Challenge

Week 12 Challenge

Aim:- What is the difference between active and passive earth pressure? Design a well foundation for the pier. Calculate the steel in steining and kg/cumec for all other components of well foundation.

Que 1) Difference between active and passive earth pressure?

  • Active Earth Pressure

Active state is developed when the wall moves away from the back fill.The active earth pressure is less than pressure at rest because the internal resistance is mobilize in the soil of back fill when wall moves away from the back fill.

  • Passive Earth pressure

In passive state the wall is pushed towards the back fill. The passive earth pressure is greater than earth pressure at rest because shearing resistance is built up between two surface of soil mass.

Que 2) Design a well foundation for the pier

BASIC DESIGN DATA
Span and Cross section Data
C/C of expansion gap (Left Span ) = 31.00 m
C/C of bearing (Left Span) = 30.00 m
Distance of bearing to expansion gap (Left span) = 0.50 m
C/C of expansion gap (Right Span) = 31.00 m
C/C of bearing (Right Span) = 30.00 m
Distance of bearing to expansion gap (Right span) = 0.50 m
Total width = 12.00 m
Carriageway width = 8.50 m
No of bearing = 4.00 Nos
C/c spacing of longitudinal girders = 3.00
Footpath Width (Left side) = 1.50 m
Footpath Width (Right side) = 1.50 m
Crash Barrier Width (Left side) = 0.50 m
Crash Barrier Width (Right side) = 0.50 m
Handrail Width (Left side) = 0.00 m
Handrail Width (Right side) = 0.00 m
Wearing Coat Thickness = 0.065 m
Depth of superstructure (Left Span) = 1.32 m
Depth of superstructure (Right Span) = 1.32 m
CG of superstructure from bottom (Left Span) = 0.88 m
CG of superstructure from bottom (Right Span) = 0.88 m
Height of crash barrier = 0.90 m
Bearing thickness (Max) = 0.15 m
Height of pedestal = 0.25 m
Hozi. Distance of FRL from pedestal of leas height = 0.00 m
Expansion joint = 0.04 m
Skew Angle = 0.00 m
Superelevation/camber = 2.50 %
Type of superstructure (Left Span) = PSC Girder and Deck
Type of superstructure (Right span) = PSC Girder and Deck
Salient Levels
Finished Road Level FRL = 232.111 m
Bearing Level (Avg) BRL = 229.842 m
Pier Cap Top Level CTL = 229.424 m
High Flood Level HFL = 228.700 m
Ground Level GL = 226.248 m
Wellcap Top Level WCTL = 225.748 m
Wellcap Bottom Level WCBL = 223.748 m
Maximum Scour Level MSL = 217.840 m
Zero Shear Level ZSL = 205.248 m
Founding Level FL = 198.748 m
Material Data
For Pier cap, pier and Footing
Grade of concrete fck = M 35
Design strength of concrete fcd 15.63 Mpa
Modulus of Elasticity of steel
Es = 2.10E+05
Modulus of Elasticity of concrete Ec = 3.20E+04
Mean tensile strength of concrete fctm = 2.8
For Well stening
Grade of concrete fck = M 30
Design strength of concrete fcd 13.4 Mpa
Modulus of Elasticity of steel Es = 2.10E+05
Modulus of Elasticity of concrete Ec = 3.10E+04
Mean tensile strength of concrete fctm = 2.8
Grade of steel fyk = Fe 500
Design strength of steel Fyd 434.78 Mpa
Density of concrete (RCC & PCC) Conc_dens = 2.5 t/m3
Density of weearing course = 2.2 t/m3
Coefficient of Thermal Expansion = 12000000
Shrinkage Strain For Concrete = 20000
Partial Safety Factors
For Loads
Ultimate Limit State (For Verification Of Structural Strength
Load Basic Comb Seismic
Comb
Dead Load 1.35 1.35
SIDL (except surfacing) 1.35 1.35
SIDL (surfacing) 1.75 1.75
Live load and associated
loads (Leading)
1.5 0.2
Live load and associated
loads (Accompanying)
1.15 0.2
Water Current 1 1
Buoyancy 0.15 0.15
Hydrodynamic Effect - 1
Wind (Leading) 1.5 -
Wind (Accompanying) 0.9 -
Seismic Effect (During
service)
- 1.5
Seismic Effect (During
construction)
- 0.75
Serviceability Limit State
Load Rare Comb Quasi-
permanent
Comb
Dead Load 1 1
SIDL (except surfacing) 1 1
SIDL (surfacing) 1.2 1
Live load and associated
loads (Leading)
1 -
Live load and associated
loads (Accompanying)
0.75 0
Water Current 1 -
Buoyancy 0.15 0.15
Thermal Load (Leading) 1.0 -
Thermal Load
(Accompanying)
0.6 0.5
Wind (Leading) 1.0 -
Wind (Accompanying) 0.6 0
For Material
Material Basic Comb Seismic
Comb
Concrete 1.5 1.5
Reinforcing steel 1.15 1.15
Load Data
Dead Load
Left Span
Total weight of superstructure = 592.00 t
Right Span
Total weight of superstructure = 592.00 t
SIDL
Load Intensity due to wearing course = 0.22 t/m2
Self weight of crash barrier = 34.10 t/m
FPLL
Maximum intensity of footpath live load = 500.00 kg/m2
Live Load
Both Span Loaded
1 Lane 70R- Wheeled
1 Lane Class A
3 Lane Class A
1 Lane Class A + 1 lane 70R - Wheeled
One Span Loaded
1 Lane 70R- Wheeled
1 Lane Class A
3 Lane Class A
1 Lane Class A + 1 lane 70R - Wheeled
%reduction = 90.00 %
Fraction of live load remaining in seismc case = 0.20
Factor by which seismic force should be increase for fdn design = 0.00
Wind Load Data
Basic Wind Speed = 50.00 m/s
Type of tarrain = plain terrain
For DL+SIDL For LL
Gust Factor, G 2.0 2.0
Drag Coeficient, CD 2.1 1.2
Lift Coeficient, CL 0.75 -
Parameter for wind forces on substructure
For Cap
Gust Factor, G = 2.00
Height/Breadth = 0.15
Drag Coefficient, CD = 1.20
For Shaft
Gust Factor, G = 2.00
Height / Breadth = 0.68
Drag Cpefficient, CD = 0.80
For Circular well
Gust Factor, G = 2.00
Height / Breadth = 1.92
Drag Cpefficient, CD = 72.00

