Truss Bridge

I will be explaining four of the most popular types of truss bridges in this paragraph. One type of truss is the Allan truss bridge. The Allan truss bridge been in the world of truss bridges for a long time. A fact of the Allan truss is it was first ever build in the 1800s, and the first time the Allan truss was designed was on the date of August 13, 1894. Aldo Alan truss aren’t as common as today there still a very good truss bridge, and quite efficient. Next truss bridge is the Warren truss bridge. A Warren truss bridge is one of the most commonly built truss bridge. That because a Warren truss bridge is simple and is not a big task to build. It uses equilateral triangles to spread out all of the loads from the bridge. It works very well due to all of the triangles minimizing the forces of tension and compression. It’s said to be really light but very efficient, and strong. Another type of truss bridge is a much known truss bridge which is the Baltimore truss bridge. A Baltimore truss bridge is very common to a Pratt truss, the only differences are its additional branchy which is much lower compare to the Pratt truss. The reasons of that are it prevents bucking in the members. The Baltimore truss was first built in the year 1871 for railroads it was first build in the areas such as Baltimore, Pennsylvania, and Ohio. Today it’s one of the most famous type truss bridges in the world. The last bridge on the list is a Pratt truss bridge. It was first develop in the 1800s, and was designed by Caleb Pratt and Thomas in the year 1844. It has a unique and good usage of iron and was first used as a railway which was very popular. It’s very solid and good at taking on compression and tension. Its form is vertical and diagonal that go towards the center of the bridge. Today it’s known as a simple and strong truss bridges that work very efficient and give it one of the tops spots as one of the truss bridges

Calculations were performed to determine the effectiveness of the design of the platform. Allowing for a safety factor of 1.5 times the design weight of 10kg and considering the bridge must not be overdesigned; plans were made for the bridge to fail at 25kg, 2.5 times that of the design weight. According to the calculations, the bridge would hold a load of over 15kg and experience failure at 20kg in the members. These calculations were later disproven in the testing, breaking 8kg earlier than expected, due to unforseen errors. An analysis of the bridge design and calculations has been included at the end of this report.

Since the early days, the men try overcome environmental challenges and, in this process, ends up creating amazing masterpieces of engineering. Among this works, the bridges appears as the clearest representatives of how the mankind could adapt to Earth’s contours. If the shape of landscape can’t be changed, the bridges are the solution to link two places and allows the connection of the traffic to improve aspects such as the communication and the trade. Depending to the need, to the sources and to the environment, the bridge can be constructed in a specific configuration. There are five main sorts of bridges configurations. First, there is the simplest bridge, the beam bridge. Second, the arch bridge, one of the oldest kind. There are the truss, composed of set of trellises. Lastly, there are the cable-stayed and

The Pratt truss bridge was originally founded by Caleb and Thomas Pratt in 1844. It is mainly used to carry trains. The biggest advantage of this bridge was its low costs for construction and the materials to construct a truss bridge are minimal. It also use materials that is cheaper and light in weight. We can easily identify a pratt truss by detecting its diagonal members, which (excluding for the very end ones) all slant down and in toward the center of the span. The pratt truss was designed by applying few laws that related to the mechanics of materials concept. The bridge is mainly built using steel girders to support the construction of the structure. The below part of bridge weight is high so, it need an enough support to prevent from

Truss bridges have been around for a long time. I see truss bridges the most out of all the different types of bridges and to me it seems like the most popular type of bridge. In addition there are thirty different types of Truss bridges which means that there is a bigger variety of Truss Bridges instead of just having one type. Truss bridges have triangular shaped beams that go all across the bridge. The bridge also is above the roadway instead of under the roadway like the arch bridge. Truss bridges could also stretch very far. The longest cantilever Truss bridge that goes is called Crescent City Connection and it is 13,418 feet long with a width of 52 feet. There is also a really long Truss bridge that is near Hoboken, the name of the bridge

All are very effective and work well if built in the right conditions. The thing that separates these bridges from one another is that they all have different points of compression and tension. Tension is two forces of opposition that pull away from each other to keep it from being pulled together. If you imagine a rope in a game of tug-of-war, the rope has a lot of tension because it is being pulled apart, but the opposing force inside of the rope is trying to keep it together. The same can be applied to a bridge truss because the tension truss is opposing the compression truss by pulling the bridge apart. Tension also pulls the platform of the bridge by stretching it to keep the bridge from collapsing. Compression is two forces in opposition that push an object together to try to compress it. If you think of someone standing on a soda can, the soda can tries to resist being squished, but the weight of the person standing on the can still squashes it. This example can also pertain to the truss on a bridge. A compression truss opposes the tension truss by pulling the bridge together. Compression is also placed on the top of a truss and in its bases. The compression at the top of the bridge counteracts with the tension of the platform and balances out each force. The compression in its bases is from the weight of the platform and trusses. Bridge engineers calculate the tension and

