T Girder Bridge Deck Diaphragm-20 m

Page 17

DESIGN OF DECK-SLAB 1.0

INTRODUCTION : The deck-slab is designed as continuous over three supports with overhang on either side. Live-load combinations of Class-A X 2 Lane loading ,Axle Load have been checked. Bending Moments at various sections as shown below are found using STAAD-Pro software after calculating effective load intensities for each case.

2.0

DESIGN DATA: I Density of concrete

=

2.40 t/m3

ii Grade of concrete

=

M- 25

iii Reinforcement

=

iv Permissible stress in concrete

=

8.33 N/mm2

v Permissible stress in steel

=

200 N/mm2

vi Maximum permissible shear stress =

2.10 N/mm2

HYSD bars conforming to IS: 1786

vii Live Load a) Class A x 2 Lanes viii Impact Factor =

3.0

50.0% For Class-A

REFERENCES: i. IRC: 6 - 2000 ii. IRC: 21 - 2000

550 550

(other side) C/L Carriageway 1

2

3

300 200 50

235 1

2

150 3

325 1500

325 1800

1800

Page 18

4.0

LOAD CALCULATION

a)

Dead Load: (loads are calculated for one meter strip) In cantilever portion, Load is linearly varying in cantilever portion At end = At 1-1 = In intermediate portion, Uniformly applied load

b)

0.48 t/m 0.6 t/m

=

0.564 t/m

= =

0.3 t/m 0.396 t/m

=

0.180 t/m

SIDL : Outer side, S/W of Parapet/Side rail Due to road kerb U.D.L due to wearing coat = 0.075 x 2.4

0.3

0.3

0.15

0.15 0.396

0.55

0.18

0.396

0.55

Page 19

c)

Live load: Transverse Positions for various Live load cases have been shown in proceeding sheets.Effective load intensities are calculated & used in STAADPro 2007 as input to analyse the deck-slab for various load cases.

4.0 CALCULATION OF EFFECTIVE LOAD INTENSITY THICKNESS OF THE WEARING COAT DEPTH OF SLAB WIDTH OF SLAB ( c/c of diaphragm) b EFFECTIVE LENGTH lo VALUE OF a CONTACT AREA: CLASS A WIDTH FOR OVERLAP CLASS 70 R (Max. Axle Load) WIDTH FOR OVERLAP CLASS 70 R (T) CLASS 70 R (Max. Axle Load) WIDTH FOR OVERLAP

= = = = = 1 2 3 4

500 1.20 m 360 1.22 m 840 360 1.22 m

IMPACT FACTOR (%) : CLASS A

0.550

0.95

0.075 0.235 18.460 1.80 2.6

250 (FOR LOAD

11.4

t)

260 (FOR LOAD

20

t)

4570 (FOR LOAD

70

t)

260 (FOR LOAD

20

t)

50

1.80 3.6 6.60

m m m m

1.80 0.95

0.55

Page 20

LOAD CASE

LOAD

1

LOAD WITH

Most Eccentric position for Class A x 2 lanes

CONTACT AREA

a

DISP. ALONG SPAN

beff.

b

0.550 0.550 0.550 0.550

1.12 1.12 1.12 1.12

1.060 1.393 1.393 1.393

1.2 1.2 1.2 1.2

IMPACT

P1 P2 P3 P4

#

5.70 5.70 5.70 5.70

8.55 8.55 8.55 8.55

1 1 1 1

500 500 500 500

250 250 250 250

EFF. OVERLAPPIN LOAD G INT. NO YES YES YES

8.066 6.595 6.595 6.595

# indicates load is in cantilever portion

LOAD CASE

LOAD

2

LOAD WITH

Class A single lane Eccentrically placed

CONTACT AREA

a

DISP. ALONG SPAN

beff.

b

0.550 0.550

1.12 1.12

1.060 1.393

1.2 1.2

IMPACT

P1 P2

#

5.70 5.70

8.55 8.55

1 1

LOAD CASE

LOAD

500 500

3

LOAD WITH

250 250

5.70 5.70

8.55 8.55

CONTACT AREA 1 1

NO YES

8.066 6.595

One Wheel of Class A single lane placed Centrally on span

a

IMPACT

P1 P2

EFF. OVERLAPPIN LOAD G INT.

