×
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

Pot bearings on curved girder bridge

Pot bearings on curved girder bridge

Pot bearings on curved girder bridge

(OP)
I have a 5 span curved girder steel bridge with 125' end spans and 180' middle spans.  The piers and abutments are all laid out radially and the third pier (or 4th support) is fixed while the remaining supports are expansion.  I was wondering at what angle the guided pot bearings should be placed on the supports?  Should they be oriented at a straight line to the fixed bearing point or at a tangent to the curve?

RE: Pot bearings on curved girder bridge

Hi tphel,

Both orientations have there benefits and disadvantages, and there are no hard and fast rules.  It is better to minimize the introduction of forces and deformations so, typically I place my bearings at the abutment tangent to the curve to allow movement at the expansion joint without distortion and place the bearings at the piers in line with the centre of fixity at the third pier.

Regards

VOD

RE: Pot bearings on curved girder bridge

(OP)
VOD,

Thank you for your prompt reply, one further question, at what angle should I place my fixed bearing, should that be at a tangent with the curve as well?

TP

RE: Pot bearings on curved girder bridge

The guided bearings should be placed at straight line(s) to the center of fixity for the bridge (typically a point at the middle of the fixed support). It is also possible to place these bearings at the tangent to the curve, but only when the degree of the curvature is small, and when you will be able to accommodate transverse movement at the bearings by specifying additional free play at the guides. Curved bridges typically behave as rigid bodies due to the presence of full depth diaphragms, so accommodation of transverse movement at the supports by flexing of the webs is not achievable.

RE: Pot bearings on curved girder bridge

A fixed bearing is fixed for translation in all directions anyway.  But for the sake of it, yes, tangent to the curve to line up any anchor bolts to the pier cap.

Regards

VOD

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