Week 10 Challenge

Given Data:

1. Span of the bridge = 10m

2. Type of snow is settled snow

3. The deck of bridge is flat with B <30 degree

4. The depth of accumulation of snow = 1250 mm

5. Height of Parapet Wall = 1.5m

6. Thickness of Deck Slab = 0.9m

7. Width of Carraigeway = 18m

8. Height of Pier = 5m ( Assumed)

9. Size of longitudinal girder = 1.5m x 0.9m ( Assumed)

10.Size of cross girder = 1m x 0.75m ( Assumed)

11. Size of Pier = 1m dia ( Assumed)

Calculation of Snow Load:

Density of setteled snow = 2.5 kN/m3

Depth of snow = 1.25m

Deck of bridge is flat with β <30 degree

Snow load, So = 2.5 x 1.25 x 10

So = 31.25kN/m

Shape coefficient from As per IS: 875 (Part 4 )- 1987

For β < 30 degree, μ1 = 0.8

Design Snow Load, S = μ x So

As per IS: 875 (Part 4 )- 1987

S = 0.8 x 31.25 = 25 kN/m

Staad Pro Analysis:

First I created the model as per given data and assign there property as per given data, after that i assigned fixed support to the piers.

After that I go to the load case details where I first defined the Snow load. In snow load I go to the member load, In member load I go to uniform force where I first defined the snow load -25kN/m in GY direction which I calculated earlier. After that I select the two cross beams in z direction and assigned it to the selected beams.

After that I again go to the load case details where I again defined the Snow load. In snow load I go to the plate load, In plate load I go to pressure on full plate where as per IS 875 Part(IV) minimum snow load of 9kN/m2 should be applied to the structure, So I applied in GY direction as W1= -9kN/m2. After that I select the deck slab and assigned it to the selected plates.

After that I run the analysis command and go to the post processing mode. Where I 1st select the deck slab plates. And checked for the maximun bending moment in Mx direction. Where maximum bending moment in Mx direction is 83.196kN-m/m

After that I again select the deck slab plates. And checked for the maximun bending moment in MY direction. Where maximum bending moment in MY direction is -44.8kN-m/m.

After that I again select the deck slab plates. And checked for the maximun shear force in SQX direction. Where maximun shear force in SQX direction is 100.853kN/m2.

After that I again select the deck slab plates. And checked for the maximun shear force in SQY direction. Where maximun shear force in SQY direction is 79.309kN/m2

After that I go to the beam result where I select the cross beam element. After that I go to the section forces where i checked for maximun bending moment in MY direction. Where I got maximun bending moment 2.489kN-m in MY direction.

After that I again go to the section forces where i checked for maximun bending moment in MZ direction. Where I got maximun bending moment 112.381kN-m in MZ direction.

vAfter that I again go to the section forces where i checked for maximun shear force in FY direction. Where I got maximun shear force 90.018kN in FY direction.

After that I again go to the section forces where i checked for maximun shear force in FZ direction. Where I got maximun shear force 3.092kN in FZ direction.