Design of Bridge Pier

Design of R.C.C. Bridge Piers of Ladpura Bridge on RMC Design parameters :

Canal discharge Q =

188.45

cumecs

Clear span between piers =

8 .0 0

m

Thickness of road wa deck slab =

0.8

m

!.".#. of canal $%" of &ridge =

'5(.4'

!.".#. of canal )%" of &ridge =

'5(.4'

m

Canal bed #e*el )%" of &ridge =

'5+.''

m

#ace,s "ilt factor -f =

1.00

&earing Capacit of "oil =

'5

t%m'

/idth of roadwa slab of bridge =

+.5

m

/idth of erb on roadwa bridge =

0

m

Thickness of erb =

0

m

/eight of ailing per m run of bridge =

0.2

3ccen of C%# road deck slab from pier ce nter=

ton%m

0

m

eight of ier upto &ed block top #6# from C&# =

4.1

m

Thickness of &ed block =

0.(

m

0

m'

1.5

m

5

m

5.+

m

#6# of wearing top of road wa deck slab =

'58.''

m

#6# of deck slab bearing

'52.+'

m

#6# of top of foundaon block of ier

'5+.''

m

7rea of bridge oisng pla9orm = /idth of pier #ength of pier at bed block bo:om le*el = #ength of pier at C&# =

;o of bas of bridge

+

;os

#ength of ier at !"# )%" of bridge

5.0+

m

#ength of ier at C&# )%" of bridge

5.+

m

#ength of foundaon block at foundaon #6#

2.5

m

/idth of foundaon block at foundaon #6#

4

m

1.5

m

1

m

'.(>

m

4 .0 4

m

eight of foundaon block at ier
7ncipated depth of scour around piers = 1.5 -   =

#e*el of foundaon of iers should not be less than 1 m below ancipated depth of scour #e*el of foundaon = sa

' 5 1 .+ 8

m

' 5 1 .2 0

m

Evaluaon of fores ang on t!e Pier (a) Dead "eig!t of super struture -i /eight eight of slab slab with with wearin wearing g coat coat =

((.50 ((.50

tonne tonness

-iii -iii /eigh eightt of ail ailin ings gs =

1+.+ 1+.+0 0

tonn tonnes es

$%.&'

tonnes

#otal

() Live Loads ?a@imum li*e load reacon on pier is obtained when fourth a@le load 11.4 t at center of pier

-i eacon from right span =

1(.20

tonnes

-ii eacon from leA span =

1'.55

tonnes

Total #i*e #oad reaco on the ier from li*e loads =

'>.'4

Bmpact !actor =

tonnes

0.'>

"o ?a@imum li*e load reacon with impact =

$.&*

tonnes

Eentriit+ of live load

eccentricit of #.#. from center of pier about < a@is =

'.,,

m

eccentricit of #.# from center of pier about D
'.--

m

8.+(

tonnes

() Braing Fore Bt is eEual to '0F of total li*e load present on the bridge = educed le*el of applicaon of braking force =

'5>.4'

m

eight of appicaon force abo*e bearing le*el =

'.100

m

Bncrease in reacon due to braking force =

-.&,

tonnes

(d) #emperature fore due to sliding frion eacon on sliding end when loads are placed so as to produc ma@imum reacon at sliding end #i*e load eacon at sliding end =

14.+'

Bmpact factor =

0.'>

#i*e load with impact =

18.51

tonnes

)ead #oad reacon =

2>.80

tonnes

1.85

tonnes

Bncrease due to braking force = Total G

100.45

tonnes

tonnes

!ricon in sliding bearing - with coeH. of sliding fricon as 0.0+ = .#. of point of applicaon =

*,$.*

.'-

tonnes

m

(e) /ind fore "ince intensit of wind pressure depends upon t he height of the point abo*e mean retarding surfaceI so two cases for calculaon of wind forces ha*e been considered -i /hen le*el of water in the canal is at !.".#. -ii /hen depth of water is Jero (i) /!en level of "ater in t!e anal is at F.0.L.

7*erage height of ele*aon area =

1.80

Bntensit of wind pressure =

4(.+

kg%m'

3@posed 3le*aon area =

12.10

m'

Total /ind force on structure =

'.

