.82-0.3)2-0.32.5)*1.35			=	-7.92	t/m²
	A-A		28.86-((9.82-1)2-12.5)*1.35			=	8.43	t/m²
Net	Toe End		37.32-((226.58-224.25)2+0.32.5)*1.35			=	30.02	t/m²
	B-B		31.27-(12.5)1.35			=	27.90	t/m²
	at deff from A-A		25.1-((9.82-0.872)2-0.8722.5)*1.35			=	3.90	t/m²
	at deff from B-B		35.12-(0.7452.5)1.35			=	32.60	t/m²

	Overall depth	at A-A	((1-0.3)*(5-0.9125)/5)+0.3			=	0.872	mm
	Overall depth	at B-B	((1-0.3)*(2.5-0.9125)/2.5)+0.3			=	0.745	mm
	Effective depth provided		At top		d_provided				=

		Section
	Pressure(t/m²)	Heel End	A-A	Toe End	B-B	at deff from A-A	at deff from B-B
	Gross Pressure (Case 1)	17.8	29.8	38.2	32.2	26.1	36.0
	Gross Pressure (Case 2)	16.8	28.9	37.3	31.3	25.1	35.1
	NetPressure (Case 1)	-6.9	9.4	30.9	28.8	4.8	33.5
	Net Pressure (Case 2)	-7.9	8.4	30.0	27.9	3.9	32.6

Design of Heel Slab

Design for Flexure

Critical section is at face of wall

Overall depth of Section

1000

Design moment per m width

((-6.92*5^2)/2+((0.5(9.38-(-6.92))*5^2))/3

M_u

-18.59

t-m

178

((-7.92*5^2)/2+((0.5(8.43-(-7.92))*5^2))/3

M_u

-30.87

t-m

230

R_lim

5.86

Mpa

1 Mpa=1N/m²

Effective depth required

d_reqd

Sqrt(M_u/R_lim*b)

178

Effective depth provided

At top

d_provided

912.5

178

At top

d_provided

912.5

230

Mu/bd²

0.22

A_st,required

A_st

A_st,required

A_st

472.02

mm²

Minimum,A_{st required} per m width

(max. of 0.26fctm/fyk*bt*d and 0.0013bt*d)

1,186.25

mm²

Governing,A_{st required} per m width

1,530.24

1186.25

1,186.25

mm²

Provide

25 mm Dia.

Bars

200 mm c/c

at top

25 mm Dia.

Bars

200 mm c/c

A_st,provide

4,908.74

mm²

R_u

Mu/bd²

R_u

0.371

A_st,required

787.58

mm²

Minimum,A_{st required} per m width

(max. of 0.26fctm/fck*bt*d and 0.0013bt*d)

787.58

mm²

Governing,A_{st required} per m width

1,530.24

1186.25

787.58

mm²

Provide

25 mm Dia.

Bars

200 mm c/c

Bottom

25 mm Dia.

Bars

200 mm c/c

A_st,provided

4,908.74

mm²

Design of One way Shear

Critical section is at deff distance from the face of abutment wall

Overall depth of section

0.872

Design shear force per m width

V_u

11.93

Tensile reinforcement

A_st

4,908.74

mm²

Width of beam

b_w

1000

Effective depth

784.75

Area of Concrete

A_c

7.79E+05

mm²

Axial force due to prestress

N_Ed

Cl.10.2.3,IRC 112-2011

1.50

Cl.10.3.2,IRC:112-2011

0.34

n/mm²

Concrete Compressive stress at centroidal axis due to axial loading or prestressing

N_Ed/A_c<0.2f_cd

A_sl/b_w*d<=0.02

0.00626

Cl.10.3.2,IRC:112-2011

Shear Capacity of section without Shear reinforcement(Cl10.3.2,IRC:112-2011,Page no-88)

Design Shear Resistance(V_Rd.c)

[0.12K(80p_lf_cd)^^0.33+0.15*𝜕cp]*b_w*d>=(Vmin+0.15*𝜕cp)b_w*d

V_Rd.c

0.365

0.266

Design of Toe Slab

Design for Flexure

Critical section is at face of wall

Overall depth of Section

1000

Design moment per m width

(35.01*1.7^2)/2+(0.5*(32.63-35.01)*1.7^2)/3

M_u

94.47

t-m

(34.11*1.7^2)/2+(0.5*(35.08-34.11)*1.7^2)/3

M_u

91.60

t-m

Design

M_u

94.47

t-m

49.76x10^7

N-mm

R_lim

5.86

Mpa

1 Mpa=1 N/mm²

Effective depth required

d_reqd

Sqrt(M_u/R_lim*b)

402

Effective depth provided

d_provided

912.5

Mu/bd²

1.13

A_st,required

A_st

0.973f_cd/f_yd[1-sqrt(1-2.055R_lim/f_cd)bd

A_st,required

A_st

2,476.66

mm²

Not Satisfied

Minimum,A_{st required} per m width

(max. of 0.26fctm/fyk*bt*d and 0.0013bt*d)

1186.25

mm²

Governing,A_{st required} per m width

1,530.24

1186.25

2,476.66

mm²

Provide

25 mm Dia.

