Week 2 Challenge

Aim: 

To apply the IRC live loads in the model in Stadd Pro and perform structural analysis for the given data.

Given:

• Width of the bridge deck is 7m, 
• Span of the bridge is 24m,
• Pier size is 2 m diameter,
• The seismic zone is Zone III,
• Wind speed is 42 km/hr,
• Unit weight of soil is 18 kN/m3.

Procedure:

Step 1: Open Stadd Pro connect edition software -> create a new file with the units set to metric standards.

Step 2: Select the geometry tab and enter the values of the node in the y column in the node table as 0 and 12 respectively which will create two nodes.

Step 3: Select add beam cursor and connect the two nodes creating a beam, this beam is one of the piers of the bridge.

Step 4: Select the beam cursor in the Select window -> Select the beam and Copy - paste the beam creating a new beam at a distance of 1.9m. Now, two piers are created. Repeat the same process by selecting both beams to create two more piers at the same distance of 1.9m.

Step 5: Select all the beams using the beam cursor -> Select the translational repeat command from the geometry tab -> In the X direction for 1 step and spacing 24m  create four more piers and also select link steps. Delete the linked beam connecting the bottom nodes.

Step 6: Connect the top of piers across the Z direction using Add beam command to create cross girders. Select the cross girders using the beam cursor from the select tab -> Using translational repeat create cross girders across the X direction for two steps for a spacing of 8 m. 

Step 7: Select the bottom left-most node using the node cursor (z=0 and y=12) -> Copy and paste that node in the x-direction for a spacing of 0.6m. Select the left-most and newly created node and copy and paste in the z-direction for a spacing of 0.57m.

Step 8: Select add plate command from the geometry tab and create a four-noded plate over the created four nodes.

Step 9: Select the plate using the plate cursor from the select tab -> Translational repeat the created plate over the X and Z direction for 40 and 10 steps, with 0.6 m and 0.57 m spacing respectively.

Step 10: Select the bottom left-most node using the node cursor (z=0 and y=0) -> Copy and paste that node in the x-direction for a spacing of 0.6m. Select the left-most and newly created node and copy and paste in the z-direction for a spacing of 0.57m.

Step 11: Select add plate command from the geometry tab and create a four-noded plate over the created four nodes.

Step 12: Select the plate using the plate cursor from the select tab -> Translational repeat the created plate over the X and Z directions for 5 and 10 steps, with 0.6 m and 0.57 m spacing respectively.

Step 13: Using copy and paste and as a reference point create the same plates in the -X direction. Select the leftmost line of plates along the Z direction and translational repeat it along -the Z direction for 4 steps and a spacing of 0.57 m. Also, Select the rightmost line of plates along the Z direction and translational repeat it along the Z direction for 4 steps and a spacing of 0.57 m. 

Step 14: Copy and paste these plates using a reference point ( pier bottom node ) on the other side of the piers.

Step 15: Specification tab -> Select Foundation -> Select plate mat and give the subgrade modulus as 12500 (Assumption). Subgrade modulus is the ratio of the Safe bearing capacity of the soil under site to that of permissible deflection obtained from the soil report. Assign this plate mat to the plate under the pier.

Step 16: Pier - In the Properties tab -> select define -> circle -> 2m -> Assign -> close.

Step 17: Main Girder - In the Properties tab -> select define -> tapered -> F1=1.7m F2=0.5m F3=1.7m F4=2m F5=0.2m F6=2m F7=0.2m -> Assign -> close.

Step 18: Cross Girder - In the Properties tab -> select define -> tapered -> F1=1.5m F2=0.3m F3=1.5m F4=0.3m F5=0.1m F6=0.3m F7=0.1m -> Assign -> close. 

Step 19: Deck - In the Properties tab -> select Thickness -> 0.25m -> Assign -> close.

Step 20: Plate Mat - In the Properties tab -> select Thickness -> 1.5m -> Assign -> close.

Step 21: In the Materials tab -> Select concrete and assign to view.

Step 22: Select the Main girders using beam cursor from select tab -> In property tab -> assign the tapered 1 for main girders.

Step 23: Select the Cross girders using beam cursor from select tab -> In property tab -> assign the tapered 2 for cross girders.

Step 24: Select the Deck slab plates using plate cursor from select tab -> In property tab -> assign the Thickness 0.25m for deck slab.

Step 25: Select the Plate Mat plates using plate cursor from select tab -> In property tab -> assign the Thickness 1.5m for plate mat.

Step 26: Select the Pier beams using beam cursor from select tab -> In property tab -> assign the Circle 2m for Pier.

Step 27: In loading tab -> Defenitions -> Vehicle definition, click add -> Width= 1.8m, Class A load details from IRC guidlines as 27kN - 0m, 27kN - 1.1m, 114kN - 3.2m, 114kN - 1.2m, 68kN - 4.3m, 68kN - 3m, 68kN - 3m, 68kN - 3m.

Step 28: In loading tab -> Load case details -> Generate 3 load types by clicking add -> load generation -> click add three times.

Step 29: Click the generated load 1 -> add -> enter the node value of 0.57 in the Z as the initial position and load increment in the X direction as 1 m. 

Step 30: Click the generated load 2 -> add -> enter the node value of 2.28 in the Z as the initial position and load increment in the X direction as 1 m. 

Step 31: Click the generated load 3 -> add -> enter the node value of 3.99 in the Z as the initial position and load increment in the X direction as 1 m. 

Step 32: Save the file and Run the analysis by -> Click analysis and design tab -> click define commands -> no print, click add -> click run analysis and check for errors after computation.

Thus the structural analysis of the given data has been done and the results are interpreted below.

Results: 

The results can be obtained after analysis of the model and can be viewed in the post-processing tab under the workflow section

The deflection of the Model can be seen below.,

The Reaction of the Model can be seen below.,

The Beam results of the Model can be seen below.,

These results are the representation of the deflection, reactions of supports, moment across X, Y, Z, and Axial load caused due to the live loads moving across the bridge's effective span of 24 m along X global direction.

Note: Since the model results are huge, I have attached the file below for reference.