STUDENT STEEL BRIDGE COMPETITION 2013.pdf

205 downloads 22371 Views 9MB Size Report
Sep 15, 2012 ... ANALYSIS, DESIGN AND DOCUMENTATION OF STEEL BRIDGES. USING STAAD.Pro V8i AND STRUCTURAL MODELER INTEGRATION.
2013 STUDENT STEEL BRIDGE COMPETITION STRUCTURAL ANALYSIS, DESIGN, AND DRAWING PRODUCTION USING BENTLEY PRODUCTS

AISC/ASCE STUDENT STEEL BRIDGE COMPETITION – 2013

ANALYSIS, DESIGN AND DOCUMENTATION OF STEEL BRIDGES USING STAAD.Pro V8i AND STRUCTURAL MODELER INTEGRATION

By

RAVINDRA OZARKER, P.E., P.ENG.

September 15, 2012 2

Table of Contents 1.0 Introduction

……………………………………………………………………………..……….. 5

2.0

Creating the Bridge Geometry/Structural Analysis …………………………………..………….. 8

3.0

Step-by-Step Tutorial ……………………………………..…………………………………….. 21 Exercise 1: Overall Bridge Geometry…………………………………………………………… 21 Exercise 2: Creating the Leg Structure ……………………………………………………….… 30 Exercise 3: Modifying the Deck Geometry …………………………………………………….. 40 Exercise 4: Creating Member Offsets …………………………………………………………

51

Exercise 5: Physical Member Formation ……………………………………………………….. 61 Exercise 6: Truss Specification Creation and Assignment ……………………………………... 63 Exercise 7: Support Creation and Assignment …………………………………………………. 66 Exercise 8: Property Creation and Assignment ………………………………………………… 67 Exercise 9: Formation of Cantilever Section…………………………………………………… 74 Exercise 10: Creating Load Cases & Items …………………………………………………….. 83 Exercise 11: Performing Analysis ……………………………………………………………… 91 Exercise 12: Understanding the Results ………………………………………………………

92

Exercise 13: Design of the Structure using AISC 360-05 …………………………………….. 102 4.0 STAAD.Pro and Structural Modeler Integration ………………………………………………….. 105 5.0 Help, Questions, Comments ………………………………………………………………………

3

118

Appendices A: Creating Bridge Geometry Using STAAD.Pro V8i Grid System ………………………………….. 120 B: Creating Bridge Geometry Using STAAD.Pro V8i dxf Import …………………………………….. 126 C: STAAD.Pro Input Command File …………………………………………………………………... 134 D: Specifying Proper Slenderness Lengths in STAAD.Pro …………………………...……………...

146

E: Dataset Installation ………………………………………………………………………………..… 154

4

1.0 Introduction The Student Steel Bridge Competition is sponsored by the American Institute of Steel Construction (AISC), American Society of Civil Engineers (ASCE) and cosponsored by the American Iron and Steel Institute (AISI), Bentley Systems, Inc., Canadian Institute of Steel Construction (CISC), James F. Lincoln Arc Welding Foundation, National Steel Bridge Alliance (NSBA), Nelson Stud Welding, Nucor Corporation, and Steel Structures Education Foundation (SSEF). Students design and erect a steel bridge by themselves but may seek advice from faculty and student organization advisers. Civil Engineering students are challenged to an inter-collegiate competition that includes design, fabrication, and construction of a scaled steel bridge. Participating students gain practical experience in structural design, fabrication processes, construction planning, organization, project management, and teamwork. In the industry, commercial structural analysis and design software integrated within a BIM (Building Information Modeling) or BrIM (Bridge Information Modeling) environment are used extensively to complete projects on time and at the same time lets engineers maintain accuracy and come up with very efficient design alternatives. The correct combination of software tools can make the bridge design, fabrication and construction task very easy.

STAAD.Pro is the professional’s choice for steel, concrete, timber, aluminum and cold-formed steel structures, culverts, petrochemical plants, tunnels, bridges, piles and much more. It is a general purpose structural analysis and design tool. Structural Modeler is an advanced, yet intuitive and easy-to-use building information modeling (BIM) application that empowers structural engineers and designers to create structural system models and related engineering drawings (i.e. documentation).

5

STAAD.Pro and Structural Modeler are integrated. STAAD.Pro models can be imported into Structural Modeler and Structural Modeler models can be exported out to STAAD.Pro. The purpose of this document is to help students analyze and design their bridge models using Bentley’s STAAD.Pro software and produce engineering layout drawings using Structural Modeler. This document does not teach how to compare advantages of various alternatives that are allowed in this competition. Designers must consider carefully the comparative advantages of various alternatives. For example, a truss bridge may be stiffer than a girder bridge but slower to construct. Successful teams analyze and compare alternative designs prior to fabrication. Following are some statements from the Student Steel Bridge Competition 2013 Rules manual. This Year’s Problem Statement: The new Hill Music Hall and Marian Paroo Memorial Library sparked revitalization of the River City waterfront, with restaurants, theaters, and luxury condominiums scrambling for space in the old brick warehouses. The resulting vehicle traffic now exceeds the capacity of city streets. Therefore, the River City Development Corporation (RCDC) is requesting design/build proposals for a bridge to provide direct access from suburbs across the river. Construction Speed The bridge with the lowest total time will win in this category. Construction Economy The bridge with the lowest construction cost (Cc) will win in the construction economy category. Construction cost is computed as Cc = Total time (minutes) x number of builders x 50,000 ($/builder-minute) + load test penalties ($). Total time is defined in 7.2.3, and load test time penalties are prescribed in 12.2, 12.4, and 12.5. The number of builders includes all members and associates of the competing organization who physically assist the team at any time during timed construction or repair. Lightness The bridge with the least total weight will win in the lightness category. Total weight is the weight of the bridge (determined by scales provided by the host student organization) plus weight penalties prescribed in 9.3, 9.4, and 10.2. Decking, tools, temporary pier, lateral restraint devices, and posters are not included in total weight. Stiffness The bridge with the lowest aggregate deflection will win in the stiffness category. Aggregate deflection is determined from measurements as prescribed in 12.5. Structural Efficiency The bridge with the lowest structural cost (Cs) will win in the structural efficiency

6

category. Structural cost is computed as For a bridge that weighs 400 pounds or less, Cs = Total weight (pounds) x 10,000 ($/pound) + Aggregate deflection (inches) x 1,000,000 ($/inch) + Load test penalties ($) For a bridge that weighs more than 400 pounds, Cs = [Total weight (pounds)]2 x 25 ($/pound2) + Aggregate deflection (inches) x 1,000,000 ($/inch) + Load test penalties ($) Total weight is defined in 7.2.4, aggregate deflection is defined in 7.2.5, and load test weight penalties are prescribed in 12.4 and 12.5. Overall Performance The overall performance rating of a bridge is the sum of construction cost and structural cost, (Cc + Cs). The bridge achieving the lowest value of this total wins the overall competition.

7

Overall Performance The overall performance rating of a bridge is the sum of construction cost and structural cost (Cc + Cs). The bridge achieving the lowest value of this total wins the overall competition. From the above statements it is clear that a bridge that is light and stiff (i.e. structurally efficient) may not necessarily be an overall winner. Designers need to keep other criteria such as constructability and cost (i.e. construction economy) in mind. This document and software packages discussed here will help students analyze and understand their structures better to achieve structural efficiency. The documentation that will be produced can be used to discuss/plan construction economy.

8

2.0 Creating the Bridge Geometry/Structural Analysis STAAD.Pro can make your bridge design and analysis task easier. The bridge geometry in STAAD.Pro can be constructed in many ways: 1. 2. 3. 4. 5.

STAAD.Pro user interface Structure Wizard Using a DXF import (importing a dxf MicroStation or AutoCAD drawing) Structural Modeler ProSteel 3D

In this case part of the bridge geometry will be created using Structure Wizard. The bridge geometry is shown in Figure 1.

9

Note: The bridge model constructed in this tutorial does not fully comply with the 2013 rules. For example, the maximum allowable length of the bridge is 17 feet. This tutorial illustrates a model bridge with 21 feet span. There are other grometric contrains that the designers need to be aware of. The goal of this tutorial is to show designers how these complex bridge models can be analyzed and designed using STAAD.Pro.

(a) Bridge Geometry Discussed In This Tutorial

(b) Property Assignment

10

(c) Lateral Load Test

11

(d) Vertical Load Test – Step 1

(e) Vertical Load Test – Step 2 Figure 1: Bridge Geometry and Loading Process

12

Note: If custom cross sections are used for the bridge members, the custom shapes can be modeled as General Sections. You may have to use STAAD.SectionWizard. Alternatively, a General Section can be also created in STAAD.Pro V8i using the instructions on the following link: ftp://ftp2.bentley.com/dist/collateral/Web/Building/STAADPro/Modeling_Custom Shapes in STAAD_PRO.pdf The loads on the bridge will be placed based upon the roll of first dice. The following table shows the possible values of L and locations where the displacements will be measured.

Note: The loading on the bridge model constructed in this tutorial does not fully comply with the 2013 rules. The goal of this tutorial is to show designers how these complex bridge models can be analyzed and designed using STAAD.Pro. In this tutorial, the following load pattern will be used.

13

Following are all possible values of L and LC based on the roll of the two dice.

DICE 1  1  1  1  1  1  1  2  2  2  2  2  2  3  3  3  3  3  3  4  4  4  4  4  4  5  5  5  5  5  5  6  6  6  6  6  6 

DICE 2  1  2  3  4  5  6  1  2  3  4  5  6  1  2  3  4  5  6  1  2  3  4  5  6  1  2  3  4  5  6  1  2  3  4  5  6 

L (FT)  0  0  0  0  0  0  3  3  3  3  3  3  6  6  6  6  6  6  7  7  7  7  7  7  9  9  9  9  9  9  12  12  12  12  12  12 

14

TB (FT)  3  3  3  3  3  3  6  6  6  6  6  6  9  9  9  9  9  9  7  7  7  7  7  7  9  9  9  9  9  9  12  12  12  12  12  12 

TC (FT)  1  1.5  1.5  2  2  2.5  1  1.5  1.5  2  2  2.5  1  1.5  1.5  2  2  2.5  1  1.5  1.5  2  2  2.5  1  1.5  1.5  2  2  2.5  1  1.5  1.5  2  2  2.5 

Table 1: Bridge Loading

Loading Type

L=0 ft VLT PRELOAD  L=0 ft VLT STEP 1  L=0 ft VLT STEP 2 

Components Self weight of the structure Distributed Load as shown below:

VLT PRELOAD Left Side: 0.2 kip/(4 beams * 3ft deck) = 0.017 k/ft load on each member. Right Side: 0.05 kip/(4 beams * 3ft deck) = 0.0042 k/ft load on each member.

