Adding Dead and Superimposed Dead Load

The next step is to define the dead and superimposed dead loads.

(If not continuing from last section, open "EU Example 10_2 Full_Structure.sst" via Help | Tutorials | Open Tutorial Model... from the main menu.)

1. In the Structure Loads navigation window click on the toolbar button and select Beam Member Load | Beam Element Load from the drop down list.
2. Add a new row using the table + button.
3. Click on the () toolbar button then click on “De-select all”. Set Select By to “Structure Property” and add “Steel Flanges”, “H Piles” and “Steel Web” to the Selected Groups list.
4. Click on the “Save” button and save the member selection as “Steel only” before closing the Member Selection Filter form.
5. Change Direction to “Global Z” in the first row of the table, Load Value to “Volume”, Load W1 to “-77” and the Name to “Steel Dead Loads (Beam)”.
6. Draw a box around the entire structure before closing the Define Beam Loading form.
7. Click on the toolbar button and select “Finite Element Load | External Load”.
8. Change the Load Type to “Force/volume”, Direction to “Global Z”, Load to “-77” and Name to “Steel Dead Loads (FE)”.
9. Draw a box around the entire structure and then close the Define Finite Element Loading form.
10. Click on the toolbar button and add another Beam Member Load | Beam Element Load.
11. Click on the () toolbar button and de-select all.
12. Set Select By to “Structure Property” and add “Edge Upstand”, “Cracked Slab”, “Slab” and “Diaphragm” to the Selected Groups.
13. Click on the “Save” button, and save the selection as “Concrete Only” before closing the Member Selection Filter form.
14. Change Direction to “Global Z”, Load Value to “Volume”, Load W1 to “-25” and the Name to “Concrete Dead Loads (Beam)”.
15. Draw a box around the structure to select all the concrete beams before closing the Define Beam Loading form.
16. Click on the toolbar button and select “Finite Element Load | External Load”.
17. Change the Load Type to “Force/volume”, Direction to “Global Z”, Load to “-25” and Name to “Concrete Dead Loads (FE)”.
18. Draw a box around the entire structure and then close the Define Finite Element Loading form.
19. The next step is to define the dead load compilations. In the Structure Compilations navigation window, click on the button and choose “Dead Loads at Stage 1”.
20. Set the Limit State field to “ULS STR/GEO” and then click on the Find and Add to Table button to populate the table. The gamma factors for the Steel dead loads will need changing to “1.2”.
21. Set the name to “DL ULS” and close the form.
22. This process needs to be repeated for SLS. Click on the button and choose “Dead Loads at Stage 1”.
23. Change Limit State to “SLS Characteristic” then click on the Find and Add to Table button.
24. Set the name to “DL SLS” and then close the form.
25. The next step is to define the superimposed dead loads. In the Structure Loads navigation window toolbar click on + and select “Bridge Deck Patch Load”.
26. Change Define Loading by to “coordinate” and Load per unit area to “2kN.m²”.
27. Change Snap mode in the graphics window to “Intersection” and click on the four corners of the deck to define the patch (the original point needs selecting again at the end).
28. Change Name to “Surfacing” and then close the form.
29. In the Structure Compilations navigation window click on the toolbar button and select “Superimposed Dead Loads”.
30. Set the Limit State field to “ULS STR/GEO” and then click on the + button to add a new line.
31. Click in the Load Name drop down list and select “L5: Surfacing”..
32. Set the name to “SDL ULS” and close the form.
33. Right-click on “C3: SDL ULS STR/GEO” on the Navigation Pane and select “Copy”.
34. Change Limit State to “SLS Characteristic” and answer “Yes” when prompted to change the factors.
35. Change the name to “SDL SLS” and close the form.
36. Use the Member selection filter function to select all members.
37. Save the file as “My EU Example 10_2 Dead_And_SDL.sst”.