500 500

250 250

0.900 0.900

DISP. ALONG SPAN 1.12 1.12

beff.

b

1.570 1.570

1.2 1.2

EFF. OVERLAPPIN LOAD G INT. YES YES

6.173 6.173

INPUT FILE: STUP27M.STD 1. STAAD PLANE 20M DECK SLAB ANALYSIS OVER 3 GIRDERS 2. INPUT WIDTH 72 3. UNIT METER MTON 4. JOINT COORDINATES 5. 1 .000 .000 .000 6. 2 1.500 .000 .000 7. 3 3.200 .000 .000 8. 4 5.100 .000 .000 9. 5 6.600 .000 .000 10. MEMBER INCIDENCES 11. 1 1 2 12. 2 2 3 13. 3 3 4 14. 4 4 5 15. MEMBER PROPERTY INDIAN 16. 1 TO 4 PRI YD .2 ZD 1. 17. CONSTANT 18. E CONCRETE ALL 19. DENSITY CONCRETE ALL 20. SUPPORT 21. 2 TO 4 PINNED 22. LOAD 1 DEAD LOAD 23. SELFWEIGHT Y -1. 24. MEMBER LOAD 25. *WEARING COURSE 26. 1 UNI GY -.18 .55 1.5 27. 4 UNI GY -.18 0. .95 28. 2 3 UNI GY -.12 29. *HANDRAIL 30. 1 CON GY -.3 .15 31. 4 CON GY -.3 1.25 32. * ROAD KERB 33. 1 UNI GY -.3 0. .55 34. 4 UNI GY -.3 .95 1.5 35. LOAD 2 LIVE LOAD ( MOST ECCY. POSITION - 2 LANES) 36. MEMBER LOAD 37. 1 CON GY -8.366 .85 38. 2 TO 4 CON GY -6.663 .55 39. LOAD 3 LIVE LOAD ( MOST ECCY. POSITION - 1 LANE) 40. MEMBER LOAD 41. 1 CON GY -8.366 .85 42. 2 CON GY -6.663 .55 43. LOAD 4 LIVE LOAD ( CENTRALLY PLACED - 1 LANE) 44. MEMBER LOAD 45. 1 CON GY -6.259 .9 46. 2 TO 4 CON GY -6.259 .9 47. PERFORM ANALYSIS

48. PRINT SUPPORT REACTIONS SUPPORT REACTION SUPPORT REACTIONS -UNIT MTON METE STRUCTURE TYPE = PLANE JOINT LOAD FORCE-X FORCE-Y FORCE-Z MOM-X MOM-Y 2 1 0.00 2.50 0.00 0.00 0.00 2 0.00 15.62 0.00 0.00 0.00 3 0.00 15.72 0.00 0.00 0.00 4 0.00 11.15 0.00 0.00 0.00 3 1 0.00 -0.36 0.00 0.00 0.00 2 0.00 1.94 0.00 0.00 0.00 3 0.00 -0.86 0.00 0.00 0.00 4 0.00 1.35 0.00 0.00 0.00 4 1 0.00 2.43 0.00 0.00 0.00 2 0.00 10.80 0.00 0.00 0.00 3 0.00 0.17 0.00 0.00 0.00 4 0.00 12.54 0.00 0.00 0.00 ************** END OF LATEST ANALYSIS RESULT **************

