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7/30/2019 Caltrans See Thru Rail Webinar 24aug2011
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See-Through Bridge Rai ls
Shannon Post / Greg Kaderabek
Caltrans
Divis ion of Engineer ing Services
Augus t, 2011
Agenda:
1. Introduction
Bridge Barriers and Railings
2. Development of See-Through Rails
Applications
Desired Features
3. See -Through Alternatives
4. Cost Comparison
5. FAQs
6. Next Steps
7. Your Questions..
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Bridge Rai ls
Classes of RailingsRailing Types Function
a.) Vehicular Barrier Railings Retain and redirect errant vehicles
b.) Combination Vehicular Barrierand Pedestrian Railings
Dual function of retaining both vehicles and
pedestrians on the bridge. Consist of twoparts: concrete parapet, generally with asidewalk and a metal hand railing or fence-type railing
c.) Pedestrian RailingsPrevent pedestrians from accidentallyfalling from the structure
d.) Bicycle Railings
Retain bicycles and riders on the structure.May be a combination type consisting of avehicular railing surmounted by a fence ormetal handrail
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Bridge Rai ls
Design and Crash CriteriaCriteria SpecificationStructural
DesignAASHTO LRFD Bridge Design Specifications, 4thEdition with California Amendments
Crash Testing
NCHRP Report 350 (six test levels)
NEW!AASHTO Manual for Assessing SafetyHardware (MASH)
a.) Test Level 2
(TL-2)
Local and collector roads with favorable site conditions
Roadways with speeds up to 45 mph
Crash test with a small car and pickup truck at 45 mph
b.) Test Level 4
(TL-4)
High speed highways, freeways, expressways and Interstate
Roadways with vehicle speeds greater than 45 mph
Crash test with small car/pickup at 62 mph, medium size truck at50 mph
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Bridge Rai ls
See-Through AlternativesAppl icat ions:California Coastal Commission/ Local Coastal Program
Context Sensitive Solutions (CSS)
Bridge or Roadside
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Bridge Rai ls
See-Through AlternativesDesired 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, textureand other treatments
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Bridge Rai ls
See-Through AlternativesMetal Bridge Rails Concrete Barriers
TL-4 TL-4
California ST-10 Concrete Barrier Type 80California ST-20S Concrete Barrier Type 90
California ST-30
California ST-70
TL-2 TL-2California ST-40 Concrete Barrier Type 80SW
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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 railto 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 railface
California ST-10 Bridge Rail separated from the Pedestrian Handrailby 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 requiredBicycle 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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CaliforniaST-30BridgeRail
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/bicyclerail to increase height to a minimum of 42.
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CaliforniaST-30BridgeRail
South Fork Dibble Creek, Tehama County
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CaliforniaST-70BridgeRail
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 thanthe 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 aminimum of 42 as well as modification of the clear opening for use as apedestrian/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 withArchitectural Treatment and with Bicycle Rail Offset 15from 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 toincrease height to a minimum of 42 as well as modification to reducethe 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 ofdeck).
Comments: Cannot be used on bridge decks with high speedvehicular 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 B ridge Rails
Cost ComparisonBridg e Rai l Estimated
Cost/LF
Cos t/Cos t 732
Concrete Barrier Type 732 $88/LF 1.00
California ST-10 $204/LF 2.32
California ST-20S $297/LF 3.37
California ST-30 ---- ----
California ST-70 ---- ----
California ST-40 ---- ----Concrete Barrier Type 80 $264/LF 3.00
Concrete Barrier Type 90 ---- ----
Concrete Barrier Type 80SW $313/LF 3.55
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See-Through Bridge Rails
Summary
Metal Bridge Rails Concrete Barriers
TL-4 TL-4
California ST-10 (H=33) +, ^ Conc Barrier Type 80 (H= 32) +, ^,#
California ST-20S (H= 54) ++ Conc Barrier Type 90 (H= 32) ++,^, #
California ST-30 (H=32) +,^
California ST-70 (H= 46.5) ++
TL-2 TL-2California ST-40 (H=42) + Conc Barrier Type 80SW (H=42) +, #
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 Rai ls
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 bicyclistsfrom 54 to 42 at their 2006 annual meeting.