Bearing Data
Type of bearing = POT-PTFE
No. of Bearing over pier on support line = 8 Nos
Type of Substructure = Circular pier with pier cap
Number of pier shaft = 1.00
Transerse eccentricity of substructure with footing/cap = 0.00 m
Pedestal
Length = 0.90 m
Width = 0.90 m
Height = 0.25 m
Nos = 4.00
Pier Cap
Rectangular Part
Length (T-T) = 11.00 m
Length (L-L) = 3.80 m
Height = 0.80 m
Trapoizodal Part
Length (T-T) = 2.70 m
Length (T-L) = 3.80 m
Height = 0.85 m
Pier Shaft
Dimension along traffic = 3.00 m
Dimension perpendicular to traffic = 3.00 m
Foundation Data
Type of foundation Well Foundation
Total No of circular well = 1
Dia of well cap = 7.3 m
External dia of well = 7.3 m
Thickness of well cap = 2 m
Thickness of stening required = 1.138 m
Thickness of stening = 1.15 m
Thickness of top plug = 0 m
Thickness of intermediate plug = 0 m
Thickness of bottom plug ( top cylindrical portion) = 0.3 m
Thickness of bottom plug ( Bottom cylindrical portion) = 1.9 m
Height of well curb = 2.2 m
Projection of well curb from outer face of stening = 0.075 m
Thickness of well curb at bottom = 0.15 m
Depth of Bottom plug above well curb top = 0.3 m
Grip length of well = 12.95 m
Height of water fill = 22.5 m
Height of sand fill = 0 m
Clear Cover
Pier Cap = 50 mm
Pier Shaft = 50 mm
Foundation = 75 mm
LOAD CALCULATION FROM SUPERSTRUCTURE
Dead Laod Of Superstructure
Left Span
Reaction from left span = 592 t
Reaction from Right span = 592 t
Total reaction on pier = 1184 t
Longitudinal movement = 0 t-m
Transverse ecc. Of DL from c/l from of pier = 0 t
Transverse movement = 0 t
SIDL (Crash barrier, railing, foothpath) - Excluding wearing course
Left span
Crash barrier weight = 85.25 t
Railing weight = 0 t
Footpath / service weight = 0 t
Right span
Crash barrier weight = 85.25 t
Railing weight = 0 t
Footpath / service weight = 0 t
Total reaction on pier (SIDL excluding w/c) = 170.50
Longitudinal Movement (CB) = 0 t-m
Total Longitudinal Movement (SIDL excluding w/c) = 0 t-m
SIDL ( Wearing course)
load intensity ue to wearing course = 0.22 t/m2
Left span
DL of wearing course = 37.6805
Right span
DL of wearing course = 37.6805
Total Reaction on pier (SIDL/ w/c) = 75.361
Longitudinal movement ( wearing course ) = 0
Summary of Load from Superstructure
Bearing Level
Load Item Pmax Pmin ML MT HL HT
t t t-m t-m t-m t-m
DL 1184.0 1184.0 0.0 0.0 0.0 0.0
SIDL (excluding w/c) 170.5 170.5 0.0 0.0 0.0 0.0
SIDL w/c) 75.4 75.4 0.0 0.0 0.0 0.0
Pier bottom Level
Load Item Pmax Pmin ML MT HL HT
t t t-m t-m t-m t-m
DL 1184.0 1184.0 0.0 0.0 0.0 0.0
SIDL (excluding w/c) 170.5 170.5 0.0 0.0 0.0 0.0
SIDL w/c) 75.4 75.4 0.0 0.0 0.0 0.0
Cap Bottom level
load Item Pmax Pmin ML MT HL HT
t t t-m t-m t-m t-m
DL 1184.0 1184.0 0.0 0.0 0.0 0.0
SIDL (excluding w/c) 170.5 170.5 0.0 0.0 0.0 0.0
SIDL w/c) 75.4 75.4 0.0 0.0 0.0 0.0
Point of zero shear
load Item Pmax Pmin ML MT HL HT
t t t-m t-m t-m t-m
DL 1184.0 1184.0 0.0 0.0 0.0 0.0
SIDL (excluding w/c) 170.5 170.5 0.0 0.0 0.0 0.0
SIDL w/c) 75.4 75.4 0.0 0.0 0.0 0.0
Founding Level
load Item Pmax Pmin ML MT HL HT
t t t-m t-m t-m t-m
DL 1184.0 1184.0 0.0 0.0 0.0 0.0
SIDL (excluding w/c) 170.5 170.5 0.0 0.0 0.0 0.0
SIDL w/c) 75.4 75.4 0.0 0.0 0.0 0.0
One Span dislodged condition
Dead Load Of Superstructure
Vertical load on pier = 592 t
Longitudinal Movement = 296 t- m
Transverse Movement
SIDL (Crash barrier, railing, foothpath) - Excluding wearing course
Vertical load on pier = 85.25 t
Longitudinal Movement = 42.625 t- m
Transverse Movement =
SIDL ( Wearing course)
Vertical load on pier = 37.6805 t
Longitudinal Movement = 18.84 t- m
Transverse Movement =
Total Load = 714.9305
Longitudinal Movement = 357.47
Bearing Level
Load Item Pmax Pmin ML MT HL HT
t t t-m t-m t-m t-m
DL 296.0 592.0 148.0 0.0 0.0 0.0
SIDL (excluding w/c) 85.3 85.3 42.6 0.0 0.0 0.0
SIDL w/c) 37.7 37.7 18.8 0.0 0.0 0.0
Pier bottom Level
Load Item Pmax Pmin ML MT HL HT
t t t-m t-m t-m t-m
DL 296.0 592.0 148.0 0.0 0.0 0.0
SIDL (excluding w/c) 85.3 85.3 42.6 0.0 0.0 0.0
SIDL w/c) 37.7 37.7 18.8 0.0 0.0 0.0
Well Cap Bottom level
Load Item Pmax Pmin ML MT HL HT
t t t-m t-m t-m t-m
DL 296.0 592.0 49.8 0.0 0.0 0.0
SIDL (excluding w/c) 85.3 85.3 6.7 0.0 0.0 0.0
SIDL w/c) 37.7 37.7 5.7 0.0 0.0 0.0
Max scour Level
Load Item Pmax Pmin ML MT HL HT
t t t-m t-m t-m t-m
DL 296 592 49.8 0 0 0
SIDL (excluding w/c) 85.25 85.25 6.7 0 0 0
SIDL w/c) 37.6805 37.6805 5.7 0 0 0
Point of zero shear
Load Item Pmax Pmin ML MT HL HT
t t t-m t-m t-m t-m
DL 296 592 49.8 0 0 0
SIDL (excluding w/c) 85.25 85.25 6.7 0 0 0
SIDL w/c) 37.6805 37.6805 5.7 0 0 0
Founding Level
Load Item Pmax Pmin ML MT HL HT
t t t-m t-m t-m t-m
DL 296 592 49.8 0 0 0
SIDL (excluding w/c) 85.25 85.25 6.7 0 0 0
SIDL w/c) 37.6805 37.6805 5.7 0 0 0
LIVE LOAD CALCULATON
Following Live Load cases are consider
1. 1 lane 70-R Wheeled
2. 1 lane Class A
3. 3 lane Class A
4. 1 Lane 70R- Wheeled + 1 Lane Class A
DL + SIDL reaction from left span = 715 t
DL + SIDL reaction from Right span = 715 t
Number of bearing = 8
Bearing type is = POT-PTEF
Both span Loaded
(1) 1 lane 70 R- Wheeled
Load Distance from 17t
17 0 0
17 1.37 23.29
17 4.42 75.14
17 5.79 98.43
12 7.92 95.04
12 9.44 113.28
8 13.4 107.2
100 512.38 sum
CG from = 5.1238
CG Left Span CG Right Span
17 1.37 23.29 17 0 0
12 3.5 42 17 1.37 23.29
12 5.02 60.24 17 4.42 75.14
8 8.98 71.84
49 197.37 51 98.43
CG from 4.03 CG from 1.93