%$tonnes

.#. of point of applicaon =

m

*,$.*

m

+00.00

kg%m

/ind force on li*e load Bntensit of wind force = #ength of li*e load = length of one span =

>.50

m

Total wind force on li*e load =

'.85

tonnes


*,%.1*

m

(ii) /!en dept! of "ater is 2ero

7*erage height of area of ele*aon abo*e bed le*el =

5.00

m

Bntensit of wind pressure =

85.0

kg%sEm

3@posed 3le*aon area =

42.5

sEm

Total wind force on structure =

4.04

tonnes


*,,.$*

m

/ind force on li*e load Total wind force on li*e load =

'.85


tonnes

*,%.1*

m

(f) Dead Loads of 0u 0truture (i) Dead Load of ed lo lan area =

10.('

Thickness =

0.(

"Em m

/eig!t of ed lo 3

-,.%

tonnes

*.-'

tonnes

(ii) Dead Load of pier Dead load of pier 3 (iii) Fore due to uo+an+

lan area at !.".#. =

(.(0

"Em

/eight of /ater displaced = Fore due to uo+an+ allo"ing -,4 up"ard fore 3

'1.1'

tonnes .-$

tonnes

(g) Fore on pier due to urrent of "ater

?a@imum 6elocit of Kow -6 = Q% =

'.45

m%s

6'=

(.0'

?a@imum *alue of depth of scour = 1.5  = 4.04 m ' 7ssuming *ariaon of 6 to be linear than its *alue at bed le*el = ressure due to water current =  6'

1.'5

where  =

'(

ressure at water le*el =

15(.5(

kg%m'

ressure at bed le*el =

+'.(1

kg%m'

7rea on which pressure acts =

4.80

"Em

Total force due to water current =

0.45

tonnes

eight of center of pressure from bed le*el =

1.>5

m

(!) Fore on pier due to urrent of "ater perpendiular to lengt! of pier

?a@imum *ariaon in direcon of current = '0 0 ?a@imum 6elocit at top = 6 sin '0 =

0.84 6'=

6alue of 6' at bed le*el = 7ssuming  =

0.20

0.0' 80

for rectangular shape

ressure at water le*el =

5(.+0

kg%m'

ressure at bed le*el =

1.'2

kg%m'

7rea on which pressure acts =

1(.48

"Em

for pointed ;ose 45 degree angled

Total force due to water current =

0.42

tonnes

eight of center of pressure from bed le*el =

'.11

m

(i) Fore on pier due to pressure of "ater perpendiular to lengt! of pier "!en "ater 5o"s in alternate  #ateral !orces on pier when one gate is opened for Kow and adacent one are c losed ! = g ` h7

` h =

1.(1

m

7rea under inKuence for water pressure =

14.1+

sEm

Total pressure force ! = g ` h7=

''.80

tonnes

Center of pressure below water surface p =- B0%7` h  L` h B0= h+-a'L4abLb'%+( a b= p=

5.4(

1.85

m+

m

#e*el of center of pressure abo*e base =

'54.5(( m

C!e for stresses in t!e pier at Bed Level "it! R.L. 3 7rea -7 = B@@=

(.8+

"Em

1.12

m4

B=

1'.1(

m4

*,.**

m

Case - : /!en Live load on t!e ridge and anal is running at F.0.L. (i) 6eral dead loads

-a )ead #oad of super structure =

2>.80

tonnes

-b )ead load of bed block =

15.>+

tonnes

-c )ead #oad due to self weight of ier =

'+.10

tonnes

-d Bncrease in reacon due to braking =

1.85

tonnes

(ii) Live load "it! impat fator 3

+2.8'

tonnes

(iii) Buo+an+ fore ang up"ards 3

<+.12

tonnes

0o 7et veral do"n"ard fore (P) 3

-,,. tonnes

Moment aout 898 a8is

)ue to braking force =

51.8+

t.m

)ue to sliding fricon =

1'.+(

t.m

)ue to water current in perpendicular direcon =

1.00

t.m

)ue to water pressure when alternate gates open =

+0.20

t.m

>5.8>

t.m

%.''