Bars

200 mm c/c

at bottom

25 mm Dia.

Bars

200 mm c/c

A_st,provide

4,908.74

mm²

Design of One way Shear

Critical section is at deff distance from the face of abutment wall

Overall depth of section

0.745

Design shear force per m width

V_u

8.60

Tensile reinforcement

A_st

4,908.74

mm²

Width of beam

b_w

1000

Effective depth

657.00

Area of Concrete

A_c

6.57E+05

mm²

Axial force

N_Ed

No axial force act here

Cl.10.2.3,IRC 112-2011

1.55

Cl.10.3.2,IRC:112-2011

Vmin

0.031k^^3/2fck^^1/2

0.35

n/mm²

Concrete Compressive stress at centroidal axis due to axial loading or prestressing

N_Ed/A_c<0.2f_cd

0.00E+00

t/mm²

<.2fcd=3.1267

A_sl/b_w*d<=0.02

0.00747

<=0.02

Cl.10.3.2,IRC:112-2011

Shear Capacity of section with out shear reinforcement(Cl10.3.2,IRC:112-2011,Page no-88)

V_Rd.c

[0.12K(80p_lf_cd)^^0.33+0.15*𝜕cp]*b_w*d>=(Vmin+0.15*𝜕cp)b_w*d

0.334

0.233

Distribution Reinforcment

Secondary reinforcment required per meter

495.33

mm²

20% of main reinforcement, Cl.16.6.1,IRC 112-2011

Provide

12 mm Dia.

Bars

200 mm c/c

A_st,provided

565.49

mm²

Serviceability Limit State(SLS) Combination-02

Max.Pressure at toe(Corner -1) and corresponding pressure at heel

Corner

Gross Pressure

t/m2

29.6

23.8

13.1

19.1

Heel End

(23.78+29.56)/2

16.12

t/m²

A-A

16.12+5/8.5*(26.67-16.12)

22.33

t/m²

Gross

Toe End

(23.78+29.56)/2

26.67

t/m²

B-B

16.12+(8.5-2.5)/8.5*(26.67-16.12)

23.57

t/m²

at deff from A-A

22.33-0.9125/5*(22.33-16.12)

21.20

t/m²

at deff from B-B

26.67-0.9125/2.5*(26.67-23.57)

25.54

t/m²

Heel End

16.12-((9.82-0.3)*2-0.3*2.5)*1.35

-8.56

t/m²

A-A

22.33-((9.82-1)*2-1*2.5)*1.35

1.90

t/m²

Net

Toe End

26.67-((226.58-224.25)*2+0.3*2.5)*1.35

19.37

t/m²

B-B

23.57-(1*2.5)*1.35

20.20

t/m²

at deff from A-A

21.2-((9.82-0.872)*2-0.872*2.5)*1.35

-0.01

t/m²

at deff from B-B

25.54-(0.745*2.5)*1.35

23.44

t/m²

Overall depth

at A-A

((1-0.3)*(5-0.9125)/5)+0.3

0.872

Overall depth

at B-B

((1-0.3)*(2.5-0.9125)/2.5)+0.3

0.745

Min.Pressure at heel(Corner -3) and corresponding pressure at toe

Corner

Gross Pressure

t/m2

29.3

23.0

12.6

18.7

Heel End

(22.99+29.34)/2

15.69

t/m²

A-A

15.69+5/8.5*(26.17-15.69)

21.85

t/m²

Gross

Toe End

(22.99+29.34)/2

26.17

t/m²

B-B

15.69+(8.5-2.5)/8.5*(26.17-15.69)

23.09

t/m²

at deff from A-A

21.85-0.9125/5*(21.85-15.69)

20.73

t/m²

at deff from B-B

26.17-0.9125/2.5*(26.17-23.09)

25.04

t/m²

Heel End

15.69-((9.82-0.3)*2-0.3*2.5)*1.35

-8.99

t/m²

A-A

21.85-((9.82-1)*2-1*2.5)*1.35

1.43

t/m²

Net

Toe End

26.17-((226.58-224.25)*2+0.3*2.5)*1.35

18.87

t/m²

B-B

23.09-(1*2.5)*1.35

19.71

t/m²

at deff from A-A

20.73-((9.82-0.872)*2-0.872*2.5)*1.35

-0.51

t/m²

at deff from B-B

25.04-(0.745*2.5)*1.35

22.94

t/m²

Overall depth

at A-A

((1-0.3)*(5-0.9125)/5)+0.3

0.872

Overall depth

at B-B

((1-0.3)*(2.5-0.9125)/2.5)+0.3

0.745

Section

Pressure(t/m²)