MOM Z 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00

49. PRINT MEMBER FORCES ALL MEMBER FORCES ALL MEMBER END FORCES MEMBER 1

LOAD 1 2 3 4

2

1 2 3 4

3

1 2 3 4

STRUCTURE TYPE = PLANE

ALL UNITS ARE -- MTON METE

JT

AXIAL

SHEAR-Y

SHEAR-Z

TORSION

MOM-Y

MOM-Z

1 2 1 2 1 2 1 2

0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00

0.00 1.22 0.00 8.37 0.00 8.37 0.00 6.26

0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00

0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00

0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00

0.00 -1.06 0.00 -4.60 0.00 -4.60 0.00 -3.13

2 3 2 3 2 3 2 3

0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00

1.28 -0.19 7.25 -0.59 7.35 -0.69 4.89 1.37

0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00

0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00

0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00

1.06 0.26 4.60 0.12 4.60 0.30 3.13 0.04

3 4 3 4 3 4 3 4

0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00

-0.17 1.25 2.52 4.14 -0.17 0.17 -0.02 6.28

0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00

0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00

0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00

-0.26 -1.01 -0.12 -3.66 -0.30 0.00 -0.04 -5.63

4

1

4 5 4 5 4 5 4 5

0.00 1.18 0.00 0.00 0.00 0.00 0.00 0.00 2 0.00 6.66 0.00 0.00 0.00 0.00 0.00 0.00 3 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 4 0.00 6.26 0.00 0.00 0.00 0.00 0.00 0.00 ************** END OF LATEST ANALYSIS RESULT **************

0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00

50. SECTION 0.88 MEMBER 1 51. PRINT MEMBER SECTION FORCES LIST 1 MEMBER SECTION FORCES LIST MEMBER FORCES AT INTERMEDIATE SECTIONS MEMB

LOAD 1 1 2 3 4

SEC 0.88 0.88 0.88 0.88

SHEAR-Y SHEAR-Z -1.12 0.00 -8.37 0.00 -8.37 0.00 -6.26 0.00

ALL UNITS ARE -- MTON METE

MOM-Y 0.00 0.00 0.00 0.00

MOM-Z 0.86 3.20 3.20 2.08

************** END OF LATEST ANALYSIS RESULT ************** 52. SECTION 0.09 0.5 0.91 MEMBER 2 3 53. PRINT MEMBER SECTION FORCES LIST 2 3 MEMBER

SECTION

FORCES

LIST

MEMBER FORCES AT INTERMEDIATE SECTIONS MEMB

LOAD 2

1

2

3

4

3

1

2

SEC

SHEAR-Y

SHEAR-Z

ALL UNITS ARE -- MTON METE

MOM-Y

MOM-Z

0.09 0.50 0.91 0.09 0.50 0.91 0.09 0.50 0.91 0.09 0.50 0.91

1.18 0.73 0.29 7.25 0.59 0.59 7.35 0.69 0.69 4.89 4.89 -1.37

0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00

0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00

0.86 0.15 -0.22 3.43 0.41 -0.03 3.41 0.32 -0.19 2.34 -1.27 -0.26

0.09 0.50 0.91 0.09 0.50

-0.27 -0.71 -1.15 2.52 -4.14

0.00 0.00 0.00 0.00 0.00

0.00 0.00 0.00 0.00 0.00

-0.23 0.13 0.82 -0.53 -0.06

1.01 0.00 3.66 0.00 0.00 0.00 5.63 0.00

0.91 0.09 0.50 0.91 4 0.09 0.50 0.91 ************** END 54. FINISH 3

-4.14 -0.17 -0.17 -0.17 -0.02 -0.02 -6.28 OF LATEST

0.00 0.00 2.99 0.00 0.00 -0.27 0.00 0.00 -0.15 0.00 0.00 -0.03 0.00 0.00 -0.04 0.00 0.00 -0.02 0.00 0.00 4.62 ANALYSIS RESULT **************

Page 22

7.0

SUMMARY OF DESIGN MOMENTS

SECT.

