Wednesday, June 8, 2016

Fast Lane: #TechTuesday: Building Bridges from the Ground Up

Header for US Department of Transportation Blog

Innovation is paramount at USDOT. We have long supported cutting-edge transportation research and development, and believe in giving innovators access to the data and tools necessary to help launch pioneering technologies in their own communities. This partnership of research and deployment can generate even more creative problem-solving and forward-looking solutions for meeting our current and future infrastructure challenges. That said, I’m excited to give our Chief Innovation Officer a platform here on my blog every week to showcase the hard work being done at the Department that will allow for 50 more years of thought leadership and innovative transportation solutions. Welcome to #TechTuesday!
-Transportation Secretary Anthony Foxx

Ever think about how engineers will design bridges in the future?  That topic may not be the first thing on your mind but it is a critical one.  The American Society of Civil Engineers (ASCE) points out that 66,749 bridges – totaling about a third of the bridge decking in the US – are structurally deficient and will need to be replaced or repaired.  We have a lot of bridge building in our future!
How do we make sure these new bridges will last, not just for a while but for 100 years or more?  The key is to eliminate some of the ways a bridge can fail. 
One important factor is bridge scour – the way that the water and debris erode the soil around the footings as they flow past the bridge.  Too much erosion and the bridge can lose its support, causing it to fail or collapse.  In theory, if you know enough about the soil and the flow of water crossing the bridge opening, proper placement of bridge supports can ensure they never wash away.  But, to do this you need precise measurements of the water flow and soil erodibility at a bridge site andaccurate mathematical models that predict the forces created by the flow.
That’s where Dr. Kornel Kerenyi and his team at the Federal Highway Administration’s Turner Fairbank Highway Research Center come in.
Step into his lab and you’ll see all sorts of amazing things – a 90 feet long man-made water channel that can simulate an artificial river, laser scanners, robots and ultrasonic velocity probes – all coordinated to showcase bridge design of the future. 
By changing the slope and width of the channel sections in the flume, the speed of the flowing water and the sediment injected in the stream, Kornel’s team can create a physical model of various river bed conditions.  Using the latest 3D printing technologies, they produce scale models of bridge designs and measure the interactions of water and bridge with millimeter precision.
Results of these experiments are sent to researchers at the Argonne National Laboratory’s Transportation Research and Analysis Cluster Computing Center to calibrate their computer simulations. Together, this work allows designers to create virtual bridge designs and see what forces the water flow and sediment erosion will create on those designs.
So will the bridge design last a century?  There is one last piece necessary to answer this question.  The simulation needs to know how well the soil under the footings can resist erosion caused by the force of the flowing water.
A Robotic Data Collection Arm and Mobile Sediment Bed in the Multifunctional Flume System
Kornel has a solution for that as well.  Together with FHWA hydraulic engineer Bart Bergendahl, he patented a design that can go directly to a point in the riverbed, automatically flow water across a sample of the soil there and measure its erosion resistance.  In the future, Kornel can even envision drones assisting this design process by measuring the river’s depth and flow at specific locations or even transporting other soil samples to nearby testing facilities.
ASCE recognized Kornel’s work with the 2016 Henry L. Michel award for Industry Advancement of Research.  You probably won’t recognize it but will surely appreciate it as you drive across tomorrow’s bridges, admiring the view.


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