See-Through Bridge Rails

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See-Through Bridge Rails

• Agenda
• Introduction
• Bridge Barriers and Railings
• Development of See-Through Rails
• Applications
• Desired Features
• See -Through Alternatives
• Cost Comparison
• FAQs
• Next Steps
• Your Questions..

Shannon Post/ Greg Kaderabek Caltrans Division of
Engineering Services August, 2011
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Bridge RailsClasses of Railings
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Bridge RailsDesign and Crash Criteria
4
Bridge RailsSee-Through Alternatives

• Applications
• California Coastal Commission/ Local Coastal
  Program
• Context Sensitive Solutions (CSS)
• Bridge or Roadside

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Bridge RailsSee-Through Alternatives

• Desired Features
• Visibility minimize impairment of views from
  the bridge aesthetically pleasing view of the
  bridge from public areas
• Rail Height consistent with minimum required
  height for anticipated users (vehicle, bicycle
  and/or pedestrians)
• Aesthetics enhance visual appeal by applying
  color, texture and other treatments

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Bridge RailsSee-Through Alternatives
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California ST 10 Bridge Rail

• Description See through 2-bar curb-mounted
  steel bridge rail
• Test Level TL-4
• Standard Plans B11-68, B11-69, B11-70
• Height 33 above bridge deck (27 steel rail
  plus 6 curb)
• Comments Requires additional rail for use as a
  pedestrian/bicycle rail to increase height to a
  minimum of 42.
• Successfully used on past projects in the
  Coastal Zone.

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California ST 10 Bridge Rail

• California ST-10 Bridge Rail with Bicycle Rail
  offset 15 from rail face
• California ST-10 Bridge Rail separated from the
  Pedestrian Handrail by a Walkway.

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California ST 10 Bridge Rail
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California ST-20S Bridge Rail

• Description See through 5-bar curb-mounted
  steel bridge rail
• Test Level TL-4
• Bridge Standard Detail Sheets see website
• Height 54 above bridge deck (48 steel rail
  plus 6 curb)
• Comments The rail is 12 higher than the
  minimum required Bicycle Rail or Pedestrian Rail
  height of 42.

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California ST-20S Bridge Rail

• Van Duzen River Bridge
• Humboldt County

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California ST-30 Bridge Rail

• Description See through 2-bar curb-mounted
  steel bridge rail
• Test Level TL-4
• Standard Plans Standard Plan B11-65
• Height 32 above bridge deck (25 steel rail
  plus 7 curb)
• Comments Requires additional rail for use as a
  pedestrian/bicycle rail to increase height to a
  minimum of 42.

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California ST-30 Bridge Rail

• South Fork Dibble Creek, Tehama County

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California ST-70 Bridge Rail

• Description See through 4-bar curb-mounted
  steel bridge rail
• Test Level TL-4
• Bridge Standard Detail Sheets see website
• Height 46.5 above bridge deck (40.5 steel
  rail plus 6 curb)
• Comments Rail is similar to California ST-20S
  Bridge rail except that the top 7.5 high
  handrail has been removed. This rail is 4.5
  higher than the minimum required Bicycle Rail or
  Pedestrian Rail height of 42.

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California ST 40 Bridge Rail

• Description See through 4-bar sidewalk mounted
  steel bridge rail.
• Test Level TL-2
• Standard Plans Standard Plans B11-66, B11-67
• Height 42above sidewalk. 8 high
  sidewalk/curb next to traffic (9 at edge of
  deck).
• Constraints Cannot be used on bridge decks
  with vehicular traffic signed for greater than 45
  mph.

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California ST 40 Bridge Rail

• Renderings of California ST-40

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Concrete Barrier Type 80

• Description See through concrete barrier.
• Test Level TL-4
• Standard Plans Standard Plans B11-60, B11-61,
  XS Sheet website
• Height 32 above bridge deck.
• Comments Requires addition of steel rail on
  top to increase height to a minimum of 42 as
  well as modification of the clear opening for use
  as a pedestrian/bicycle rail.
• Successfully used on past projects in the Coastal
  Zone.

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Concrete Barrier Type 80

• Photo of Concrete Barrier Type 80 - Modified with
  Architectural Treatment and with Bicycle Rail
  Offset 15 from Rail Face.

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Concrete Barrier Type 80

• Sheffield Drive Bridge
• Santa Barbara County

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Concrete Barrier Type 90

• Description Concrete barrier with see through
  steel rail on top.
• Test Level 4 TL-4
• Bridge Standard Detail Sheets See website.
• Height 32 above bridge deck.
• Comments In order to also be used as a
  pedestrian/bicycle rail, requires additional
  steel rail mounted at least 15 behind the rail
  face to increase height to a minimum of 42 as
  well as modification to reduce the clear
  openings.