Heel End

A-A

Toe End

B-B

at deff from A-A

at deff from B-B

Gross Pressure
(Case 1)

16.1

22.3

26.7

23.6

21.2

25.5

Gross Pressure
(Case 2)

15.7

21.9

26.2

23.1

20.7

25.0

NetPressure
(Case 1)

-8.6

1.9

19.4

20.2

0.0

23.4

Net Pressure
(Case 2)

-9.0

1.4

18.9

19.7

-0.5

22.9

Modular Ratio

6.25E+00

Permissible stress in concrete

0.48*fck

16.8

Mpa

Permissible stress in Steel

0.8*fyk

400

Mpa

Neutral Axis Depth

[(-m*Ast)+sqrt[m*Ast)^2+2*1000*Ast*m*d]/1000

207.92

Stress in Concrete

[(-Mu)x10^7]/(((1000/3)*NA^3+m*Ast*(d-NA)^2))/NA

7.23

Mpa

Stress in Concrete

[(-Mu)x10^7]/(((1000/3)*NA^3+m*Ast*(d-NA)^2))/(d-NA)*m

153.12

Mpa

side

Face

Moment

deff

A_st.provided

Neutral Axis Depth

Stress in Concrete

Stress in Steel

Check

t-m

mm²/m

Mpa

Heel

Top

-63.38

912.5

4,908.74

207.92

7.23

153.12

Bottom

-68.97

912.5

4,908.74

207.92

7.23

153.12

Toe

Bottom

61.39

912.5

4,908.74

207.92

7.23

153.12

	Crack Width Check
	Combination for Design of Foundation
	Combination 3(SLS Qausi permanent Combination)
1	LWL
1.1	Maximum Reaction Case
1.2	Maximum Moment Case

1	LWL
1.1	Maximum Reaction Case
			Unfactored					factored
		Partial Safety Factor	P_max	P_min	ML due to HL about toe	ML due to P about toe	MT	P_max	P_min	ML due to HL about toe	ML due to P about toe	MT
		Partial Safety Factor	t	t	t-m	t-m	t-m	t	t	t-m	t-m	t-m
	DL-Sup	1	105.00	105.00	-	315.00	-	105.00	105.00	-	315.00	-
	SIDL(exclu.W/C)	1	29.98	29.98	-	89.93	-	29.98	29.98	-	89.93	-
	SIDL(W/C)	1.2	9.27	9.27	-	27.80	-	11.12	11.12	-	33.36	-
	LL1	0	97.32	85.14	-133.73	291.97	192.55	-	-	-	-	-
	EPLL1	0	-	-	-	-	-	-	-	-	-	-
	Shearing Rating	0	-	-	-43.10	-	-	-	-	-	-	-
	Earth Pressure	1	315.16	315.16	-1,299.20	860.33	-	315.16	315.16	-1,299.20	860.33	-
	LL Surcharge	0	-	-	372.19	-	-	-	-	-	-	-
	Weight of Sub-structure	1	230.63	230.63	-	709.16	-	230.63	230.63	-	709.16	-
	Weight of Foundation	1	176.25	176.25	-	749.06	-	176.25	176.25	-	749.06	-
	Return Wall Weight	1	56.21	56.21	-	339.56	339.40	56.21	56.21	-	339.56	339.40
	Backfill Weight	1	1,032.75	1,032.75	-	6,274.66	-	1,032.75	1,032.75	-	6,274.66	-
	Total							1957.1	1957.1	-1299.2	9371.1	339.4
	Eccentricity of vertical load from c/l of footing						=	(ML due to P/Load P)-(width of footing/2)
	Eccentricity of vertical load fron c/l of footing						=	0.538	m
	Longitudinal Moment about c/l of footing				ML		=	245.81	t-m
1.2	Maximum Moment Case
			Unfactored					factored
		Partial Safety Factor	P_max	P_min	ML due to HL about toe	ML due to P about toe	MT	P_max	P_min	ML due to HL about toe	ML due to P about toe	MT
		Partial Safety Factor	t	t	t-m	t-m	t-m	t	t	t-m	t-m	t-m
	DL-Sup	1	105.00	105	0	218.9	0	105.0	105.0	0.0	218.9	0.0
	SIDL(exclu.W/C)	1	29.98	29.977632	0	29.3	0	30.0	30.0	0.0	29.3	0.0
	SIDL(W/C)	1.2	9.27	9.2664	0	25.4	0	11.1	11.1	0.0	30.5	0.0
	LL1	0	81.63	70.30	-135.48	244.89	237.14	0.0	0.0	0.0	0.0	0.0
	EPLL1	0	0	0	0	0.0	0	0.0	0.0	0.0	0.0	0.0
	Shearing Rating	0	0	0	-43.1	0.0	0.0	0.0	0.0	0.0	0.0	0.0
	Earth Pressure	1	114.71	114.71023	-1686.4	1033.2	0.0	114.7	114.7	-1686.4	1033.2	0.0
	LL Surcharge	0	0	0	-453.5	0.0	0.0	0.0	0.0	0.0	0.0	0.0
	Weight of Sub-structure	1	230.63	230.625	0	577.9	0	230.6	230.6	0.0	577.9	0.0
	Weight of Foundation	1	176.25	176.25	0	587.8	0	176.3	176.3	0.0	587.8	0.0
	Return Wall Weight	1	56.21	56.2115	0	304.6	339.4	56.2	56.2	0.0	304.6	339.4
	Backfill Weight	1	1,032.75	1032.7506	0	5604.1	0	1032.8	1032.8	0.0	5604.1	0.0
	Total							1756.6	1756.6	-1686.4	8386.2	339.4
	Eccentricity of vertical load from c/l of footing						=	(ML due to P/Load P)-(width of footing/2)
	Eccentricity of vertical load fron c/l of footing						=	0.524	m
	Longitudinal Moment about c/l of footing				ML		=	765.90	t-m