Live Load Reaction
Ra = 5.76 t
Rb = 43.24 t
Rc = 48.57 t
Rd = 2.43 t
Breaking force in Left span = 9.8
Decrease in Rb due to breaking force = 1
Breaking force in Right span = 10.2
Decrease in Rc due to breaking force = 0.4
Net Rb = 42.24
Net Rc = 48.17
Vertical force on pier 90.41
Longitudinal moment 21.11883333
Total braking force at bearing level 10 t
Total Horizontal force (Longtudinal) HL = 10 t
Total Horizontal force (Transverse) HT = 0 t

(2) 1 lane Class A
Load Distance from 17t
2.7 0 0
2.7 1.1 2.97
11.4 4.30 49.02
11.4 5.50 62.7
6.8 9.80 66.64
6.8 12.80 87.04
6.8 15.8 107.44
6.8 18.8 127.84
55.4 503.65 sum
CG from = 9.091155
CG Left Span CG Right Span
6.8 3 20.4 2.7 0 0
6.8 6 40.8 2.7 1.1 2.97
6.8 9 61.2 11.4 4.3 49.02
11.4 5.5 62.7
6.8 9.8 66.64
20.4 122.4 35 181.33
CG from 6.00 CG from 5.180857

Live Load Reaction
Ra = 3.74 t
Rb = 16.66 t
Rc = 29.54 t
Rd = 5.46 t
Breaking force in Left span = 4.08
Decrease in Rb due to breaking force = 0.8
Breaking force in Right span = 7
Decrease in Rc due to breaking force = 0.8
Net Rb = 15.86
Net Rc = 28.74
Vertical force on pier 44.60
Longitudinal moment 6.4395
Total braking force at bearing level 5.5 t
Total Horizontal force (Longtudinal) HL = 5.5 t
Total Horizontal force (Transverse) HT = 0 t

(3) 3 lane Class A
Live Load Reaction
Ra = 10.10 t
Rb = 44.98 t
Rc = 79.76 t
Rd = 14.74 t
Breaking force in Left span = 5.1
Decrease in Rb due to breaking force = 1
Breaking force in Right span = 8.75
Decrease in Rc due to breaking force = 1
Net Rb = 43.98
Net Rc = 78.76
Vertical force on pier 122.74
Longitudinal moment 17.39
Total braking force at bearing level 12.5 t
Total Horizontal force (Longtudinal) HL = 12.5 t
Total Horizontal force (Transverse) HT = 0 t

(4) 1 lane 70 R- Wheeled + 1 lane Class A
Live Load Reaction
Ra = 8.55 t
Rb = 53.91 t
Rc = 70.30 t
Rd = 7.10 t
Breaking force in Left span = 10.82
Decrease in Rb due to breaking force = 2.1
Breaking force in Right span = 11.95
Decrease in Rc due to breaking force = 2.1
Net Rb = 51.81
Net Rc = 68.20
Vertical force on pier 120.01
Longitudinal moment 8.19
Total braking force at bearing level 11.4 t
Total Horizontal force (Longtudinal) HL = 11.4 t
Total Horizontal force (Transverse) HT = 0 t

Summary of Load from Superstructure
Both Span Loaded
Load Item Pmax Pmin ML MT HL HT
t t t-m t-m t-m t-m
1 Lane 70 R - W 90.4 90.4 21.1 262.6 10.0 0.0
1 Lane Class A 44.6 44.6 6.4 198.5 5.5 0.0
3 Lane Class A 122.7 122.7 43.4 178.0 12.5 0.0
1 L 70 R -W + 1 L Class A 120.01 120.01 8.19 192.85 11.4 0.0
Final Summary
Normal Case
Bearing Case
Pmax Pmin ML MT HL HT
t t t-m t-m t-m t-m
LL 1 122.74 122.74 43.38 177.97 12.5 0.0
LL 2 122.74 122.74 43.38 177.97 12.5 0.0
LL 3 90.4 90.4 21.1 262.6 10.0 0.0
Pier bottom level
Pmax Pmin ML MT HL HT
t t t-m t-m t-m t-m
LL 1 122.74 122.74 43.38 177.97 12.5 0.0
LL 2 122.74 122.74 43.38 177.97 12.5 0.0
LL 3 90.4 90.4 21.1 262.6 10.0 0.0
Cap bottom level
Pmax Pmin ML MT HL HT
t t t-m t-m t-m t-m
LL 1 122.74 122.74 43.38 177.97 12.5 0.0
LL 2 122.74 122.74 43.38 177.97 12.5 0.0
LL 3 90.4 90.4 21.1 262.6 10.0 0.0
Max scour level
Pmax Pmin ML MT HL HT
t t t-m t-m t-m t-m
LL 1 122.74 122.74 43.38 177.97 12.5 0.0
LL 2 122.74 122.74 43.38 177.97 12.5 0.0
LL 3 90.4 90.4 21.1 262.6 10.0 0.0
Point of zero shear
Pmax Pmin ML MT HL HT
t t t-m t-m t-m t-m
LL 1 122.74 122.74 43.38 177.97 12.5 0.0
LL 2 122.74 122.74 43.38 177.97 12.5 0.0
LL 3 90.4 90.4 21.1 262.6 10.0 0.0
Founding level
Pmax Pmin ML MT HL HT
t t t-m t-m t-m t-m
LL 1 122.74 122.74 43.38 177.97 12.5 0.0
LL 2 122.74 122.74 43.38 177.97 12.5 0.0
LL 3 90.4 90.4 21.1 262.6 10.0 0.0
Calculation Of Load at Pier Bottom Level