VLT STEP 1:  Left Side: 1.8 kip/(4 beams * 3ft deck) = 0.15 k/ft load on each member. Right Side: 0.05 kip/(4 beams * 3ft deck) = 0.0042k/ft load on each member.

VLT STEP 2:  Left Side: 1.8 kip/(4 beams * 3ft deck) = 0.15 k/ft load on each member. Right Side: 0.7 kip/(4 beams * 3ft deck) = 0.0058k/ft load on each member.

L=3 ft VLT PRELOAD  L=3 ft VLT STEP 1  L=3 ft VLT STEP 2   

Self weight of the structure Distributed Load as shown below:

VLT PRELOAD Left Side: 0.2 kip/(4 beams * 3ft deck) = 0.017 k/ft load on each member. Right Side: 0.05 kip/(4 beams * 3ft deck) = 0.0042 k/ft load on each member.

VLT STEP 1:  Left Side: 1.8 kip/(4 beams * 3ft deck) = 0.15 k/ft load on each member.

15

Right Side: 0.05 kip/(4 beams * 3ft deck) = 0.0042k/ft load on each member.

VLT STEP 2:  Left Side: 1.8 kip/(4 beams * 3ft deck) = 0.15 k/ft load on each member. Right Side: 0.7 kip/(4 beams * 3ft deck) = 0.0058k/ft load on each member.

L=6 ft VLT PRELOAD  L=6 ft VLT STEP 1  L=6 ft VLT STEP 2 

Self weight of the structure Distributed Load as shown below:

VLT PRELOAD Left Side: 0.2 kip/(4 beams * 3ft deck) = 0.017 k/ft load on each member. Right Side: 0.05 kip/(4 beams * 3ft deck) = 0.0042 k/ft load on each member.

VLT STEP 1:  Left Side: 1.8 kip/(4 beams * 3ft deck) = 0.15 k/ft load on each member. Right Side: 0.05 kip/(4 beams * 3ft deck) = 0.0042k/ft load on each member.

VLT STEP 2:  Left Side: 1.8 kip/(4 beams * 3ft deck) = 0.15 k/ft load on each member. Right Side: 0.7 kip/(4 beams * 3ft deck) = 0.0058k/ft load on each member.

16

L=7 ft VLT PRELOAD  L=7 ft VLT STEP 1  L=7 ft VLT STEP 2     

Self weight of the structure Distributed Load as shown below:

VLT PRELOAD Left Side: 0.2 kip/(4 beams * 3ft deck) = 0.017 k/ft load on each member. Right Side: 0.05 kip/(4 beams * 3ft deck) = 0.0042 k/ft load on each member.

VLT STEP 1:  Left Side: 1.8 kip/(4 beams * 3ft deck) = 0.15 k/ft load on each member. Right Side: 0.05 kip/(4 beams * 3ft deck) = 0.0042k/ft load on each member.

VLT STEP 2:  Left Side: 1.8 kip/(4 beams * 3ft deck) = 0.15 k/ft load on each member. Right Side: 0.7 kip/(4 beams * 3ft deck) = 0.0058k/ft load on each member.

17

L=9 ft VLT PRELOAD  L=9 ft VLT STEP 1  L=9 ft VLT STEP 2   

Self weight of the structure Distributed Load as shown below:

VLT PRELOAD Left Side: 0.2 kip/(4 beams * 3ft deck) = 0.017 k/ft load on each member. Right Side: 0.05 kip/(4 beams * 3ft deck) = 0.0042 k/ft load on each member.

VLT STEP 1:  Left Side: 1.8 kip/(4 beams * 3ft deck) = 0.15 k/ft load on each member. Right Side: 0.05 kip/(4 beams * 3ft deck) = 0.0042k/ft load on each member.

VLT STEP 2:  Left Side: 1.8 kip/(4 beams * 3ft deck) = 0.15 k/ft load on each member. Right Side: 0.7 kip/(4 beams * 3ft deck) = 0.0058k/ft load on each member.

18

L=12 ft VLT PRELOAD  L=12 ft VLT STEP 1  L=12 ft VLT STEP 2 

Self weight of the structure Distributed Load as shown below:

VLT PRELOAD Left Side: 0.2 kip/(4 beams * 3ft deck) = 0.017 k/ft load on each member. Right Side: 0.05 kip/(4 beams * 3ft deck) = 0.0042 k/ft load on each member.

VLT STEP 1:  Left Side: 1.8 kip/(4 beams * 3ft deck) = 0.15 k/ft load on each member. Right Side: 0.05 kip/(4 beams * 3ft deck) = 0.0042k/ft load on each member.

VLT STEP 2:  Left Side: 1.8 kip/(4 beams * 3ft deck) = 0.15 k/ft load on each member. Right Side: 0.7 kip/(4 beams * 3ft deck) = 0.0058k/ft load on each member

19

Weight of the structure Lateral Load

Self weight of the structure Self weight of the structure Distributed Load as shown below: 0.075 kip/(2 beams * 3ft deck) = 0.0125 k/ft load on each member. 0.075 kip point Load as shown below

Notes: (1) L is defined in Section 8 of the document entitled Student Steel Bridge Competition - 2011 Rules

20

3.0 Step-by-Step Tutorial Exercise 1: Overall Bridge Geometry 1. Launch STAAD.Pro by clicking on the Start->All Programs->STAAD.Pro V8i->STAAD.Pro icon. The STAAD.Pro V8i introduction screen will appear as shown in Figure 2. Note: Make sure that US Design Codes is checked and has a green light besides it. The US Design Codes is not checked, you will need to check this box and close the STAAD.Pro interface and re-open it again.

Figure 2: STAAD.Pro Introduction Screen

2. Click on File->Configure. The Configure Program dialog box will appear. Make sure that the Base Unit is set to English. Note: If you will be constructing your bridge model in the metric unit system, make sure that you set the base unit system to Metric.

21

Figure 3: Base Unit System Setup

3. Click on the File->New menu command. The New dialog box will appear. 4. Provide the model options as shown in Figure 4.

Figure 4: The New Dialog box

5. Click on the Next button. The Where do you want to go Today? Dialog box will appear as shown in Figure 5. 6. Click on the Finish button. 7. The STAAD.Pro V8i user interface will appear as shown in Figure 6.

22

Figure 5: The Where do you want to go Today? dialog box

Figure 6: STAAD.Pro User Interface

8. You could create the bridge geometry using the grid options shown in Figure 6. Appendix A of this document illustrates the procedure of creating a simple bridge geometry using the grid system. You could also create a bridge geometry using MicroStation XM and export that drawing as a dxf. Appendix B discusses how this can be achieved. In this tutorial, the Structure Wizard will be used to create the bridge geometry. 9. Click on the Geometry->Run Structure Wizard menu command. The Structure Wizard user interface will appear as shown in Figure 7.

23

Figure 7: Structure Wizard User Interface

10. Double click on the Pratt Truss icon on the left. The Select Parameters dialog box will appear as shown in Figure 8. Note: In this dialog box, you can adjust the bay-to-bay spacing by simply clicking on the … icon. Make sure that the summation of the bay-spacing is equal to total length and width that you have specified respectively.

Figure 8: Structure Wizard User Interface

11. Input the parameters in the Select Parameters dialog box as illustrated in Figure 8. 12. Press the Apply button. The structural geometry will appear as shown in Figure 9.

24

Figure 9: Bridge Structure Geometry in Structure Wizard

13. To transfer the structure to STAAD.Pro, select the File->Merge Model With STAAD.Pro Model menu command. Structure Wizard interface will close and a conformation dialog box will appear.

Figure 10: Confirmation dialog box

14. Click Yes for the conformation dialog box. The Paste Prototype Model dialog box will appear. 15. Click on the Ok button. The bridge geometry will be created in STAAD.Pro as shown in Figure 11.

25

Note: The Y Axis should be the axis of gravity in your STAAD.Pro models.

Figure 11: Bridge geometry in STAAD.Pro interface

16. The bridge geometry seen in Figure 11 has to be mirrored in the XZ-plane. 17. Select the Beams Cursor from the left hand side.

Figure 12: Beams Cursor

18. Select all the beams in the graphics window. Ctrl + A will select all the beams in the model. 19. Click on Geometry->Mirror command. The Mirror dialog box will appear as shown in Figure 13.

26

Figure 13: The Mirror dialog box

20. Input the mirror parameters as shown in Figure 13. 21. Click the OK button. The structure will be mirrored about the X-Z plane as shown in Figure 14.

Figure 14: Bridge structure is mirrored about the X-Z plane

27

Note: Basic 3D Navigation Tools: Use the arrow keys on the keyboard to rotate structure, the middle mouse roller button to zoom in and out. If you press the roller button and hold it down, you will be able to pan. You may also use the icons in the icon bar. )

(i.e.

22. Select the node points as shown in Figure 15 using the nodes cursor.

Figure 15: Node points selected

23. Select the Geometry->Translational Repeat menu command.

Figure 16: Translational repeat command selected

24. Select the Geometry->Translational Repeat menu command.

28

Figure 17: Translational repeat command selected

25. The 3D Repeat dialog box will appear as shown in Figure 17. Input the mirror parameters as shown in Figure 17. 26. Click the Ok button. The legs of the bridge structure will appear as shown in Figure 18.

Figure 18: Legs of the bridge are created

29

Exercise 2: Creating the Leg Structure 1. Select the leg members and right click with the mouse and select the Insert Node option.

Figure 1: Legs of the bridge are created

2. Select the leg members and right click with the mouse and select the Insert Node option.

Figure 2: Legs of the bridge are created

3. Click the Ok button. The legs of the bridge structure will be subdivided to create the lattice leg attachment points.

30

Figure 3: Legs of the bridge are created

4. Select the node point on the bottom left hand side corner.

Figure 4: Legs of the bridge are created

5. Select the node point on the bottom left hand side corner. 6. Right click on the screen and select the copy command. This will copy the highlighted node to the memory.

31

Figure 5: Legs of the bridge are created

7. Right click on the screen and select the Paste command. The Paste with Move dialog box will appear.

Figure 6: Legs of the bridge are created

32

Figure 7: Legs of the bridge are created

8. Input the parameters as illustrated in Figure 7 and Press the Ok button. You will note a new node point at the lower left hand side of the structure.

Figure 8: Legs of the bridge are created

9. Select the Geometry->Add Beam->Add beam from Point to Point menu command.

33

Figure 9: Legs of the bridge are created

10. Connect the nodes with a new beam element as shown in Figure 10. 11. Delete all the leg members except the member that was created in the above step and the small lattice leg attachment points.

Figure 10: Legs of the bridge are created

12. Divide the beam into three equally parts. Right click on the beam and select the Insert Node command. 13. Input the information in the Insert Nodes dialog box as shown in Figure 11. 2 is entered in the n= input box.

