Refined analysis, soil structure interaction examined in Midas webinars
By Yanling Leng
When talking about refined analysis, most engineers might think of using it only for complex bridges and bridges that are beyond the range of applicability of the AASHTO LRFD formulas. For the design and load rating of normal local bridges, many favor a general philosophy of keeping the analyses simple to minimize errors, or to remain true to the accepted, proven engineering practices. However, this might come at a cost to our nation and may not foster the most effective use of limited resources.
In a recent webinar with Midas, I argued that refined analysis is the future for bridge analysis—including for the optimum design and load rating of normal local bridges—and is a must-have skill for bridge engineers of today.
A properly and efficiently executed refined analysis can provide substantially better information about a bridge and allow for more cost-effective design. While a refined analysis is not guaranteed to improve a load rating enough to avoid a posting, it is always a more accurate representation of a structure, compared to approximate methods.
To learn more, watch my webinar on the Midas website.
In another Midas presentation, I discussed the complex topic of soil structure interaction (SSI), for which codes/standards contain limited guidance. I shared some experience I had gained at IMEG in the design of a three-span continuous concrete slab integral abutment bridge supported on drilled shaft. In the workshop, I introduced the fundamentals of SSI for integral abutment, as well as drilled shaft. And I presented the design methods for integral abutments and drilled shafts, both simplified methods and more sophisticated methods. In the end, I demonstrated the finite element model I built to model SSI using Midas Civil. I also discussed how to obtain the parameters needed for SSI analysis and answered relevant questions.