Tag Archive for: bridge

Under (and Over) the Sea: Traveling with a Bridge Tunnel

,

Have you ever been driving on a bridge you’re not familiar with and then, all of a sudden, the road starts to lead you underwater? You may feel nervous, amazed, and even confused at first, but bridge tunnels are safe and incredibly effective transportation. Here is an overview of a bridge tunnel, its purpose, and some famous examples from around the world.

What is a Bridge Tunnel?

Bridge tunnels are structures that feature both a bridge section and at least one underwater tunnel section. The purpose of these structures is to allow for the continuous and simultaneous flow of vehicle and boat traffic.

An alternate solution is a moveable bridge, which is a bridge that can move or lift in order to accommodate the passage of boats and ships. There are many types of movable bridges that have been in use for hundreds of years, including drawbridges, vertical-lift bridges, and swing (pivot) bridges.

The drawback is that moveable bridge traffic can hold up traffic and aggravate commuters, especially near bodies of water where shipping is common.

Enter the bridge tunnel. This engineering marvel makes it so that all traffic can continue to flow; boats, trucks, cars, and cargo ships can all use the same transportation space in peace without disrupting one another.

Famous Bridge Tunnels

The Chesapeake Bay Bridge Tunnel

Did you know that all of the bridge tunnels in the United States are located in the state of Virginia? Perhaps the most famous of these Virginian marvels is the Chesapeake Bay Bridge Tunnel. This 60-year-old structure spans 17.6 miles in total length, from shore to shore. This tunnel consists mostly of bridge roads, but because of the importance of shipping in the bay, two tunnel sections were built into the main shipping channel crossings.

Each tunnel is over one mile long and easily allows for the passing of ferries and cargo ships without disrupting the flow of traffic. At the time of its completion in 1964, it was named “one of the seven engineering wonders of the modern world.”

The Hampton Roads and Monitor-Merrimac Memorial Bridge Tunnels

Prior to the Chesapeake Bay, Virginia boasted the world’s first-ever bridge tunnel to finish construction. The Hampton Roads Bridge Tunnel, which connects Hampton and Newport News to Norfolk and Virginia Beach, was completed in 1957 and measures 3.5 miles in length.

The third and final bridge tunnel located in the United States is the Monitor-Merrimac Memorial Bridge Tunnel, which connects the Virginia Peninsula cities of Newport News and Hampton to Suffolk and Chesapeake. This was completed in 1992 and measures 4.6 miles in length.

These two bridge tunnels have significantly improved the flow and amount of tourism traffic between all of these high-volume areas, which benefits residents and visitors alike.

The Hong Kong-Zhuhai-Macau Bridge

In 2018, the world’s longest bridge tunnel completed construction and opened for public transportation in China. The Hong Kong-Zhuhai-Macau bridge measures a total of 34 miles in length, connecting Hong Kong to the Pearl River Delta in Guangdong province and the city of Macau. By significantly reducing travel time between these three regions, Chinese government officials are optimistic about the economic benefits and tourism booms for all areas.

The Way of the Future?

Whether traveling by land or sea, commuting over a bridge tunnel can save a lot of traffic jams and headaches. As more and more cities see the potential benefits of these structures, perhaps these architectural wonders will be the way of the future. If a body of water is long enough and the traffic in the area is heavy enough to warrant building a bridge tunnel, it could help commuters, residents, and visitors all have a better travel experience.

Built to Last

With more than 80 years of bridge-building expertise and as an AISC-recognized supplier, we know what it takes to complete the task, no matter the difficulty. We use only the best resources to build strong, dependable bridges. We take pride in offering a huge selection of prefabricated bridge designs that we are certain will perfectly suit the demands of your particular project.

Contact us today to start your next project, or check out our premier BridgeScope tool to get a head start on the process.

5 Famous Bridges Around the World

,

Some locations are defined by their distinct skylines or unique transportation systems. But many iconic cities also boast famous bridges that decorate their harbors. These examples stand across the world as great bridges that are the peak of architectural accomplishment.

These bridge designs have been adapted and enhanced in keeping with modern innovations, and each design serves a particular purpose for their city’s needs.

In appreciation for these marvels of human innovation, here are five of the world’s most famous bridges.

1. The Danyang-Kunshan – Suzhou, China

The Danyang-Kunshan bridge in China is the world’s longest bridge, measuring over 100 miles (164.8 kilometers) in length. This bridge connects Shanghai and Nanjing, two of the largest cities in China.

The bridge was completed within its original 4-year timeline, despite difficult terrain and canals, due in large part to the over 10,000 construction workers working on the project. The construction of the bridge cost $8.5 billion and was expertly designed to withstand the typhoons and earthquakes that frequent China’s landscape.

2. The Millau Viaduct – Creissels, France

The Millau Viaduct in France is the world’s tallest bridge, with a structural height of 336 meters (1,104 ft), which is taller than the Eiffel Tower! This cable-stayed bridge crosses the Gorge valley of the river Tarn, which has helped with traffic congestion by shortening the travel time between Clermont-Ferrand and Beziers. The Millau Viaduct is supported by multi-span cables placed in the middle and two thin, flexible columns that form a supportive and easily recognizable A-frame.