34

Figure 11: Insert nodes dialog box

14. Click the Ok button. 15. Select the new leg members as shown in Figure 12.

Figure 12: The beam members are selected

16. Select the Geometry->Circular Repeat menu command. 17. The 3D Circular dialog box will appear. Input the data in the 3D Circular dialog box as shown in Figure 13.

35

Figure 13: 3D Circular dialog box

18. Click on the node icon as shown in Figure 13. Select the node point as shown in Figure 14.

Figure 14: Node point is clicked

19. Press the Ok button. The leg members will be created as shown in Figure 15.

Figure 15: Lattice leg member is created

36

20. Select the lattice leg member as shown in Figure 15. 21. Right click on select the Copy command.

Figure 16: Copy command is selected

22. Right click on select the Paste Beams command. The Paste with Move dialog box will appear.

Figure 17: Paste Beams command is selected

23. Press the Reference Pt. button. The Specify Reference Point dialog box will appear.

Figure 18: Reference Pt. button is pressed

37

Figure 19: Specify Reference Point dialog box

24. Press the Ok button and click on the lower node of the lattice leg attachment points to create the rest of the leg members as shown in Figure 20.

Figure 20: Rest of the leg members are created

38

25. Press the Ok button and click on the lower node of the lattice leg attachment points to create the rest of the leg members as shown in Figure 20.

39

Exercise 3: Modifying the Deck Geometry 1. Select the members as shown in Figure 1. Press the delete key on your keyboard to delete these members.

Figure 1: Members are being deleted

2. Draw a member as shown in Figure 2.

Figure 2: New Member is created

3. Select all members in the model by pressing the CTRL+A key on the keyboard.

40

Figure 3: Intersect menu command

4. Select the Geometry->Intersect Selected Members->Intersect command menu. 5. Press the Ok button.

Figure 4: Intersect menu command

6. Select the members as illustrated in Figure 4. 7. Press the delete key on the keyboard. 8. Select the member as illustrated in Figure 5.

41

Creating Additional Members:

Figure 5: Member 14 selected

9. Right click and select the insert node command. 10. Click on the Add Mid Point button and click on the ok button in the Insert Nodes dialog box.

Figure 6: Member 14 selected

11. Select the member as illustrated in Figure 6. 12. Segment the beam at the following locations as shown in Figure 7.

42

Figure 7: Member 14 is being segmented

13. Click the Ok button.

Figure 8: Member 154 is selected

14. Select a beam as shown in Figure 8. 15. Segment the beam at the following locations as shown in Figure 9. 16. Click the Ok button.

43

Figure 9: Member 154 is being segmented

17. Select a beam as shown in Figure 10.

Figure 10: Member 153 is selected

18. Segment the beam at the following locations as shown in Figure 11. 19. Click the Ok button.

44

Figure 11: Member 153 is being segmented

20. Add new beam members as shown in Figure 12.

Figure 12: New members are added

21. The next bay members will be subdivided similarly. Select the member as shown in Figure 13.

45

Figure 13: Member is selected

22. Right click and select the Insert Node command. Input the data in the Insert Nodes dialog box as illustrated in Figure 14. 23. Click the Ok button.

Figure 14: Member is being divided into smaller pieces

46

Figure 15: Member is selected

24. Select the member as shown in Figure 15.

Figure 16: Member is being divided into smaller pieces

25. Right click and select the Insert Node command. Input the data in the Insert Nodes dialog box as illustrated in Figure 16.

47

Figure 17: Members are selected – They will be mirrored about the Y-Z plane.

26. Click the Ok button. 27. Add new beam members as shown in Figure 17. 28. Select the beams shown in Figure 17. Select the Geometry->Mirror menu command. The Mirror dialog box will appear.

Figure 18: Mirror dialog box

48

29. Input the information in the Mirror dialog box as shown in Figure 18. Note that node 11 at X=10.5 maybe different in the model that you have constructed. Please use the node icon to pick a suitable point on the mirror plane.

Figure 19: Members are mirrored

Figure 20: Member is selected

30. Select the member as shown in Figure 20. 31. Right click and select the Insert Node command. 32. The Insert Nodes dialog box will appear. Input the parameters as shown in Figure 21. 33. Press the Ok button.

49

Figure 21: Member is being divided into smaller pieces

Figure 22: Final Geometry

50

Exercise 4: Creating Member Offsets 1. Select the General->Spec control tab on the left. 2. Press the Beam button in the data area. 3. Select the Offset tab in the Member Specification dialog box. 4. Enter the inputs as shown in Figure 1. 5. Press the Add button. You will note that the START 0 0 0.625 specification command will appear on the right hand side.

Figure 1: Member Start end offset

6. Press the Beam button in the data area. 7. Select the Offset tab in the Member Specification dialog box. 8. Enter the inputs as shown in Figure 2. 9. Press the Add button. You will note that the END 0 0 0.625 specification command will appear on the right hand side.

51

Figure 2: Member end node offset

10. Select the member as shown in Figure 3. 11. Select the START 0 0 0.625 specification command. Press the Assign button. 12. Select the End 0 0 0.625 specification command. Press the Assign button.

Figure 3: Select the segmented member

13. Select the End 0 0 0.625 specification command. Press the Assign button.

52

14. Draw a beam from Node 1 to Node 2 as illustrated in Figure 4.

Figure 4: Select the segmented member

15. This beam is created because we need to model two beams that are running parallel to each other and sandwiching intermediate members as illustrated in Figure 5.

Figure 5: 3D illustration of member offset

16. Check the Highlight Assigned Geometry check box. 17. Select the End 0 0 0.625 specification command. 18. Click the Select->By Inverse-> Inverse Geometry Selection menu command.

53

Figure 6: Inverse Geometry Selection command

19. Click the View>View Selected Objects Only menu command. Select the Geometry cursor. Press the Ctrl+A. 20. Click the Geometry->Break Beam at selected node point menu command.

54

Figure 7: Inverse the geometry selection

Figure 8: Break Beams at Selected Nodes menu command selected

55

21. Select the General->Spec control tab on the left. 22. Press the Beam button in the data area. 23. Select the Offset tab in the Member Specification dialog box. 24. Enter the inputs as shown in Figure 9. 25. Press the Add button. You will note that the START 0 0 0.-625 specification command will appear on the right hand side.

Figure 9: Member Start end offset

26. Press the Beam button in the data area. 27. Select the Offset tab in the Member Specification dialog box. 28. Enter the inputs as shown in Figure 10. 29. Press the Add button. You will note that the END 0 0 -0.625 specification command will appear on the right hand side.

56

Figure 10: Member End node offset

30. Select the member as shown in Figure 11. 31. Select the START 0 0 -0.625 specification command. Press the Assign button. 32. Select the End 0 0 -0.625 specification command. Press the Assign button.

Figure 11: Select the members

57

33. Click on View->Whole Structure menu command. 34. Select the View from +Z icon

.

35. Select the members as shown in Figure 12 by rubberbanding the top cord members.

Figure 12: Select the members

36. Select the Isometric View icon 37. Press and hold the Ctrl key on the keyboard and click on the members that need to be removed from the current selection as shown in Figure 13.

Figure 13: Unselect the members

38. Select the Geometry->Translational Repeat command. The 3D Repeat box will appear.

58

Figure 14: Translational Repeat Command

39. Select the Geometry->Translational Repeat command. Enter the parameters as shown in the 3D Repeat dialog box in Figure 15.

Figure 15: 3D Repeat Dialog box

40. Press the Ok button. The selected geometry will be copied to the other side of the bridge.

59

Figure 16: Members are missing

41. Node that in some instances STAAD may not copy two members between the same node points as illustrated in Figure 16. The user has to manually create these members using the draw beam from point-to-point menu command and apply the correct offsets. 42. The final bridge geometry is illustrated in Figure 17.

Figure 17: Final Bridge Geometry

60

Exercise 5: Physical Member Formation 1. Select the Select->Beams Parallel To->X axis menu command.

Figure 1: Select Beams Parallel to X Axis menu command

2. Select the Select->Beams Parallel To->X axis menu command. 3. Select the View->View Selected Objects Only menu command. 4. Select the View from +Z icon

.

5. Select the members as shown in Figure 2 by rubberbanding the top cord members.

Figure 2: Top chord members of bridge are selected

6. Select the View->New View menu command. 7. Click the Ok button. 8. Select the View from +Z icon

.

61

9. Select the members as shown in Figure 3 (i.e. plan view of top chord members) by rubberbanding the top cord members. (Just one side).

Figure 3: Select the members

10. Right click and select the Form Member option. 11. Select the members as shown in Figure 4 by rubberbanding the top cord members.

Figure 4: Select the members

12. Right click and select the Form Member option. 13. Repeat the above two steps for the remaining two member rows.

14. Select the Physical member cursor. 15. Click on a member. You will note that the entire Physical Member can be selected with a single click. 16. Click on the View->Whole Structure menu command.

62

Exercise 6: Truss Specification Creation and Assignment 1. Click on the General->Spec menu command. 2. Click on the Beam button. The Member Specification dialog box will appear as shown in Figure 1.

Figure 1: Select the members

3. Select the Truss tab in the Member Specification dialog box. 4. Press the Add button. 5. Select the Member Truss specification from the right hand side data area. 6. Select the View from +z icon (

).

7. Select the members as shown in Figure 2.

63

Figure 2: Select the members

8. Press the Assign button on the right hand side. 9. The Truss specification will appear in the graphics window.

Figure 3: Select the members

Note: Assigning too many releases may make the structure unstable. Pay close attention to how the beam elements will behave in the real structure and the type of connections that are provided at the joints. Always check the Statics Check in the post processing mode to make sure that the structure is in equilibrium for all load cases.

64

Exercise: Create the highlighted members using the tools that you have learned:

65

Exercise 7: Support Creation and Assignment 1. Select the General->Property control tab on the left. 2. Click on the Create button on the right hand side Data Area. The Create Support dialog box will appear.

Figure 1: Create Support dialog box

3. Click on the Pinned tab. 4. Click on the Add tab. 5. Select the S2 Support 2 entry in the data area. 6. View the structure from +Z using the ( 7. Select the nodes cursor(

) icon.

).

8. Rubberband the nodes at the base and assign the pinned supports.

66

Exercise 8: Property Creation and Assignment

Figure 1: Member Properties

1. Open the My Bridge_1.std file if you have not followed the previous exercises. 2. Click the General tab on the left. 3. Click on the Section Database button in the data area. 4. Select the Tube property item in the Section Profile Tables dialog box and provide the inputs as shown in Figure 2. Note: The unit converter can be launched by pressing the F2 key. If you enter 2 “ and press the enter key in the unit converter, the text box will display the dimension converted to the default unit system being used in your model. The space is required between the dimension and the unit for the unit converter. For example, 12in will not work but 12 in will work.