Normal Case
Calculation Of Self Weight
Pedestal
Length = 0.9 m
Weidth = 0.9 m
Height = 0.25 m
Nos. = 4 Nos
Total Weight of pedestial = 2.025 t
Pier Cap
Rectangular part
Length = 11 m
Width = 3.8 m
Height = 0.8 m
Volume = 33.44 m3
Weight = 83.6 t
Length (Top) = 11 m
Width (Top) = 3.8 m
Length (Bottom) = 2.7 m
Width (Bottom) = 3.8 m
Height = 0.85 m
Top plan area = 41.8 m2
Bottom plan area = 10.26 m2
volume = 20.61792 m3
weight = 51.5448 t
Total weight of pier cap = 135.1448 t
Pier shaft
Area of Cross section of rectangular = 7.07 m2
Height = 2.026 m
Nos. = 1
weight = 35.80955 t
Total Weight of Substructure = 172.9793 t
Transverse Movement = 0 t-m
Loads at Wellcap bottom Level
Normal Cases
Calculation of Self weight
Rectangular part = 196.8 m3
Total volume = 196.8 m3
Weight = 492
LWL Case
Total wight of footing = 492 t
Longitudinal Moment 0 t-m
Transverse Movement 0 t-m
Summary of force at pier bottom Level
Load Item Pmax Pmin ML MT HL HT
t t t-m t-m t t
Substructure Weight 172.979349 172.979349 0 0 0 0
Weight of footing 492 492 0 0 0 0
Weight of soil on footing 0 0 0 0 0 0
Calculation Of Wind Forces
Basic Wind Speed = 47 m/s
Type of terrain = Plain terrain
Type of Superstructure = slab
Type of substructure = Circular pier with pier cap
Left Span
Length of superstructure in L-L direction (Square) = 31 m
Length of superstructure in L-L direction (Square) = 31 m
Length of superstructure in L-L direction (Square) = 12 m
Total dept of superstructure (include Cras barrier) = 1.875 m
Average height of exposes surface from ground level = 6.86 m
Vz = 47.58 m/s
Pz = 1116.9 N/m2
Wind Forces On DL + SIDL
Gust factor = 2
Drag coefficient = 2.1
Exposed solid area A1 = 58.125 m2
Force in transverse direction FT = 6.80 t
acting at RL = 230.61 m
Force in longitudinal direction FL = 1.70 t
acting at RL = 230.6115 m
Plan Area A3 = 372 m2
Lift coefficient CL = 0.75
Force in veertical direction FV = -62 t
Right Span
Length of superstructure in L-L direction (Square) = 31 m
Length of superstructure in L-L direction (Square) = 31 m
Length of superstructure in L-L direction (Square) = 12 m
Total dept of superstructure (include Cras barrier) = 1.87 m
Average height of exposes surface from ground level = 6.8635 m
Vz = 39.6 m/s
Pz = 940.6 N/m2
Wind Forces On DL + SIDL
Gust factor = 2
Drag coefficient = 1.3
Exposed solid area A1 = 57.97 m2
Force in transverse direction FT = 6.80 t
acting at RL = 230.609 m
Force in longitudinal direction FL = 1.7 t
acting at RL = 230.609 m
Plan Area A3 = 372 m2
Lift coefficient CL = 0.75
Force in veertical direction FV = -90 t
Total Wind forces at bearing level from superstructure
Both Span present One Span present
HL wind = 1.7 HL wind = 0.9
HT wind = 6.8 HT wind = 3.4
P wind = -90.0 P wind = -45.0
Forces at Pier shaft bottom level
Both Span present Both Span present
HL wind = 1.7 HL wind = 0.9
HT wind = 6.8 HT wind = 3.4
P wind = -90.0 P wind = -45.0
ML due to HL = 9.6 ML due to HL = 4.8
ML due to P = 0.0 ML due to P = 0.0
MT = 38.6 MT = 19.3
Fores at Foundation bottom level
Both Span present Both Span present
HL wind = 1.7 HL wind = 0.9
HT wind = 6.8 HT wind = 3.4
P wind = -90.0 P wind = -45.0
ML due to HL = 9.6 ML due to HL = 4.8
ML due to P = 0.0 ML due to P = 0.0
MT = 38.6 MT = 19.3

Average height of exposed surface from the ground level = 5.676 m
Vz = 39.6 m/s
Pz = 940.6 N/m2
Exposed solid area A1 = 5.8 m2
Gust factor G = 2
Width of Cap (skew) b = 3.8 m
Length of Cap (skew) t = 11 m
t/b = 2.89
Height / Breadth = 0.43
Drag coefficient = 0.7
Force in transverse direction FT = 0.801 t
acting at RL = 229.674 m
Forces at Pier shaft bottom level due to wind forces on pier cap
HL wind = 0 t
HT wind = 0.8 t
ML = 0 t-m
MT = 16.1584 t-m
Forces at Footing bottom level due to wind forces on pier cap
HL wind = 0 t
HT wind = 0.8 t
ML = 0 t-m
MT = 17.5984 t-m

