1. ENCE466 Design and Analysis of Straight Highway Bridges Tutorial (for Steel Bridges)
C. C. Fu, Ph.D., P.E.
The BEST Center
Department of Civil & Environ. Engineering
University of Maryland
2010

2. Figure 1: Typical Bridge Cross Section
DASH Input for Example 2
Figure 1: Typical Bridge Cross Section

3. Bridge and Roadway Alignment

4. Bridge Superstructure Design

5. Bridge Substructure Design

6. Design Guidelines (1)

7. Design Guidelines (2)

8. DASH Input for Example 2 Span interval can be any numbers from 4-20
4 modes: Steel Composite & Noncomposite, RC & PC
8 modes for steel

9. DASH Input for Example 2
Position will affect the Effective Width and Distribution Factor
Haunch will affect the section properties and weight
% of composite will affect the moment distribution
Detailed factor applied to steel section only

10. DASH Input for Example 2
Figure 2: Framing Plan

11. Distance between centerlines of bearings
DASH Input for Example 2
Distance between centerlines of bearings

12. Spacing is required for Distribution Factor and DL calculation
DASH Input for Example 2
Spacing is required for Distribution Factor and DL calculation

13. DASH Input for Example 2
Figure 3: Elevation of Interior Girder

14. 2 unique PG sections are defined
DASH Input for Example 2
2 unique PG sections are defined

15. DASH Input for Example 2
Members are defined from left to right in an ascending order
These 3 entries are for non-prismatic members
These 3 entries are for hybrid members

16. DASH Input for Example 2 HL-93 or HS loading from 1 to 99
If =2 proportional to the HS loading
For fatigue use

17. DASH Input for Example 2
If not a staging case, slab loads have to be defined span by span or total span length.
For a staging case, slab distances can be arbitrary.
Pouring no. & Day are used for staging

18. Not for hybrid sections
DASH Input for Example 2
For the proper calculation of moment capacity, distance has to be equally divided by the lateral bracing spacing
Not for hybrid sections

19. MERLIN-DASH Execution Utility

20. Case Study: Bulb-Tee (BT-72), Single Span, Composite Deck, based on Standard Specifications
Bridge Cross Section (Ref. PCI Bridge Design Manual Example 9-3)

21. Structural Details (03012)
Position will affect the Effective Width and Distribution Factor
Haunch will affect the section properties and weight
These two entries are used for steel girder only

22. Span Lengths (03062)
For single span, only input for Span Length (2) and Overhangs (1&3)

23. Beam Spacing (03042)
Spacing is required for Distribution Factor and DL calculation

24. AASHTO-PCI-BT-72 Bulb-Tee
Internally Stored Girder Sections in Win-DASH/P:
AASHTO I – VI
Bulb Tee BT-54, 63, & 72

25. PC Section (04012)
ID 0 is for internally stored AASHTO Girder. 72 is for BT-72

26. Composite Section (calculated by Win-DASH/P)

27. Strand Pattern (Ref. PCI Bridge Design Manual)

28. Longitudinal Strand Profile (Ref. PCI Bridge Design Manual)

29. Member and Tendon Geometry (05032)
Lines 1-4 are for straight tendons input by rows.
Line 5 is for draped tendons input by groups where distance refers to the C.G. of the group

30. Arbitrary Uniform and Concentrated Loads (11012)
SDL for wearing surface

31. Auto Generation of Dead and Superimposed Dead Loads (02012)
Slab thickness for section property calculation and slab + integral wearing surface for DL calculation

32. Alternate Input of Slab Loads (10012)
Slab thickness for section property calculation and intensity based on slab + integral wearing surface for DL

33. Slab Information (12034)

34. Precast Beam Information (12036)
fc’ at 28 days is for service condition.
fc’ at release is for initial condition

35. Prestressing Steel Properties (04032)
fsi=0.75fs’ is used in this example
If leaving blanks, losses will be calculated by the program based on the AASHTO