	Summary
	Service Condition-Qausi Parmanent Case
			P_max	P_min	ML	MT
			t	t	t-m	t-m
	Maximum Reaction Case		1957.1	1957.1	245.81	339.4
	Maximum Moment Case		1756.6	1756.6	765.90	339.4


	Area of Base		A	12*8.5	=	102.00	m²	Corner-01	p1	=	P/A+ML/Zl+MT/Zt
	Longinitudinal Section Modulus		Z_L	12*8.5^2/6	=	144.50	m³	Corner-02	p2	=	P/A+(ML/Zl-MT/Zt)
	Transverse Section Modulus		Z_T	8.5*12^2/6	=	204.00	m³	Corner-03	p3	=	P/A-ML/Zl-MT/Zt
								Corner-04	p4	=	P/A-ML/Zl+MT/Zt

	Combination of Base pressure for foundation
	D-1 Combination-01
	Service Condition
		Forces/Moments				For P_max				For P_min
		P_max	P_min	ML	MT	P/A+ML/Zl+MT/Zt	P/A+ML/Zl-MT/Zt	P/A-ML/Zl-MT/Zt	P/A-(ML/Zl+MT/Zt)	P/A+ML/Zl+MT/Zt	P/A+ML/Zl-MT/Zt	P/A-ML/Zl-MT/Zt	P/A-(ML/Zl+MT/Zt)
		t	t	t-m	t-m	t/m²	t/m²	t/m²	t/m²	t/m²	t/m²	t/m²	t/m²
Maximum Reaction Case		1,957.10	1,957.10	245.81	339.40	22.55	19.22	15.82	19.15	22.55	19.22	15.82	19.15
Maximum Moment Case		1,756.64	1,756.64	765.90	339.40	24.19	20.86	10.26	13.59	24.19	20.86	10.26	13.59

Corner 1,4	Toe End
Corner 2,3	Heel end

Serviceability Limit state (SLS) combo-3
Max.Pressure at toe and corresponding pressure at heel			Min.Pressure at heel and corresponding pressure at toe
Corner	Gross Pressure		Corner	Gross Pressure
Corner	t/m2		Corner	t/m2
1	24.2		1	29.3
2	20.9		2	23.0
3	15.8		3	12.6
4	19.1		4	18.7

Using interpolation of triangles, the pressure at face to the support & at "d" distance from the support is determined

Heel End		(15.82+20.86)/2	=	17.5	t/m²
A-A		17.49+5/8.5*(22.52-17.49)	=	20.4	t/m²
Toe End		(15.82+20.86)/2	=	22.5	t/m²
B-B		17.49+(8.5-2.5)/8.5*(22.52-17.49)	=	21.0	t/m²
at deff from A-A		20.45-0.9125/5*(20.45-17.49)	=	19.5	t/m²
at deff from B-B		22.52-0.9125/2.5*(22.52-21.04)	=	22.0	t/m²

Heel End		17.49-((9.82-0.3)2-0.32.5)*1.35	=	-7.2	t/m²
A-A		20.45-((9.82-1)2-12.5)*1.35	=	0.0	t/m²
Toe End		22.52-((226.58-224.25)2+0.32.5)*1.35	=	15.2	t/m²
B-B		21.04-(12.5)1.35	=	17.7	t/m²
at deff from A-A		19.53-((9.82-0.872)2-0.8722.5)*1.35	=	-1.7	t/m²
at deff from B-B		21.98-(0.7452.5)1.35	=	19.5	t/m²