Projected area in elevation in transverse direction ( Expose area )
Average height of exposed surface from the ground level = 9.3 m
Vz = 39.6 m/s
Pz = 940.6 N/m2
Exposed solid area LWL case A1 = 6.192 m2
Gust factor G = 2
t/b = 0
Height / Breadth = 0.688
Drag coefficient CD = 1.2
Force in transverse direction FT = 8.747 t
acting at RL = 228.392 m
Forces at Pier shaft bottom level due to wind forces on pier shaft
HL wind = 0 t
HT wind = 8.747 t
ML = 0 t-m
MT = 176.671906 t-m
Forces at Footing bottom level due to wind forces on pier shaft
HL wind = 0 t
HT wind = 8.747 t
ML = 0 t-m
MT = 192.416506 t-m
Summary Of forces due to wind on Superstructure + Substructure
Both span present
At pier Bottom Level
Pmax Pmin ML MT HL HT
t t t t t t
90.0 -90.0 9.6 231.4 1.7 16.35
At pier Footing Level
Pmax Pmin ML MT HL HT
t t t t t t
90.0 -90.0 9.6 248.6 1.7 16.35
One Span Dislodged
At pier Bottom Level
Pmax Pmin ML MT HL HT
t t t t t t
45.0 -45.0 4.8 212.1 0.85 12.95
At pier Footing Level
Pmax Pmin ML MT HL HT
t t t t t t
45 -45 4.8246 229.3 0.85 12.95
Calculation of weight of well
Weight of well cap
Length of well cap (revised as per new arrangement) = 7.95 m
Width of well cap (revised as per new arrangement) = 8.1 m
Thickness of well cap = 2 m
Weight of well cap = 321.975 t
Weight of top plug
Internal dia of well = 5 m
Height of top plug = 0 m
Weight of top plug = 0 t
Weight of steining
External dia of well = 7.3 m
Internal dia of well = 5 m
Height of steining at point of zero shear = 18.5 m
Weight of steining at point of zero shear = 1027.6 t
Height of steining at founding level = 25 m
Weight of steining at founding level = 1266.5 t
Weight of water fill
Internal dia of well = 5 m
Height of water fill at point of zero shear = 18.5 m
Weight of water fill at point of zero shear = 362.2 t
Height of water fill at founding level = 22.5 m
Weight of water fill at founding level = 441.8 t
Weight of intermediate plug
Internal dia of well = 5 m
Height of intermediate plug = 0.3 m
Weight of intermediate plug = 14.7 t
Weight of sand fill
Internal dia of well = 5 m
Height of sand fill at point of zero shear = 6.1 m
Weight of sand fill at point of zero shear = 241.5 t
Height of sand fill at founding level = 0 m
Weight of sand fill at founding level = 0 t
Weight of bottom plug
Dia of bottom plug in cylindrical portion = 5 m
Area of c/s of bottom plug in cylindrical portion = 19.6 m2
Dia of bottom plug at founding level = 7.2 m
Area of c/s of bottom plug at founding level = 40.2 m2
Height of top cylindrical portion = 0.6 m
Height of bottom conical portion = 1.9 m
Weight of bottom plug = 168.6 t
Weight of well curb
Area of c/s of well curb = 1.531 m2
Average dia of ring = 5.667 m
Weight of well curb = 68.1 t
Total weight of well at zero shear level = 1953.275 t
Total weight of well = 2281.675 t
Weight of soil on curb projection
External dia of well = 7.3 m
Length of projection = 0.075 m
Area of c/s of soil on projection = 1.738 m2
Normal case = 24.6 m
Height of soil on projection (LWL case without scour) =
Calculation of buoyancy on well
HFL CASE
Volume of well upto FL = 1130.05 m3
Buoyancy force on well upto FL = -1130.1 t
Buoyancy force on well upto ZSL = -858 t
At Zero shear Level
Load Item Pmax Pmin ML MT HL HT
t t t-m t-m t t
Weight of well 1954.4 1954.4 0 0 0 0
Wt of soil on projection 0 0 0 0 0 0
Buoyancy on well -1130.1 -1130.1 0 0 0 0
At Founding Level
Load Item Pmax Pmin ML MT HL HT
t t t-m t-m t t
Weight of well 2281.7 2281.7 0 0 0 0
Wt of soil on projection 0 0 0 0 0 0
Buoyancy on well -1130.1 -1130.1 0 0 0 0
ACTIVE EARTH PRESSURE
Description RL at top RL at bottom height width b = angle of inclination of wall with horizontal f = angle of shearing resistance d = angle of friction between soil and wall I = angle of inclination of soil with horizontal kah kph c g kah.g.h top kah.g.h bottom -2c.(kah)^0.5 Int of Active Earth Pressure at top Int of Active Earth pressure at bottom FOS Force -normal RL of acting force M - founding level -normal
1 FRL-Well cap top 214.500 204.500 10.000 1.800 1.571 0.000 0.000 0.000 1.000 1.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 1 0.0 0.000
2 Well cap top-lbl 204.500 204.000 0.500 7.300 1.571 0.000 0.000 0.000 1.000 1.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 1 0.0 204.165 0.0
3 lbl-lay1 204.000 193.071 10.929 7.300 1.571 0.524 0.349 0.000 0.279 5.737 0.000 1.030 0.000 3.145 0.000 0.000 3.145 2 0.0 196.678 0.0
4 layer 1-MSL 193.071 190.450 2.621 7.300 1.571 0.576 0.384 0.000 0.245 7.496 0.000 1.010 3.145 3.794 0.000 3.145 3.794 2 0.0 191.720 0.0
5 MSL -Layer 2 190.450 190.450 0.000 7.300 1.571 0.576 0.384 0.000 0.245 7.496 0.000 1.010 3.794 3.794 0.000 3.794 3.794 2 0.0 190.450 0.0
6 Layer 2- Layer 3 190.450 190.071 0.379 7.300 1.571 0.576 0.384 0.000 0.245 7.496 0.000 1.010 3.794 3.888 0.000 3.794 3.888 2 5.3 190.260 67.8
7 Layer 3- Layer 4 190.071 185.571 4.500 7.300 1.571 0.576 0.384 0.000 0.245 7.496 0.000 1.020 3.888 5.013 0.000 3.888 5.013 2 73.1 187.726 747.6
8 Layer 4- well curb top 185.571 179.571 6.000 7.300 1.571 0.593 0.393 0.000 0.235 8.197 0.000 1.030 5.013 6.465 0.000 5.013 6.465 2 125.7 182.445 621.5
9 well kerb top-Layer 5 179.571 179.571 0.000 7.300 1.571 0.593 0.393 0.000 0.235 8.197 0.000 1.030 6.465 6.465 0.000 6.465 6.465 2 0.0 179.571 0.0
10 Layer 5- FL 179.571 177.500 2.071 7.300 1.571 0.593 0.393 0.000 0.235 8.197 0.000 1.030 6.465 6.966 0.000 6.465 6.966 2 50.8 178.523 51.9
254.9 1488.8
PASSIVE EARTH PRESSURE
Description RL at top RL at bottom height width b = angle of inclination of wall with horizontal f = angle of shearing resistance d = angle of friction between soil and wall I = angle of inclination of soil with horizontal kah kph c g kah.g.h top kah.g.h bottom -2c.(kah)^0.5 Int of Active Earth Pressure at top Int of Active Earth pressure at bottom FOS Force -normal RL of acting force M - founding level -normal
1 MSL -Layer 2 190.45 190.45 0.000 7.300 1.571 0.576 0.384 0.000 0.245 7.496 0.000 1.010 0.000 0.000 0.000 0.000 0.000 2 0.0 190.450 0.0
