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What’s Up With These New<br />
Bridge Rails<br />
John M. Holt, P.E.<br />
Transportation Short Course<br />
October 2012
• Agents of Change<br />
Outline<br />
• Bridge Railing Manual<br />
• New Rails<br />
– T131RC, T1W, C1W, T1F, T66, Picket Rail,<br />
T80SS, T80HT, T80TT, and PR3<br />
• Rails Under Development<br />
• Rails Not Under Development<br />
• Summary
Agents of Change<br />
• Adoption of MASH<br />
• More severe small car impact angle<br />
• Heavier pickup with higher c.g.<br />
• More severe TL-4 requirements<br />
• Adoption of 31” tall guardrail<br />
• 31” doesn’t equal 27”—no more T6, T101,<br />
and T101RC, but…<br />
• T6 still allowed as temporary rail for<br />
phased bridge construction
• AASHTO LRFD<br />
Agents of Change<br />
• Bicycle rail height reduced from 54” to 42”<br />
• Historic bridge preservation<br />
• Need modern crashworthy rails
Bridge Railing Manual<br />
• Significantly Revised in April 2012<br />
– Included new rail types<br />
– Noted future retirement of T101, T6, etc., with<br />
adoption of 31” tall guardrail<br />
– Provides list of in-service rails that are<br />
considered to meet current requirements<br />
– Provides a table of actions necessary for existing<br />
rails based on project type<br />
– References adoption of Manual for Assessing<br />
Safety Hardware (MASH)
New Rails—Type T131RC<br />
• The replacement of the T101RC<br />
• Crash tested by TTI to meet MASH Test<br />
Level 3, including guardrail transition tests<br />
• Test specimen included a lightly reinforced<br />
curb<br />
• 36” tall rail<br />
• Standard will be issued in October or<br />
November
New Rails—Type T131RC
New Rails—Type T131RC
New Rails—Type T131RC
New Rails—Type T131RC
New Rails—Type T131RC
New Rails—Type T1W<br />
• A Texas version of the Wyoming TL-3 Rail<br />
• Evaluated for Test Level 3<br />
• 32” tall overall, with a 9” tall curb, two 6 x 2 x<br />
¼ HSS rails, and steel posts<br />
• Best railing for allowing flood waters to pass<br />
through<br />
• Most “open” rail type in TxDOT inventory
New Rails—Type T1W
New Rails—Type T1W
New Rails—Type C1W<br />
• A combination pedestrian/traffic version of<br />
the T1W<br />
• Evaluated for Test Level 2<br />
• 42” tall overall, with 9” tall curb, four 6 x 2 x<br />
¼ HSS rails, and steel posts<br />
• Most “open” and lightest combination rail in<br />
TxDOT inventory
New Rails—Type C1W
New Rails—Type C1W
New Rails—Type T1F<br />
• A unique 33” tall rail developed to take<br />
advantage of the constructability offered by<br />
the aluminum half-ellipse rail<br />
• Our first rail evaluated with MASH criteria
New Rails—Type T1F
New Rails—Type T66<br />
• A 32” tall concrete rail meant to replicate the<br />
style of the old Type K rail<br />
• Derived from the Caltrans Type 80 rail<br />
• Altered post geometry from the Caltrans<br />
original
New Rails—Type T66
New Rails—Type T66
New Rails—Picket Rail<br />
• A 36” steel rail targeted for historic bridge<br />
preservation projects<br />
• Texas Historical Commission involved in<br />
development<br />
• TTI crash tested this rail successfully at<br />
MASH TL-3
New Rails—Picket Rail
New Rails—Picket Rail
New Rails—Picket Rail
New Rails—Picket Rail
New Rails—T80SS<br />
• 42” tall single<br />
slope rail that<br />
meets TL-5<br />
• Matches 42”<br />
SSCB<br />
• Least expensive<br />
TL-5 rail in<br />
TxDOT inventory
New Rails—T80HT<br />
• An updated version<br />
of the Type HT with<br />
an F-shape profile<br />
combined with inline<br />
anchor bolts<br />
• 50” tall overall
New Rails—T80TT<br />
• An updated version of<br />
the Type TT—switched<br />
to a single slope base<br />
section and eliminated<br />
“windows”<br />
• 90” Tall, weighs 1260<br />
plf<br />
• Used in the Dallas<br />
District recently<br />
• Not issued as a<br />
standard rail
New Rails—PR3 Rail<br />
• A 43.75” tall steel picket pedestrian rail<br />
• A bicycle rail version, the B3, was developed<br />
and issued as a standard, but was retired<br />
when AASHTO reduced the minimum bicycle<br />
rail height to 42”.
New Rails—PR3 Rail<br />
Photo of<br />
Type B3<br />
rail, now<br />
retired with<br />
change in<br />
minimum<br />
bicycle rail<br />
height<br />
Type PR3 is<br />
similar, 12”<br />
shorter
New Rails—PR3 Rail
Rails Under Development<br />
• A replacement for the T6<br />
• Goals:<br />
• Can be used to replace existing T6<br />
installations, if necessary<br />
• Compatible with 31” tall guardrail<br />
• Could be used as a temporary rail<br />
• Test Level 2 installations<br />
• Crash testing scheduled this FY
Rails Not Under Development<br />
• A replacement for the T101<br />
• We’ve tried
T101, MASH TL-3, Pickup
T131, MASH TL-3, Pickup<br />
The T131 represents a<br />
replacement to the T101
Summary<br />
• TxDOT has a number of new rails that:<br />
– Meet updated crash test requirements<br />
– Should require less maintenance after hits<br />
– Look better<br />
– Meet broader range of needs<br />
– Provide more options
Questions<br />
• Email John.Holt@txdot.gov<br />
• Or Call 512-416-2212
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