Design of Two Cell Box Structure

8/11/2019 Design of Two Cell Box Structure

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DESIGN DATA:

27.160 m

22.050 m

20.550 m

25.485 m

12.000 m

11.000 m0.400 m

0.400 m

0.400 m

0.300 m

0.056 m

8.000 + 0.350 = 8.350 m

8.000 + 0.350 = 8.350 m

5.754 + 0.400 = 6.154 m

0.500 m

1.250 x 0.250 m

1.250 x 0.250 m

1.675 m

2.400 t / m

1.000 t / m

M 35

1190 t / m

20400 t / m

m - 10

0.368

0.877

192 t / m

Top slab = 16.70 x 0.40 x 2.40 = 16.032 t / m

bottom slab = 16.70 x 0.40 x 2.40 = 16.032 t / m

End Webs = 2 x 6.154 x 0.40 x 2.40 = 11.816 t / m

Central Web = 1 x 6.154 x 0.30 x 2.40 = 4.431 t / m

Haunches ( 16 nos.) = 16 x 0.125 x 1.25 x 2.40 = 6.000 t / m

54.311 t / m

( 54.311 / 16.700 ) = 3.252 t / m

Say, 3.300 t / m

Wearing Coat (@ 0.20 t / sqm.) = 0.200 t / m

2 x ( 0.700 / 12.000 ) = 0.117 t / m

Total = ( 0.200 + 0.117 ) =

0.317 t / m

DRY CONDITION

Due to DL of Box and SIDL = ( 3.300 + 0.317 ) = 3.617 t / m

Due to LL-70R Wheeled Load = 100 / ( 12 x 16.70 ) = 0.499 t / m

Due to Earth inside the Box = 1.10 x 2.00 = 2.200 t / m

Total Base Pressure = ( 3.617 + 0.499 + 2.200 ) = 6.316 t / m

Eff. horizontal span end cell(upto c/l of web) =

CALCULATION OF LOADS AND CORRESPONDING BASE PRESSURE:

Total Weight =

SUPERIMPOSED DEAD LOAD ( Per metre width ):

Formation Level along c/l of carriageway (m) =

Bed Level (m) =

Founding Level (m) =

Heighest Flood Level (m) =

Overall width of bridge =

width of carriageway =Thickness of top slab =

Thickness of bottom slab =

Thickness of Web =

Thickness of Central Web =

Tkickness of wearing coat =

Modular ratio,

Eff. horizontal span inner cell(upto c/l of web) =

Eff. vertical span (upto c/l of slab) =

width of crash barrier =

Size of haunches in outer webs -

Size of haunches in inner web -

Depth of water at HFL. from formation lvl =

Unit wt of concrete =

Submerged density of earth =

Grade of Concrete -

Permissible Compressive stress in Concrete -

Permissible Tensile stress in Steel -

Equivalent upward Base pressure =

DEAD LOAD-( Per metre width ):

