{live-template:Test Problem}



h1. 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|kb:Bridge modeler]

* Two-span bridge created manually

* One-span bridge created using the bridge modeler

* One-span bridge created manually


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|kb:Bridge bent].

* A straight [tendon|kb: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.


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|kb:Frame] 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.

h1. Model screenshots

Flexural response is depicted in Figures 1 and 2:


!figure 2.png|align=center,border=0!

{center-text}Figure 1 - Moment diagram, 2-span bridge with tendon{center-text}


!figure 3.png|align=center,border=0!

{center-text}Figure 2 - Moment diagram, 1-span bridge with tendon{center-text}


Section cuts reveal that individual element forces closely correlate with those induced by prestressing.

h1. See Also

* [tp:Obtaining hyperstatic forces for bridge object superstructures] test problem

h1. Attachments

* [SAP2000 V12.0.2 model |Tendon force vs. Frame response^SAP2000 V12.0.2 model.zip] (zipped .SDB file)