67

Figure 2: Property Definition

5. Click the Add button. 6. Provide the inputs as shown in Figure 3 in the Section Profile Tables dialog box.

Figure 3: Property Definition

7. Click the Add button. 8. Provide the inputs as shown in Figure 4 in the Section Profile Tables dialog box.

68

Figure 4: Property Definition

9. Click the Add button.

Figure 5: Property Definition

10. Select the inputs as shown in Figure 5. 11. Click the Add button. 12. Click the Close button. The property definitions should appear in the Properties dialog box in the Data Area.

69

Figure 6: Properties dialog box

13. Select the first tube property in the Properties dialog box in the Data Area. 14. Select the members as shown in Figure 7.

Figure 7: Member Selection

70

15. Select the Assign to Selected Beams assignment option in the Properties dialog box. 16. Click on the Assign button. The property reference number will appear in the graphics window. 17. Select the second tube property in the Properties dialog box in the Data Area. 18. Select the members as shown in Figure 8.

Figure 8: Member Selection

19. Click on the Assign button. The property reference number will appear in the graphics window. 20. Select the third tube property in the Properties dialog box in the Data Area. 21. Select the members as shown in Figure 9.

Figure 9: Member Selection

71

22. Click on the Assign button. The property reference number will appear in the graphics window. 23. Select the PIPS20 property in the Properties dialog box in the Data Area. 24. Select the members as shown in Figure 10.

Figure 10: Member Selection

25. Click on the Assign button. The property reference number will appear in the graphics window. 26. Click anywhere in the white space in the graphics window to get rid of the member selection. Right click in the Graphics Window and select the 3D Rendering. The rendered view of the structure will appear in a separate window as shown in Figure 11.

72

Figure 11: 3D Rendered View of the structure

Note: Standard AISC sections are available by clicking the Section Database button on the right. In the American Databases, Pipes and Tubes can be created using the Tubes and Pipes items in the Section Profile dialog box. The American section database can be modified by clicking on Tools->Modify Section Database menu command.

73

Exercise 9: Formation of Cantilever Section 1. Open the My Bridge_2 file if you have not followed Exercises 1 to 7. 2. Click on the view from positive z icon (

) to see an elevation view of the structure.

3. Click on the Geometry control tab on the left hand side of the screen. 4. Click on the Nodes cursor (

)

5. Select the node as shown in Figure 1. The information for the node point will be displayed on the right hand side Nodes Table.

Figure 1: Nodes table is displayed on the right

Make sure the X coordinate for that node point is close to 15ft but not less than 15 ft. Note the X node coordinate. In the case of this file, the node coordinate is 15.14 ft. 6. Draw a window on the node point as shown in Figure 2.

74

Figure 2: Draw a drag window to select multiple nodes

7. Select the View->View Selected Objects Only menu command. 8. Click the Isometric View (

) icon. Two nodes will appear in the graphics.

9. Select the first node using the Nodes cursor (

).

10. The information for the selected node will be displayed in the Nodes table on the right hand side. 11. Change the X coordinate of the selected node to 15 as shown in Figure 3. 12. Repeat this Step 11 for the other node.

75

Figure 3: Draw a drag window to select multiple nodes

13. Select the View->Whole Structure menu command.

Figure 4: Right hand side support beams are selected

14. The right supports need to be moved to x = 15 ft location from the x = 21 ft location. 15. You could select these right hand side supports and group them together. In the case of the My Bridge_2.std file, a right_support beam group has been created.

76

Figure 5: RIGHT_SUPPORT group name

16. Click on Select->By Group Name menu command. Select the Right_Support group name and you will note that the beams will be highlighted in the STAAD.Pro graphics window. 17. If you choose to move the supports by a distance of -6ft without moving the nodes to 15ft, you will note that additional nodes will be formed on the physical beams. The physical beams will have to be created again. Rather than doing this, we have manually moved the existing nodes near x=15 (i.e. could be x=15.19, 51.21) to x=15. 18. Right click in the STAAD.Pro graphics window and select the Move command. 19. The Move dialog box will appear. Type in -6 ft in the Move Entities dialog box as shown in Figure 6.

77

Figure 6: Move command

20. Click on the Ok button and click on the Ok button on the dialog box that will appear. Click on the Yes button. 21. The list of duplicate nodes will be displayed. Click on each entry and press the Merge>> followed by OK and OK buttons. 22. Click the Close button. 23. This operation will more the right support by 6 ft to the left and also merge the duplicate nodes for the user. 24. Select and delete the beams shown in Figure 7.

78

Figure 7: Members to be deleted

25. Click on Geometry->Add Beam->Add Beam by Perpendicular Intersection and create the beams as illustrated in Figure 8.

Figure 8: Members to be added

79

26. Select and delete the beams shown in Figure 9.

Figure 9: Delete Beams

27. Click on Geometry->Add Beam->Add Beam from Point to Point menu command. 28. Create the beams as shown in Figure 10.

Figure 10: Add Beams

80

29. Now that you have learned about property assignment, assign property reference 2 to the members highlighted in Figure 11.

Figure 11: Property Assignment

30. Assign property reference 1 to the members highlighted in Figure12.

81

. Figure 12: Property Assignment

82

Exercise 10: Creating Load Cases & Items 1. Open the My Bridge_3.std if you were not able to complete the previous exercises. 2. Click on the General->Loads & Definition control tab on the left. 3. Click on the Load Cases Details tree item on the right. Three load cases have to be created. 4. Click on the Add button in the Load & Definitions dialog box on the right. The Add New: Load Cases dialog box will appear as shown in Figure 1.

Figure 1: Add New: Load Cases dialog box

5. Enter L1=8.8 FT AND L2=1.1 FT in the Title text input box as shown in Figure 1. Press the Add button. 6. Press the Close button. We will now attempt to add the selfweight load 7. Select the L1=8.8 FT AND L2=1.1 FT title in the Load Cases Details tree item on the right. 8. The Add New: Load Items dialog box will appear as shown in Figure 2.

Figure 2: Selfweight Definition

9. Select the inputs as shown in Figure 2 and press the Add button.

83

10. As a result, the load item should have SELFWEIGHT Y -1 included. 11. Select the SELFWEIGHT Y -1 item and select the Assign to View option. 12. Press the Assign button. We will now attempt to add the test loads as distributed loads. 13. Select the L1=8.8 FT AND L2=1.1 FT title in the Load Cases Details tree item on the right. 14. Select the Toggle Physical Member mode as shown in Figure 3.

Figure 3: Selfweight Definition

15. Select the Add button in the Data Area. 16. Select the Physical Member Load->Uniform Load item in the Add New: Load Items dialog box.

Figure 4: Add New: Load Items dialog box

17. Input the parameters as shown in Figure 4. 18. Click the Add button. 19. Input the parameters as shown in Figure 5. 20. Click the Add button.

84

Figure 5: Add New: Load Items dialog box

21. Click the Close button. 22. Select the UNI GY -0.017 0 3 command in the data area. 23. Select the physical member cursor (

).

24. Rubberband the entire bridge structure. 25. The physical members will be highlighted as shown in Figure 6.

Figure 6: Physical beam members are highlighted

85

26. Select the Assign To View option and click the Assign button. 27. Select the UNI GY -0. 18 21 command in the data area. 28. Select the Assign To View option and click the Assign button. Due to a refreshing problem in STAAD.Pro, the loads may not appear as shown in Figure 7. Simply close and re-open the model to see the loads as shown in Figure 7. You will need to click on General control tab and then select Load Case Details-> L=0 VLT PRELOAD->UNY GY to see the loading.

Figure 7: Physical beam members are loaded

29. Create the other seventeen load cases as shown in Table 1 and Figure 8.

Figure 8: Seventeen more load cases are created

86

30. Click on the Load Cases Details tree item on the right. Three load cases have to be created. 31. Click on the Add button in the Load & Definitions dialog box on the right. 32. Enter Weight in the Title text input box. Press the Add button. 33. Press the Close button. We will now attempt to add the selfweight load 34. Select the Weight of the Structure title in the Load Cases Details tree item on the right. 35. The Add New: Load Items dialog box will appear. 36. Select the inputs as shown in Figure 2 and press the Add button. 37. As a result, the load item should have SELFWEIGHT Y -1 included. Select the SELFWEIGHT Y -1 command. 38. Select the Assign to View option. 39. Click the Assign button. Click the Ok button on the confirmation dialog box. 40. Click on the Load Cases Details tree item on the right. 41. Click on the Add button in the Load & Definitions dialog box on the right. 42. Enter Lateral Load in the Title text input box. Press the Add button. 43. Press the Close button. We will now attempt to add the selfweight load 44. Select the Lateral Load title in the Load Cases Details tree item on the right. 45. Click the Add button. 46. The Add New: Load Items dialog box will appear. 47. Select the inputs as shown in Figure 2 and press the Add button. 48. As a result, the load item should have SELFWEIGHT Y -1 included. Select the SELFWEIGHT Y -1 command. 49. Click the Assign button. Click the Ok button on the confirmation dialog box. 50. Select the Lateral Load title in the Load Cases Details tree item on the right. 51. Click the Add button. 52. The Add New: Load Items dialog box will appear.

87

53. Select the Physical Member Load->Uniform Load item in the Add New: Load Items dialog box.

Figure 9: Add New: Load Items dialog box

54. Input the parameters as shown in Figure 9. 55. Click the Add button. 56. Select the Physical Member Load->Concentrated Force item in the Add New: Load Items dialog box. 57. Input the parameters as shown in Figure 10. 58. Click the Add button. 59. Press the Close button. 60. Select the physical member cursor (

).

61. Select the UNI GY -0.0125 6.5 9.5 command in the data area in the last load case. 62. Select the Use Cursor to Assign option and click on the two physical beams as illustrated in Figure 11.

88

Figure 10: Add New: Load Items dialog box

Figure 11: Physical Beams to which loads have to be assigned using “Use Cursor to Assign” option

63. Select the physical member cursor (

).

64. Select the CON GZ -0.075 8 command in the data area in the last load case. 65. Select the Use Cursor to Assign option and click on the physical beam as illustrated in Figure 12.

89

Figure 12: Physical beam to which concentrated lateral load have to be assigned using “Use Cursor to Assign” option

90

Exercise 11: Performing Analysis 1. Open the My Bridge_4.std file if you did not follow the previous exercises. 2. Click on Analysis/Print control tab on the left. The Analysis/Print Commands dialog box will appear. 3. Select the All option in the Perform Analysis tab and press the Add button.

Figure 1: The Analysis/Print Commands dialog box

4. Click the Close button. 5. Click on Analyze->Run Analysis command. The STAAD Analysis and Design dialog box will appear. 6. You should not have zero errors in the STAAD Analysis and Design dialog box. 7. Select the Go To Post Processing Mode option button and click on the OK button.