Overall depth	at A-A	((1-0.3)*(5-0.9125)/5)+0.3	=	0.872	mm
Overall depth	at B-B	((1-0.3)*(2.5-0.9125)/2.5)+0.3	=	0.745	mm

Crack-Width Check as Per IRC 112
Condition of Exposure						=	Moderate
Size of Footing						=	7.50m	x	12.00m
Refer Previous Design data Calculations for the below Data
Heel Slab
Overall depth of Section						=	1000	mm
Effective depth Provided					d_provided	=	912.5	mm	ok
Provided	25 mm Dia.	Bars	@	200 mm c/c		=	200	mm c/c	+
	25 mm Dia.	Bars	@	200 mm c/c		=	200	mm c/c
A_st,provided						=	4,908.74	mm²	at Top
						=
Toe Slab
Overall depth of Section						=	1000	mm
Effective depth Provided					d_provided	=	912.5	mm	ok
Provided	25 mm Dia.	Bars	@	200 mm c/c		=	200	mm c/c	+
	25 mm Dia.	Bars	@	200 mm c/c		=	200	mm c/c
A_st,provided						=	4,908.74	mm²	at Bottom

Min.Pressure at heel and corresponding pressure at toe
Corner	Gross Pressure
Corner	t/m2
1	23.6
2	19.8
3	20.9
4	17.1


Heel End		(19.8+23.6)/2			=	19.00	t/m²
A-A		19+5/8.5*(21.7-19)			=	20.59	t/m²
Toe End		(19.8+23.6)/2			=	21.70	t/m²
B-B		19+(8.5-2.5)/8.5*(21.7-19)			=	20.91	t/m²
at deff from A-A		20.59-0.9125/5*(20.59-19)			=	20.30	t/m²
at deff from B-B		21.7-0.9125/2.5*(21.7-20.91)			=	21.41	t/m²

Heel End		19-((9.82-0.3)2-0.32.5)*1.35			=	-5.68	t/m²
A-A		20.59-((9.82-1)2-12.5)*1.35			=	0.16	t/m²
Toe End		21.7-((226.58-224.25)2+0.32.5)*1.35			=	14.40	t/m²
B-B		20.91-(12.5)1.35			=	17.53	t/m²
at deff from A-A		20.3-((9.82-0.872)2-0.8722.5)*1.35			=	-0.94	t/m²
at deff from B-B		21.41-(0.7452.5)1.35			=	19.30	t/m²

Overall depth	at A-A	((1-0.3)*(5-0.9125)/5)+0.3			=	0.872	mm
Overall depth	at B-B	((1-0.3)*(2.5-0.9125)/2.5)+0.3			=	0.745	mm

	Section
Pressure(t/m²)	Heel End	A-A	Toe End	B-B	at deff from A-A	at deff from B-B
Gross Pressure (Case 1)	19.0	20.6	21.7	20.9	20.3	21.4
Gross Pressure (Case 2)	19.0	20.6	21.7	20.9	20.3	21.4
NetPressure (Case 1)	-5.7	0.2	14.4	17.5	-0.9	19.3
Net Pressure (Case 2)	-5.7	0.2	14.4	17.5	-0.9	19.3

Modular Ratio

Es/Ecm

6.25

m =Es/Ecm

Spacing of Steel provided

100

Ecm

Grade of Concrete

f_ck

M 35

Mpa

(Refer from table No.6.5,IRC:112-2011)

Tensile Strength of Concrete

f_ctm

2.80

Mpa

Characteristic strength of Concrete

f_ck

Mpa

Grade of Steel

Fe 500

Characteristic strength of Steel

f_yk

500

Mpa

Modulus of Elasticity of Concrete

E_cm

32000

Mpa

Modulus of Elasticity of Steel

E_s

200000

Mpa

Depth

1000

Width considered

1000

Cover

Face

Moment

Moment/m width

deff

A_st.provided

Neutral Axis Depth

Check

t-m

mm²/m

Top

-46.64

-3.89

912.5

4,908.74

207.92

Bottom

-46.64

-3.89

912.5

4,908.74

207.92

Bottom

48.25

4.02

912.5

4,908.74

207.92

Moment

(-7.85*4.8^2)/2+((0.5*(-1.9-(-7.85))*4.8^2))/3

-67.968

t-m

207.92

Moment per m width

-67.968/12

-5.66

t-m

side

Face

S_r,max

MI of Cracked Section

Stress in Concrete

Stress in Steel

Crack Width (W_k)

