Week 7 Challenge

Bridge structures are likely to be in river, canal or stream where it have to face water current load. While designing bridge, we can't ignore this important load and it's consequences (Bending moment, shear force etc).

In this job the pier is in water and flood level is 2m above foundation level. Mean velocity of the river is 3m/s. Span of bridge is 45m. Shape of pier is supposed to be circular or semicircular end, so coefficient k will be 0.66.

The height of Pier subjected to water current H = 2m

The mean velocity of the river V = 3m/s

Maximum velocity V = `square root`2 X V = 4.24 m/s

Water current load P = 52 k V`square`= 52 X 0.66 X 4.24 X 4.24 = 616.991kN/m2

Frame Modelling pier height 2m and span 45m

Property assigned to Pier

Property assigned to girder

Material assigned

Support

Two cases considered

1st case

2nd case

Load assigned

Analysis done

Bending moment Z axis for water current case 1

Reaction

Static check

Height of pier supposed 10m and pier dia 1.2m

The height of Pier subjected to water current H = 2m

The mean velocity of the river V = 3m/s

Maximum velocity V = `square root`2 X V = 4.24 m/s

Water current load P = 52 k V`square`= 52 X 0.66 X 4.24 X 4.24 = 616.991kN/m2

616.991kN/m2 X 1.2m = 740.39kN/m

Frame made for 10m high pier and 45m span.

Property to pier assigned

Property assigned to girder

Fixed support.

Two load case considered

Case 1

Point inserted in 2m high

Load assigned up to m height

Case 2

Analysis done

Bending moment Z axis

Shear force Y direction

Reaction.