91

Exercise 12: Understanding the Results 1. Open the My Bridge_5.std file if you have not followed the above exercises. Note: If you are not using the My Bridge_5.std file, you will have to create a group of beams that represent the cantilever bridge section. You may just call the beam group Cantilever. 2. Click on Analyze->Run Analysis command. The STAAD Analysis and Design dialog box will appear. 3. You should not have zero errors in the STAAD Analysis and Design dialog box. 4. Select the Go To Post Processing Mode option button and click on the OK button. 5. Select the Node->Displacement tab. The displacement of each and every node can be determined by simply clicking on a node point in the graphics window and looking at the displacement table on the right.

Figure 1: Displacements – Lateral Load Case

92

6. Click on the Summary tab in the Node Displacements table on the right. Note the Min Y displacement row. The Min Y displacement represents the max –ve displacement in the structure for all load cases. If you highlight the Min Y row, you will see the node with max –ve displacement highlighted in the graphics window.

Figure 2: Maximum Y Displacement

7. Let us say that the maximum displacement for the cantilever section is to be determined. The STAAD.Pro user can data filtering options provided with these tables. Right click on the Node Displacements table on the right. 8. Select Results Setup option. 9. Click on the Range tab. 10. Select the Group option. 11. Select G2:_Cantiliver as shown in Figure 3.

93

Figure 3: Results Setup

12. Click on the Ok button. 13. You will see that the Summary tab has now been updated. The max –ve displacement is now reported for the cantilever section of the bridge as shown in Figure 4.

Figure 4: Results Setup

94

14. Select the Node->Reactions tab. The support reaction of each and every support node can be determined by simply clicking on a node point in the graphics window and looking at the support reaction table on the right. Note: Make sure that the Difference row for each load case in the Statics Check Results window is close to zero. A non-zero value usually indicates instability in the structure. You may use the 0.99 MPX 0.99 MPY 0.99 MPZ at the joints to avoid using a completely released joint. Note that in this example, instability is reported at certain joints. For example, a joint at which four truss members are framing together and lie in the same plane. This problem can be solved by designing the connections to take moments, providing extra truss members connecting at that joint, or using partial moment release.

Figure 5: Support Reactions

15. Select the Beam->Forces tab. The bending moment diagram will be displayed. The user may turn on the deflection and loading diagrams using the icons.

95

Figure 6: Beam end and section forces

Figure 7: Moment, deflection and load diagram

96

16. The tables on the right show the forces for each beam member in the model. Right click on this table and select the Results Setup option. 17. You may specify which load case, member or group results need to be displayed.

Figure 8: Result sorting tool

18. Select the Beam->Stresses tab. The combined axial stress distribution diagram can be seen for any member.

97

Figure 9: Combined axial and bending stress distribution diagram

19. Select the Beam->Graphs tab. The moment, shear, and axial force diagram can be seen for any member.

98

Figure 10: Moment, shear, and axial force diagram

20. Click on the Modeling tab. 21. Right click in the graphical user interface and select Labels. Suppose you wanted to see the members that had a combined axial and bending stress of 500 psi. 22. Select the Force Limits tab and provide the inputs as shown in Figure 11. 23. Click on the Apply button. The beams shown in red in Figure 12 have exceeded the combined axial and bending stress of 500 psi. 24. This procedure can be used to find which members are exceeding say a 30 ksi criteria.

99

Figure 11: Force Limits

100

Figure 12: Combined axial and bending stress contour

Experiment with the model and try changing some of the truss connections to partial moment releases. Try changing the section sizes of the members.

101

Exercise 13: Design of the Structure using AISC 360-05 Note: STAAD.Pro cannot perform code checking on square prismatic steel sections defined in this model. The user could define a general section or create a tube section using the section database to perform the code checking as per the AISC 360-05 code. 1. Open the My Bridge_6.std file if you have not followed the exercise above. 2. Click on Design->Steel control tab on the left. 3. Select the AISC 360-05 code in the Current Code selection box in the data area. 4. Click the Define Parameters button in the data area. The Design Parameters dialog box will appear as shown in Figure 1. 5. Select the FYLD design parameter and enter and assign the yield strength of steel to be used for the bridge if not 36 ksi. In the case of this tutorial, the yield strength (i.e. 50 ksi) will be used. Input the value of 7200 kip/ft2 and press the Add button. 6. Select the Method parameter and select the LRFD code. 7. Click on the Add button. 8. Click on the Close button. 9. Assign the FYLD parameters to the view. 10. Click the Commands button. The Design Commands dialog box will appear. 11. Select the Check Code command and press the Add button 12. Assign the Check Code command to all members.

Figure 1: The Design Parameters dialog box

13. Click on Analyze->Run Analysis command. The STAAD Analysis and Design dialog box will appear.

102

14. You should not have zero errors in the STAAD Analysis and Design dialog box. 15. Select the Go To Post Processing Mode option button and click on the OK button. 16. In the Postprocessing mode->Beam->Unity Check, you will note the check code results as shown in Figure 2. 17. Right click in the graphics and select Labels->Design Results. 18. Uncheck the Show Values check box. 19. You may provide your own color coding in this dialog box. Any member over a unity/design ratio ratio of 1 will be colored in green by default. 20. Click the Ok button in the Diagrams dialog box.

103

Figure 2: Design results

21. The members shown in red and blue have failed. There are other design parameters that the user should look at. For example, look at the information provided in Appendix D of this manual. 22. You may have to check for the capacity of the connection using the AISC code. The following calculation can be used. Vr=s n m As Fu s = Factored shear resistance = 0.67 As = Cross section area of bolt = π/4 (d2) = π/4 (0.32) = 0.071 in2 n = Number of bolts = 2 m = Number of shear planes = 2 Ab = Cross section of bolt = 0.3 Fu = Bolt tensile strength = 150 kips/in2 Vr=0.67 x 2 x 2 x 0.071 x 150 = 28.5 kips Max Tension = 2 Kips (From STAAD.Pro) < 28.5 Kips

104

4.0 STAAD.Pro and Structural Modeler Integration The bridge frame could first be constructed and analyzed using STAAD.Pro. After the analysis and design has been finalized, the 3D model can be exported to Structural Modeler for drawing generation. Structural Modeler is an advanced drawing generation and 3D modeling software that will allow the engineer to generate floor plans, sections, and elevations using an existing STAAD.Pro model. The entire 3D model is stored in Structural Modeler along with the different elevations, plans, and sections that the user has requested. Structural Modeler also keeps track of materials, quantities, cost reports, and specifications, all automatically tracked within the design file. Plans, sections, elevations, bills of materials - all are stored or linked to the 3D model, so any changes made to the design file will automatically update the reports and drawings.

105

1. Launch Structural Modeler. 2. Set the User to Structural, Project to Structural_Imperial, and Interface to default.

3. A new Structural Modeler File. In the File Open dialog box, click the New File icon (

).

4. Select an appropriate folder and type the file name Bridge_Model. 5. Click on the Save button. 6. Select the Bridge Model.dgn file and click the Open button. The Structural Modeler GUI will open as shown in Figure 1. 7. Select the Settings->Design File menu command and set the Master Unit to Meters in the Working Units section. 8. Click the Ok button

Figure 1: Structural Modeler Graphical User Interface

106

Hint: You can change the background color from black to white using the Workspace>Preferences->View Options->Black Background -> White menu command. 9. Make sure that the Structural->Analytical Features menu command is checked on. 10. Import the bridge frame STAAD.Pro model into Structural Modeler using the Structural Analytical->Data Exchange->Analysis Import control tab on your left. 11. The Import From Analysis Program dialog box will appear as shown in Figure 2.

Figure 2: Import from Analysis Program dialog box.

Note the Map Section Names option in the Import from Analysis Program dialog box. This box contains a link to the mapping file for the AISC sections. AISC sections will most probably not be used for the bridges in constructed by most students. Hence, we will need to first create the section in the Structural Modeler Database and then create a mapping of the sections used in STAAD.Pro with the sections in Structural Modeler. The following directory will usually contain the section profiles: C:\Documents and Settings\All Users\Application Data\Bentley\MicroStation V8i (SELECTseries 1)\WorkSpace\TriForma\tf_imperial\data 12. The us.xml file is the one used the most. You could easily find the xml file used on your machine by simply clicking on Structural Physical->Steel Column –> Primary tab on the left. 13. The Place Steel Column dialog box will appear. As shown below.

107

Figure 3: Place Column dialog box.

14. Press the magnifying glass icon as shown above. The Structural Sections dialog box will appear as shown in Figure 4.

Figure 4: Section Database.

108

15. Select the File->Open menu command. The Section File Manager box will appear as shown below.

Figure 5: Section File Manager

16. Hoover your mouse cursor over the Section Files seen at the bottom of the dialog box and you will notice the name and location of the xml file being used for your installation. The *.xml version of a section file format is a true XML file. In XML files, commands are written as open and close statements. If a command is opened but not closed, it could keep the entire file from being usable. The following shows an example of lines in the us.xml file:

Figure 6: XML Text

109

You can see in this small section that the first line starts with Snap/Grid Node->Beam menu item.

Figure A1: Snap/Node Beam dialog box

3. Click on the Create button. 4. The Grid Definition dialog box will appear as shown in Figure A2.

121

Figure A2: Grid definition dialog box

5. Input the grid creation parameters as shown in Figure A2. 6. Click the Ok button. 7. The Linear entry will appear in the Snap/Node Beam dialog box. Check the Linear entry and you will notice that the linear grid will appear in the STAAD.Pro graphics window.

Figure A3: Grid Creation

122

8. Click the Snap/Node/Beam button and create the grillage of beams as shown in Figure A4.

Figure A4: Grid Creation

9. Click the Snap/Node/Beam button and create the grillage of beams as shown in Figure A4. 10. Select the Beams Cursor from the left hand side.

Figure A4: Beams Cursor

11. Select all the beams in the graphics window. Ctrl + A will select all the beams in the model. 12. Click on Geometry->Translational repeat command. The 3D Repeat dialog box will appear as shown in Figure A5.

123

Figure A5: 3D Repeat dialog box

13. Input the 3D Repeat parameters as shown in Figure A5. 14. Click the OK button. The bridge geometry will be created as shown in Figure A6.

Figure A6: Translational Repeat

15. Create the vertical diagonal members using the Geometry->Add Beam->Add Beam From Point to Point menu command.

124

Figure A7: Vertical diagonals created using the Geometry->Add Beams menu command

16. Click the Snap/Node/Beam button and create the grillage of beams as shown in Figure A4.

125

APPENDIX B

CREATING BRIDGE GEOMETRY USING STAAD.PRO V8I DXF IMPORT

126

1. Open MicroStation XM. 2. Open the DGN_Example.dgn file distributed with this tutorial.

Figure B1: Elliptical Base Bridge stick model constructed in MicroStation

3. Click on file File->Export->DGN, DWG, DXF. The Export File dialog box will appear as shown in Figure B2. 4. Select the dxf export option as shown in Figure B2.

