Week 9 Challenge

Aim and Introduction:-

• The aim of this challenge is to calculate the impact of wave load 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 structure as per the given data is to be modeled for calculating the wave load effect on the structure from the given data.
• Then the model will be created in Staad pro., wave load is applied on the the structure and the reactions, stresses and bending moments due to the loading is being analyzed for the structure as given.

Data Given:-

• ηmax - 3m
• No. of I girder - 3
• Ht. of I girder - 1.7m
• Width of top & bottom flange - 2.5m
• Thickness of web & Flange - 500mm
• Span of bridge - 12m
• Width of Deck - 9m
• thickness of Deck Slab - 2m
• r - 5
• Cva - 3
• Elavation of Storm - 8.5m
• Cr - 0.4

Calculation of the Wave Forces :-

Total ht. of the super structure = 1.7 + 2.0 = 3.7m

ΔZh = ηmax - centroid of I girder

= (8.5+3.0) - (7+1.7/2)

= 3.65m

ΔZv = ηmax - elevation of bottom deck

= (8.5+3.0) - (7+2)

= 2.5m

Vertical Load = Fv=γ x ΔZv x Av

= 10 x 2.5 x (9 x (3.7/2))

= 416.25 KN

Horizontal Load = Fh=γ x ΔZh x Ah

= 10 x 3.65 x (24 x 3.7)

= 3241.20 KN

Maximum Verical Load = Fv-max = Cva x Fv

= 3 x 416.25

= 1248.75 KN

Maximum Horizontl Load = Fh-max = (1 + Cr (N-1)) x Cva x Fh

= (1+0.4(3-1)) x 3 x 3241.20

= 17502.48 KN

STAAD Pro. Analysis:-

• The bridge has been created by considering the given data by considering three girders for the deck of the bridge and the cross section of the bridge is taken as 9 m carriage way width.

The bridge model has been created by considering the following details.

• Pier - 1.2m x 1.2m
• pier Ht. - 7.0m
• Main girder - I girder
• cross girder - 0.75m x 1.0m
• Deck slab (Plate) thickness - 2.0m

All the properties of the structure has been defined as per the requirement.

Properties has been assigned to the structure.

Fixed support for the bridge has been considered and assigned to the bottom nodes.

The 3D render view of the defined structure.

Load & Definations:-

• The wave loads for the bridge deck at mid point of the structure has been defined as per the calculation and has been assigned to the respective node points.

• The loads on the bridge due to the wave load for maximum horizontal and vertical load has also been calculated, defined and assigned to the concerned nodes in the Staad.PRO model.
• 
• Then the structure is being analyzed and and results as 0 error and 0 warning.

• The deflection results due to wave load case 1

• The deflection results due to wave load case 2.

• Reactions at foundations due to wave load case1.

• Reactions at foundations due to wave load case2.

• Annotating the maximum Mz value for the piers with mid point and end point moments for wave load case -2.

• Annotating the maximum Mz value for the piers with mid point and end point moments for wave load case -1.

• Annotating the maximum Mz value for the main and cross girder with mid point and end point moments for wave load case -1.

• Annotating the maximum Mz value for the main and cross girder with mid point and end point moments for wave load case -2.

• Beam stress due to wave load case 1.

• Beam stress due to wave load case 2.

• Plate stress variation on the deck slab of the structure due to wave load case-1.

• Plate stress variation on the deck slab of the structure due to wave load case-2.

The reports for the maximum or minimum bending moment, shear forces or axial load stresses can be generated by generating the report from the Staad Pro. Model.