×
INTELLIGENT WORK FORUMS
FOR ENGINEERING PROFESSIONALS

Log In

Come Join Us!

Are you an
Engineering professional?
Join Eng-Tips Forums!
  • Talk With Other Members
  • Be Notified Of Responses
    To Your Posts
  • Keyword Search
  • One-Click Access To Your
    Favorite Forums
  • Automated Signatures
    On Your Posts
  • Best Of All, It's Free!
  • Students Click Here

*Eng-Tips's functionality depends on members receiving e-mail. By joining you are opting in to receive e-mail.

Posting Guidelines

Promoting, selling, recruiting, coursework and thesis posting is forbidden.

Students Click Here

Jobs

Crest-sag-crest sequence a problem?

Crest-sag-crest sequence a problem?

Crest-sag-crest sequence a problem?

(OP)
We have a bridge approach that has settled, creating a crest-sag-crest sequence in the asphalt road profile. The question is whether anyone knows of a standard, "best practice", guideline, etc. that identifies when this situation becomes unacceptable, from either a safety or comfort standpoint. Grateful for any guidance, or even pointing me in the right direction where I can make further inquiries. Thanks!

Margaret Gibbs
Opus Hamilton (Vancouver, B.C., Canada)
margaret.gibbs@opushamilton.ca
tel 604-684-4488

RE: Crest-sag-crest sequence a problem?

Pg 269 to 283 in the AASHTO green book.  These are known as broken back curves.  They are undesireable, but if they meet criteria for sight distance, comfort, and drainage, they should be OK as far as I know.

RE: Crest-sag-crest sequence a problem?

Hi Opham
this problem happens if approach settlement is not well addressed at advance . Normally there are some requirements regarding eveness of the pavement surface using 3m straight edge in longitudenal and transverse direction.

It may be the bridge owner have a criteria for total post constrcution settlement or post constrcution settlement within say 5 yrs after constrcution that define acceptability.
 
you need to take the matter very seriously.Investigat if the problem is only related to settlement? how much more to expect? at what rate? How are you going to adress it sometimes top up will induce more settlement and you will end up in a circle ?

I hope this give you the little help you asked for.

thanks
CD

Red Flag This Post

Please let us know here why this post is inappropriate. Reasons such as off-topic, duplicates, flames, illegal, vulgar, or students posting their homework.

Red Flag Submitted

Thank you for helping keep Eng-Tips Forums free from inappropriate posts.
The Eng-Tips staff will check this out and take appropriate action.

Reply To This Thread

Posting in the Eng-Tips forums is a member-only feature.

Click Here to join Eng-Tips and talk with other members!


Resources