2 Layer 2- Layer 3 190.45 190.071 0.379 7.300 1.571 0.576 0.384 0.000 0.245 7.496 0.000 1.010 0.000 2.869 0.000 0.000 2.869 2 2.0 190.196 25.2
3 Layer 3- Layer 4 190.071 185.571 4.500 7.300 1.571 0.576 0.384 0.000 0.245 7.496 0.000 1.020 2.869 37.274 0.000 2.869 37.274 2 329.7 187.178 3190.7
4 Layer 4- well curb top 185.571 179.571 6.000 7.300 1.571 0.593 0.393 0.000 0.235 8.197 0.000 1.030 37.274 87.933 0.000 37.274 87.933 2 1371.0 182.166 6397.7
5 well kerb top-Layer 5 179.571 179.571 0.000 7.300 1.571 0.593 0.393 0.000 0.235 8.197 0.000 1.030 87.933 87.933 0.000 87.933 87.933 2 0.0 179.571 0.0
6 Layer 5- FL 179.571 177.5 2.071 7.300 1.571 0.593 0.393 0.000 0.235 8.197 0.000 1.030 87.933 105.419 0.000 87.933 105.419 2 730.8 178.504 733.9
2433.5 10347.5
Normal case - LWL
Case Force (t) Moment (tm)
Active Pressure 254.87 1488.8
Passive Pressure 2433.47 10348
Let point of zero shear occure at Y m below MSL
Assume Y 4.088 m
Horizontal force HR 72.68 t
Now, total active force + FR-total passive force 0
160.16+72.68-232.83 = 0
Therefore point of zero shear occures at RL 186.362 m
Combination Of Base Pressure
Normal Case
Both Span present
LWL (Low Water Level) WITHOUT SCOUR
Maximum Reaction case (P)
Load Item Unfactored Forces
Pmax Pmin ML MT HL HT
t t t-m t-m t t
DL (superstructure) 1184.0 1184.0 0.0 0.0 0.0 0.0
SIDL (Excluding W/C) 170.5 170.5 0.0 0.0 0.0 0.0
SIDL (w/c) 75.4 75.4 0.0 0.0 0.0 0.0
LL1 118.3 118.3 542.1 256.3 11.4 0.0
Sustructure Weight 173.0 173.0 0.0 0.0 0.0 0.0
Weight of soil on footing 0.0 0.0 0.0 0.0 0.0 0.0
Weight of footing 492.0 492.0 0.0 0.0 0.0 0.0
Wind Load 90.0 -90.0 9.6 248.6 1.7 16.3
Total for unfactored load 2303.2 2123.2 551.8 504.9 13.1 16.3
Maximum Longitudinal Movement case (ML)
Load Item Unfactored Forces
Pmax Pmin ML MT HL HT
t t t-m t-m t t
DL (superstructure) 1184.0 1184.0 0.0 0.0 0.0 0.0
SIDL (Excluding W/C) 170.5 170.5 0.0 0.0 0.0 0.0
SIDL (w/c) 75.4 75.4 0.0 0.0 0.0 0.0
LL2 118.3 118.3 542.1 256.3 11.4 0.0
Sustructure Weight 173.0 173.0 0.0 0.0 0.0 0.0
Weight of soil on footing 0.0 0.0 0.0 0.0 0.0 0.0
Weight of footing 492.0 492.0 0.0 0.0 0.0 0.0
Wind Load 90.0 -90.0 9.6 248.6 1.7 16.3
Total for unfactored load 2303.2 2123.2 551.8 504.9 13.1 16.3
Maximum Transverse Case
Load Item Unfactored Forces
Pmax Pmin ML MT HL HT
t t t-m t-m t t
DL (superstructure) 1184.0 1184.0 0.0 0.0 0.0 0.0
SIDL (Excluding W/C) 170.5 170.5 0.0 0.0 0.0 0.0
SIDL (w/c) 75.4 75.4 0.0 0.0 0.0 0.0
LL3 82.0 82.0 438.8 385.8 10.0 0.0
Sustructure Weight 173.0 173.0 0.0 0.0 0.0 0.0
Weight of soil on footing 0.0 0.0 0.0 0.0 0.0 0.0
Weight of footing 492.0 492.0 0.0 0.0 0.0 0.0
Wind Load 90.0 -90.0 9.6 248.6 1.7 16.3
Total for unfactored load 2266.8 2086.8 448.4 634.4 11.7 16.3
One Span Dislodge Condition
Load Item Unfactored Forces
Pmax Pmin ML MT HL HT
t t t-m t-m t t
DL (superstructure) 592.0 592.0 49.8 0.0 0.0 0.0
SIDL (Excluding W/C) 85.3 85.3 6.7 0.0 0.0 0.0
SIDL (w/c) 37.7 37.7 5.7 0.0 0.0 0.0
Sustructure Weight 173.0 173.0 0.0 0.0 0.0 0.0
Weight of soil on footing 0.0 0.0 0.0 0.0 0.0 0.0
Weight of footing 492.0 492.0 0.0 0.0 0.0 0.0
Wind Load 45.0 -45.0 4.8 229.3 0.9 12.9
Total for unfactored load 1424.9 1334.9 67.0 229.3 0.9 12.9
SUMMARY OF LOAD CASES FOR NORMAL CASE
LWL Without Scour
Both Span Present Condition
Load Item Pmax Pmin ML MT HL HT
t t t-m t-m t t
N1 2303.2 2123.2 551.8 504.9 13.1 16.3
N2 2303.2 2123.2 551.8 504.9 13.1 16.3
N3 2266.8 2086.8 448.4 634.4 11.7 16.3
One Span Dislodged Condition
Load Item Pmax Pmin ML MT HL HT
t t t-m t-m t t
N4 1424.9 1334.9 67.0 229.3 1.0 11.2
Base pressure check
Dia of well at the base 7.45 m
Area of well at base A 43.59 m^2
Section modulus of well at baZ 40.59 m^3
Actual tilt in longitudinal direction 1 in 36.5
Actual tilt inn transverse direction 1 in 35.6
Actual shift at bottom in long direction -0.06
Actual shift at bottom in tran direction 0.108 m
Well cap shift in long. Direction from bottom 0.34
Well cap shift in tran. Direction from bottom 0.433
Gross SBC (LEL) 80 t/m^3
Basic Combination
Both Span present (LWL, Low Water Level Case)
Maximum Reaction Case P
Load Item Partial
Safety
Factor
Unfactored Forces Factored Forces
Pmax Pmin ML MT HL HT Pmax Pmin ML MT HL HT
t t t-m t-m t t t t t-m t-m t t
DL (superstructure) 1.35 1184.00 1184.00 0.00 0.00 0.00 0.00 1598.4 1598.4 0.0 0.0 0.0 0
SIDL (Excluding W/C) 1.35 170.50 170.50 0.00 0.00 0.00 0.00 230.2 230.2 0.0 0.0 0.0 0
SIDL (w/c) 1.75 75.36 75.36 0.00 0.00 0.00 0.00 131.9 131.9 0.0 0.0 0.0 0
LL1 (Leading) 1.5 118.31 118.31 542.11 256.26 11.40 0.00 177.5 177.5 813.2 384.4 17.1 0
LL1 (Accompanying) 1.15 118.31 118.31 542.11 256.26 11.40 0.00 136.1 136.1 623.4 294.7 13.1 0
Thermal Load (Accompanying) 0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0
Sustructure Weight 1.35 172.98 172.98 0.00 0.00 0.00 0.00 233.5 233.5 0.0 0.0 0.0 0
Weight of soil on footing 1.35 0.0 0.0 0.0 0.00 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0
Weight of footing 1.35 492.00 492.00 0.00 0.00 0.00 0.00 664.2 664.2 0.0 0.0 0.0 0
Wind Load (Leading) 1.5 90.0 -90.0 9.6 248.61 1.7 16.3 135.0 -135.0 14.5 372.9 2.6 24.5205
Wind Load (Accompanying) 0.9 90.0 -90.0 9.6 248.61 1.7 16.3 81.0 -81.0 8.7 223.8 1.5 14.7123
Total LL Leading 3170.7 2900.7 827.6 757.3 19.7 24.5
LL Accompanying 3075.2 2913.2 632.1 518.5 14.6 14.7
Maximum Longitudinal Movement Case (ML)
Load Item Partial
Safety
Factor
Unfactored Forces Factored Forces
Pmax Pmin ML MT HL HT Pmax Pmin ML MT HL HT
t t t-m t-m t t t t t-m t-m t t
DL (superstructure) 1.35 1184.0 1184.0 0.0 0.0 0.0 0.0 1598.4 1598.4 0.0 0.0 0.0 0
SIDL (Excluding W/C) 1.35 170.5 170.5 0.0 0.0 0.0 0.0 230.2 230.2 0.0 0.0 0.0 0
SIDL (w/c) 1.75 75.4 75.4 0.0 0.0 0.0 0.0 131.9 131.9 0.0 0.0 0.0 0
LL2 (Leading) 1.5 118.3 118.3 542.1 256.3 11.4 0.0 177.5 177.5 813.2 384.4 17.1 0
LL2 (Accompanying) 1.15 118.3 118.3 542.1 256.3 11.4 0.0 136.1 136.1 623.4 294.7 13.1 0
