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See-Through Bridge Rails

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Concrete Barrier Type 80 Sheffield Drive Bridge Santa Barbara County Concrete Barrier Type 90 Description: Concrete barrier with see through steel rail on top. – PowerPoint PPT presentation

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Title: See-Through Bridge Rails


1
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
2
Bridge RailsClasses of Railings
3
Bridge RailsDesign and Crash Criteria
4
Bridge RailsSee-Through Alternatives
  • Applications
  • California Coastal Commission/ Local Coastal
    Program
  • Context Sensitive Solutions (CSS)
  • Bridge or Roadside

5
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

6
Bridge RailsSee-Through Alternatives
7
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.

8
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.

9
California ST 10 Bridge Rail
10
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.

11
California ST-20S Bridge Rail
  • Van Duzen River Bridge
  • Humboldt County

12
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.

13
California ST-30 Bridge Rail
  • South Fork Dibble Creek, Tehama County

14
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.

15
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.

16
California ST 40 Bridge Rail
  • Renderings of California ST-40

17
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.

18
Concrete Barrier Type 80
  • Photo of Concrete Barrier Type 80 - Modified with
    Architectural Treatment and with Bicycle Rail
    Offset 15 from Rail Face.

19
Concrete Barrier Type 80
  • Sheffield Drive Bridge
  • Santa Barbara County

20
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.

21
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).

22
Concrete Barrier Type 80SW
  • Canal Street Bridge
  • El Dorado County

23
See-Through Bridge RailsCost Comparison
24
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

25
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

26
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.

27
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.

28
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.

29
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

30
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.

31
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/

32
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
33
See-Through Bridge Rails
Questions????
Shannon Post/ Greg Kaderabek Division of
Engineering Services August, 2011
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