Equivalent upward Base pressure =

0.317 t / m

CHECK FOR BASE PRESSURE

Crash Barrier ( @ 0.70 t/m on each side ) =

k -

Lever arm factor, j -

Moment of Resistance, Q -


2/15

HFL CONDITION

Due to DL of Box, SIDL & LL = ( 3.617 + 0.499 ) = 4.116 t / m

Due to Water inside the Box = ( 4.423 x 1.000 ) = 4.423 t / m

Buoyancy = ( 4.823 x - 1.000 ) = - 4.823 t / m

Total Base Pressure = ( 4.116 + 4.423 - 4.823 ) = 3.716 t / m

EARTH PRESSURE

CASE - 1

Dry Density of Soil = 2.000 t / m

0.5

CASE - 2

Dry Density of Soil = 1.800 t / m

0.3

Cooefficient of Earth Pressure at rest =

Cooefficient of Earth Pressure at rest =


3/15

Height (m)Location of Earth

PressureCase - 1

Surcharge for

1.2 mCase - 2

Surcharge for

1.2 m

0.256 C/l of top slab 0.256 1.2 0.138 0.648

1.956 Face of top haunch 1.956 1.2 1.056 0.648

3.333 Mid. of web 3.333 1.2 1.8 0.648

4.71 Face of bot. haunch 4.71 1.2 2.543 0.648

6.41 C/l bottom slab 6.41 1.2 3.461 0.648

Height (m)Location of Earth

PressureCase - 1

Surcharge for

1.2 mCase - 2

Surcharge for

1.2 m

0.256 C/l of top slab 0.256 1.2 0.138 0.648

1.675 H.F.L. Level 1.675 1.2 0.905 0.648

1.956 Face of top haunch 1.956 1.2 1.056 0.648

3.333 Mid. of web 3.333 1.2 1.8 0.648

4.71 Face of bot. haunch 4.022 1.2 2.488 0.648

6.41 C/l bottom slab 4.872 1.2 3.338 0.648

For Dry Condition

H.F.L. Condition


4/15


5/15


6/15


7/15

9.9 0.7

2 1

3

100 mm

100 mm

6

4 5

5.8 0.8

S No. t b t F (force) Acting atEccentricity

e

1 0.7 1.0 0.08 2.04 0.04 m from top 0.16

2 9.9 / 2 1.0 0.08 14.41 0.027 m from top 0.173

3 0.7 / 2 1.0 0.1 1.27 0.113 m from top 0.087

4 5.8 / 2 1.0 0.08 8.44 0.027 m from bottom -0.173

5 0.8 1.0 0.08 2.33 0.04 m from bottom -0.16

6 0.8 / 2 1.0 0.1 1.46 0.113 m from bottom -0.087

F = 29.95 F.e = 0.97

2

t2

Hence, t = 0.8 C

0.1

M = [ F x e ] = Ec x x t x A x e

0.97 = 36.387 x x 0.0667

0.08

0.08

0.1

0.08

0.08

EFFECT OF TEMPERATURE FALL

80 mm

80 mm

A = b x t


8/15

Where

L0=

a =

=b / L0= 12 / 8 = 1.5

2.48

b1=

0.5 1.62 2.06 7.32 0.5

11

0.5 1.63 1.93 7.44 0.5

11

2.48

Live Load a (m) b1(m) beff(m) beff/2 (m)Max.

available

Width (m)

Load

Intensity

70 3.712 0.952 6.065 3.033 7.213 9.705

70 3.664 0.952 6.051 3.026 7.206 9.715

70 3.362 0.952 5.933 2.966 7.146 9.795

70 3.736 0.952 6.072 3.036 7.216 9.701

63.7 2.08 0.952 4.825 2.413 6.593 9.665

70 4.012 0.952 6.121 3.061 7.241 9.668

70 2.285 0.952 5.068 2.534 6.714 10.426

For Max. BM (Sagging) in Midspan

For Max. BM (Sagging) at end of haunch 1

Effective width =beff. .a.[ 1 - a / L0] + b 1

Hence as per cl. 305.16.2 of IRC:21, =

breath of loads over the deck slab after 45 dispersion through wearing coat

the effective span

A constant depending upon the ratio b/l0, where b is the width of the slab

the distance of centre of gravity of the concn load from the nearer

= 0.84 + 2 x 0.056 = 0.952 m (for 70R tracked)

= 0.81 + 2 x 0.056 = 0.922 m (for 70R wheeled)

TRANSVERSE POSITION OF LIVE LOAD ( CLASS 70R TRACKED)

TRANSVERSE POSITION OF LIVE LOAD ( CLASS 70R WHEELED)

CALCULATION OF EFFECTIVE WIDTH AND LOAD INTENSITY =

For Max. BM (Hogging) at End web

Class 70R Tracked Load

For Max. BM (Hogging) in Midspan

For Max. BM (Hogging) at start of haunch 2

For Max. BM (Hogging) at middle web

For Max. BM (Hogging) at end of haunch 9


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17.0 1.31 0.92 3.661 1.831 5.591 3.041

