Cable stayed bridge - connection at an abutment column to prevent uplift

[kww2008]

What is the best way to connect the end of deck girder to the top of an abutment column of a cable stayed bridge? The support is connected to both the stiffening girder and a back-stay cable. The support has to be able to resist an uplift force (from live load) and to move longitudinally.

 

[Qshake]

There are two methods to accomplish this, use of steel tie-down links or concrete ballast. The tie-down links will resist the tension while permitting longitudinal movement through pin connections. The method of concrete ballast will aid in eliminating uplift and permit the longitudinal movement more or less as a typical bridge does.

Regards,
Qshake

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[graybeach]

I like concrete counterweights because they are less likely to have corrosion issues. They are not so good in high seismic areas though. Making the cable stayed back span continuous with the approach spans can be helpful. This also provides protection for deicing salt if you are using tie-downs.

 

[kww2008]

Thank you Qshake and greybeach for comments. I am trying to use concrete infill over a length next to the end of the steel girder box to resist uplift under dead load condition. Under dead and live loading condition, hold down bearings will resist uplift forces.

 

[ImminentCollapse]

If you do go with the steel tie-downs, do some extra due diligence. I recall reading about or seeing a presentation on a cable stayed bridge having problems with rods cracking. Accurately defining stress ranges, details, materials selection, and maintenance are all very important.

IC