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USB-Blog-How-it-Works-Engineering-Bridges-To-Handle-Stress

Bridges are often seen as immovable structures, but in truth, they are quite dynamic. Bridges must be engineered to move with environmental stressors in order to avoid unnecessary wear and tear. Additionally, different load types, weather conditions, and traffic can all cause bridges to adjust at various times. In a way, a bridge is an engineering marvel. So, how does it work? Below are some of the key components of bridge engineering and how they handle stress.

Oh, Gravity!

Gravity has the most profound impact on a bridge. Gravity is a constant – no matter what the other conditions, gravity is always acting on a structure, trying to pull it down. Bridges are at an even more unfair advantage against gravity since they span open spaces. For instance, a building, like a skyscraper, is also affected by gravity, but the ground the building is built on pushes back, creating an equilibrium of sorts. Bridges have no ground beneath them to act as a counterbalance to gravity. However, bridge failures are rare, thank goodness! So, how do designers go about engineering bridges to compensate for this gravitational pull?

Compression and tension are carefully balanced by channeling the bridge’s load onto the abutments (the supports on either end of the bridge) and the piers (the supports underneath the bridge).

Other Factors When Engineering Bridges

While gravity may be the most consistent force acting on a bridge, there are a handful of other elements that have a significant impact.

Loads – Bridge loads change often from vehicle to vehicle. Even a bridge specifically designed for one type of job, i.e. a train bridge, will find its load varying often. Different trains and their cargo weigh different amounts. Hence, it is imperative to engineer bridges that can adapt to these loads by flexing and bending and then returning to their normal state once the load passes.

Weather – Weather can wreck havoc on most structures, and bridges are no exception. Earthquakes and hurricanes can greatly impact structural integrity, while tides and wind can cause twisting and swaying. However, water is the most worrisome factor, because its different states generate different results. As snow or rain, water can make a bridge surface slippery; but, as ice, water can get into the crevices of a bridge and expand, causing more issues once the ice melts.

All these elements must be taken into consideration when designing and constructing a bridge. Only true experts understand what it takes to build a robust, durable, and functional bridge.

Find Out More Today

To find out more about how we go about engineering bridges to meet various workloads and demands, please contact U.S. Bridge today. Our team of engineering experts have been building bridges for decades. U.S. Bridge can bring that level of expertise to your next project too.

Optimal Design Of Through-Truss Steel Bridges

Truss bridges are one of the oldest bridge types in America. In fact, even novice bridge enthusiasts can easily spot one, since they are identified by their singular design feature: the truss, which forms triangular units. Truss bridges are used for a variety of reasons, mainly because they can easily accommodate dynamic loads. A through-truss bridge is one in which the roadway dissects the truss, meaning the truss is seen both above and below the deck. Here are a few interesting facts about the optimal design of through-truss steel bridges.

Factors that Impact Truss Steel Bridge Design

When studying through-truss steel bridges, engineers are primarily concerned with three things: optimum weight, optimum height and building material. A combination of these factors greatly impacts not only the cost of the bridge, but also its longevity and usefulness. Additional factors such as weather and use are also taken into consideration.

Determining the Optimal Through-Truss Design

In 2014, students at the civil engineering school at the University of Manchester in the UK studied through-truss bridge design with the goal of understanding the best combination of the above. They were most concerned with bridge stability, longevity, and cost-effectiveness. They determined that the element with the most impact on bridge design was the decking material. While minor adjustments can be made in the width and height, the weight of the decking material has the largest impact on the longevity of the bridge. They also realized that reinforced concrete decking is the most cost-effective; however, when reducing weight is the primarily concern, steel is the best option.

Through-Truss Bridges and U.S. Bridge

U.S. Bridge has been a leader in bridge building since 1936. Our expert staff of engineers, builders, and designers are well-versed in all bridge types, including through-truss steel bridges. Still family-owned and operated, U.S. Bridge is committed to providing customers with the latest in bridge design and construction. Our past clients include state and local governments, as well as businesses.

If you would like to find out more about U.S. Bridge, our work and our team of experts, please contact us today. We are happy to discuss your steel bridge needs and look forward to working with you.

U.S. Bridge Featured in Cannelville Road Bridge Case Study

Once in awhile we are requested to perform along side of the best in our industry. The Cannelville Road Bridge was one of those stories. In Muskingum County we built a bridge that uses an innovative press-brake-formed steel tub girder (PBTG) system. We are proud of our technical prowess and innovation. We always build schedules […]