1-1 2-2 3-3

LIVE LOAD MOMENTS HOGGING SAGGING

3.20 0.41 2.99

0.00 1.27 1.93

DEAD LOAD MOMENTS & SIDL MOMENTS HOGGING SAGGING

0.86 0.15 0.82

0.00 0.23

For Cantilever portion Dead Load Moment at section 1-1 Live-Load Moment 8.0

0.86 3.20

tm tm

DESIGN OF REINFORCEMENT

DIA. OF MAIN REINF. DIA. OF DISTRIBUTION REINF. DEPTH OF SLAB - AT INTERM. SECTION. DEPTH OF SLAB - AT CANTIL.SECTION. CLEAR COVER TO REINFORCEMENT EFF. DEPTH FOR MAIN STEEL - AT INTERM. SECTION. EFF. DEPTH FOR MAIN STEEL - AT CANTIL. SECTION. EFF. DEPTH FOR DISTRIB. STEEL - AT INTERM. SECTION. EFF. DEPTH FOR DISTRIB. STEEL - AT CANTIL. SECTION. MIN. REINFORCEMENT GRADE OF CONCRETE MPERM. BENDING COMP. STRESS CONSTANT j, CONSTANT Q, SECT.

DESIGN MOMENTS

MAIN STEEL AT BOTTOM

12 10 235 250 40 189 204 178 183 2.82 25 8.33 0.902 110

DISTRIB. MOMENTS

mm mm mm mm mm mm mm mm mm cm2 N/mm2 N/mm2 t/m2

DISTRIBUTION STEEL AT AT TOP BOTTOM

HOGGING

SAGGING

AT TOP

HOGGING

SAGGING

1-1

4.06

0.00

10.82

0.00

1.13

0.00

3.36

0.00

2-2

0.56

1.27

1.61

3.65

0.15

0.38

0.47

1.16

3-3

3.81

2.16

10.96

6.21

1.06

0.63

3.24

1.91

DEPTH REQUIRED AT SECTION 1-1 = DEPTH REQUIRED AT INTERMEDIATE-SECTIONS = SECT. AT

1-1 2-2 3-3

MAIN STEEL TOP

12#@ 200 + 12#@200C/C 12#@ 200 + 12#@200C/C 12#@ 200 + 12#@200C/C

PROVIDED AT BOTTOM

191.7 mm

< Provided ,Hence O.K.

185.7 mm

< Provided ,Hence O.K.

AT

DISTRIB. STEEL PROVIDED TOP AT BOTTOM

8# @ 200 C/C

10# @ 200 C/C

10# @ 200 C/C

12 # @ 150 C/C

8# @ 200 C/C

8# @ 200 C/C

12 # @ 150 C/C

10# @ 200 C/C

8# @ 200 C/C

9.0 DESIGN OF DIAPHRAGM : 9.1 Design of End Diaphragm : Dead Load Analysis :

0.28

Load from the hatched area will constitute the local effect. 1.8 m Self weight of Diaphragm =

1.8 m

2.45 t

Deck slab & Wearing coat = ( 5.5 x 0.28 + 1/2 x 1.8 x 0.9 x 2 ) x 0.234 x 2.4 = 1.32 t Wearing coat = ( 5.5 x 0.28 + 1/2 x 1.8 x 0.9 x 2 ) x 0.075 x 2.2 = Total load = 6.21+ 1.49 + 0.29 =

4.19 t

This load is assumed as a uniform load over a length of 5.0m U.D.L = 4.19 / 3.6 =

1.16 t/m

Load outside deck slab etc. outside the hatched area will be carried by the main girder and transmitted directly to the bearings without causing any bending moment and shear forces in the diaphragm. Total D L effect is as below 1.16 t/m A

B 1.8 m

C 1.8 m

Maximum + Ve moment = 0.07 x 1.84 x 1.8² = Maximum - Ve moment = 0.125 x 1.84 x 1.8² = Maximum shear force = 0.55 x 1.84 x 1.8 =

