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Oregon PCB

Question
State
Description Text Attached are 2 sketches for your consideration with the following queries:
  • Temporary Precast Concrete barrier Pin and Loop/Anchors 2 (ODOT)
  • Securing Concrete Barrier to Roadway (ODOT)
Are you aware if this Barrier has been crash tested for highways of 80kM/hr to NCHRP Report 350, and/or S6-06? (Bridge Barrier)


For a separated highway (I.e. 2 lanes in each direction, barriers on each side), would it be acceptable to use the Single Pin-Shoulder Installation for the Fast lane Barrier protections for construction workers operating in the area between the highway (I.e. Median)?


Or should the Median Installation (2 pins) be used, even though there are "two layers of defense"? (Note 7 indicates that 2-pins are needed for a median of less than 8', but does this include 2 barriers?)


Does this detail in conjunction with a sliding distance of 500mm away from the impact side provide a crash tested barrier that should be considered safe for use in protecting median construction work and workers?


Is it necessary to have a design engineer seal the proposed design for a temporary use?


Your valuable input is appreciated if possible.
Keywords
  • Temporary Barriers
Other Keywords none
Date August 24, 2010
Attachment Oregon_1.pdf
Attachment Oregon_2.pdf


Response
Response

I am not aware of any crash testing programs directed toward the evaluation of the Oregon TCB in anchored/tied-down configurations. However, some of the Oregon anchorage details are similar in concept to those used by MwRSF for an Midwest Pooled Fund F-shape TCB as well as by TTI in other TCB designs.

 

In general, anchorage options can be adapted over to alternative TCBs without actual crash testing if several conditions are believed to be met, including demonstration that equivalent or greater structural capacity is provided. Thus, one would require that the Oregon barrier provides equal or greater flexural capacity, shear strength, torsion resistance, etc. as compared to the as-tested TCBs where anchorage systems were evaluated. The Oregon joint detail should provide equal or greater strength between adjacent segments as compared to the as-tested TCBs. Barrier regions surrounding the openings where the vertical or sloped anchors are inserted in the Oregon barrier should provide equal or greater capacity as compared to the as-tested TCBs. The anchorage hardware should also provide equivalent structural capacity. Barrier lengths should also be similar. If these general conditions are met, then it would seem reasonable to adapt prior crashworthy anchorage options to similar TCBs.

 

MwRSF could provide you with research/test reports for anchorage systems that have been developed and crash tested at 100 km/hr for use with the Midwest F-shape TCB. TTI researchers would have similar information for those systems that were developed and tested by their personnel.

See my comments below in red in response to your questions.

Are you aware if this Barrier has been crash tested for highways of 80kM/hr to NCHRP Report 350, and/or S6-06? (Bridge Barrier)

**Comments provided above. I am not aware of the Oregon TCB being crash tested under NCHRP Report No. 350 when installed with various anchorage options. However, it should be noted that some options shown in the attachments have similarity to anchor methods used with other crash tested barriers.


For a separated highway (I.e. 2 lanes in each direction, barriers on each side), would it be acceptable to use the Single Pin-Shoulder Installation for the Fast lane Barrier protections for construction workers operating in the area between the highway (I.e. Median)?

**Yes, as long as the Oregon barrier provided equivalent or greater safety performance compared to the pinned TCB configured and tested by TTI.

 

Or should the Median Installation (2 pins) be used, even though there are "two layers of defense"? (Note 7 indicates that 2-pins are needed for a median of less than 8', but does this include 2 barriers?)

**TCBs pinned on both sides have only been subjected to limited crash testing when used with a median TCB transition between free-standing TCBs and permanent barrier.


Does this detail in conjunction with a sliding distance of 500mm away from the impact side provide a crash tested barrier that should be considered safe for use in protecting median construction work and workers?

**I am not sure that I understand the question.


Is it necessary to have a design engineer seal the proposed design for a temporary use?

**This is a question better suited for the DOTs. However, someone needs to ensure that the barrier hardware and its placement meet current safety practices.

 

Date August 30, 2010


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