Thermal Load (Accompanying) 0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0
Sustructure Weight 1.35 173.0 173.0 0.0 0.0 0.0 0.0 233.5 233.5 0.0 0.0 0.0 0
Weight of soil on footing 1.35 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0
Weight of footing 1.35 492.0 492.0 0.0 0.0 0.0 0.0 664.2 664.2 0.0 0.0 0.0 0
Wind Load (Leading) 1.5 90.0 -90.0 9.6 248.6 1.7 16.35 135.0 -135.0 14.5 372.9 2.6 24.5205
Wind Load (Accompanying) 0.9 90.0 -90.0 9.6 248.6 1.7 16.35 81.0 -81.0 8.7 223.8 1.5 14.7123
Total LL Leading 3170.7 2900.7 827.6 757.3 19.7 24.5
LL Accompanying 3075.2 2913.2 632.1 518.5 14.6 14.7
Maximum Transverse Movement Case (MT)
Load Item Partial
Safety
Factor
Unfactored Forces Factored Forces
Pmax Pmin ML MT HL HT Pmax Pmin ML MT HL HT
t t t-m t-m t t t t t-m t-m t t
DL (superstructure) 1.35 1184.00 1184.00 0.00 0.00 0.00 0.00 1598.4 1598.4 0.0 0.0 0.0 0
SIDL (Excluding W/C) 1.35 170.50 170.50 0.00 0.00 0.00 0.00 230.2 230.2 0.0 0.0 0.0 0
SIDL (w/c) 1.75 75.36 75.36 0.00 0.00 0.00 0.00 131.9 131.9 0.0 0.0 0.0 0
LL3 (Leading) 1.5 81.99 81.99 438.78 385.78 10.00 0.00 123.0 123.0 658.2 578.7 15.0 0
LL3 (Accompanying) 1.15 81.99 81.99 438.78 385.78 10.00 0.00 94.3 94.3 504.6 443.7 11.5 0
Thermal Load (Accompanying) 0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0
Sustructure Weight 1.35 172.98 172.98 0.00 0.00 0.00 0.00 233.5 233.5 0.0 0.0 0.0 0
Weight of soil on footing 1.35 0.0 0.0 0.0 0.00 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0
Weight of footing 1.35 492.00 492.00 0.00 0.00 0.00 0.00 664.2 664.2 0.0 0.0 0.0 0
Wind Load (Leading) 1.5 90.0 -90.0 9.6 248.61 1.7 16.3 135.0 -135.0 14.5 372.9 2.6 24.5205
Wind Load (Accompanying) 0.9 90.0 -90.0 9.6 248.61 1.7 16.3 81.0 -81.0 8.7 223.8 1.5 14.7123
Total LL Leading 3116.2 2846.2 672.6 951.6 17.6 24.5
LL Accompanying 3033.5 2871.5 513.3 667.4 13.0 14.7
One Span Dislodged Condition
Maximum Transverse Movement Case (MT)
Load Item Partial
Safety
Factor
Unfactored Forces Factored Forces
Pmax Pmin ML MT HL HT Pmax Pmin ML MT HL HT
t t t-m t-m t t t t t-m t-m t t
DL (superstructure) 1.35 592.0 592.0 49.8 0.0 0.0 0.0 799.2 799.2 67.2 0.0 0.0 0
SIDL (Excluding W/C) 1.35 85.3 85.3 6.7 0.0 0.0 0.0 115.1 115.1 9.0 0.0 0.0 0
SIDL (w/c) 1.75 37.7 37.7 5.7 0.0 0.0 0.0 65.9 65.9 10.0 0.0 0.0 0
LL3 (Leading) 1.5 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0
LL3 (Accompanying) 1.15 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0
Thermal Load (Accompanying) 0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0
Sustructure Weight 1.35 173.0 173.0 0.0 0.0 0.0 0.0 233.5 233.5 0.0 0.0 0.0 0
Weight of soil on footing 1.35 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0
Weight of footing 1.35 492.0 492.0 0.0 0.0 0.0 0.0 664.2 664.2 0.0 0.0 0.0 0
Wind Load (Leading) 1.5 45.0 -45.0 4.8 229.3 0.9 12.95 67.5 -67.5 7.2 344.0 1.3 19.4205
Wind Load (Accompanying) 0.9 45.0 -45.0 4.8 229.3 0.9 12.95 40.5 -40.5 4.3 206.4 0.8 11.6523
Total LL Leading 1945.5 1810.5 93.5 344.0 1.3 19.4
LL Accompanying 1918.5 1837.5 90.6 206.4 0.8 11.7
SUMMARY OF LOAD CASES FOR BASIC COMNINATION (LWL CASE)
Both Span present condition (LWL Case)
Load Case No. Live Load
Case
LL
Leading / Accomp
Pmax Pmin ML MT HL HT
t t t-m t-m t t
(C-1)1 LL 1 Case LL Leading 3170.7 2900.7 827.6 757.3 19.7 24.5
(C-1)2 LL Accompanying 3075.2 2913.2 632.1 518.5 14.6 14.7
(C-1)3 LL 2 Case LL Leading 3170.7 2900.7 827.6 757.3 19.7 24.5
(C-1)4 LL Accompanying 3075.2 2913.2 632.1 518.5 14.6 14.7
(C-1)5 LL 3 Case LL Leading 3116.2 2846.2 672.6 951.6 17.6 24.5
(C-1)6 LL Accompanying 3033.5 2871.5 513.3 667.4 13.0 14.7
One Span Dislodge condition (LWL Case)
Load Case No. LL
Leading / Accomp
Pmax Pmin ML MT HL HT
t t t-m t-m t t
(C - 1) 7 LL Leading 1945.5 1810.5 93.5 344.0 1.3 19.4
(C - 1) 8 LL Accompanying 1918.5 1837.5 90.6 206.4 0.8 11.7
Steining Check
Dia of well at the base 7.45 m
Area of well at base A 43.59 m^2
Section modulus of well at baZ 40.59 m^3
Actual tilt in longitudinal direction 1 in 36.5
Actual tilt inn transverse direction 1 in 35.6
Actual shift at bottom in long direction -0.06
Actual shift at bottom in tran direction 0.108 m
Well cap shift in long. Direction from bottom 0.34
Well cap shift in tran. Direction from bottom 0.433
LWL without scour
Gross SBC (LEL) 80 t/m^3
oad case No. Pmax Pmin ML MT HL HT ML due to tilt & shift MT due to tilt and shift M Moment due to passive resistance Moment due to active resisttance Net moment P/A+M/Z P/A-M/Z Check
t t tm tm t t tm tm tm tm tm tm tm tm
N1 3170.7 2846.2 827.6 951.6 19.7 24.5 72.73 46.335 57.73 774.8 1774 10348 150.3
Steining is designed as PCC section with minimum 0.12% of steel asCL.708.304 of IRC:78-2014. Capacity of section, stress and crack width is checked for the assumed steining section and following reinforcements.
Clear cover 75 mm
Minimum area of vertical reinforcement required 26662.7 mm^2
Provide 120 nos 12 nos. on outer face 12 on inner face
Area of vertical rein. Provided 27143.36 mm^2
The minimum stress in steining is 0.94 Mpa (as shown in Annexure-A) for rare combination of loads.
Hoop reinforcement shall not be less than 0.04% of the volume/ unit length of the steining
Volume of hoop reinforcement 8887566 mm^3/m
Provide 10 mm dia @ 300 mm c/c
Length of outer hoop steel 22493.8 mm
Length of inner hoop steel 15847.96 mm
Volume of hoop reinforcement 10037851 mm^3/m
Well Curb Reinforcement
Outer dia. Of well 7.3 m
Inner dia. Of well 5 m
Height of well curb 2.2 m
Area of c/s of well curb 1.53 m^2
Avg. dia of ring 5.6 m
Weight of well curb 68.15 t
Min area of rein. required 72 kg/m^3 of concrete IRC78-2014:CL.708.7.3
Min required wt of reinfocement 1962.71 Kg
Reinforcement provided
Discription No Bar Dia Af(m^2) Dia of ring Length (m) Weight (kg)
W1, outer ring 8 160 7.351 23.09 291.6
W3, innner top ring 7 120 6.267 19.69 122.35
W2, inner bottom ring 9 160 6.233 19.58 278.16
W5, ring connector 120 160 5.5 1041.3
W6, hora connector 960 100 0.559 330.86
Total Reinforcement 2063.4 mm^2 OK