Check

mm⁴

Mpa

Heel

Top

444.39

1.82E+10

0.64

13.58

0.00004

0.018

Bottom

444.39

1.82E+10

0.64

13.58

0.00004

0.018

Toe

Bottom

444.39

1.82E+10

0.64

13.58

0.00002

0.009

Calcualtion of P_p,eff

Where

A_c,eff is the effective area of concrete in tension surrounding the reinforcement, of depth he,eff where h_e,eff is lesser of

2.5*(h-d);(h-x)/2;h/2

( refer Fig.12.2)

Overall depth

A_s

4,908.74

effective depth

2.5*(h-d)

218.75

Neutral axis depth from top

(h-x)/2

264.03

h/2

500

0.02244

=	437.5	444.39	Nearly Close	^3
=	437.5	1,029.70

K₁	=	0.8
K₂	=	0.5
C	=	75
We will be adopted S_r,max is 444.39 mm for checking.

MI of Cracked section		((207.92)^3/31000)+((6.254909*(912.5-207.92)^2))	=	1.82E+10

K_t

0.5

-0.0002878

0.00004074

Take Maximum Value of-0.00029,0.00004

0.018

W_max

0.3

From table 12.1,IRC:112-2011

Hence Ok

As per Code:-

Design of Concrete

Input Data

Nature of Bending

(Hogging)

Width of Plate

1000

Depth of Plate/Top Slab

900

Clear cover to reinforcement on earth face

C_T

No of Reinforcement Layers provided

Diameter of Tension Steel

1^st Layer

mm @200c/c

1^st Layer

mm @200c/c

Diameter of Tension Steel

2^nd Layer

mm @200c/c

2^nd Layer

mm @200c/c

Diameter of Tension Steel

3^rd Layer

mm @200c/c

3^rd Layer

mm @200c/c

Effective Depth

799

Diameter of Shear Reinforcement

Characteristic compressive strength of concrete.

f_ck

N/mm²

Characteristic yield a strength of the steel.

f_yk

500

N/mm²

Design yield the strength of main reinforcement.

f_yd

435

N/mm²

Characteristic yield the strength of stirrups

f_ywk

500

N/mm²

Mean value of axial tensile strength of concrete.

f_ctm

.259*fck^2/3

N/mm²

As per IRC: 112 -2011 Annexture-2

f_ctm

3.03

N/mm²

Bending moment as per ULS combination.

M_u

1000

KN-m

Effective depth as per provided.

d_eff.provided

799

1000

A_st provided.

Pi()/4*32^2*5*1

A_st,provided

4,021

mm²

0.5%

<2.5%

Minimum reinforcement as per IRC 112,Cl.16.6 .1 .1.

So, Section is under-Reinforced

A_{st ,min}

0.26*f_ctm*b_t*d/f_yk & 0.0013b_t*d whichover is greater-

A_{st ,min}

1,258

A_{st ,min}

1,039

0.16%

<0.5%

A_{st ,min}

1,258

Max.Value

A_st,provided

4,021

Limiting depth of neutral axis as per IRC 112 ,Table no-4.2

X_u,lim/d

0.46

Depth ratio.

Calculate the neutral axis from top fibre. As per below formula

X_u/d

0.152

Depth ratio.

X_u/d<Xu_,lim/d

0.152

Under-Reinforced

After that we will calculate the Ultimate bending moment.

M_u=

"0.87*fy*d*(1-0.42*Xu/d)

M_u

1,308

KN-m

Hence it is safe

e_cu3=0.0035

Ultimate tensile strength in the steel

Check for stresses and crack width.

Properties of middle Wall

Width of middle wall.

B_s

1000

Thickness of middle wall

T_s

900

Diameter of tensile reinforcement outer layer.

d₁

CGOP section from inner face

900/2

Y_inner

450

CG of section from outer face.

900/3

Y_outer

450

Area of steel provided.

A_st,prov

4,021

Effective depth

900-cover

d_eff

799

Modulus of elasticity of steel.

E_s

2.00E+05

N/mm²

Modulus of elasticity of concrete.

E_cm

3.30E+04

N/mm²

Long term modular ratio.

IRC 21- 2000. Cl.No.A 1.

12.1

Es/0.5*Ecm

Properties of gross section.

Values

Unit

Cross area.

9.00E+05

mm²

1000*900

b*D

Gross moment of inertia.

