Design of Pier

8/18/2019 Design of Pier

1/11

Two Lane Bridge

0.200 m 0.200 m 738.029 m

1.450 m 736.58

AHFL = 735.654 m 0.93 m

0.300 m . m A1

0.650 m 0.350 m A2

5.900 m

6.920 m 7.573 m 8.073 m

7.573 m

6.923 m

CBL = 728.081 m

0.000 m

Pier Bottom Level 728.081

7.900 m

0.000 m

727.831 m 0.500 m 0.250 m

727.581 m Foundation Level 0.250 m

727.431 m 0.150 m M10

DESIGN OF PIER

8.600 m

7.900 m

735.654 m

1.000 m

735.00 m


2/11

0.600 m

8.900 m

0.300 m A1

0.350 m A2

5.900 m

5.900 m

0.600 m

CBL 728.081 m

1.500 m soil FILL 0.000 m

1.500 m 7.900 m

3.600 m 0.500 m

727.831 m 0.000 m

0.250 m

727.581 m

0.150 m 7.900 m

3.600 m

As per IS 456 CL.25.1.2,

A compression member may be considered as short

when both the slenderness ratios ly/b are less than 12

Height of pier= L = 6.920 m

l = Effective Heigh = 1.2 x L 8.304 m

b = Width of member 1.10m

Accordingl Slenderness Ratio = l/b = 7.55


3/11

DATA : CANAL PARTICULARS

DISCHARGE (DESIGNED) = 44.81 Cumec

BED WIDTH = 2.75m 0

FULL SUPPLY DEPTH = 3.273m

SIDE SLOPES INNER = 2.0:1

= 2.0:1

= 1: 3000

= 1.47 m/s

= 0.018

= 1.000 m

C.B.L =

=

DATA : SINGLE LANE BRIDGE PARTICULARS

=

Depth of deck slab = 0.575 m

Thickness of wearing coat = 0.075 m

=

==

= 8.600 m

=

=

=

= 8.900 m

= 5.900 m

= 1.100 m

= 0.300 m

= 0.350 m

= 5.900 m

=

=

=

R.L Of Pier Bottom Lvel =

R.L Of Bottom Of Foundation =

PIER DESIGN

DEAD LOAD OF SLB = 206.742 t

= 93.787 t

= 18.757 t (Refer: IRC- 6-2014 Cl. 211.2(a)

= 9.379 t

1) Dead Load Of Super Structure = 206.742 t

2) Live Load Reaction On Pier = 93.787 t

736.304 m

735.654 m

735.654 m

R.L Of Top Of Deck Slab

R.L Of Top Of Pier

R.L Of Pier At Bottom of pier cap

Effective span

C/C Of Piers And Abutment

Density Of Concrete.

Top Length Of Pier Cap

Outer To Outer

Bed Fall

Velocity

Rugosity Coefficient (N)

LIVE LOAD REACTION ON PIER(Class

"A" Loading with impact)

BREAKING FORCE (20% of Live Load)

736.579 m

727.581 m

728.081 m

735.004 m

736.579 m

Free Board

Aflux high flood Level (AHFL)

Bottom Lvl Of Slab

Top Of Deck Slab

Pier Bottom LevelFoundation Level

10.910 m

10.370 m

727.581 m728.081 m

2.5 t/cum

728.081 m

Carriage Way Width

Density Of M10 Bed Concrete. 2.4 t/cum

BRAKING FORCE ON PIER(50% of

Breaking force)

Bottom Length Of Pier Cap

Width Of Pier Cap

Straight Thickness Of Pier Cap

Tapering Thickness Of Pier Cap

Overall Length Of Pier


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3) DEAD LOAD OF SUB STRUCTURE

A) Pier Cap

Rectangular Potion = 8.9 x 1.1 x 0.3

A1 = 2.937 cum

2.937 x 2.5

7.343 t

= 8.9 x (1.1+0.6)/2 *0.35*2.5

= 2.570 t

= (area of circle x6.92) + (0.6x5.3x6.92)

((PI() x0.6^2/4)x6.92)+(0.6x5.3x6.92)))