0.26 tm 0.47 tm 1.15 t

0.42 t

Live Load Analysis : o

Parts of live load in 45 influnce area will only go to the diaphrm. Parts outside this area will go directly to the main girder and will not cause any B.M and S.F in the diaphragm. Class A x 2 lanes will cause max. effect. Case I : Placing One track in the mid span

TR - I

TR - I 0.90 m

0.90 m

beff for 5.7t load along traffic dirn = 0.82 m A

1.8 m

B

1.8 m

C

Load from each Track = 1.5 x 5.7 = 8.55 t 0.82 1.18 0.5 Reaction at A

RA = 8.55 x (0.406 - 0.094 ) =

2.67 t [Coefficients are taken from " STEEL DESIGNERS MANUAL"]

Max. span moment = 2.67 x 0.9 = 2.40 tm Max. support moment = 2.67 x 1.8 - 8.55 x 0.9 = Shear force at B = 2.67 - 8.55 =

-2.89 tm -5.88 t

Summary of Design moment and shear force : Moment at support Moment at mid span

=

3.36 tm =

2.66 tm

Maximum shear force =

7.04 t

Overall depth available near outer girder location = 1.6 - 0.1 = Effective depth = 1500 - 50 - 12 - 10 = Width of beam =

1428 mm 325 mm 2

Moment of resistance = 110 x 0.325 x 1.828 =

= = 51.05 tm

Area of steel required = 3.79 / ( 2 x 0.902 x 1.828 ) -2

But minimum steel = 0.2 x 32.5 x 142.8 x 10 = Provide 5 nos 20 # bars both at top and bottom. Provide 2 L 10 # stirrups @ 200 c/c all through

1.5 m 1.428 m 0.325 m >> 1.31 sq.cm 9.282 Sq.cm

3.36 tm

Jacking condition. Reaction at end bearing due to dead load and SIDL = Reaction at inner bearing due to dead load and SIDL =

31.92 t 31.92 t

End cross girder will be designed for jack lifting . BM & SF Ref. STAAD Output Jack lifting file 1. STAAD PLANE JACK LIFTING ANALYSIS OF GIRDERS

INPUT FILE: 20 M _Diaphragm.STD 2. START JOB INFORMATION 3. ENGINEER DATE 01-SEP-12 4. END JOB INFORMATION 5. INPUT WIDTH 79 6. UNIT METER MTON 7. JOINT COORDINATES 8. 1 0 0 0; 2 0.6 0 0; 3 1.2 0 0; 4 1.8 0 0; 5 2.4 0 0; 6 3 0 0; 7 3.6 0 0 9. MEMBER INCIDENCES 10. 1 1 2; 2 2 3; 3 3 4; 4 4 5; 5 5 6; 6 6 7 11. DEFINE MATERIAL START 12. ISOTROPIC CONCRETE 13. E 2.17185E+007 14. POISSON 0.17 15. DENSITY 23.5616 16. ALPHA 1E-005 17. DAMP 0.05 18. END DEFINE MATERIAL 19. CONSTANTS 20. MATERIAL CONCRETE ALL 21. MEMBER PROPERTY INDIAN 22. 1 TO 6 PRIS YD 1.965 ZD 0.325 23. SUPPORTS 24. 2 3 5 6 PINNED 25. LOAD 1 DEAD LOAD 26. SELFWEIGHT Y -1 27. JOINT LOAD 28. 1 FY -31.923 29. 4 FY -31.923 30. 7 FY -31.923 31. PERFORM ANALYSIS 32. PRINT SUPPORT REACTION JACK LIFTING ANALYSIS OF GIRDERS SUPPORT REACTIONS -UNIT MTON METE STRUCTURE TYPE = PLANE ----------------JOINT

