Session 9 Guardrail Attachments to Bridge Ends

1. Session 9Guardrail Attachments to Bridge Ends

2. Common Deficiencies in Bridge Railings • Inadequate Dynamic Strength • Potential for Snagging • Use of “Safety” Walk • Inadequate Transition

3. Transitions • Guardrail Deflects – Bridge Ends DONOT!! • Bridge End Connections are an example of a change in the type of Barrier Deflection Characteristics • Must Reduce the Deflection of the Guardrail before you reach the Bridge End from 3’ to Zero • Must have adequate Structural Connection

4. Transition Considerations • Adequate structural connection to the bridge railing • Reduced post spacing and nested rail to increase stiffness gradually • Block outs and rub rails used to minimize snagging

5. How can you REDUCE DEFLECTION of Standard Strong Post W-Beam Guardrail • Normal Guardrail Post Spacing is 6’3” • Reduce Post Spacing to 3’ 1½” and reduce deflection by 50% • Nest the Guardrail (double thickness) and reduce deflection by 50% • Add a Guardrail panel to the back of the Post and reduce deflection by 50% • Add a Rub Rail and reduce deflection by nearly 50% & reduce snagging potential • Combine 2 of the above and reduce deflection by 75%

6. How can you REDUCE DEFLECTION of Standard Strong Post W-Beam Guardrail Reduced Post Spacing Nested

7. Gradually Increase Stiffness by Increasing the number of Post

8. Rub Rail Components - Std Draw RBC-001 002 & 003 “Guardrail Connection to Bridge End Type A and A-1 Components” Rub Rail Not Island Curb Rub Rail

9. Standard Drawing RBC-001Guardrail Connector to Bridge End Type A and A-1

10. Inadequate Structural Connection or Stiffening of Approach Rail

11. Adequate Structural Connection Terminal Sect No 2 Plate A & B

12. Inadequate Reduction in Deflection and Structural Connection

13. Transition of Curb and Rub Rail to Bridge’s Safety Shape

14. Addition of a Spacer Tube

15. Combination of all of the Proceeding for a Successful Transition

16. Std Draw RBC-001 Guardrail Connection to Bridge End Type A and A-1

17. Curb Inlet Type BShould have Island Curb in Throat of the Inlet • Std Draw RBC-001 Note 5 “Island Curb” • Std Draw RBD-280 “Match Adjacent Curb”

18. Curb Inlet Type BShould have Island Curb in Throat of the Inlet • Lt Std Draw RBD-280 Curb Box Inlet Type B (Detail Drawing) “Match Adjacent Curb” • Rt Std Draw RDB-281 Curb Box Inlet Type B (Steel Drawing) "Island Curb Detail”

19. Type B Drainage Box As-Builts vs. Std Draw Construction memo No 5-11July 6, 2011 • Have not been getting Island Curb on Type B Inlet therefore a Const Memo was Issued • See Std Draw RBC-001, RBD-280, RBD-281 Previous Slides • Corrective Actions: • Retrofit by extending the double ply rail from 25 linear feet to 50 linear feet • Replace the drain box top with the correct one

20. Std Draw RDB-280 Curb Box Inlet Type B 2012 Design Changed Detail to Show Island Curb instead of Std Curb Changed to Island Curb

21. Normally getting Standard Curb instead of Island Curb

22. What makes this a good Guardrail Connection to Bridge End? Q & A Time