6.08E+10

mm⁴

(1000*900^3)/12

(b*D³)/12

Properties of uncrackked transformed section

Y_iT	=	((bDD/2)+(m-1)(Astd))/((9Bd)+(m-1)Ast)
	=	467
Y_bT	=	D-Y_tT	900-467
	=	433
Y_sT	=	d-Y_tT	799-467
	=	332
I_T	=	(bD³/12+bD(D/2-YiT)²)+((m-1)Ast*(d-YsT)²)
	=	6.59E+10

Properties of uncrackked transformed section	Values	Unit
Y_iT	467	mm
CG of uncracked section from tension face, Y_bT	433	mm
CG of uncracked section from tension steel,Y_sT	332	mm
Uncracked moment of inertia, I_T	6.59E+10	mm⁴

Properties of cracked section :

BY²_outCr/2=mAst*(d-Y_outCr)
1000/2Y²_outCr=12.124021*(799-Y_outCr)
500a²+48742a-4E+07=0
a	=	238
Y_outCr	=	238



Properties of crackked transformed section			Values	Unit
Y_outCr			238	mm
CG of uncracked section from inner face, Y_innCr			662	mm
CG of uncracked section from tension steel,Y_sCr			561	mm
Uncracked moment of inertia, I_cr			1.98E+10	mm⁴

Stresses under Rare Combination

Calculation of Stresses for Middle Wall

Bending Moment( rare combination)

M_rare

700

kNm

IRC6-2017

Compressive Stress in concrete at outer face,

f_cc

(M/I)*Y_out.Cr

Safe for fcc

f_cc

8.41

N/mm²

M_cr

Tensile Stress in concrete at Steel level

f_ct,steel

(M/I)*Y_s.Cr

f_ct,steel

19.79

N/mm²

M_rare

Tensile Stress in Steel

f_st

m*(M/I)*Y_scr

So, Section is Cracked

Safe for fst

f_st

239.87

N/mm²

We will take all values in cracked section

Permissible compressive Stress in Concrete

0.48fck

19.2

N/mm²

IRC:112-2011, Cl No.12.2.1

Permissible Tensile Stress in Steel

0.8fy or 300

400

N/mm²

IRC:112-2011, Cl No.12.2.2

300

N/mm²

400>300

Calcualtion of Crack width for Middle wall

Bending Moment ( Quasi-Permanent combination)

M_quasi

550

kNm

Permissible compressive Stress in Concrete

f_cc

0.36*fck

IRC:112-2011, Cl No.12.2.2

f_cc

14.4

N/mm²

Cracking Moment of the section

M_cr

I_{gr(MOI Uncracked)}*f_ctm/Y_{b(CG of Uncracked)}

M_cr

461

kNm

Cracked Section

When M_cr is less than M_quasi

So, Section is Cracked

Calculate the Crack width

Compressive Stress in concrete at outer face,

f_cc

(M/I)*Y_out.Cr

6.61

N/mm²

Tensile Stress in concrete at Steel level

f_ct,steel

(M/I)*Y_s.Cr

15.55

N/mm²

Cracked Section

Section is Cracked,f_st>f_ct,steel

Distance of Neutral Axis from outer face for cracked section

d_eff/(1+f_ct.steel*m/f_cc)

27.06

Calculation the Crack width

Wheere

W_k

S_r,max

Maximum Crack Spacing

S_r,max

Clear Cover to longitudinal reinforcement

0.8

for deformed bars

0.5

for bending

𝜌𝑝,𝑒𝑓𝑓

∅

Diameter of bar

e_sm

Mean strain in the reinforcement.

e_cm

Mean strain in the concrete between cracks

Now

𝜎𝑠𝑐

Stress in the tension reinforcementin crack section

𝛼𝑒

Moduler Ratio

E_s/E_cm

𝜌𝑝,𝑒𝑓𝑓

A_s

Area of Steel

A_c,eff

Effeective area of concrete in tension surrounding the reinforcement=b_w*h_c,eff

h_c,eff

h_c,eff is the lesser of

2.5*(h-d)

252.5

(900-799)*2.5

(h-x)/3

291.0

(900-27.06)/3

h/2

450

900/2

h_c,eff

252.50

A_c,eff

252500

mm²

𝜌𝑝,𝑒𝑓𝑓

0.01593

K_t

0.5

factor dependent on duration of load

𝜎𝑠𝑐

188

N/mm²

f_ct,eff

3.03

N/mm2

fctm

Mean value of axial tensile strength of concrete.