The Caltrans initiated a bicycle rail height study that concluded thata 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, 2008lowering 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 Rai ls
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 bythe PDT and used in the environmental process.
During the Design phase, need to ensure that the aesthetic bridgerail 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 Rai ls
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 isrequired 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 Rai ls
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, butcan be modified for other uses by special design.
a) For example, a see-through rail can be used on the roadsideby mounting the rail on a reinforced concrete trench footing oron a trench footing on CIDH piles.
b) See-through rails can also be used with earth retainingsystems, however the design of the earth retaining systemneeds to consider vehicular impact loads.
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See-Through Bridge Rai ls
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 appliedto the surface of rails. Drawings and reports detailing the texturerelief limits on rail can be found at the Caltrans LandscapeArchitecture website:
http://www.dot.ca.gov/hq/LandArch/barrier_aesthetics/index.htm
http://www.dot.ca.gov/hq/LandArch/barrier_aesthetics/index.htmhttp://www.dot.ca.gov/hq/LandArch/barrier_aesthetics/index.htm7/30/2019 Caltrans See Thru Rail Webinar 24aug2011
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See-Through Bridge Rai ls
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 isoffset 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 asidewalk may have roadway appendages if the appendage is offset 8
behind the front face of rail. Rails with a sidewalk in low speed locations donot require an offset for appendages, but special attachment details mayapply depending on the rail type.
Contact Caltrans/DES when there is a need for any roadway appendage tobe attached to top or backside of rail.
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See-Through Bridge Rai ls
Bridge Standard Detail Sheets (aka XSSheets) website:
http://www.dot.ca.gov/hq/esc/techpubs/manual/bridgemanuals/bridge-standard-detail-sheets/
http://www.dot.ca.gov/hq/esc/techpubs/manual/bridgemanuals/bridge-standard-detail-sheets/http://www.dot.ca.gov/hq/esc/techpubs/manual/bridgemanuals/bridge-standard-detail-sheets/http://www.dot.ca.gov/hq/esc/techpubs/manual/bridgemanuals/bridge-standard-detail-sheets/http://www.dot.ca.gov/hq/esc/techpubs/manual/bridgemanuals/bridge-standard-detail-sheets/http://www.dot.ca.gov/hq/esc/techpubs/manual/bridgemanuals/bridge-standard-detail-sheets/http://www.dot.ca.gov/hq/esc/techpubs/manual/bridgemanuals/bridge-standard-detail-sheets/http://www.dot.ca.gov/hq/esc/techpubs/manual/bridgemanuals/bridge-standard-detail-sheets/http://www.dot.ca.gov/hq/esc/techpubs/manual/bridgemanuals/bridge-standard-detail-sheets/http://www.dot.ca.gov/hq/esc/techpubs/manual/bridgemanuals/bridge-standard-detail-sheets/http://www.dot.ca.gov/hq/esc/techpubs/manual/bridgemanuals/bridge-standard-detail-sheets/http://www.dot.ca.gov/hq/esc/techpubs/manual/bridgemanuals/bridge-standard-detail-sheets/7/30/2019 Caltrans See Thru Rail Webinar 24aug2011
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See-Through Bridge Rails
Next Steps
Shanno n Post/ Greg Kaderabek
Divis ion of Engineer ing Services
Aug ust, 2011
Guidance
DRAFT Desig n Inform ation Bul let in (DIB),
Br idge Rai l Development, Design and Select ion
Guidelines
Update Highway Design Manual
Bridg e Rails and Barr iers: A Reference Guide
for Transpo rtat ion Projects in the Coastal Zone
Crash Test ing/ Development of
addit io nal alternatives
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See-Through Bridge Rai ls
Shanno n Post/ Greg Kaderabek
Divis ion of Engineer ing Services
Aug ust, 2011