Dallas Bridge Margaret McDermott Eliminates Testing to Save Money

Margaret Mcdermott Bridge Construction
Margaret Mcdermott Bridge Construction

Photo by Art Davis, CC BY-SA 4.0, via Wikimedia Commons 

The Margaret McDermott Dallas Bridge over the Trinity River in Dallas, Texas was intended to replace the I-30 bridge built in the late 50s to early 60s. The bridge cost over $100 million to build and features a design resembling a suspension bridge. The part of the bridge designed for pedestrians and cyclists was supposed to open in 2017, but it remains closed. Now, it is going to take two more years and $7 million dollars more before pedestrians will be allowed to use the bridge.  

Why did this disastrous result happen? The simple answer is a lack of bridge testing. In order to lower costs, the hike and bike bridges used value engineering to cut costs by $3 million. According to the Cambridge Dictionary, value engineering is “the process of reducing the cost of producing a product without reducing its quality or how effective it is.” However, in this case, an important cable testing was skipped to save $30,000, despite the fact that strong winds are predominant in this area. After the cables were attached, heavy winds caused them to vibrate and twist, which caused several cable anchor rods to crack and fail (The Dallas Morning News). 

This issue has created a lengthy back-and-forth between the architect (Santiago Calatrava), city officials, and the Texas Department of Transportation. There is a lot of finger pointing when it comes to who is to blame for putting off proper testing. Calatrava states they pushed the city of Dallas to do the proper testing and even offered to front the costs, but it was not done.  Still, officials at City Hall and the Texas Department of Transportation have put the blame back on Calatrava. 

For now, the two cable-stayed structures of the Margaret McDermott Dalla Bridge system remain closed as no one is willing to certify that they are safe for use. Clearly, the $30,000 saved by skipping bridge testing did not pay off, and ended up costing the city way more than they planned for.  

Lessons Learned  

Photo of iCOR being used on concrete

When it comes to bridge testing, do not cut corners. Investing in a thorough, accurate method of testing can save you money and stress in the long run. Furthermore, after the bridge is built, do not forget to continue testing for damage and deterioration. Options for bridge testing include: visual inspection, acoustical techniques, infrared/thermal imaging inspection, coring and chipping, and ground-penetrating radar (GPR). If you are looking for a non-destructive technique to detect the rate of corrosion in your structure, check out our award-winning device iCOR®. This tool uses our patented Connectionless Electrical Pulse Response Analysis (CEPRA) technology to perform three-in-one concrete testing measurements of: rebar corrosion rate, half-cell potential, and in-situ electrical resistivity. Finally, if you need to conduct a half-cell potential test according to ASTM C876, check out XCell™

Click here for an analysis of each of the testing methods mentioned! 

Sources 

Cambridge Dictionary

NBCDFW

D Magazine

The Dallas Morning News

*Editor’s Note: This post was originally published in February 2018 and has been updated for accuracy and comprehensiveness. 

Leave a Reply

Your email address will not be published. Required fields are marked *

Related Articles

Concrete strength monitoring with thermocouples

Choosing the Right Concrete Thermocouple for Your Jobsite

*For eligible new customers only Get a Free Trial Kit Free Sensor* Free Shipping No Strings Get Your Trial Kit What Is a Concrete Thermocouple?  In layman’s terms, a thermocouple is an electric device that measures temperature, essentially making it a type of thermometer. That being said, it is not the kind of thermometer you would use to measure your body temperature when running a fever, or to deduce what the atmospheric weather is today, or as an in-built mechanism within your refrigerators and heaters. So, what exactly sets a concrete…

SmartRock Sensor and Mobile App

The Importance of Monitoring Temperature Differentials in Mass Concrete

Closely monitoring concrete temperatures is critical for ensuring proper strength development of concrete structures, regardless of their application or size. However, when it comes to mass concrete structures, temperature differentials also need to be considered due to the risk of a large difference between the relatively hot internal temperature and cool surface temperature. If a too-large temperature differential occurs, the surface of mass concrete will start cracking, which is detrimental to its…

Aerial view of construction site

Rebound Hammer vs. The Maturity Method: Which Should You Choose?

Schmidt/Rebound Hammer Method The concrete rebound hammer test (often referred to as Schmidt Hammer) was invented in 1948 and is still a popular choice to test the compressive strength of concrete. To use this method, the rebound hammer must first be calibrated against a steel test anvil. Once calibrated, a spring release mechanism is used to activate a hammer which impacts a plunger to drive into the surface of the concrete. After…

We use cookies to provide you with a better experience, analyze site traffic and assist in our marketing efforts. By continuing to use this website, you consent to the use of cookies in accordance with our Privacy Policy Page.