t.m

)ue to eccentricit of #i*e #oad =

'0.80

t.m

)ue to wind force on super structure =

+.'5

t.m

12.(2

t.m

0.8>

t.m

4'.(0

t.m

1.''

t.m

>0.'(

t%m'

#otal Moment (M8) 3

sa Moment aout +9+ a8is

)ue to wind force on li*e load = )ue to water current force in long. )ir = #otal Moment (M+) 3

sa ;ow stress =

P M x A



I xx

( x m ) 

M y I yy

( y m )

?a@imum compressi*e stress M comIma@=

N '50 t%m'

?inimum compressi*e stress M comImin=

<45.'2

t%m' =

;%mm'

<0.45+

owe*er steel pro*ided in pier will take care of tension.

Case * : /!en Live load on t!e ridge and 7o "ater in anal (i) 6eral dead loads


2>.80

tonnes


15.>+

tonnes


'+.10

tonnes


1.85

tonnes

+2.8'

tonnes

(ii) Live load "it! impat fator 3


-,&.,' tonnes



51.8+

t.m


1'.+(

t.m

#otal Moment (M8) 3

(4.1>

t.m

,.''

t.m


'0.80

t.m


+.'5

t.m

)ue to wind force on li*e load =

12.(2

t.m

#otal Moment (M+) 3

41.2'

t.m

1*.''

t.m


2+.8>

t%m'


<'2.44


sa ;ow stress =

P M x A



I xx

( x m ) 

M y I yy

( y m )

-Tensile t%m' =

;%mm'

N '50 t%m' <0.'24

;%mm'

*,-.$'

m

owe*er steel pro*ided in pier will take care of tension.

C!e for stresses in t!e pier at foundaon Level "it! R.L. 3 7rea -7 = B@@=

+0.00

"Em

40.00

m4

B=

140.(+

m4

Case - : /!en Live load on t!e ridge and anal is running at F.0.L. (i) 6eral dead loads


2>.80

tonnes


15.>+

tonnes


'+.10

tonnes


1.85

tonnes

(e) Live load "it! impat fator 3

+2.8'

tonnes

(f) Buo+an+ fore ang up"ards 3

<+.12

tonnes

(g) Dead load of foundaon lo 3

>8.0'

tonnes


*,.1 tonnes



(4.54

t.m


1(.>4

t.m

)ue to water current in perpendicular direcon =

1.21

t.m

)ue to water pressure when alternate gates open =

(5.+(

t.m

148.55

t.m

-1%.''

t.m


'0.80

t.m

)ue to wind force on super structure = )ue to wind force on li*e load =

4.45 ''.00

t.m t.m

)ue to water current force in long. )ir =

1.52

t.m

48.8'

t.m

1%.''

t.m

12.'0

-Compressi* e t%m' N '5 t%m'

#otal Moment (M8) 3


#otal Moment (M+) 3

sa ;ow stress =

P M x A



I xx

( x m ) 

M y I yy

( y m )

?a@imum compressi*e stress M comIma@= ?inimum compressi*e stress M comImin=

<0.+1

<0.00+

t%m' =

Case * : /!en Live load on t!e ridge and 7o "ater in anal (i) 6eral dead loads


2>.80

tonnes


15.>+

tonnes


'+.10

tonnes


1.85

tonnes

(e) Live load "it! impat fator 3

+2.8'

tonnes

(f) Dead Load of foundaon lo 3

11'.50

tonnes


*$-.'' tonnes



(4.54

t.m


1(.>4

t.m

#otal Moment (M8) 3

81.48

t.m

&*.''

t.m



'0.80

t.m


4.45

t.m

''.00

t.m

)ue to wind force on li*e load = #otal Moment (M+) 3

sa ;ow stress =

P M x A



I xx

( x m ) 

M y I yy

( y m )

42.'5

t.m

1&.''

t.m

;%mm' O..


14.41


+.(5

t%m' t%m' =

N '5 t%m' 0.0+2

;%mm'

7rea of steel 0.+F of gross seconal area as per B C '1 ro*ide '0 mm dia main reinforcement at spacing of 1>0 mm with es bar 1' mm dia '00 mm c%c

O..

a+s

Design of Reinforement for foundaon Blo of Ladpura Bridge of RMC : '5

k;%m'

'.'

degree

-&.'

k;%m+

&earing capacit of "oil%ock G

FG

7ngle of internal fricon of soil mass

$nit /eight of soil G Coecient of fricon between soil and concrete G Concrete Prade ? '0 with Mcbc G "teel of Prade !e 415 with Mst

'.,

.$

;%mm'

*'.'

