Week 11 Challenge

Aim :- Calculate the temperature load for the RC bridge with M40 grade to be constructed in delhi and perform using STAAD.pro software.

`**`Manual Calculation`**`

1) Maximum temperature in the loacation as per IRC 6 isotherm at the location = 47.5 degree.

2) Minimum temperature in the loacation as per IRC 6 isotherm at the location = -2.5 degree.

`***`Effective temperature difference

= [47.5-(-2.5)]/2 + 10

= 25 + 10

= 35 degree.

`***`Stress due to temperature.

= `alpha` X `Delta T` X E

= `11.27X10^-6` X 35 X 5000 (40) `1/2`

= 12.47 kN/`m^3`

`***`Maximum permissible stress.

=(`2/3`) X 0.7 X `sqrt fck`

=(`2/3`) X 0.7 X (40)`1/2`

= 2.95 kN/`m^2`

Hence,

The stress are restricted to 3 kN/`m^2`

• Maximum Temperature = 47.5 degree.
• Minimum Temperature = -2.5 degree.
• Positive temperature difference

- Temperature at top = 47.5 degree.

- Temperature at buttom = (`2.1/17.8`) X 47.5

= 5.60 degree

`***` This temperature variation is applied as loading in STAAD.pro.

`**` Analyze Using STAAD.pro Software `**`

Step (1) :- Opening of STAAD.pro software.

• First open a staad.pro software
• Fill model information regarding structure.
• Then click on create to open a model.

Step (2) :- Creating a Pier in model

• Create a first node using cordinate.
• Select that node and copy it in Y direction upto 10 meter using translational repeat option.
• 
• In translational repeat option select direction as Y and spacing as 10 meter aslo select link step option to connect the node then click on Ok to create.
• Again select the pier using beam cursor and copy it in X direction upto 9 meter using translational repeat option.
• 
• In above window select direction as X and spacing as 9 meter because length of the span is given in question as 9 meter then click on Ok to create.
• Hence pier is created.

Step (3) :- Creating piercap and girder in model.

• First we need to create the piercap.
• For creating piercap select both top node of the piers using node cursor.
• Then copy them in inverse Z direction upto 3 meter using translational repeat option.
• 
• In translational repeat option select direction as Z and spacing is -3 meter because we copying node in inverse direction.
• Also select link steps option to connect both the node.
• Again select top node of the piers using node cursor.
• And copy them in Z direction upto 3 meter using translational repeat option.
• 
• In above window select direction as Z also spacing is 3 meter click on link step to connect both the node then click on Ok to create.
• :. lenght to the piercap is given in question is 6 meter.
• Hence piercap is created.
• 
• Now we need to created girder in model.
• For that geometry then click on Add beam option, then cursor will change.
• By using that cursor connect all top node in model which is parallel to X direction.
• Girder is created in model.

Step (4) :- Creating Deckslab

• Creating 7 meter width of deckslab.
• Select first node of the model using node cursor.
• 
• Copy that node in X direction upto 0.5 meter using translational repeat option.
• 
• In above window select direction as X and spacing should be 0.5 meter then click on Ok to copy.
• Again select both the node and copy then in inverse Z direction upto 0.5 meter using translational repeat option.
• Then Add plate in created node, For that go to geometry in that click on add plate option then cursor will change.
• By using that cursor connect all four node and create one plate.
• After that select that plate by using plate cursor and copy it in X direction.
• 
• In transational repeat option select direction as X and spacing should be 0.5 meter.
• No of step is 17 ( :. Span is given 9 meter in question so, 9/0.5=18, 18-1 = '17' no of step) click Ok to copy.
• Again select all the plate by using plate cursor which we created before and copy them in Z direction using translational repeat option.
• 
• In translational repeat option select direction as Z and spacing should be 0.5 meter.
• No of step is 13 (:. Width of the deckslab is given 7 meter so, 7/0.5=14, 14-1= '13' no of step) click Ok to copy.
• Hence deckslab is created.

Step (5) :- Assigning support to the pier.

• First go to specification in this menu click on Fixed support option.
• Then support window will open.
• 
• In above window first select support then select buttom node of the pier after select assign to selected node option then click on Assign button to created the support.
• Hence, support is assign to the structure.

Step (6) :- Assigning property to the pier.

• For that first go to specification then click on prismatic option then property window will open.
• 
• In property window select circle and put diameter of circle as 2.5 meter which is given in the question.
• Then click on Add button.
• After that select both the pire using and assign this property to it.

Step (7) :- Adding property to the piercap.

• Go to specification then click on prismatic option then property window will open.
• 
• In above window select trapezoidal then assume the size of piercap like above window then click on Add.
• Select both the pier cap and assign this property to it.

Step (8) :- Adding property to the box girder.

• Repeat same procedure as mention in step 6.
• 
• In above window select tapared tube section and also select square type section.
• Put the size girder as mention in above window then click on add.
• Select all the girder and assign this property to it.

Step (9) :- Adding and assigning plate thickness to the deckslab.

• First go to specification then click on plate thickness option, then property element window will open.
• 
• Put plate thickness as 0.550 meter in above window which is given in question, then click on add.
• Select all the plate using plate cursor and assign this property to it.

[ 3D Model ]

Note :- Crosscheck the model which we created is correct or not (:. Multiple structure, Missing property , Duplcate thing)

Step (10) :- Applying Temperture Load on structure.

• First go to loading option in right side of the window then this window will shown.
• 
• In above window click on load cases details and create load case 1 as temperature load
• After creating load case select thet load case and click on add button then this window will open.
• 
• In this window select temperature load and put all the load as we calculated earlier manually and click on add.
• Then select that load and assign to the structure model.

Step (11) :- Analysis of model.

• For analysis of the structure go to analysis and design option.
• In that click on run analyis option then analyis process will start.
• 
• After sucessfull analysis of the structure click on post processing mode to view the result.

Result :-

A) Bending Moment result

B) Plate stress in MY and MX local.