Week 12 Challenge

Aim and Introduction:-

• The aim of this challenge is to determine the forces on the structure due to application of barge load and to calculate the effect of the barge load on the structure as various forces like shear force, bending moment etc using staad Pro.
• So first of all the details components for calculating the magnitude of the barge load as per the given data is to be determined with reference to the concern IRC codes.
• Then the model will be created in Staad pro., barge load is applied on the the structure as different load cases and the reactions, stresses and bending moments due to the loading is being analyzed for the structure as given.

Data Given:-

• Span of bridge - 12m
• Width of Bridge - 7m
• Pier Size - 2.5m x 2.5m
• Rise of Bridge - 5m
• Dimension of cross girder - 0.75m x 1.8m
• Thickness of Deck Slab - 500mm
• Dead weight of panamax vessel - 52500T
• Each container - 6.1TEU
• Speed of boat - 60Km/hr
• hydrodynamic co-ifficient - 1.25
• Grade of concrete - M40

Calculation of the componets of barge Load :-

Barge Collision Energy -

KE=500 x CH x W x V^2

Where,

W - Barge Displacement Tonnage (T)

V - Barge impact speed (m/s)

KE - Barge Collision Energy (N-m)

CH - Hydrodynamic Co-ifficient

KE = 500 x 1.25 x 52500 x (60x5/18)^2

= 9.114 x10^9 N-m

Barge Damage Depth ' aa' = 3100 x ( [1+1.3 x 10^(-7) x KE]^0.5-1)

=3100 x ( [1+1.3 x 10^(-7) x 1.18125 x 10^(11)]^0.5-1)

= 103654 mm

Barge collision Impact force 'Pb'

For aB>=100 mm, Pb = 6.0 x 10^6 +1600 x (ab)

= 171846400 N

STAAD Pro. Analysis:-

• The bridge has been created by considering 1 spans and the cross section of the bridge is taken as 7 m width.

• The model has been created by considering the pier total height of pier as 12 m + 5m due to draft height + bridge height.
• The width of bridge has been taken as 7 m

• Groups has been created for indivisual components as pier, main girder , cross Girder etc for the structure.

• Properties for different sections has been defined and assigned to to the structure.

• Fixed support has been created and assigned to the defined structure.

• 3D render view of the bridge structure.

• The barge impact load has been defined as a nodal load. The impact load will be applied on any of the one pier. When any accident happens the impact of the force on pier will be maximum in the direction of movement of the vessel.

• The impact load has been applied and assigned to the node.

• The structure is being analyzed and the result come out with 0 error and 0 warnings.

Result:-

• The Displacement of the structure due to the impact load.

• Report has been generated and it can be summerized that maximum deflection is occur at node number 8 with 557.61mm.

• The reactions at each foundation due to the load can be generated.

• Maximum value of Mz for the piers at ends has been annotated.

• Maximum value of Mz at mid points for the main girders.

• Maximum value of Mz at mid points for the cross girders.

• Maximum value of Mz for the struts.

• Maximum value of Mz for the trusses.

• Maximum value of Fy for the trusses.

• Maximum value of Fy for the struts.

• Maximum value of Fy for the cross girders.

• Maximum value of Fy for the main girders.

• Maximum value of Fy for the piers.

• Plate stress My due to the barge load onthe structure.

• The stress variation in the plates of the deck slab of the structure in SQY for the loading of barge load case.

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 for barge impact load case.