​

DESIGN OF WELL CAP
Well cap has been designed as a plate supported at the boundary by steining and subjected to vertical loads & moments through the
substructure .The load is considered after 45o dispersion through the depth of the slab, upon the effective depth. Since the vertical load after
dispersion practically covers the entire dredge hole area, the load is considered as UDL and bending moments calculated accordingly. 50% of
the sagging moment at the centre of well cap is considered at support to account for partial fixidity of the well cap with the steining. Effect of
moment is considered by considering an equivalent triangular distribution of load for shear force. For the moment , effect has been taken as
per " Formula for stress & strain " by R.F. Roark & Young.
1.80 m 7.30 m
1.150 m 7.00 m (false
5.00 m steining
excluded)
1.80 m
False steining
2.00 m
Well steining
Design for shear : D
I) Shear force on well cap due to moment M
where M is the moment at the base of the
well cap. Bending moment M acting on well
cap through substructure is equivalent to
that of triangular load distribution as shown
in the figure.
Maximum loading intensity due to triangular
distribution , po = M*R/(pi*R4/4)
= 4*M/(pi*R3)
Shear force /m run at a distance "a" from centre = Sm
Sm =p*a/4 = po*a2/4R
where p = po*a/R & R = D/2
Do
po p
a
D
ii) Shear force on well cap due to udl
Let q be the intensity of udl
Total load = pi*a2*q
Shear force/m run = Su = q*pi*a2/2*pi*a = q*a/2
Total shear force/m run = Sm + Su
217
Design for flexure :
I) Due to externally applied moment, Mm
Mm = po*a2*( 5 + n )/ 72*(3)0.5 where po = as mentioned earlier
a = Do/2
n = Poisson's ratio = 0.20
(refer Roark's Handbook for Stress & Strain, page 435)
ii) Due to udl, Mo Mm = q*Do2*(5+n) / 72*30.5
Mm = q*Do2*(5+0.2) / 72*30.5
Sagging moment at centre = Mo = q*Do2/ 30 Mm = q*Do2/24
The value of moment has been taken as 80%
Hogging moment at centre = q*Do2/ 60 of the moment at the centre with udl to account
for partial fixity.
Total moment/ m run = Mo + Mm
Outer diametre of well cap (excluding false steining)= 7.30 m
Depth of well cap = 2.00 m
Dispersion of load at 45o from pier is taken upto the cg of bottom steel reinforcement i.e.upto a depth
i.e. upto a depth of , " d " = 1.913m
Dispersion length along
longitudinal direction = 5.625m
Dispersion length along
transverse direction = 5.625m limited to a value of 7.30 m
Hence, the loaded area = 24.85m2 T-T axis
(Loaded area has been calculated based on actual
dispersion)
L-L axis
Check for shear :
Case 3 normal lwl no scour
Total load at well cap bottom = 3038.2 t
MRes = 1189.6 t-m
a = 0.59 m
Weight due to well cap = 209.3 t
i) Shear force due to moment
Maximum load intensity ( po ) = 31.1 t
Shear force/m run, Sm = 0.7 t/m
ii) Shear force due to vertical load
Load from superstructure &
substructure = 2755.7 t
Intensity due to load from
self weight of well cap = 5.0 t/m2
Intensity due to load from
superstructure & substructure = 110.9 t/m2
Total load intensity = 115.9 t/m2
Shear force will be calculated at a distance " d " from inner face of steining.
Shear force/m run, Su = 34.0 t/m
Total shear force/m run = 34.8 t/m
Shear stress = V/b*d = 18.19 t/m2
or = 0.182 N/mm2
218
Check for Shear
Design Shear force VRd = 34.8
Shear capacity of section without shear reinforcement
Overall Depth of section = 2000.0
Effective Depth d = 1912.5
K = 1 + 200 ≤
d
νmin = 0.031K3/2fck1/2 =
σcp = NEd/Ac < 0.2fcd
ρl = Asl ≤ 0.02
bwd
VRd.c = [0.12K(80ρlfck)0.33 + 0.15σcp]bwd
= 59.3 t
Shear reinforcement not required
Check for flexure :
Governing case
i) Moment due to udl load :
c/c Distance of steining, Do = 6.150 m
a = 3.075 m
Max.sagging moment, Mo = 146.11 t-m
Max. Hogging moment, Mo' = 73.06 t-m
ii) Moment due externally applied load :
Moment Mm = 11.3 t-m
Total moment = Mo + Mm = 157.45 t-m 84.39 t-m at top
Rlim = #NAME? MPa
dreqd = √(Mu/(Rlim*b)) =
R = Mu/bd2 = 0.43 bottom
R = Mu/bd2 = 0.23 top
Ast, required bottom = 1920.6 mm2/m
Ast, required top = 1022.5 mm2/m
Ast, required minimum = 2784.6 mm2/m (max. Of 0.26fctm/fyk*bt*d and 0.0013bt*d)
Ast, required governing bottom = 2784.6 mm2/m
Ast, required governing top = 2784.6 mm2/m
Provide reinforcement:
f20 @ 110 c/c
Ast provided = 2855.99 mm2/m So O.K.
at bottom
f32 @ 250 c/c + f25 @ 250 c/c
Ast provided = 5180.49 mm2/m So O.K.

Quantity of Steel in kg/cum

Well cap 100 kg/cum
Well Curb 75 kg/cum
Well steining 30 kg/cum
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