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(gentle music)

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- [Announcer] Bridge engineers,

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working with the strut and
tie modeling technique.

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Now have a much clear
understanding of its design needs.

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Thanks to researchers

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with the Center For
Transportation Research

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at the University of Texas.

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In part, the strut and tie analysis

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will help create safer bridges
and more consistent designs.

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- So the specification
currently requires footings

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to be designed by strut and tie analysis,

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but the strut and tie analysis provisions

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were based on the testing of
deep beams and not footings.

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So this research was hoping
to extend the knowledge

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and better represent the footing behavior.

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- Designers were making a
variety of different decisions

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because the specifications are not clear

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as to the decision making process

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that resulted in some design details

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with constructability issues

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some details that are overly conservative

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and others that made
TxDOT engineers question

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their viability.

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- The research was successful

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in accomplishing our main goal.

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We were able to refine
the design procedures

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and increase our understanding
of the footing behavior.

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This was accomplished by 16
full-scale test specimens

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and then Finite Element Analysis
to verify the test results

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of the physical tests.

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- We tested some footings in a scale

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and loading scheme that is
more realistic if you will

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than what's been done
before or more comprehensive

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is probably a better way of putting it.

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Detailed Finite Element Analysis

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to where additional insights were gained

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led our team to reach conclusions

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that basically provided
a lot of clarification

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as to what to do and what not to do.

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- We will look at all
of the recommendations

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and they were a lot.

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This research project was really like,

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six research projects put together.

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There was a lot of
information we got from this.

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So we'll look at all of
their recommendations

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and decide which ones we wanna adopt.

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And we may change our
design practice accordingly.

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- [Announcer] For more information

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and define the publications
for this project.

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Please visit the TxDOT Research Library

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at the link shown below.