;%mm'

Design onstants : For M ' onrete and Fe 1-, steel reinforement "e !ave t!e follo"ing :

?odular rao m ='80%+Mcbc=

14.00

bal=1%-1L-Mst%mMcbc=

0.'8>

bal=1
0.>04

c=0.5Mcbckbal bal=

0.820

a= -1
4

0.+++

C

LD

7

Consider dimensions of foong to be checked G #ength of column in @<@ dir =

5.+

m

/idth of column in < dir =

1.5

m

#ength of foong base in @<@ dir

2.5

m

/idth of foong base in < dir

4

m

?oment about @<@ direcon =

14>0.00

k;.m

?oment about < direcon =

4>0.00

k;.m

6ercal load on column =

'5++.4+

k;

?a@imum soil pressure at toe =

12'.01

k;%m'

?inimum soil pressure at heel

<+.1'

k;%m'

ressure intensit under column a@is =

84.45

Bntensit of soil pressure below the column face =

< 2.5 5.+

k;%m' 14(.+'8 k;%m'

Canle*er length for bending about crical face = Total force under canle*er length =

L

1.10

m

200.+5+ k;

)istance of centroid about crical face = &ending moment about crical face =

0.51

)

m

& 1.5

+5>.5> k;.m

/idth of secon at crcal face 1.81+ m )epth of foong base as reEuired from bending consideraon = ro*ide depth of foong base a

>00

mm

3Hec*e co*er of reinforcemen

(0

mm

422.(4

mm

7" 3 "CO$B;P )3T CBT3BO; 7;) BC '1 )3"BP; CBT3BO;

Total depth of foong base at column face =

>(0

mm

ro*ide total depth of foong base at end =

500

mm

C!e for 0!ear Fore (a) Pun!ing 0!ear fore :

!or punching shear stress point of *iew the crrical secon occurs at distance d%' from coloumn face. osion of crical face =

450

mm from coloumn face

3H. #ength of crical plane for punching shear stress =

5.25

m

3H. /idth of crical plane for punching shear stress =

1.>5

m

unching shear force -! =

158(.5(

k;

)epth of secon at punching shear line of inKuence =

0.2+44

m

unching shear stress at secon for crical punching shear force=

140.'8' k;%m'

ermissible shear stress in punching shear = ks @ 0.1( Öfck =

215.54

k;%m'

#!e seon is safe from pun!ing s!ear point of vie" ;.<. (a) ;ne "a+ 0!ear fore :

!or one wa shear stress point of *iew the crical secon occurs at distance d from column face. osion of crical face for onewa shear =

>00

mm from column face

Canle*er length to right of crical plane =

0.'

m

Bntensit of pressure at crical plane =

1(2.+44 k;%m'

The secon at crical plane will be trapeJoidal with Top width of trapeJoid =

+.5454545455 m

3Hec*e depth of crical seco 5'+.(+(+(+(+(4 mm )epth of ;eutral 7@is = kd, =

151.15

/idth of secon at neutral a@is le*el =

mm 4.+(2

"hear force at crical secon =

1+5.24

k;

"hear stress at crcal secon =

0.''2

;%mm'

ermissible shear stress at secon due to direct shear=

m

0.'8

;%mm'

"econ is safe in direct shear O..

Design for ending #ension :

7rea of steel reEuired for bending -7st = 7rea of steel wire 1( mm dia =

'00.>(

;o of bars reEuired for bendin

10

1>''.1' mm' mm' ;os

ro*ide 1( mm dia ") bars at spacing R

400.0

mm c%c

owe*er pro*ide 1( mm dia bars at spacing

'00.0

mm c%c at bo:om of foong

ro*ide same spacing of bars in other direcon also. 7lso pro*ide 1' mm ") bars R '00 mm c%c for temp%shrinkage on top face of foundaon block.

Design of Bridge Pier

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