=

23.96 x 2.5

= 59.900 t

= 3.6 x 0.25 x 7.9

=

7.11 x 2.5

= 17.775 t

= 0.25 x 3.6 x 7.9

=7.11 x 2.5

= 17.775 t

= 0.15 x 3.6 x 7.9

=

4.27 x 2.4

= 10.238 t

NO

BOUYANCY

15%

BOUYANC

Y

100%

BOUYANC

Y

206.742 206.742 206.742

93.787 93.787 93.787

300.528 300.528 300.528

7.343 7.343 7.343

2.570 2.570 2.570

59.900 56.306 35.940

69.812 66.218 45.852

276.554 272.960 252.594

370.340 366.746 346.380

17.775 16.709 10.665

17.775 16.709 10.66510.238 23.036 14.334

45.788 56.453 35.664

TOTAL

Total

1.FOOTING ABOVE SECTION

2.FOOTING BELOW SECTION

7.110 cum

7.110 cum

1.DEAD LOAD OF SUPER STRUCTURE

FOOTING SECTION(1)

FOOTING SECTION (2)

SUMMURY OF LOADS

a) UPTO SILL LEVEL

2.i)BED BLOCK RECTANGULAR

2.ii)TRAPEZOIDAL PORTION

3.)PIER SECTOIN

23.960 cum

Trapezoidal Portion

PIER SECTION UPTO SILL LEVEL

FOOTING Bed M10

4.266 cum

3. BED CONCRETE (M10) BELOW FOOTING SECTION

Total

TOTAL LOADS UPTO SILL LEVEL WITHOUT LL

TOTAL LOADS UPTO SILL LEVEL WITH LL

b) UPTO FOUNDING LEVEL

2.LIVE LOAD ON SUPER STRUCTURE


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Transverse moment = 9.01 x1.9

MOMENT AT PIER BOTTOM LEVEL 728.081M

Leverarm = ((1.45 +0.925 )/2)+ 0.65 +6.92

8.758

Transverse moment = 8.76 x1.9

Longitudinal Wind Force on super structure at 25 % of transverse wind force

MOMENT AT FOUNDATION LEVEL 727.431M

Longitudinal Force = 1.9 x ( 25/100 )

= 0.475

Longitudinal moment = 9.41 x0.48

MOMENT AT 605.068M


= 0.475


MOMENT AT 605.368M


= 0.475




= 0.475


Down ward vertical wind load Fv = PZ x A3 x G x CL

A1 = Area in Plan= 8.9x10.91 = 97.099 m2

G = Gust Factor = 2

CL = Lift co-efficient

CL = 0.75

Down ward vertical wind load Fv = 32.91 x (8.9 x10.91) x2 x 0.75

4.793 t

The bridges shall not be considered to be carrying any live load when wind speed exceeds 36 m/s

( refer cl 209.3.7 of IRC-6:2010, page -28)

B). SUBSTRUCTURE

Transverse Wind Force FT = PZ x A1 x G x CD

A1 =

A1 = 4.54 mm²

G = Gust Factor

G = 2

CD = Drag co-efficient depending upon the shape of Sub structure

CD from (Table-5 of IRC 6-2010) = 1.700 H/B = 13.700

CD = 1.700 t/b = 0.102

16.639 t-m

( refer cl 209.3.5 of IRC-6:2010, page -28)

Down ward vertical wind load Fv

Solid area in normal projected elevation

4.469 t-m

4.160 t-m

4792.971 kg

17.114 t-m

4.397 t-m

4.279 t-m


7/11

Transverse Wind Force FT = 400.300 kg

Transverse Wind Force FT = 0.410 t (Refer cl 209.3.3 of IRC-6:2014, pg-31)


Leverarm = (0.65 + 6.92 + 0.25+0.25+0.15)

8.220 m

Transverse moment = 3.370 tm

MOMENT AT 605.068M

Leverarm = (0.65 + 6.92 + 0.25+0.25)

8.070 m


MOMENT AT 605.368M

Leverarm = (0.65 + 6.92 + 0.25)

7.820 m



Leverarm = (0.65 + 6.92)

7.570 m


i.e 0.14*25/100 = 0.035


Longitudinal Force = 0.1025

Longitudinal moment = 0.1 x 8.22

MOMENT AT 605.068M



MOMENT AT 605.368MLongitudinal Force = 0.1025





0.776 t-m

At foundation AT 605.068M @ 605.368M At Pier Bottom

Lever arm 8.220 m 8.070 m 7.820 m 7.570 m

Transverse moment 3.370 t-m 3.309 t-m 3.206 t-m 3.104 t-m

Longitudinal moment 0.843 t-m 0.827 t-m 0.802 t-m 0.776 t-m

Level at Vertical force t Force Hzl. - X in t Hzl. - Z in t ML in tm MT in tm At sill level

605.768 4.793 0.578 2.310 4.936 19.743 t-m

605.368 4.793 0.578 2.310 5.080 20.320 t-m

605.068 4.793 0.578 2.310 5.224 20.898 t-m

604.768 4.793 0.578 2.310 5.311 21.244 t-m at foundation level

4) Water Currents

Longitudinal Wind Force on super structure at 25 % of transverse wind force

Total Wind Loads at base with out Live Load

0.843 t-m

0.827 t-m

0.802 t-m


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9/11

Since, the pressure due to water current is very low, force due to water current shall be neglected

