Harped or Straight Strand

 

Harped strands are draped at the girders harping points. Harping (draping) is created by the difference in vertical adjustment between the strand group at the girder ends and harping points.

Adjustable Straight Strands are straight along the entire length of the girder. The entire group can be vertically adjusted. Adjustable Straight Strands located above the girder's upper kern location can be used by the automated design algorithm to alleviate girder end stresses.

 

Commercial harping device. Photo: Concrete Industries Inc.

End of debonding tube sealed with duct tape to the strand. Photo: Standard Concrete Products.

 

 

 

A 205-ft-long girder used for the Alaskan Way Viaduct using bundled harped strands. Photo: Concrete Technology Corporation.

 

A 191-ft-long bridge girder used for the Cody Avenue Bridge in Okaloosa County, Fla., which used a straight strand profile during production. Photo: Dura-Stress Inc.

Example of tube for bundling of strands at the harp point. Figure: PCI Bridge Design Manual.

 

https://utsv.net/prestressed-concrete/basic-concept-method

the tendons are harped (using ‘hold-downs’ in the pre-tensioning bed) or draped (using a post-tensioning duct)

 

 

 

참고자료

Asp2014Fall-CBT-PretensioningStrandProfiles

https://www.aspirebridge.com/magazine/2014Fall/Asp2014Fall-CBT-PretensioningStrandProfiles.pdf

 

 

https://www.wsdot.wa.gov/eesc/bridge/software/Documentation/PGSuper/4.1/index.html

 

 

https://utsv.net/prestressed-concrete/basic-concept-method