127

Figure B2: The Export File dialog box in Microstation

5. Select an appropriate location to save the dxf file. Click the Save button. 6. Close MicroStation. 7. Launch STAAD.Pro by clicking on the Start->All Programs->STAAD.Pro V8i->STAAD.Pro icon. The STAAD.Pro V8i introduction screen will appear. 8. Click on the File->New menu command. The New dialog box will appear. 9. Provide the model options as shown in Figure B3.

Figure B3: The New Dialog box

128

10. Click on the Next button. The Where do you want to go Today? Dialog box will appear as shown in Figure B4. 11. Click on the Finish button. 12. The STAAD.Pro V8i user interface will appear as shown in Figure B5.

Figure B4: The Where do you want to go Today? dialog box

129

Figure B5: STAAD.Pro User Interface

13. Click on File->Import menu command. The Import dialog box will appear as shown in Figure B6.

Figure B6: The Import dialog box

14. Select the 3D DXF import option and click the Import button. 15. The Open dialog box will appear. Select the DGN_Example.dxf file which was created in Step 5. 16. Click on the Open button. The DXF Import dialog box will appear as shown in Figure B7.

130

Figure B7: The Import dialog box

17. Select the Y Up option. The Y Axis should be the axis of gravity in your STAAD.Pro models. 18. Click on the OK button. The Set Current Input Units box will appear. The MicroStation file was created using the foot unit system. Select Foot and KiloPound in the Set Current Input Units box and press the OK button. The bridge geometry will appear as shown in Figure B8.

Figure B7: The Import dialog box

131

Figure B8: Bridge Frame Imported from MicroStation

19. Delete the unwanted lines as highlighted in Red in Figure B8. The STAAD.Pro user must check if the imported model is ok from a structural analysis point of view. The Tools menu command is very useful for checking structural integrity of the imported stick model. For more information about dxf import/export please refer to the whitepaper on the following link: ftp://ftp2.bentley.com/dist/collateral/Web/Building/STAADPro/DXF_Import_into_STAAD_PRO.pdf 20. Click the Snap/Node/Beam button and create the grillage of beams as shown in Figure A4. 21. Select the Beams Cursor from the left hand side.

Figure B9: Beams Cursor

22. Select all the beams in the graphics window. Ctrl + A will select all the beams in the model. 23. Click on Geometry->Translational repeat command. The 3D Repeat dialog box will appear as shown in Figure B10.

132

Figure B10: 3D Repeat dialog box

24. Input the 3D Repeat parameters as shown in Figure B10. 25. Click the OK button. The bridge geometry will be created as shown in Figure B11.

Figure B11: Translational Repeat

133

APPENDIX C

STAAD.PRO INPUT COMMAND FILE

134

You may copy the following text into the STAAD.Pro editor to view this model in STAAD.Pro To Launch the STAAD.Pro editor click on Edit->Edit Input Command File menu command. Replace the text in the editor with the following text.

135

STAAD SPACE START JOB INFORMATION ENGINEER DATE 10-Sep-09 END JOB INFORMATION INPUT WIDTH 79 UNIT FEET KIP JOINT COORDINATES 1 0 0 0; 2 5.25 0 0; 3 10.5 0 0; 4 15.75 0 0; 5 21 0 0; 6 5.25 -1.67 0; 9 0 0 5; 10 5.25 0 5; 11 10.5 0 5; 12 15.75 0 5; 13 21 0 5; 14 5.25 -1.67 5; 21 0 -0.5 0; 22 15 -0.5 0; 23 0 -0.5 5; 24 15 -0.5 5; 25 0.25 -2.667 5.25; 26 0.0833333 -1.22233 5.08333; 27 0.166667 -1.94467 5.16667; 28 0.25 -2.667 4.75; 29 0.0833333 -1.22233 4.91667; 30 0.166667 -1.94467 4.83333; 31 -0.25 -2.667 4.75; 32 -0.0833333 -1.22233 4.91667; 33 -0.166667 -1.94467 4.83333; 34 -0.25 -2.667 5.25; 35 -0.0833333 -1.22233 5.08333; 36 -0.166667 -1.94467 5.16667; 37 0.0833333 -1.22233 0.0833333; 38 0.166667 -1.94467 0.166667; 39 0.25 -2.667 0.25; 40 0.25 -2.667 -0.25; 41 0.0833333 -1.22233 -0.0833333; 42 0.166667 -1.94467 -0.166667; 43 -0.25 -2.667 -0.25; 44 -0.0833333 -1.22233 -0.0833333; 45 -0.166667 -1.94467 -0.166667; 46 -0.25 -2.667 0.25; 47 -0.0833333 -1.22233 0.0833333; 48 -0.166667 -1.94467 0.166667; 49 15.0833 -1.22233 0.0833333; 50 15.1667 -1.94467 0.166667; 51 15.25 -2.667 0.25; 52 15.25 -2.667 -0.25; 53 15.0833 -1.22233 -0.0833333; 54 15.1667 -1.94467 -0.166667; 55 14.75 -2.667 -0.25; 56 14.9167 -1.22233 -0.0833333; 57 14.8333 -1.94467 -0.166667; 58 14.75 -2.667 0.25; 59 14.9167 -1.22233 0.0833333; 60 14.8333 -1.94467 0.166667; 61 15.0833 -1.22233 5.08333; 62 15.1667 -1.94467 5.16667; 63 15.25 -2.667 5.25; 64 15.25 -2.667 4.75; 65 15.0833 -1.22233 4.91667; 66 15.1667 -1.94467 4.83333; 67 14.75 -2.667 4.75; 68 14.9167 -1.22233 4.91667; 69 14.8333 -1.94467 4.83333; 70 14.75 -2.667 5.25;

136

71 14.9167 -1.22233 5.08333; 72 14.8333 -1.94467 5.16667; 73 1.57186 -0.5 5; 74 8.92814 -0.5 5; 75 12.0719 -0.5 5; 76 19.4281 -0.5 5; 77 5.25 -0.5 5; 78 15.75 -0.5 5; 79 10.5 -0.5 5; 80 2.625 0 5; 81 0.5 0 5; 82 2 0 5; 83 2.955 0 5; 84 3.605 0 5; 85 4.265 0 5; 86 4.925 0 5; 87 2.62186 -0.5 5; 88 3.27186 -0.5 5; 89 3.94186 -0.5 5; 90 4.59186 -0.5 5; 91 5.86 0 5; 92 7.09 0 5; 93 8.32 0 5; 94 8.93 0 5; 95 6.48 -0.5 5; 96 7.7 -0.5 5; 97 18.375 0 5; 98 19 0 5; 99 18.045 0 5; 100 17.395 0 5; 101 16.735 0 5; 102 16.075 0 5; 103 18.3781 -0.5 5; 104 17.7281 -0.5 5; 105 17.0581 -0.5 5; 106 16.4081 -0.5 5; 107 15 0 5; 108 13.91 0 5; 109 12.68 0 5; 110 12.07 0 5; 111 14.52 -0.5 5; 112 13.3 -0.5 5; 113 20.5 0 5; 114 1.57186 -0.500001 0; 115 8.92814 -0.500001 0; 116 12.0719 -0.500013 0; 117 19.4281 -0.500012 0; 118 5.25 -0.5 0; 119 15.75 -0.5 0; 120 10.5 -0.5 0; 121 2.625 0 0; 122 0.5 0 0; 123 2 0 0; 124 2.955 0 0; 125 3.605 0 0; 126 4.265 0 0; 127 4.925 0 0; 128 2.62186 -0.5 0; 129 3.27186 -0.5 0; 130 3.94186 -0.5 0; 131 4.59186 -0.5 0; 132 5.86 0 0; 133 7.09 0 0; 134 8.32 0 0; 135 8.93 0 0; 136 6.48 -0.5 0; 137 7.7 -0.5 0; 138 18.375 0 0; 139 19 0 0; 140 18.045 0 0; 141 17.395 0 0; 142 16.735 0 0; 143 16.075 0 0; 144 18.3781 -0.5 0; 145 17.7281 -0.5 0; 146 17.0581 -0.5 0; 147 16.4081 -0.5 0; 148 15 0 0; 149 13.91 0 0; 150 12.68 0 0; 151 12.07 0 0; 152 14.52 -0.5 0; 153 13.3 -0.5 0; 154 20.5 0 0; 155 0 0 2.5; 156 21 0 2.5; 157 0 0 0.5; 158 5.25 0 0.493827; 159 10.5 0 0.5; 160 15.75 0 0.5; 161 21 0 0.5; 162 0 0 4.5; 163 5.25 0 4.50617; 164 10.5 0 4.5; 165 15.75 0 4.5; 166 21 0 4.5; 167 15 0 0.5; 169 15 0 2.5; 171 15 0 4.5; 172 10.5 -1.67 5; 173 10.5 -1.67 0; MEMBER INCIDENCES 5 6 173; 7 1 114; 8 6 115; 9 3 116; 11 2 118; 12 4 119; 13 3 120; 14 9 81; 15 10 91; 16 11 110; 17 12 102; 18 14 172; 20 9 73; 21 14 74; 22 11 75; 24 10 77; 25 12 78; 26 11 79; 27 1 157; 28 2 158; 29 3 159; 30 4 160; 31 5 161; 35 1 21; 36 148 22; 37 9 23; 38 107 24; 43 23 26; 44 26 27; 45 27 25; 46 25 28; 47 26 29; 48 27 30; 49 23 29; 50 29 30; 51 30 28; 52 28 31; 53 29 32; 54 30 33; 55 23 32; 56 32 33; 57 33 31; 58 31 34; 59 32 35; 60 33 36; 61 23 35; 62 35 36;