LOAD 2 3 5 6

1 1 1 1

FORCE-X FORCE-Y FORCE-Z MOM-X MOM-Y MOM Z 0 58.09 0 0 0 0 8.61 0 0 0 0 8.61 0 0 0 0 58.09 0 0 0

************** END OF LATEST ANALYSIS RESULT ************** 33. PRINT MEMBER FORCES ALL

0 0 0 0

JACK LIFTING ANALYSIS OF GIRDERS MEMBER END FORCES STRUCTURE TYPE = PLANE ----------------ALL UNITS ARE -- MTON METE (LOCAL ) MEMBER LOAD 1

JT

AXIAL

SHEAR-Y SHEAR-Z TORSION MOM-Y -31.92 0 0 38.19 0 0

1

1 2

0 0

2

1

2 3

0 0

19.90 -13.63

0 0

3

1

3 4

0 0

22.23 -15.96

4

1

4 5

0 0

5

1

5 6

6

1

6 7

0 -21.04

0 0

0 0

21.04 -10.98

0 0

0 0

0 0

10.98 0.48

-15.96 22.23

0 0

0 0

0 0

-0.48 -10.98

0 0

-13.63 19.90

0 0

0 0

0 0

10.98 -21.04

0 0

38.19 -31.92

0 0

0 0

0 0

21.04 0

************** END OF LATEST ANALYSIS RESULT ************** 34. FINISH Max. hogging moment at support = Max. sagging moment at span = Max. shear force =

21.04

t-m

0.5

t-m

38.2

t

Cross girder will be designed as continuous rectanguler deep beam Effetive span ( l ) =

1.32 m

Over all depth ( D ) =

1.60 m

l/D = Lever arm z =

0.83 0.66

< 1 As per Cl. 29.2 IS 456 -2000

0.26 Bottom reinforcement = Minimum Reinforcement required is ,

cm² 9.28

Providing

16 20.11

# in five layers. cm²

11.14 16

cm² # in five layers.

10 No. dia Ast provided =

Top reinforcement = Providing 10 No. dia

MOM-Z 0 0

cm²

Ast provided =

20.11

cm²

Reinforcement shall be provided as per Cl 29.2 IS:456-2000 and is shown in drawing. For Shear Providing 2 Legged # 16 stirrups Asw = 59.93 x 10000 s 200 x 202.8 x 2.0

6.69 cm²/m

=

Providing 2 -Legged 16 # stirrups @150 c/c 9.2 Design of Intermediate Diaphragm : Self weight of Diaphragm =

2.43 t

Self weight of Deck Slab and Wearing coat = 2 x 1/2 x 1.8 x 0.9 x 2 x 0.234 x 2.4

1.82 t 1.8

U.D.L = ( 2.43 + 1.82 ) / 3.6 =

1.8

1.18 t/m

The support of the intermediate diaphragm will act as a spring , hence reaction = (2.43 + 1.82 ) / 3 = 1.42 t 1.18 t/m Dead load bending moment At A = 0 A B C At B =1.18x0.9-1.42x0.9²/2 = 0.80 tm 1.8 m 1.8 m At C = 1.18x1.8-1.62x1.8²/2 =

0.64 tm

Dead load shear force At A = At B = At C =

1.42 t 0.35 t -0.71 t

Live Load : Parts of live load in 45o influnce area will only go to the diaphrm. Parts outside this area will go directly to the main girder and will not cause any B.M and S.F in the diaphragm. Live load on diaphragm from each track = 1.5 x 5.7 = Reaction = 2 x8.6 /3

=

5.7 t

Maximum L.L moment = 5.7 x 1.8 - 8.6 x 0.9 = Design moment = d eff. = 1950-62-10 =

8.6 t

2.6 tm 3.20 tm

1878 mm = Width =

Area of steel required = 3.20 / ( 2 x 0.902 x 1.478 ) = Provide 4 nos 20 # bars both at top and bottom. Provide 2 L 10 # stirrups @ 200 c/c all through

1.878 m 325 mm 0.95 Sqcm

=

0.325 m