Challenge

Week 5 Challenge

Aim and Introduction:-

The aim of this challenge is to calculate and evaluate the zone and the types of wind load acting on the structure and to calculate the effect on the structure as various forces like shear force, bending moment etc using staad Pro.
So first of all the factors for the wind load is need to be determined from the given data. For determining the same IS-875 (part-III) is to be refered.
Then the model will be created in Staad pro., wind load is to be applied in each side of the the structure separately and the reactions due to the loading is being analyzed for the structure as given.

Data Given:-

For calculating the Design wind speed, it can be mathematically expressed as

Vz = Vb x k1 x k2 x k3 x k4

where, k1 = Risk factor

k2 = Terrain Factor

k3 = Topographic Factor

k4 = Importance Factor

The Location is at Mumbai and the height is 9m above the GL. But as per IS - 875 (part-III) the basic wind speed map of INDIA as given in Fig-1 in the mentioned code is only applicable for the structure above 10m. But still consider the structure is applicable for wind load ( category -2 as it is located in open terrain with well scattered obstructions of height less than 10m.) for which
Vb = 44m/s (From Fig -1 ) (IS - 875 Part - III)

Then ,

Generally it is at 10m above ground level based on 50 years mean return period.

K1 is taken corresponds to 44m/s wind speed and for important structures.

K2 = For Category 2 as it is located in open terrain with well scattered obstructions of height less than 10m.

= 1.0 (from Table - 2, IS - 875 part-III)

The value of K2 is taken coressponse to 10 m ht with category -2

( Considering the upwind slope below 3 degree)

(Consider as it is a important structure and also for Mumbai, as it is a coastal city) (Cyclonic Factor)

So,

Vz = Vb x k1 x k2 x k3 x k4

= 44 x 1.07 x 1.0 x 1.0 x 1.3

= 61.204 m/s

The Design wind pressure

Pz = 0.6 x Vz^2

= 0.6 x 61.204 x 61.204

= 2.248 Kn/m2

STAAD Pro. Analysis:-

The bridge has been created by considering 3 spans of 10m length and the cross section of the bridge as 8 m width.
Plate mesh also created for the deck slab.

Pier = As given

Main Girder = 0.75m x 1.5m

Cross Girder = 0.5m x 1.0m

Thickness of deck Slab = 400 mm

Groups has been created for diffrent types of structure components and material properties has been assigned respectively.

wind definition has been created and wind load different sides has been applied on the structure. The wind load of 3.372 kN/m2 has been calculated for the pier.