137

63 36 34; 64 34 25; 65 35 26; 66 36 27; 67 21 37; 68 37 38; 69 38 39; 70 39 40; 71 37 41; 72 38 42; 73 21 41; 74 41 42; 75 42 40; 76 40 43; 77 41 44; 78 42 45; 79 21 44; 80 44 45; 81 45 43; 82 43 46; 83 44 47; 84 45 48; 85 21 47; 86 47 48; 87 48 46; 88 46 39; 89 47 37; 90 48 38; 91 22 49; 92 49 50; 93 50 51; 94 51 52; 95 49 53; 96 50 54; 97 22 53; 98 53 54; 99 54 52; 100 52 55; 101 53 56; 102 54 57; 103 22 56; 104 56 57; 105 57 55; 106 55 58; 107 56 59; 108 57 60; 109 22 59; 110 59 60; 111 60 58; 112 58 51; 113 59 49; 114 60 50; 115 24 61; 116 61 62; 117 62 63; 118 63 64; 119 61 65; 120 62 66; 121 24 65; 122 65 66; 123 66 64; 124 64 67; 125 65 68; 126 66 69; 127 24 68; 128 68 69; 129 69 67; 130 67 70; 131 68 71; 132 69 72; 133 24 71; 134 71 72; 135 72 70; 136 70 63; 137 71 61; 138 72 62; 140 73 14; 141 74 11; 143 76 13; 144 77 14; 148 78 106; 149 75 112; 150 79 75; 151 74 79; 152 77 95; 153 73 87; 154 80 83; 155 81 82; 156 82 80; 157 83 84; 158 84 85; 159 85 86; 160 86 10; 161 87 88; 162 88 89; 163 89 90; 164 90 77; 165 73 82; 166 82 87; 167 87 83; 168 83 88; 169 88 84; 170 84 89; 171 89 85; 172 85 90; 173 90 86; 174 86 77; 175 80 87; 176 91 92; 177 92 93; 178 93 94; 179 94 11; 180 95 96; 181 96 74; 182 77 91; 183 91 95; 184 95 92; 185 92 96; 186 96 93; 187 93 74; 188 74 94; 189 97 98; 190 98 113; 191 99 97; 192 100 99; 193 101 100; 194 102 101; 195 103 76; 196 104 103; 197 105 104; 198 106 105; 199 107 12; 200 108 107; 201 109 108; 202 110 109; 203 111 24; 204 112 111; 205 76 98; 206 98 103; 207 103 99; 208 99 104; 209 104 100; 210 100 105; 211 105 101; 212 101 106; 213 106 102; 214 102 78; 215 97 103; 216 78 107; 218 111 108; 219 108 112; 220 112 109; 221 109 75; 222 75 110; 223 113 13; 224 9 81; 225 10 91; 226 11 110; 227 12 102; 228 80 83; 229 81 82; 230 82 80; 231 83 84; 232 84 85; 233 85 86; 234 86 10; 235 91 92; 236 92 93; 237 93 94; 238 94 11; 239 97 98; 240 98 113; 241 99 97; 242 100 99; 243 101 100; 244 102 101; 245 107 12; 246 108 107; 247 109 108; 248 110 109; 249 113 13; 250 114 6; 251 115 3; 253 117 5; 254 118 6; 257 1 122; 258 2 132; 259 3 151; 260 4 143; 261 119 147; 262 116 153; 263 120 116; 264 115 120; 265 118 136; 266 114 128; 267 121 124; 268 122 123; 269 123 121; 270 124 125; 271 125 126; 272 126 127; 273 127 2; 274 128 129; 275 129 130; 276 130 131;

138

277 131 118; 278 114 123; 279 123 128; 280 128 124; 281 124 129; 282 129 125; 283 125 130; 284 130 126; 285 126 131; 286 131 127; 287 127 118; 288 121 128; 289 132 133; 290 133 134; 291 134 135; 292 135 3; 293 136 137; 294 137 115; 295 118 132; 296 132 136; 297 136 133; 298 133 137; 299 137 134; 300 134 115; 301 115 135; 302 138 139; 303 139 154; 304 140 138; 305 141 140; 306 142 141; 307 143 142; 308 144 117; 309 145 144; 310 146 145; 311 147 146; 312 148 4; 313 149 148; 314 150 149; 315 151 150; 316 152 22; 317 153 152; 318 117 139; 319 139 144; 320 144 140; 321 140 145; 322 145 141; 323 141 146; 324 146 142; 325 142 147; 326 147 143; 327 143 119; 328 138 144; 329 119 148; 331 152 149; 332 149 153; 333 153 150; 334 150 116; 335 116 151; 336 154 5; 337 121 124; 338 122 123; 339 123 121; 340 124 125; 341 125 126; 342 126 127; 343 132 133; 344 133 134; 345 134 135; 346 138 139; 347 139 154; 348 140 138; 349 141 140; 350 142 141; 351 143 142; 352 149 148; 353 150 149; 354 151 150; 355 1 122; 356 127 2; 357 2 132; 358 135 3; 359 3 151; 360 154 5; 361 148 4; 362 4 143; 363 21 23; 364 122 81; 365 154 113; 366 22 24; 367 155 162; 368 156 166; 369 122 155; 370 155 81; 371 23 155; 372 155 21; 373 154 156; 374 156 113; 375 24 169; 376 169 22; 377 118 77; 378 120 79; 379 119 78; 380 157 155; 381 122 157; 382 21 157; 383 158 163; 384 118 158; 385 159 164; 386 160 165; 387 161 156; 388 120 159; 389 119 160; 390 22 167; 391 154 161; 392 162 9; 393 163 10; 394 164 11; 395 165 12; 396 166 13; 397 81 162; 398 23 162; 399 77 163; 400 79 164; 401 78 165; 402 24 171; 403 113 166; 405 107 111; 407 148 152; 408 22 119; 409 24 78; 411 79 172; 413 120 173; 414 172 24; 415 173 22; 416 148 167; 417 167 169; 418 169 171; 419 171 107; 420 4 169; 421 169 12; DEFINE PMEMBER 14 155 156 154 157 TO 160 15 176 TO 179 16 202 201 200 199 17 194 193 192 191 189 190 223 PMEMBER 1 224 229 230 228 231 TO 234 225 235 TO 238 226 248 247 246 245 227 244 243 242 241 239 240 249 PMEMBER 2 355 268 269 267 270 TO 272 356 357 289 TO 291 358 359 315 314 313 361 362 -

139

307 306 305 304 302 303 360 PMEMBER 3 257 338 339 337 340 TO 342 273 258 343 TO 345 292 259 354 353 352 312 260 351 350 349 348 346 347 336 PMEMBER 4 START GROUP DEFINITION MEMBER _RIGHT_SUPPORT 36 38 91 TO 138 366 375 376 390 402 _CANTILIVER 12 17 25 30 31 143 148 189 TO 199 205 TO 216 223 227 239 TO 245 249 253 260 261 302 TO 312 318 TO 329 336 346 TO 351 360 TO 362 365 368 373 374 379 386 387 389 391 395 396 401 403 408 409 420 421 JOINT END GROUP DEFINITION MEMBER OFFSET 14 TO 17 154 TO 160 176 TO 179 189 TO 194 199 TO 202 223 267 TO 272 289 TO 291 302 TO 307 313 TO 315 355 TO 362 START 0 0 0.0625 14 TO 17 154 TO 160 176 TO 179 189 TO 194 199 TO 202 223 267 TO 272 289 TO 291 302 TO 307 313 TO 315 355 TO 362 END 0 0 0.0625 28 224 TO 249 257 TO 260 273 292 312 336 TO 354 START 0 0 -0.0625 224 TO 249 257 TO 260 273 292 312 336 TO 354 END 0 0 -0.0625 28 END 0 0 -0.0563272 383 START 0 0 -0.0563272 DEFINE MATERIAL START ISOTROPIC STEEL E 4.176e+006 POISSON 0.3 DENSITY 0.489024 ALPHA 6e-006 DAMP 0.03 ISOTROPIC CONCRETE E 453600 POISSON 0.17

140

DENSITY 0.150336 ALPHA 5e-006 DAMP 0.05 END DEFINE MATERIAL MEMBER PROPERTY AMERICAN 9 11 TO 17 22 24 TO 26 141 148 TO 216 218 TO 249 251 257 TO 329 331 TO 362 369 TO 376 381 382 384 388 TO 391 397 TO 403 405 407 TO 409 420 421 TABLE ST TUBE TH 0.002917 WT 0.041667 DT 0.041667 5 8 18 21 27 TO 31 43 TO 138 140 144 250 254 363 TO 368 377 TO 380 383 385 386 TO 387 392 TO 396 411 413 TO 418 419 TABLE ST TUBE TH 0.002917 WT 0.083333 DT 0.083333 7 20 143 253 TABLE ST TUBE TH 0.002917 WT 0.125 DT 0.125 35 TO 38 TABLE ST PIPS20 CONSTANTS MATERIAL STEEL ALL SUPPORTS 25 28 31 34 39 40 43 46 51 52 55 58 63 64 67 70 PINNED MEMBER RELEASE 7 TO 9 13 20 TO 22 26 140 141 143 144 250 251 253 254 START MPX 0.99 MPY 0.99 MPZ 0.99 7 TO 9 13 20 TO 22 26 140 141 143 144 250 251 253 254 END MPX 0.99 MPY 0.99 MPZ 0.99 LOAD 1 LOADTYPE None

