POSITIONING OF IRC LIVE LOADS :

7/30/2019 POSITIONING OF IRC LIVE LOADS :

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POSITIONING OF IRC LIVE LOADS :

BRIDGEWIDTH

Coventions used below are in reference with the above figure

(a) Single L ane of IRC Class A

Longitudinal placement :

Braking force Braking force

span span

Transverse placement :

Transverse Eccectricity for three lanes = 4.20 m

(b) Two L anes of IRC Class A


Transverse Eccectricity for three lanes = 2.45 m

SPAN OF BRIDGE

Reaction for maximum moment @ T-T axis MT:

L-L AXIS

T-T AXIS

ML

MT

1.8m 1.8m0.4m

CG5.5m

Centre Line carriageway

1.7m

1.8m0.4m

CGeccentricity=4.20m

5.5m


Carriage width = 11.0m (three lanes)

e=2.45m

B CA D

2.7t2.7t11.4t11.4t6.8t6.8t6.8t6.8t

3.2m1.2m4.3m3.0m3.0m 1.1m3.0m



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(c) Three Lanes o f IRC Class A


Transverse Eccectricity = 0.70 m

(d) IRC Class 70R( wheeled )

Braking force Braking force

Longitudinal placement :

span span


Transverse Eccentricity = 2.905 m

(e) IRC Class 70R( wheeled )+One L ane of IRC Class A


1.8m 1.8m0.4m

CG

5.5m


1.7m

e=0.7m

1.8m1.7m

1.63m

CGeccentricity=2.905m

5.5m


1.93m

Carriage width = 11.0 m

1.63m

CG:100t


5.5m

1.93m 1.88m 1.8m

CG:55.4t

Class 70R Class A

Carriage width = 11.0 m

B CA D

8t12t17t17t17t17t

3.96m1.52m2.13m1.37m1.37m 3.05m

12t



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(a) Singl e Lane of IRC Class A

Longitudinal placement : Braking force Braking force

span span

(b) IRC Class 70R( wheeled )

Transverse placement : Braking force Braking force

span span

0.4m

*Reactions for abutments have been tabulated by taking RC reactions for various loading conditions.

**In this case live load effects have been reduced by 10% to account for the additional third lane.

Refer IRC: 6-1966 Clause 208.2

Reaction for maximum moment @ L-L axis ML:

B CA D

2.7t 2.7t 11.4t 11.4t 6.8t 6.8t 6.8t 6.8t

3.2m 1.2m 4.3m 3.0m 3.0m1.1m 3.0m

B CA D

8t 12t 17t 17t 17t 17t

3.96m 1.52m 2.13m 1.37m 1.37m3.05m

12t

POSITIONING OF IRC LIVE LOADS :

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