Week 11 Challenge

Aim and Introduction:-

• The aim of this challenge is to determine the forces on the structure due to application of temprature load and to calculate the effect of the temprature 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 temprature 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., temparature 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 - 9m
• Width of Bridge - 7m
• Pier Dia - 2.5m
• Width of Pier cap - 6m
• Dimension of box girder - 1500mm x 1500mm
• Thickness of web of girder - 300mm
• Thickness of Deck Slab - 550mm
• Grade of concrete - M40
• Place of the Structure - Delhi

Calculation of the Temprature Load :-

Maximum temprature at Delhi C.H.O. IRC 6 = 47.8°

Minimum temprature at delhi C.H.O. IRC 6 = -0.4°

Effective temp. = (47.8-(-0.4))/2+10

= 34.1°

Co-ifficient of thermal expansion = 11.27 x 10^(-6)

Stress due to temprature load = α x T x E

=11.27 x 10^(-6) x 34.1 x 5000 √ 40

= 12.15 KN/m2

Maximum permissible stress = (2/3) x 0.7 x √40

= 2.95 KN/m2

∴ the stress restricted to 3KN/m2

Temprature at top = 47.8°

Temprature at bottom = (2.1/17.8) x 47.8

= 5.64°

STAAD Pro. Analysis:-

• The bridge has been created by considering 1 spans of 9 m length and the cross section of the bridge is taken as 6 m pier cap width.

• The carriage way width of 7m deck slab has been created.

• Groups has been created for indivisual components as pier, pier cap& Girder of 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.

• The 3D render view of the structure.

Load & Definations:-

• Temprature load for the above structure has been defined and assigned to the whole structure.

• The model is being analyzed and the result comes with 0 error and 0 warning.

RESULTS:-

• Deflection due to defined temprature load case.

• Reactions at the foundations due to defined load case .

• The report for the end forces can be generated.

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

• Mamimum value of Mz at mid points for the girders.

• Mamimum value of Mz at mid points for the pier caps.

• Value of Fy for the piers with with annotating the value of the forces.

• Value of Fy for the main girders with with annotating the value of the forces.

• Value of Fy for the pier caps with with annotating the value of the forces.

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

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