TITLE L=0 VLT PRELOAD

SELFWEIGHT Y -1 PMEMBER LOAD 1 TO 4 UNI GY -0.017 0 3 1 TO 4 UNI GY -0.0042 18 21 LOAD 2 LOADTYPE None

TITLE L=0 VLT STEP 1

SELFWEIGHT Y -1 PMEMBER LOAD

141

1 TO 4 UNI GY -0.15 0 3 1 TO 4 UNI GY -0.0042 18 21 *** LOAD 3 LOADTYPE None

TITLE L=0 VLT STEP 2

SELFWEIGHT Y -1 PMEMBER LOAD 1 TO 4 UNI GY -0.15 0 3 1 TO 4 UNI GY -0.0058 18 21 *** LOAD 4 LOADTYPE None

TITLE L=3 VLT PRELOAD

SELFWEIGHT Y -1 PMEMBER LOAD 1 TO 4 UNI GY -0.104166 3 6 1 TO 4 UNI GY -0.0042 18 21 *** LOAD 5 LOADTYPE None

TITLE L=3 VLT STEP 1

SELFWEIGHT Y -1 PMEMBER LOAD 1 TO 4 UNI GY -0.15 3 6 1 TO 4 UNI GY -0.0042 18 21 *** LOAD 6 LOADTYPE None

TITLE L=3 VLT STEP 2

SELFWEIGHT Y -1 PMEMBER LOAD 1 TO 4 UNI GY -0.15 3 6 1 TO 4 UNI GY -0.0058 18 21 *** LOAD 7 LOADTYPE None

TITLE L=6 VLT PRELOAD

SELFWEIGHT Y -1 PMEMBER LOAD

142

1 TO 4 UNI GY -0.104166 6 9 1 TO 4 UNI GY -0.0042 18 21 *** LOAD 8 LOADTYPE None

TITLE L=6 VLT STEP 1

SELFWEIGHT Y -1 PMEMBER LOAD 1 TO 4 UNI GY -0.15 6 9 1 TO 4 UNI GY -0.0042 18 21 *** LOAD 9 LOADTYPE None

TITLE L=6 VLT STEP 2

SELFWEIGHT Y -1 PMEMBER LOAD 1 TO 4 UNI GY -0.15 6 9 1 TO 4 UNI GY -0.0058 18 21 *** LOAD 10 LOADTYPE None

TITLE L=7 VLT PRELOAD

SELFWEIGHT Y -1 PMEMBER LOAD 1 TO 4 UNI GY -0.104166 7 10 1 TO 4 UNI GY -0.0042 18 21 *** LOAD 11 LOADTYPE None

TITLE L=7 VLT STEP 1

SELFWEIGHT Y -1 PMEMBER LOAD 1 TO 4 UNI GY -0.15 7 10 1 TO 4 UNI GY -0.0042 18 21 *** LOAD 12 LOADTYPE None

TITLE L=7 VLT STEP 2

SELFWEIGHT Y -1 PMEMBER LOAD

143

1 TO 4 UNI GY -0.15 7 10 1 TO 4 UNI GY -0.0058 18 21 *** LOAD 13 LOADTYPE None

TITLE L=9 VLT PRELOAD

SELFWEIGHT Y -1 PMEMBER LOAD 1 TO 4 UNI GY -0.104166 7 10 1 TO 4 UNI GY -0.0042 18 21 *** LOAD 14 LOADTYPE None

TITLE L=9 VLT STEP 1

SELFWEIGHT Y -1 PMEMBER LOAD 1 TO 4 UNI GY -0.15 9 12 1 TO 4 UNI GY -0.0042 18 21 *** LOAD 15 LOADTYPE None

TITLE L=9 VLT STEP 2

SELFWEIGHT Y -1 PMEMBER LOAD 1 TO 4 UNI GY -0.15 9 12 1 TO 4 UNI GY -0.0058 18 21 *** LOAD 16 LOADTYPE None

TITLE L=12 VLT PRELOAD

SELFWEIGHT Y -1 PMEMBER LOAD 1 TO 4 UNI GY -0.104166 12 15 1 TO 4 UNI GY -0.0042 18 21 *** LOAD 17 LOADTYPE None

TITLE L=12 VLT STEP 1

SELFWEIGHT Y -1 PMEMBER LOAD

144

1 TO 4 UNI GY -0.15 12 15 1 TO 4 UNI GY -0.0042 18 21 *** LOAD 18 LOADTYPE None

TITLE L=12 VLT STEP 2

SELFWEIGHT Y -1 PMEMBER LOAD 1 TO 4 UNI GY -0.15 12 15 1 TO 4 UNI GY -0.0058 18 21 *** LOAD 19 LOADTYPE None

TITLE WEIGHT

SELFWEIGHT Y -1 *** LOAD 20 LOADTYPE None

TITLE LATERAL LOAD

SELFWEIGHT Y -1 PMEMBER LOAD 3 4 UNI GY -0.0125 6.5 9.5 1 CON GZ 0.075 8 PERFORM ANALYSIS PRINT ALL PARAMETER 1 CODE AISC UNIFIED FYLD 7200 ALL METHOD LRFD CHECK CODE ALL FINISH

145

APPENDIX D

SPECIFYING PROPER SLENDERNESS LENGTHS IN STAAD.PRO

146

1.0 Introduction STAAD.Pro is a general purpose structural analysis and design tool. The structural engineer may also first create the steel frame models in STAAD.Pro and design then design the steel frames using the appropriate loading and codes. The purpose of this document is to demonstrate the use of the LY and LZ design parameters in STAAD.Pro.

147

2.0 Slenderness Lengths Following figure shows four identical members attached to a steel frame. One of t he bays has secondary beam s (i.e. the rear bay). The re maining two bays have secondary beam s but the engineer did not model those intermediate beams in this model (e.g. bay at the front).

Figure 1: Steel tubes (Identical Members) attached to a steel frame There is no force directly applied to the identical members. The structure is symmetric and loads are symmetric also. One would expect either all the four members to pass or all four to fail.

Figure 2: Code Check results 148

The engineer perform ed a code check using the AISC 360-05 code on the entire fra me and obtained the results shown in Figure 2. Note that two of the four identical members at the f ront fail with a design ratio of 1.14. Th e two identical m embers at the re ar end of the structure have very low unity ratios. The beams at the front failed in STAAD.Pro due to slenderness limitations and effective length or Section E2 of the AISC 360-05 code. Let us look at the results for the front identical member. *

40

ST

TUB20203

(AISC SECTIONS) FAIL Clause E2 1.143 1 0.22 C 0.00 0.01 14.14 |-----------------------------------------------------------------------------| | SECTION CLASS: CB: 0.000 | | SLENDERNESS CHECK: ACTUAL RATIO: 228.59 ALLOWABLE RATIO: 200.00 | | SECTION CAPACITIES: (UNIT - KIP FEET) | | AX.TENS: 0.00E+00 COMPRESS:0.00E+00 TORSION: 0.00E+00 | | BEND. Z: 0.00E+00 BEND. Y: 0.00E+00 SHEAR Z: 0.00E+00 SHEAR Y: 0.00E+00 | |-----------------------------------------------------------------------------| | SECTION PROPERTIES: (UNIT - FEET) | | AXX: 0.01 AYY: 0.01 AZZ: 0.01 RZZ: 0.06 RYY: 0.06 | | SZZ: 0.00 SYY: 0.00 | |-----------------------------------------------------------------------------| | PARAMETER: (UNIT - KIP FEET) | | KL/R-Z: 228.59 KL/R-Y: 228.59 UNL: 4.7 CB: 0.00 FYLD: 5184.00 | | FU: 8352.00 NET SECTION FACTOR: 1.00 SHEAR LAG FACTOR: 1.00 STP: 1 | | DFF: 0.00 dff: 23.00 | |-----------------------------------------------------------------------------| | CRITICAL LOADS FOR EACH CLAUSE CHECK (UNITS KIP -FEET) | | CLAUSE RATIO LOAD FX VY VZ MZ MY | | Cl.D2 0.000 0 0.00E+00 | | Cl.E 0.000 0 0.00E+00 | | Cl.F-Major 0.000 0 0.00E+00 | | Cl.F-Minor 0.000 0 0.00E+00 | | Cl.H1/H2 0.000 0 0.00 0.00E+00 0.00E+00 | | Cl.G-Major 0.000 0 0.00E+00 | | Cl.G-Minor 0.000 0 0.00E+00 | | Cl.H3 0.000 0 0.00E+00 0.00E+00 0.00E+00 0.00E+00 0.00E+00 | |-----------------------------------------------------------------------------| ERROR : CALCULATED SLENDERNESS RATIO EXCEEDS ALLOWABLE LIMIT.

The beams at the fron t should have passed but faile d due to slenderness because the KL/r of the beam exceeds the allowable slenderness value of 200. The slenderness length (i.e. Lx in KLx/rx or Lz in KLz/rz) value is the member length in STAAD.Pro by default. Engineers have to check if the member length is the slende rness length based on how the structure has been modeled. In this case, the two identical members at the rear end of the st ructure have a LZ and LY of 4.71 ft. Using the infor mation presented in F igure 3 belo w, the slenderness length m ay be 4.71 for LY but LZ should be 14.14 ft. This is because there is no restraint along the Local Y axis.

149

Figure 3: Lz or Slenderness length about local z axis (out of the plane of the slope) In the case of the two identical beams at the front, you will note that we have not modeled the secondary beams. In this case, the LY (Slenderness length about the local Y axis as shown in Figure 5) should be set to 4.17 ft.

150

Figure 4: Slenderness lengths can be specified in STAAD.Pro as Design Parameters

Figure 5: Ly or Slenderness length about local y axis (in the plane of the slope)

151

After implementing these changes, you will note that the four identical beams have identical design ratios of 1.14.

Figure 6: Updated Code Check results The user may use STAAD.Pro’s Interactive Steel Designer to estimate the values of LX, LY, and LZ, however engineering judgment is required in this case also. Figure 7 shows how the LY and LZ calculated by the Interactive Steel Designer may not be correct. The LY for physical members M3 and M4 should be 4.71 ft.

152

Figure 7: Formation of Physical Members in STAAD.Pro

153

APPENDIX E DATASET INSTALLATION

154

Dataset Installation: Attached is the “Structural Analysis, Design, And Drawing Production” docum ent prepared for participants of this year’s AISC 2013 Student S teel Bridge Com petition. This year datas et zip file “STUDENT_STEEL_BRIDGE_COMPETI TION_2013_DATASETS_BENTLEY.zip” is also distributed with the manual. The manual has thirteen step-by-step exercises. 1. Unzip the contents of the zip file to a location on your computer (e.g. c:\training). You could use winzip to see/unzip the contents or you could simply right click on the file and click on explore. 2. Let us assume that you right click on the file and select Explore. Windows Explorer will appear as shown below.

3. Copy the folder inside the zip file to a safe location on your machine. 4. The STUDENT_STEEL_BRIDGE_COMPETITION_2013_DATASETS_BENTLEY folder contains three sub-folders. i ii

Microstation – Contains a dxf file for Appendix A STAAD.Pro – Contains nine STAAD.Pro models. My Bridge_1.std which contains results of following Ex. 1 to 7 in the m This file can be used for Ex. 8.

anual.

My Bridge_2.std which contains results of following Ex. 1 to 8 in the m This file can be used for Ex. 9.

anual.

My Bridge_3.std which contains results of following Ex. 1 to 9 in the m This file can be used for Ex. 10.

anual.

My Bridge_4.std which contains results of following Ex. 1 to 10 in the m anual. This file can be used for Ex. 11. My Bridge_5.std which contains results of following Ex. 1 to 11 in the m anual. This file can be used for Ex. 12. 155

My Bridge_6.std which contains results of following Ex. 1 to 12 in the m anual. This file can be used for Ex. 13. My Bridge_7.std which contains results of following Ex. 1 to 13 in the m anual. This file can be used for Section 4.0. This file has been provided so that the user can experiment with STAAD/Structural Model Integration. My Bridge_8.std which contains results of following Ex. 1 to 13 in the m anual. This file can be used for Section 4.0. This file has been provided m odified for STAAD/Structural Mod el Integ ration. Th e properties were renam ed for proper mapping and loadings were removed.

iii

My Bridge_9.std which contains results of following Ex. 1 to 13 in the m anual. This file can be used for Section 4.0. This file has been provided m odified for STAAD/Structural Mod el Integ ration. Th e properties were renam ed for proper mapping and loadings were removed. Th is f ile is ju st a backu p of My Bridge_8.std file. The My Bridge_8.std may get m odified after the first im port (i.e. additional groups will be created for des ign history reasons). If you would like to get to the unm odified version of My Bridge_8.std you m ay open My Bridge_9.std. Structural Modeler bridge_mapping_file.txt – Mapping file used in Section 4.0 Bridge_Model.dgn – S tructural Modeler file that was created using the STAAD.Pro file in Section 4.0. StructuralShapesTemplate-2.xls – The MS Excel file modified in Section 4.0 and is used to define custom shapes in Structural Modeler.

156