Structures Detailing Manual | Jan 2009
15 - Fences, Perimeter Walls and Sound Barriers |

# 15 - Fences, Perimeter Walls and Sound Barriers (01/09) 2009 Jan: Revised per TDB C08-02 to include Perimeter walls. Added notice temporarily suspending use of Design Standard Index 5250. 2005 July: Added entire chapter.

## The use of Perimeter Wall Design Standard Index 5250 has been temporarily suspended. (Contact the State Structures Design Office for further guidance.)

## 15.1 Fences

### 15.1.1 General

A. Show the limits of fencing in the plans if they are not from begin of approach slab at Begin Bridge to end of approach slab at End Bridge.

B. Show estimated quantities for bridge fencing with estimated quantities for Traffic Railing and/or concrete parapets in the superstructure details sheets.

C. Determine if bridge fencing requires grounding. If required, provide details in the superstructure sheets.

### 15.1.2 Chain Link Fabric and Tension Wire Types

A. Specify the type of chain link fabric and tension wire required for bridge fencing in the General Notes. See Design Standards Index Nos. 810 through 812, Bridge Fencing for options.

B. When PVC coated chain link fabric is specified, provide the following information in the General Notes:

1.) A note specifying the color of the PVC coating for chain link fabric.

2.) A note to paint the fence framework to match the color of the PVC chain link fabric.

3.) A note for preparation of galvanized steel for painting.

4.) A note to coat tension wire and fence fittings to match the color of the PVC chain link fabric.

### 15.1.3 Expansion Rails and Assemblies

Evaluate the expansion joints movements of the bridge. Expansion rails are required for concrete parapet installations at expansion joints where the total movement exceeds 1-inch. If the total movement at an individual expansion joint is 6-inches or less, the bridge fence will span the joint without using an expansion assembly. If the total movement at an individual expansion joint exceeds 6-inches, an Expansion Assembly must be installed at that location. Provide locations for expansion joints requiring expansion rails or expansion assemblies in the superstructure layout sheets. See Design Standards Index Nos. 810 through 812, Bridge Fencing for details.

## 15.2 Traffic Railing / Sound Barriers

### 15.2.1 General

For Bridge Decks up to a maximum thickness of 9-inches, the two Bars 5S1 (See Design Standard 5210) placed in the Bridge Deck may substitute for the longitudinal deck steel located within the limits of Bars 5V, provided that the total area of longitudinal deck steel beneath the barrier, as required by calculation, is not reduced. Show these bars on the Superstructure Sheets with the deck steel.

### 15.2.2 Form Liners

A. Form liners providing a textured finish are permitted on the outside face of Traffic Railing /Sound Barrier with the following provisions:

1.) The maximum amplitude of the form liner on the lower 32-inches section shall be limited to 1-inch depth

2.) Any form liner used above 32-inches, must provide a thickened concrete section to maintain 2-inch cover.

3.) Provide full details of this thickened section and the form liner in the plans.

B. Form liners on the inside face of Traffic Railing /Sound Barrier are not recommended.

### 15.2.3 End Treatment Options

A. Use one of the following options:

1). When the Sound Barrier terminates on the bridge, the End Taper shall be located at an open joint. When the Sound Barrier terminates on the Approach Slab, the End Taper shall terminate at Begin or End Approach Slab in the Design Standard Index No. 5210.

2.) Apply 8'-0" Traffic Railing / Sound Barrier End Taper (see Index No. 5210) adjacent to 12-inch Traffic Railing / Sound Barrier End Taper. Attach guardrail as shown on Index No. 5210. Use trench footing for 14'-0" Traffic Railing/Sound Barrier (see Index No. 5215) as the foundation for the 8'-0" Traffic Railing/Sound Barrier End Taper.

3.) Apply 8'-0" Traffic Railing/Sound Barrier End Taper (see Index No. 5210) adjacent to full height 14'-0" Traffic Railing/Sound Barrier. Attach guardrail as shown on Index No. 5210. Use trench footing for 14'-0" Traffic Railing/Sound Barrier (see Index No. 5215) as the foundation for the 8'-0" Traffic Railing/Sound Barrier End Taper.

4.) Taper 14'-0" Traffic Railing/Sound Barrier back until it is outside the clear zone. Taper rate varies based on both design speed and highway application (i.e., Interstate, urban or rural installations). See Design Standards and Plans Preparation Manual for applicable taper rates. 14'-0" Traffic Railing/Sound Barrier may be full height or tapered.

5.) Apply a wide crash cushion at the end of the 14'-0" Traffic Railing/Sound Barrier. 14'-0" Traffic Railing/Sound Barrier may be full height or tapered. Ensure the traffic face of the crash cushion is offset at least 24-inches from vertical face of Sound Barrier. See Design Standards for crash cushion options.