3. London Tower Bridge – London, UK

How many famous bridges actually have songs written about them? The London Tower Bridge is easily one of the most recognizable structures in the entire world. The two distinct towers connected by two parallel walkways have given this bridge its rightful place among the most iconic structures in history.

Located on London’s River Thames, this iconic engineering marvel was built with a combination of suspension and bascule structural elements. This bridge is called the London Tower Bridge not only for its distinct towers but also for its proximity to the historical royal prison, the Tower of London.

4. Golden Gate Bridge – San Francisco, USA

This famous bridge can boast being in the opening sequence of several American television shows (Full House to name one!). The Golden Gate Bridge is an architectural staple for the city of San Francisco and is another easily recognizable bridge.

Joseph B. Strauss designed the 894,500-ton, iconic red bridge to connect the city of San Francisco and Marin County. The Golden Gate measures 4,200 feet in length, which makes it one of the longest suspension bridges in the world.

5. Rialto Bridge – Venice, Italy

The Rialto Bridge is, by far, the shortest bridge on this list; it only stretches roughly 104 feet across the narrow Grand Canal in Venice, Italy. In addition to being a popular tourist spot, this iconic arched bridge is one of the oldest bridges that remains perfectly intact and continually in use.

The Rialto Bridge was designed in the early 16th century by Antonio da Ponte, who took his inspiration from a bridge design that dated back to the 13th century. It has two inclined ramps, three walkways, and a span that allows for easy passing of boats through the iconic Venice canals.

These five famous bridges are only a few examples of architectural marvels, but there is no shortage of functional and stunning bridges all over the world. As time goes on, architects continue to improve bridge designs in order to meet the needs of an ever-changing world.

Building the Best with U.S. Bridge

As industry leaders and pioneers in several construction industry firsts, we know the importance of high-quality materials, ground-breaking designs, and reliable engineers. We’re proud to provide a comprehensive service that is easy to understand and time-efficient. That’s why we are the go-to for so many builders!

Working with us means working with professionals at every stage of the process. Get in touch with us now to begin the process, or use our exclusive Bridgescope tool for a jumpstart.

Why We Use Steel Galvanizing for Bridges

Hot Dip Galvanized

A new bridge is a piece of infrastructure that will serve communities and transportation for decades. They must be built to last with the strongest and most durable materials. With hot-dip galvanizing, U.S. Bridge builds bridges that minimize maintenance and long-term durability regardless of the environment.

We’ve been galvanizing bridges since 1987, and we were the first to hot-dip galvanize an entire welded truss bridge. By bonding zinc to our U.S.-manufactured steel, we’re building long-lasting, reliable bridges with a sustainable process.

The Galvanizing Process

To galvanize steel, thorough cleaning of the steel is absolutely necessary. This is because zinc will only react with clean steel during the hot-dip process. Areas that are not perfectly clean will interfere with the process.

Before the Hot-Dip

Before hot-dip galvanizing, the surface must be prepared. This process includes degreasing, pickling, and fluxing.

Degreasing is the first step in cleansing the steel. It remotes dirt, oils, and organic residue. Next is pickling, which removes the iron oxides and scales from the steel’s surface to expose a bare area for galvanizing. Finally is the fluxing process, which prepares the steel for the hot-dip phase by applying a protective saline layer.

Hot-Dip Galvanizing

After the cleaning process, the steel is immersed in a kettle bath of 85% pure molten zinc at 830° F. The zinc reacts with the iron steel to form metallurgically-bonded coating. Once the steel reaches the bath temperature, the bonding is complete.

Once the steel cools down, an inspection verifies that it conforms to specifications. This includes a visual inspection and a magnetic thickness gauge that measures the coating.

Galvanizing Improves Bridge Life Cycle

The cost of hot-dip galvanized steel is roughly the same as painting a bridge. While a quality paint coat must be touched up, zinc-coated steel does not need maintenance over the bridge’s life.

However, the galvanized steel eliminates corrosion for up to 100 years in many cases. According to one study, the future maintenance of bridges can be reduced by 50% with galvanizing. With galvanized steel, the average service life is 8.5% longer. In fact, at U.S. Bridge, we have a 35-year warranty on our galvanized steel beam bridges — we’re that confident in lasting quality of galvanization.

Environmentally-Friendly

There are several environmental advantages to hot-dip galvanizing, beyond just the financial and durability impact. The key to sustainable construction of bridges is to continually lower the environmental impact of producing products. This is possible with zinc and steel.

Both zinc and steel are two naturally occurring, abundant elements. Ore — which steel is composed of — is the fourth-most abundant element on Earth. Zinc is 24th. Both are infinitely recyclable without the loss of physical or chemical properties. These materials can be used over and over without compromising their integrity.

With less maintenance, galvanizing will also prevent potentially harming environments during maintenance and traffic delays.

Build Sustainable Bridges with U.S. Bridge

In summary, hot-dip galvanizing steel is about the savings on the life-cycle of your bridge and the environmental benefits. With decades of experience in hot-dip galvanizing, we guarantee the highest level of quality in our steel bridge parts.

U.S. Bridge has been serving communities for more than 80 years, building bridges that withstand time. Our bridge experts will advise you on the best option for your bridge. Contact us today and let’s talk about how we can make your bridge project a long-lasting success.