Week 1 Challenge
1.1 AIM: Evaluate the Dead Loads for the design of box girder with span of 12 m deck width 10.2 m.
1.2 INTRODUCTION: A Simply suppoted Bridge having 12 m span of box girder is located with in radius 60 km of Bay of Bengal with Seismic Zone of IV.The Structure is designed for standrad as per IRC and IS codes.
1.3 Analysis and Design Methodology:-
The Bending Moment and Shear Forces of deck slab extracted from the STAAD pro.
1.4 STANDARD and References
(i) IRC Codes
(ii) IS 456-2000
(iii) IS 875-1 for Dead Load
(iii) IS 875-3 2015 for Wind loads
(iv) IS 1893 for EQ load
(v) All relavent codes of IS and IRC
2. INPUT DATA
1.The Span of the Bridge 12 m (Box girder).
2.Grade of Concrete (fck) = 40 N/mm2
3.Yield Strength of reinforcement =500 N/mm2
4.Unit Weight of Concrete =25 KN/m3
5.Unit Weight of Soil = 19 KN/M3
6.Seismic Zone IV
7.Wind Speed 47 KMPH
3.CALCULATION OF DEAD LOAD.
As per shown fig the width of the deck varies from 8.4 m to 11.4 m
The Average slab width =(8.4+11.4)/2=9.9 m
As shown in the Fig A=(9.9-2X4.2)/2=0.75 m
| SNO | MEMBER | Nos | WIDTH(M) | DEPTH(M) | UW OF CONCRETE | DEAD LOAD PER METER(KN/m) |
| 1. | Siffit slab(bottom slab) | 1 | 4.020 | 0.200 | 25 | 20.1 |
| 2. | Web (wall) | 2 | 1.990 | 0.250 | 25 | 24.875 |
| 3. | Top slab | 2 | 1.361 | 0.225 | 25 | 15.311 |
| 4. | Top slab Haunch | 2 | 1.2 | (0.225+0.350)/2 | 25 | 17.25 |
| 5. | Haunch | 2 | 0.269 | 0.350 | 25 | 4.707 |
| 6. | Haunch of Cantilever slab | 2 | 1.370 | (0.350+0.225)/2 | 25 | 19.693 |
| 7. | End portion of the cantilever slab(A) | 2 | 0.75 | 0.225 | 25 | 8.437 |
| Total Dead Load(UDL) | 110.373KN/m | |||||
Total Dead Load per Rmt (Uniformly Distributed Load)= 110.373 KN/m.
Span =12 m
Maximum Bending Moment= WL2/8 =110.373X12X12/8 = 1986.714 KN-m
Maximum Shear Force = WL/2 = 662.238 KN