B. Show details of selected End Treatment in the Plan Sheets.

## 15.3 Precast Sound Barriers and Perimeter Walls (01/09) 2009 Jan: Revised per TDB C08-02 to include Perimeter Walls.

### 15.3.1 General

A. The precast Sound Barriers Design Standards Index Nos. 5200 through 5206 depict 5 pile/post connection options, based on either 10'-0", or 20'-0" post spacing and are applicable for sites with soil SPT N values between 10 and 40.

B. The precast Perimeter Wall Design Standards Index No. 5250 depicts 3 pile/post connection options and 2 post/spread footing connection options, based on either 10'-0", or 20'-0" post spacing and are applicable for sites with soil SPT N values between 10 and 40.

C. Specify aesthetic requirements on the Data Tables and flush panels (Index No. 5203) or recessed panels (Index No. 5204), as required for Sound Barriers. Perimeter Walls only utilize recessed panels.

D. For Sound Barriers allow all pile/post connection options shown in, Index No. 5205, except for Option D (Sheet No. 5 of 7), which may be excluded when project aesthetics requirements dictate. For Perimeter Walls allow all pile/post and post/spread footing connection options unless underground/overhead utilities conflict with installation of the auger cast pile foundation options.

E. Data Table cells are available on the Structures Bar Menu for the summary of project aesthetic requirements, wall quantities, limits of anti-graffiti coating, and applicable proprietary panel/system options.

### 15.3.2 Soil Conditions

A. For project sites where soil N values are less than 10, specific designs are required.

B. If muck/organic soils are encountered, removal or soil improvement methods may be necessary. The limits of muck/organic soils should be shown in the plans with specified removal/improvement methods and method of payment.

C. For project sites where rock/very strong soils are encountered at shallow depths (N values greater than 40), specific designs are permitted.

### 15.3.3 Soil Survey

A. Maximum preferred boring spacing is 200 ft. and minimum boring depth is the lesser of 2.0 times the design wall height for that location or 30'-0".

B. Consider soil borings as structural borings that include SPT performed at a maximum of 36-inch intervals along the depth of the borings.

### 15.3.4 Utilities

A. Consider spread footings at locations where auger cast piles are not practical due to overhead/underground utilities.

B. Provide project specific foundation designs as necessary.

### 15.3.5 Wall Layout

During design, field stake wall alignment at 20'-0" spacing to locate potential conflicts.

### 15.3.6 Drainage Holes

A. Locate wall drain holes based on site requirements.

B. Show drain holes locations and types in the Wall Control Drawings.

### 15.3.7 Fire Access Holes

Locate fire access holes at hydrants and at other locations based on project requirements.

### 15.3.8 Anti-Graffiti Coating

A. Contact the FDOT Project Manager to determine where anti-graffiti coating is required.

B. For wall areas not receiving anti-graffiti coating specify a Class 5 Applied Finish applied in accordance with Specification Section 400. Specify Class 5 Finish color to match the anti-graffiti coating system unless otherwise directed by FDOT.

C. Tabulate limits of the anti-graffiti coating in the Wall Control Drawings.

D. Specify sacrificial or non-sacrificial coating systems as directed by FDOT District Maintenance. (See Pay Items)

### 15.3.9 Wall Textures

A. For recessed panels, textures may be specified for either the back or front face of wall. For flush panels, specify textures for the front face only. Specify a broom finish for the back face.

B. All textures shown on Index No. 5201, except Type "H", may be used for either the back face or front face of the wall. Type "H" Texture is limited to front face only.

C. Textures on the front face are formed while textures on the back face may be rolled, pressed or formed (vertical cast panels only); therefore random pattern types are more suitable on the back face.

### 15.3.10 Graphics

A. When formed wall graphics are required, show the locations in the Wall Control Drawings.

B. See the Structures Bar Menu for graphics options.

C. Create other graphics as project requirements dictate. General considerations in creating graphics are as follows:

1.) Detail wall graphics in the plans.

2.) Keep wall graphics simple.

3.) Wall graphics should be as large as possible (approximately 7 ft. in height).

4.) Consider input from local communities when determining graphics.

### 15.3.11 Vehicle Impact Loads

A. The wall systems shown on Index No. 5200 and 5250 have been designed for wind loads only, with no provisions for vehicle impact loads. See Plans Preparation Manual - Volume I (current version).

B. Locate walls outside clear recovery zone or set back 5'-0" from front face of crash-tested barrier.

C. Guardrails and delineators may be required at the back-face of walls along local streets.

### 15.3.12 Proprietary Options

A. Any of the approved proprietary Perimeter Wall or Sound Barrier panels or proprietary systems (panels and foundations) listed on the Qualified Products List may be allowed as alternates to the Precast Standards, provided the proprietary panel/system option meets the project's aesthetic requirements as shown in the Wall Control Drawings.

B. List all applicable proprietary panel/systems in the Wall Control Drawings based on project requirements.