Session 9 Guardrail Connections to Bridge Ends

Common Deficiencies in Bridge Railings Inadequate Dynamic Strength Potential for Snagging Use of “Safety” Walk Inadequate Transition 13-2

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

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

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%

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

Gradually Increase Stiffness by Increasing the number of Post 13-7

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

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

Inadequate Structural Connection or Stiffening of Approach Rail

Adequate Structural Connection Terminal Sect No 2 Plate A & B Std Draw RBC-002 & 003

Inadequate Reduction in Deflection and Structural Connection

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

Addition of a Spacer Tube

Combination of all of the Proceeding for a Successful Transition

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

Curb Inlet Type B Should have Island Curb in Throat of the Inlet Std Draw RBC-001 Note 5 “Island Curb” Std Draw RBD-280 “Match Adjacent Curb”

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

Type B Drainage Box As-Builts vs. Std Draw Construction memo No 5-11 July 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

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

Normally getting Standard Curb instead of Island Curb

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

What is the Difference in Type A and A-1 Connection to Bridge End Std Drawing RBC-001 ??? Std Draw RBC-001 Note 1. c. Std Draw RBC-001 Note 3. d.

Type A Curb is needed even if there is not a Drop Box – WHY?? Helps prevent the vehicle’s wheel from coming in contact with the Bridge End. Works in combination with the rub rail in the Transition to Safety Shape on Bridge. The Curb is not just for drainage. Curb is sometimes left off in error.

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