Bridge railings: procedure for determining the test level

[Hansonn]

Hi bridge engineers,

AASHTO specification 'Guide Specifications for Bridge Railings' 1989 includes a procedure for determining an approproate performance level for a given site. This procedure is not included in NCHRP Report 350. Please advise:
- What documents or AASHTO specifications also include this procedure?
- What is the current practice in USA in determining an appropriate test level for a bridge site?

Any idea would be greatly appreciated.

Hanson

 

[bridgebuster]

Usually, the state DOT's have standard barrier railing designs each of the various test levels. In NY and I'm sure other states as well, the selection of a railing or barrier is based on the traffic volume.

AASHTO LRFD Bridge specs provide guidance on the design of non-standard railings & barriers.

Hope that helps.

 

[Hansonn]

Thanks bridgebuster for your response.
You're right, the selection of a railing is based on a risk assessment in which traffic volume is considered. I have no problem with the design of the railing, however, the procedure for determining the appropriate test level for a bridge site is not clear to me.
Hansonn

 

[bridgebuster]

Hansonn,

Take a look at the LRFD Bridge Specifications, Section 13.7.2, which describes the traffic conditions of the test levels.

 

[Hansonn]

Thanks bridgebuster

Regards,

Hansonn

 

[bridgebuster]

no problem