PGSplice Load Rating Stresses

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ajplankis
PGSplice Load Rating Stresses

I am using PGSplice to complete a load rating on a spliced post-tensioned bridge. The bridge is passing the specification check for Service III stresses, but is failing the load rating check for Service III stresses. When I dig into it the reason seems to be that the load rating is using different stresses for the limit and the prestressing than is being used in design. Do you know if there is a reason why these would be different? See attached images, and I'll also attach my spl file.

Thank you.

Rick Brice
PGSplice Load Rating Stresses

PGSuper/PGSplice use different tension stress limits for design and load rating. WSDOT designs for 0.0 KSI tension but load rates for the AASHTO limit.

You can control which rating type (design, legal, permit) does a stress rating analysis (MBE only required it for inventory/operating level rating) and set the tension limit. Select Project > Load Rating Options... (or press the button on the toolbar with the blue RF).

ajplankis
PGSplice Load Rating Stresses

Rick, Thank you for the quick reply.

Setting a tension limit in the Load Rating Options fixes the difference in the tension limit stress, but I am still finding a pretty large difference in the pre-tension stress. The load rating shows a pretension stress of 1.990 ksi, while the spec check is showing a pretension stress of 2.236. This is enough of a difference to change from pass to fail. Do you have any idea why these two numbers would be different?

Alivia Plankis, PE

Rick Brice
PGSplice Load Rating Stresses

Service III design stresses are checked when the bridge is opened to traffic which occurs on day 80. You set the load rating to occur for the final time step, which is day 10950. A lot of losses occur during that time.

You can control these settings in the timeline manager.

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