𝛼𝑒

12.1

m=E_s/E_cm

0.000375

S_r,max

512

0.192

0.3

IRC:112-2011, Table No-12.1

Check for Shear

Design shear force

V_Ed

737

For uniform cross section

V_ccd

For uniform cross section

V_td

V_Rds

V_NS

737

Minimum allowable shear force( for maximum shear force take 𝜃 =21.80)

IRC:112-2011,Cl.no.10.3.3.2,Eq10.8

𝛼cw

Co-efficient taking account of the state of the stress in the compression chord

0.9d

Liver arm

For RCC Structure

0.52

0.6*(1-40/310)

Strength reduction factor for concrete cracked in shear

IRC:112-2011,,Eq10.6

𝜃

21.8

2.50

Design value of compression strength

f_cd

𝛼cc*f_ck/y_m

IRC:112-2011,Cl.No.10.3.1)

𝛼cc

0.67

Refer IRC:112-2011,Page No-87)

Y_m

1.5

(Partial Factor of Concrete for ULS)

f_cd

17.87

N/mm²

V_Rd,max

2,303.65

Allowable shear force without reduction factor

V_Ed

0.5*bw*d*v*fcd

(IRC:112-2011,Cl.No.10.3.2,Eq.10.5)

Wheere

Strength reduction factor=0.6*[1-(fck/310)]

b_w

1000

0.52

N/mm2

V_Ed

3,730.04

Section is Safe

Allowable shear force without shear reeinforcement

V_Rdc

(IRC:112-2011,Cl.No.10.3.2(2))

V_{Rd.c min}

V_min

Concrete compessive stress at the Centroidal axis due to axial loading or prestressing

Reinforccement ratio for longitudinal reinforcement,

1.50

Which is less than <=2

0.005

Which is less than <=0.02

Axial force is nil

V_min

0.360

V_{Rd.c min}

287.88

V_Rdc

359.91

Shear reinforcement is required

Design of Shear Reinforcement:

𝜃

The value of "^ " is determined by equating V_rd,s to V_NS

V_rd,s

The design value of shear force, which can be sustained by yielding shear reinforcement.

V_rd,s

Where

A_sw

The cross section area of the shear reinforcement

Spacing

f_ywd

The design yield strength of the shear reinforcement

Shear reinforcement due to combine shear and Torsion.

Provide

10 mm

Dia. Stirrups

spacing

200

𝜃

21.8

A_sw

392.70

mm²

0.9d

719.1

V_rd,s

1,764.94

Reinforcement ratio for Shear Reinforcement.

0.002

Check for minimum shear reinforcement

Minimum shear reinforcement ratio

0.072*sqrt(f_ck)/f_yk

0.0009

Safe

3).Shallow foundations( Stability, Designing & Construction) in Fly-Over & River Bridge:-

Shallow foundations are commonly used in both flyovers and river bridges to support the structures and transmit loads to the underlying soil. However, there are some differences in terms of stability, designing, and construction for these two types of structures due to their varying environmental conditions and load requirements.

Stability:

1.1.Flyover:

Flyovers are elevated roads or structures that span over existing roadways or intersections. They typically have a relatively uniform and stable soil profile since they are constructed above ground level. The stability concerns for flyovers primarily involve ensuring that the foundation can withstand the vertical loads from the structure itself, along with the dynamic loads from the passing vehicles.

1.1.River Bridge:

River bridges are structures that span across water bodies like rivers or streams. The soil conditions near riverbanks can be more challenging, as they may have different layers of soils, sediment, and waterlogged areas. The stability of a river bridge foundation needs to consider factors like scour (erosion of soil around bridge piers due to water flow) and potential lateral forces from water currents.

Designing:

2.1.Flyover:

The design of shallow foundations for flyovers typically involves conducting a thorough geotechnical investigation to determine the soil properties and bearing capacity. The load-bearing capacity of the foundation should be sufficient to support the weight of the flyover and the live loads from traffic. Typically, reinforced concrete footings or pile caps are used for flyover foundations.

2.1.River Bridge:

Designing shallow foundations for river bridges requires more complex considerations. The geotechnical investigation becomes crucial, not only for determining bearing capacity but also for assessing scour potential. In some cases, foundations might need to be designed with special features, such as scour protection, to prevent erosion around the bridge piers. Bridge foundations may also need to accommodate horizontal forces caused by water flow.

Construction:

3.1.Flyover:

Flyover construction typically involves building columns and spans above the ground level. The shallow foundations are constructed by excavating the soil to the required depth, compacting it, and pouring reinforced concrete into the excavated area. The columns are then built on top of these footings.

3.2.River Bridge:

Construction of a river bridge involves more challenging conditions. The foundation construction may require working in or near water, which can be complicated and may necessitate the use of cofferdams or specialized construction techniques. Scour protection measures must be installed during or after the construction of the foundation to safeguard against erosion.

Conclusion:-

In summary, while both flyovers and river bridges use shallow foundations, the key differences lie in the stability considerations, designing for longer spans and water loads, and the challenges of construction near or in water bodies. Each type of structure requires careful engineering and planning to ensure the stability and longevity of the bridge or flyover.

Week 4 Challenge

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in your own course.

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Ship work like thisin your own course.

Talk to a career counsellor

Ship work like this
in your own course.