17.0 2.68 0.92 5.435 2.718 6.778 2.508

17.0 2.62 0.92 5.381 2.69 6.75 2.518

17.0 1.25 0.92 3.558 1.779 5.488 30.098

17.0 1.45 0.92 3.894 1.947 5.824 2.919

17.0 2.82 0.92 5.554 2.777 6.837 2.487

17.0 2.48 0.92 5.246 2.623 6.683 2.544

17.0 1.11 0.92 3.309 1.654 5.239 3.245

17.0 3.9 0.92 6.077 3.038 7.098 2.395

17.0 3.08 0.92 5.743 2.871 6.931 2.453

17.0 0.03 0.92 0.996 0.498 1.992 8.533

17.0 1.34 0.92 3.712 1.856 5.642 3.013

12.0 3.47 0.92 5.951 2.976 7.036 1.706

12.0 3.36 0.92 5.902 2.951 7.011 1.712

12.0 1.86 0.92 4.507 2.254 6.314 1.901

12.0 3.38 0.92 5.911 2.956 7.016 1.71

17.0 2.84 0.92 5.57 2.785 6.845 2.484

17.0 1.47 0.92 3.926 1.963 5.856 2.903

17.0 1.58 0.92 4.099 2.049 6.029 2.82

17.0 2.95 0.92 5.653 2.827 6.887 2.469

17.0 1.75 0.92 4.313 2.156 6.216 2.735

17.0 3.12 0.92 5.642 2.821 6.881 2.471

17.0 2.18 0.92 4.855 2.428 6.488 2.62

17.0 0.81 0.92 2.736 1.368 4.666 3.643

17.0 2.52 0.92 5.203 2.601 6.661 2.552

17.0 3.89 0.92 5.878 2.939 6.999 2.429

12.0 2.33 0.92 5.017 2.509 6.569 1.827

12.0 0.81 0.92 2.736 1.368 4.666 2.572

8.0 3.15 0.92 5.787 2.893 6.953 1.515

17.0 1.63 0.92 4.175 2.088 6.105 2.784

17.0 3 0.92 5.689 2.844 6.904 2.462

For Max. BM (Sagging) at end of haunch 1

Class 70R Wheeled Load

For Max. BM (Hogging) at End web

For Max. BM (Sagging) in Midspan

For Max. BM (Hogging) at end of haunch 9

For Max. BM (Hogging) at start of haunch 2

For Max. BM (Hogging) at middle web

For Max. BM (Hogging) in Midspan


10/15

9.715 /

Corresponding base pressure =

For Max BM (Sagging) at end of haunch 1

Dispersion width =

Live load intensity as udl =








For Max BM (Sagging) at midspan

Dispersion width =


For Max BM (hogging) at middle web

Dispersion width =



Dispersion width =


For Max BM (Hogging) at start of haunch 2

Dispersion width =



For Max BM (Hogging) in Mid span

Dispersion width =

LOAD INTENSITY AND CORRESPONDING BASE PRESSURE FOR CLASS 70R TRACKED:

Dispersion width = Track length over the span after 45odispersion through wearing coat and slab

For Max BM (Hogging) at End web

Dispersion width =


11/15

( 0.263 + 0.456 ) = 0.719 m

( 0.263 + 0.912 ) = 1.175 m

( 3.041 / 1.175 ) = 2.588 t / m

( 2.508 / 1.175 ) = 2.134 t / m

( 2.518 / 1.175 ) = 2.143 t / m

( 3.098 / 1.175 ) = 2.637 t / m

0.669 t / m

( 0.263 + 0.912 ) = 1.175 m

( 0.263 + 0.456 ) = 0.719 m

( 2.919 / 1.175 ) = 2.484 t / m

( 2.487 / 1.175 ) = 2.117 t / m

( 2.544 / 1.175 ) = 2.165 t / m

( 3.245 / 1.175 ) = 2.762 t / m

0.670 t / m

( 0.263 + 0.912 ) = 1.175 m

( 0.263 + 0.912 ) = 1.175 m

( 2.395 / 1.175 ) = 2.038 t / m

( 2.453 / 1.175 ) = 2.088 t / m

( 8.533 / 1.175 ) = 7.262 t / m

( 3.013 / 1.175 ) = 2.564 t / m

( 1.706 / 1.175 ) = 1.452 t / m

( 1.712 / 1.175 ) = 1.457 t / m 1.186 t / m

( 0.263 + 0.912 ) = 1.175 m

( 0.263 + 0.912 ) = 1.175 m

( 1.901 / 1.175 ) = 1.618 t / m

( 1.710 / 1.175 ) = 1.455 t / m

( 2.484 / 1.175 ) = 2.114 t / m

( 2.903 / 1.175 ) = 2.471 t / m

( 2.820 / 1.175 ) = 2.400 t / m

( 2.469 / 1.175 ) = 2.101 t / m

0.855 t / m

for 17 t wheel

For Max BM (Hogging) at End web


For Max BM (Hogging) at Start of haunch2

for 12 t wheel

for 12 t wheel

for 17 t wheel

for 17 t wheel

for 17 t wheel


For Max BM (Hogging) at middle web

Live load intensity as udl

Disp. width of 17t load at start =

Disp. width of 17t,12t & 8t load =

for 17 t wheel

for 17 t wheel

for 17 t wheel




Disp. width of 17 t &12t wh. =

Disp. width of 12 t wh.at end =

for 17 t wheel

for 17 t wheel

for 17 t wheel

for 17 t wheel


LOAD INTENSITY AND CORRESPONDING BASE PRESSURE FOR CLASS 70R WHEELED:

Dispersion width = wheel length over the span after 45odispersion through wearing coat and slab

for 17 t wheel

for 17 t wheel

for 17 t wheel

for 12 t wheel

for 12 t wheel

Disp. width of 17t & 12t load =

Disp. width of 12 t load at end =

for 17 t wheel

For Max BM (Hogging) in mid span



Disp. width of 12t & 17t Load =

for 17 t wheel


12/15

( 0.263 + 0.912 ) = 1.175 m

( 0.263 + 0.456 ) = 0.719 m

( 2.735 / 1.175 ) = 2.328 t / m

( 2.471 / 1.175 ) = 2.103 t / m

( 2.620 / 1.175 ) = 2.230 t / m

( 3.643 / 1.175 ) = 3.100 t / m 0.687 t / m

( 0.263 + 0.912 ) = 1.175 m

( 0.263 + 0.912 ) = 1.175 m

( 2.552 / 1.175 ) = 2.172 t / m

( 2.429 / 1.175 ) = 2.067 t / m

( 1.827 / 1.175 ) = 1.555 t / m

( 2.572 / 1.175 ) = 2.189 t / m

( 1.151 / 1.175 ) = 0.980 t / m

0.631 t / m

( 0.263 + 0.912 ) = 1.175 m

( 0.263 + 0.912 ) = 1.175 m

( 2.784 / 0.912 ) = 3.053 t / m

( 2.462 / 0.912 ) = 2.700 t / m

0.314 t / m

For Max BM (Sagging) at end of huunch 9





for 17 t wheel

for 17 t wheel

for 17 t wheel

for 17 t wheel

For Max BM (Sagging) in mid span




for 17 t wheel

for 17 t wheel

for 12 t wheel

for 12 t wheel

for 8 t wheel





for 17 t wheel

for 17 t wheel




13/15

1.1

1.25

Max. Max. Max. Max. Max. Max.

sagging hogging sagging hogging sagging hogging

At the face of end web -1.914 4.862 -1.788 3.75 -1.914 4.862

At the end of haunch-1 -3.322 0 -3.175 0 -3.322 0

mid span -7.128 1.254 -5.95 1.265 -7.128 1.265

At the start of haunch-2 0 3.322 -0.338 3.375 -0.338 3.375

At the end of haunch- 2 0 8.492 0 11.938 0 11.938

At the face of end web 0 1.31 0 1.49 0 1.49

At the end of haunch-1 -1.82 0 -2.14 0 -2.14 0

mid span -2.67 0 -3.67 0 -3.67 0

At the start of haunch-2 0 2.52 0 2.85 0 2.85

At the end of haunch 0 5.715 0 8.24 0 8.24

0 1.903 0 3.875 0 3.8750.000

2.706

0.000

3.750

0.000

3.750-0.110

3.960

0.000

3.988 -

0.1103.988-1.045

5.324 -

0.863

5.025 -

1.045

5.324

SUMMARY OF BENDING MOMENT AT DIFFERENT LOCATION

(I) Due to LIVE LOAD

Impact factor (I.F.) for class 70R tracked =

Impact factor (I.F.) for class 70R wheeled =

CLASS CLASS

BOTTOM

SLAB

70R(Wheeled)70R(Tracked)

DESIGN BM

LL

LOCATION

TOP

SLAB


14/15

-1.936

6.600 -

1.800

5.975 -

1.936

6.600

-2.6732.354 -

2.513

2.938 -

2.673

2.938

-0.715

0.517 -

0.613

0.788 -

0.715

0.788

-1.496

1.474 -

1.450

1.550 -

1.496

1.550

-3.663

3.465 -

3.500

3.875 -3.663

3.875

-5.665

5.302 -

5.400

6.038 -

5.665

6.038


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Documents

Design of Two Cell Box Structure