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Concrete Barrier Type 80SW

• Description See through concrete barrier with a
  raised sidewalk.
• Test Level TL-2
• Standard Plans Standard Plans B11-62, B11-63,
  B11-64
• Height 42 above sidewalk (32 See-through
  concrete barrier plus 10 of handrail). 8 high
  sidewalk/curb next to traffic (9 at edge of
  deck).
• Comments Cannot be used on bridge decks with
  high speed vehicular traffic (greater than 45
  mph).

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Concrete Barrier Type 80SW

• Canal Street Bridge
• El Dorado County

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See-Through Bridge RailsCost Comparison
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See-Through Bridge RailsSummary

• Notes
• Standard Plans Bridge Standard Detail
  Sheet
• Requires additional rail for use as a
  pedestrian/bike rail to increase height to 42
• Can apply architectural treatment

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See-Through Bridge Rails

• Frequently Asked Questions.
• 1. What is the recommended minimum rail height
  for bridge bicycle rails? AASHTO says 42 but
  the Highway Design Manual says 54.
• AASHTO lowered the minimum required rail height
  for bicyclists from 54 to 42 at their 2006
  annual meeting.
• The Caltrans initiated a bicycle rail height
  study that concluded that a 42 minimum bicycle
  rail offset 15 from the face of the vehicular
  rail is sufficient for most situations.
• The Department issued a memorandum on November
  26, 2008 lowering the height from 54 to 42 for
  most applications.
• Caltrans recommends a minimum height of 48 where
  a combination of high bicycle speeds and high
  crash impact angles are anticipated. See AASHTO
  Bridge Design Specifications for more details

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See-Through Bridge Rails

• Frequently Asked Questions.
• 2. What is the Type Selection process for an
  aesthetic bridge rail?
• The Project Development Team (PDT) shall evaluate
  the need for a CSS rail early in the project.
• A Conceptual Bridge Rail Plan needs to be
  reviewed/approved by the PDT and used in the
  environmental process.
• During the Design phase, need to ensure that the
  aesthetic bridge rail meets all project
  requirements as well as structural/crash test
  requirements.
• Projects in the coastal zone may require special
  consideration.

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See-Through Bridge Rails

• Frequently Asked Questions.
• 3. Are there any special considerations where
  barriers are placed on a structure with a high
  super-elevation?
• All bridge barriers are to remain vertical
  regardless of the super-elevation.
• If the super-elevation is 6 or greater, a higher
  bridge rail is required on the outside of the
  curve. Issues regarding super-elevation should
  be discussed as early in the design process as
  possible.

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See-Through Bridge Rails

• Frequently Asked Questions.
• 4. Can see-through rails developed for bridges be
  used in other applications?
• The see-through rails were developed for bridge
  applications, but can be modified for other uses
  by special design.
• For example, a see-through rail can be used on
  the roadside by mounting the rail on a
  reinforced concrete trench footing or on a trench
  footing on CIDH piles.
• See-through rails can also be used with earth
  retaining systems, however the design of the
  earth retaining system needs to consider
  vehicular impact loads.

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See-Through Bridge Rails

• Frequently Asked Questions.
• 5. Are there any limitations on the type of
  aesthetic treatment that can be applied to these
  bridge rails?
• Any color can be added as architectural
  treatment.
• There are limitations on the architectural
  texture that can be applied to the surface of
  rails. Drawings and reports detailing the
  texture relief limits on rail can be found at the
  Caltrans Landscape Architecture website
• http//www.dot.ca.gov/hq/LandArch/barrier_aestheti
  cs/index.htm

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See-Through Bridge Rails

• Frequently Asked Questions.
• 6. Can these rails be used to support other
  roadway appendages, such as sign structures or
  lighting standards?
• In high speed locations (posted speeds over 45
  mph), rails can support roadway appendages
  without any further crash testing, if the
  appendage is offset 15 behind the front face of
  the rail. This applies to bicycle rail, sign
  posts, sign structures, light standards, etc.
• In low speed locations (posted speed of 45 mph or
  less) rails without a sidewalk may have roadway
  appendages if the appendage is offset 8 behind
  the front face of rail. Rails with a sidewalk in
  low speed locations do not require an offset for
  appendages, but special attachment details may
  apply depending on the rail type.
• Contact Caltrans/DES when there is a need for any
  roadway appendage to be attached to top or
  backside of rail.

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See-Through Bridge Rails

• Bridge Standard Detail Sheets (aka XS Sheets)
  website
• http//www.dot.ca.gov/hq/esc/techpubs/manual/bridg
  emanuals/bridge-standard-detail-sheets/

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See-Through Bridge RailsNext Steps

• Guidance
• DRAFT Design Information Bulletin (DIB), Bridge
  Rail Development, Design and Selection Guidelines
• Update Highway Design Manual
• Bridge Rails and Barriers A Reference Guide for
  Transportation Projects in the Coastal Zone
• Crash Testing/ Development of additional
  alternatives

Shannon Post/ Greg Kaderabek Division of
Engineering Services August, 2011
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See-Through Bridge Rails
Questions????
Shannon Post/ Greg Kaderabek Division of
Engineering Services August, 2011