ML MT ML MT ML MT

1. Dead Load Eccentricity 0.000 0.000 0.000 0.000 0.000 0.000

2.Temp And Shrinkage 0.000 0.000 0.000 0.000 1.121 0.000

3.Water Current Force 0.000 0.560 0.000 0.580 0.000 0.600

4.Floating Debris 0.000 0.000 0.000 0.000 0.000 0.000

5.Braking Force 90.954 0.000 93.299 0.000 95.643 0.000

6.Live Load Eccentricity 26.260 65.651 26.260 65.651 26.260 65.651

Total Moments Without LL 0.000 0.560 0.000 0.580 1.121 0.600

Total Moments With LL 117.214 66.211 119.559 66.231 123.025 66.251

6.Moment Due To Wind 4.936 19.743 5.080 20.320 5.224 20.898

Total Moment Without LL 4.936 20.303 5.080 20.900 6.346 21.498

Total Moment With LL 122.150 85.954 124.639 86.551 128.249 87.149

Total Load At Pier Bottom Without LL 276.554

Total Load At Pier Bottom With LL 370.340

Total Load At Foundation Without LL

Total Load At Foundation With LL

SECTIONAL PROPERTIES PIER BOTTOM

AREA (Sqm) 3.823

SECTION MODULUS (Cum)

In Longitudinal Direction 0.354

In Transverse Direction 3.481

WITHOUT BUOYANCY

P/A ML/ZL MT/ZT

t/sqm t/sqm t/sqm Max MIN.

No LL 72.344 0.000 0.161 72.505 72.183

With LL 96.878 331.114 19.021 447.013 -253.256

No LL 72.344 13.943 5.833 92.120 52.569

With LL 96.878 345.057 24.692 466.627 -272.871

15% BUOYANCY

STRESSES (t/sqm)

SUMMURY OF MOMENTSAT PIER BOTTOM LEVEL728.081 AT 727.581 LEVELAT 727.831 LEVEL

28.440

17.064

37.446

Without Wind

With Wind

FINAL STRESSES IN CONCRETE AT PIER BOTTOM LEVEL

FOUNDING


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11/11

100% BUOYANCY

P/A ML/ZL MT/ZT

t/sqm t/sqm t/sqm Max MIN.

No LL 10.136 0.000 0.016 10.152 10.119

With LL 13.433 7.226 1.769 22.429 4.437

No LL 10.136 0.311 0.584 11.031 9.241

With LL 13.433 7.538 2.337 23.308 3.559

40.000 Safe

As per IRC-78 -2000 CL.706.1.2

"The permissible increase in stresses in the various members will be 33(⅓) per cent for the

the combination of wind"

40.000 x 1.33 = 53.3 t/m2 Safe

Design of PCC footing at Earth side

Maximum Base Pressure = 24.755 t/m2

Modulus of section (Z) = (0.25) ̂ 2 x 1/6

0.010 m3

Moment Due to cantilever M = (Wl^2/2) = 24.75 x0 ̂ 2 x 1/2

0.000 tm

M = 0.000 = 0.000 t/m2

Z 0.010

MAX PERMISSBLE TENSILE STRESSES IN CONCRETE - M20 -53.0 t/m2 Safe

Hence Footing is to be design as RCC.

RCC FOOTING for PIERData

Grade of concrete = M20m = 14

sbc = 6.67Mpa

Permissible stress in steel = 240.0Mpa

k = 0.28

j = 0.91

Q = 0.85

Pressure due to DL AND LL = 24.75 24.75

Resultant = 24.75 t/m2

FLEXURE DESIGN

Bending Moment = 12.38 t-m Clear Cover = 75Effective Depth required = 382.49 mm

Effective Depth Provided = 417 Hence, OK

Ast Required = 1364.35 mm2

Astmin = 500.4 mm2

PROVIDE TOR 16 dia @ 140c/c

Ast Provided = 1436.15664 > 1364.35 Hence OK

Distribution reinforcement

Ast minimum = 600.0mm2

dia of bar = 16

Spacing HOWEVER PROVIDE TOR 16 dia @ 335c/c

Without Wind

With Wind

FINAL STRESSES IN CONCRETE AT FL

As per IRC-21 -2000 Table-9 & 11

STRESSES (t/sqm)

NET SBC WITHOUT WIND LOAD

Design of Pier

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