1. Steel and Reinforced Concrete
MERLIN-DASH
Design and Analysis of
Steel and Reinforced Concrete
Straight Highway
Bridge Systems

2. MERLIN-DASH Development
Began in 1975
Cooperative effort between Maryland State Highway & University of Maryland
Basic program completed in 1978
Microcomputer version in 1985
FHWA DP-81 began in 1988
SI version in 1994
WINDOWS version in 1995
LRFD version in 1996
WINDOWS/NT & Network version in 1997

4. FHWA DP-81 SHORT COURSE HOST STATES

5. MERLIN-DASH Program Functions
Steel & Reinforced Concrete
English & SI Units
DL, SDL & LL + I
WSD, LFD & LRFD
Analysis, Design, Code Checking, Rating & Staging

6. MERLIN-DASH Banner Page

7. MERLIN-DASH Input Utility

8. MERLIN-DASH Input Verification

9. MERLIN-DASH Execution Utility

10. MERLIN-DASH Graphic Utility

11. MERLIN-DASH Print Utility

12. New Alternations in LRFD
New Dynamic Load Allowance
New Distribution Factors
New HL-93 Truck
New Limit States
New Load Combinations
New Fatigue Consideration
New LRFD Specifications
New Design Considerations
New Rating

13. Auto Generation of LRFD New Distribution Factors
By Force: Moment & Shear
By Geometry: Skewed & Non-skewed
By Zoning: Positive & Negative Moment Areas
By Limit State: Strength & Fatigue Limit States

14. LRFD Limit States Strength I rp1DC + rp2DW + 1.75(LL + I)
Strength II rp1DC + rp2DW (LL + I)
Strength IV rp3(DC + DW)
rp1 = , rp2 = , rp3= 1.5

15. LRFD Limit States (cont.)
Service I (DC + DW) + (LL + I)
Service II (DC + DW) + 1.3(LL + I)
Fatigue (LL + I)

16. DASH Code Check Output Web Depth and Thickness Ratio Strength Category
Strength Bending Capacity
Strength Shear Capacity
Serviceability
Fatigue
Shear Connector (Fatigue)
Shear Connector (Strength)
Splice Design