Tendon force vs. frame response
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Overview
The model attached contains four separate structures, shown below in Figures 1 and 2, and listed as follows:
Two-span bridge created using the bridge modeler
Two-span bridge created manually
One-span bridge created using the bridge modeler
One-span bridge created manually
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All four structures have the following properties:
Each span length is 10m.
Concrete deck sections are 0.5m deep and 3m wide.
Simply-supported conditions are at each abutment and bent.
A straight tendon, 25mm in diameter, runs along each length. Tendons are prestressed to 10kN (without losses) and located 0.05m from the bottom of each section.
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The purpose of this model is to:
Determine and review internal forces resulting from prestressing.
Verify the prestressing forces used for flexural design check.
Compare frame-element forces to the prestressing forces, found through the Display > Show Bridge Forces/Stresses menu.
Define a section cut through the frame and tendon, review forces, and compare with frame and tendon response at section cut locations.
Model screenshots
Flexural response is depicted in Figures 1 and 2:
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Figure 1 - Moment diagram, two-span bridge with tendon
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Figure 2 - Moment diagram, one-span bridge with tendon
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Section cuts reveal that individual element forces closely correlate with those induced by prestressing.
See Also
Hyperstatic forces for bridge-object superstructures test problem
Attachments
SAP2000 V12.0.2 model (zipped .SDB file)
Metadata
Name: Tendon force vs. frame response
Description: Tendon application is validated by comparing tendon forces to those in an equivalent frame system.
Program: SAP2000
Program Version: 12.0.2
Model ID: na