Week 5 Challenge

The bridge structure are subjected to wind loads if they are located in open terrain or near coastal zone or over a river Where there will be seasonal monsoon winds and cyclons.

Wind loads are calculated as per IS 875 Part III 2015

IS 875 part III 2015 provides the basic wind speed map of India.

There are four factors governing wind load 1. Probability factor 2. Height factor 3. Topography factor 4. Importance factor

Wind zone of Mumbai is very high damage risk jone B (Wind speed = 47 m/s)

Terrain catogary is 2 as the terrain of the project is sea shore obstruction height 1 to 1.5m (Less than 10m)

1. Probability factor - for wind speed 47 m/s and for Important structures K1 = 1.07

2. Height factor - for height 9m and terrain 2 K2 = 1

3. Topography factor - Slope is less than 3 degree K3 = 1

4. Importance factor K4 = 1.40

Design Wind speed Vz = Vb X k1 X k2 X k3 X k4

Vz = 47m/s X 1.07 X 1 X 1.0 X 1.3 = 65.38m/s

Wind pressure pz = 0.6 X Vz square

= 0.6 X 65.38 X 65.38 = 2565N/m square

= 2.565kN/m square

The pier size is 1.5m X 1.5m So pressure on pier = 1.5 X 2.565 = 3.848kN/m square