A higher standard of bridge design
Staged Construction Analysis
for Prestressed Concrete Bridges
to accurately calculate the change of tensions in pre-stressing tendons for a load history through every construction stage
Issues in handling staged construction analysis for post-tensioned bridges
The behavior of pre-stressed concrete structures depends on the effect of pre-stress. When a pre-stressed concrete structure is analyzed, engineers must anticipate and correctly calculate the change of tensions throughout each stage of construction.
What highly-skilled engineers need is a feasible/efficient method to analyze the bridge model and extract tendon loss results while considering various factors that cause the loss, such as shrinkage and tendon relaxation before tensioning, elastic shortening and loading and temperature after tensioning.
Process and features helpful for checking constructability of Suspension Bridges
Significant Features and Differences in Results
I used Prestressed loads portion of the program to define the tendon profile. For me, defining the tendon in midas Civil’s manner is more intuitive. Nice thing about using this tool in midas, you can do all the calculation work in excel and copy the cells into the tool. Makes it easier for initial profile settings or if I want to adjust anything later in the design. With the use of the spreadsheets and ability to copy and paste into tendon profile tool, assignment to define all these tendons were greatly reduced, eliminating the redundant process
Doug Midkiff at AECOM Denver, co
Typically, you would use a special software like midas Civil to simulate the stage construction. Typical software packages don’t allow you to actually have separate models/structures joined together in a same model. So you need a special s/w to allow unconnected structures to account the time dependent effects and loading history on the structure.
Tony Ledesma at WSP