Location of point of zero thermal movement for bridge decks
Location of point of zero thermal movement for bridge decks
(OP)
Does any one know how this point is determined for various span configurations?
Thanks
VOD
Thanks
VOD
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Location of point of zero thermal movement for bridge decks
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Location of point of zero thermal movement for bridge decksLocation of point of zero thermal movement for bridge decks(OP)
Does any one know how this point is determined for various span configurations?
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RE: Location of point of zero thermal movement for bridge decks
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RE: Location of point of zero thermal movement for bridge decks
Have you used this before?
I have a integral multi-span continuous for LL and SIDL sitting on expansion bearings at the piers.
The Caltrans example is for bridge columns fixed top and bottom.
In my case would it be fair to assume the point of zero movement to be midway along my deck, as long as my abutment stiffnesses are equal?
Regards
VOD
RE: Location of point of zero thermal movement for bridge decks
What is your span arrangement (# spans and lengths)?
If your bridge is completely symmetrical and your abutment stiffnesses are equal and all of the pier stifnesses are equal to each other you can assume the point of zero movement at the center of the bridge.
The CALTRANS tabulated example is for "fixed-fixed" columns but the basic theory can be used for other types of conditions. It's just a simple stiffness approach where a Unit movement (say 1") is applied at each support and the corresponding force resistance is calculated based on the stiffness of the substructure unit.
What will you be using this "zero point" for in your integral bridge?
RE: Location of point of zero thermal movement for bridge decks
I am trying to determine the thermal and shrinkage movement and thus calculate the resulting force transfered to the piers via the bearings.
Regards
VOD
RE: Location of point of zero thermal movement for bridge decks
Apply a "unit" displacement (say 1") to each substructure unit. Based on the stiffness and fixity of each substructure unit (cantilever column for piers) calculate the force generated.
Then just follow the tabulated CALTRANS example to determine the point of zero moment.
You know by inspection it is somewhere in the first half of span 2 but it will depend on the relative stiffnesses of the abutments (piles) and piers (columns).