Hecox (2011) says that the arch structure of the Tillman Bridge makes the canyon walls hold the weight of both vehicles and the bridge itself. In addition, the arch structure allows a better vision of the canyon for the drivers, which was a request of the population to the engineers of the project. In the other hand, according to Jones (2015), the truss structure of the new St. Anthony Bridge also was requested by the population because they wanted to keep a truss bridge in that place. The author also affirms that the St. Anthony Bridge is a truss, but the project team proposed adding a posttensioned concrete bottom chord to the steel truss in order to reinforce it. The project team made this choice because one bridge in Minnesota has collapsed in 2007, and the engineers wanted to lessen the fracture-critical issues to avoid a new catastrophe. In addition, this posttensioning approach wiil make the structure redundant for both resiliency and long-term durability. In conclusion, both bridge's structures were right chosen in order to provide safety and beauty in both

The Principle upon which all trusses rely is that the triangle is the strongest and most rigid geometric Figure. By arranging the framework of triangles in patterns that varied from designer to designer, the structure acquired different appearances and served different purposes depending on the needs of bridge builders. The pony truss, the smallest type and ordinarily confined to lengths under 140 feet, with most under 100 feet, is distinguished by its low profile and absence of bracing above the roadway. The through truss by comparison is greater in length and height and consists of a tunnel-like structure that carries traffic through a system of overhead bracing which ties together the upper chords of the bridge.

There is always a great uncertainties in predicting the loads a bridge might experience at some time in the future. One can never be certain of the weight of the heaviest truck that will cross a bridge. For that reason, my design of a truss bridge will hold a 20-ton load limit. When analyzing both the internal forces and external forces on the bridge, assumptions are made. When taking calculations the system must be modeled as in static equilibrium so we must assume that gravity is downward and that the only force is the load on the bridge .

The truss bridge I will focus on is Hampden Bridge, located in Wagga Wagga, New South Wales. Hampden Bridge is a wood Truss bridge that crosses the Murrumbidgee River in Wagga Wagga, New South Wales. This bridge opened to the public on 11 November 1895 and it was closed in October 1995 due to Wiradjuri Bridge opening. The bridge is 100.5 metres long, all of the 3 truss spans 33.5 metres. Hampden Bridge is the first large overhead-braced truss bridge made by Percy Allan. The bridge was originally designed to be a steel, but the tenders were too expensive. timber was used as the alternative. The Hampden bridge replaced the Wagga Wagga bridge,this bridge was made in 1892 and alos crossed the Murrumbidgee river. Percy Allan made the third of five standard wooden truss bridges. there is a clear difference of development between the pre Allan era and the post Allan era. Allan completely redesigned how timber truss bridges were made in NSW. He often based his bridge design on the American Howe bridge although he exploited the much stronger woods in Australia, to reduce the design its bare essentials, this is show in the differences between the two bridges before Allan made his and Allan’s bridges all around New South

An arch bridge has a slight Bend in the middle that makes itself sturdy. Most arch bridge is as old as rock itself.A beam bridge is made of many different things mostly steel and prestressed concrete.A beam bridge is the simplest and the oldest bridge ever created. The beam bridge is so simple all it consists of is a log or we can go more advanced with steel and concrete. The beam bridge may be easy and inexpensive to build but is not the sturdiest. The beam bridge is Not sturdy because of the lack of materials used and that it is square. A beam bridge is made for depending on the place, long or short distances.Truss Bridges at the beginning were made of wood and iron . Most bridges were made of stone but the the truss Bridge was made of wood and iron because it can withstand a lot of tension unlike stone. Now a days truss bridges are made of metal. The truss bridge is a very strong bridge.The truss bridge is strong but is very very expensive and hard to build. The truss on the truss bridge is made to keep the wind from blowing it over.The truss is also to keep the tension from

Trusses are triangular shaped support beams that attach point-side down to the roadbed of the bridge on either side. This structure distributes the force of the weights to the bridge. These bridges are a lot like beam bridges, but stronger and it is perfect for heavy loads and small distances. In addition, triangular trusses will work, but will drastically decrease the weight or load your bridge can hold. (To make your bridge even stronger, attach short pieces of spaghetti to the points of the trusses to make small triangles - trusses for the trusses.) Also, the triangular shape is the best method of construction than rectangular shape as there is no bending because the bridge is strong.

Our next destination was one I couldn’t wait to go to, the Williamsburg Bridge. I was excited because I love seeing and learning about the architecture of a bridge and also being able to walk over one is so amazing! “Construction on the bridge began in 1896 and opened it on December 19, 1903. When it was completed the Williamsburg Bridge set the record for the longest suspension bridge in the world. It was also the first bridge to use steel instead of masonry towers, which reduced the side of the foundations and cost much less than masonry” (ENY, 197). It was a little longer than the Brooklyn Bridge, but what made it worse that day was the heat. It just felt like it took us forever to get over the bridge for some reason. It was interesting

It is shaped in a way to transfer weight to the towers and anchors with its tension (O'Connor, 1971, p. 372). Cables are made of high strength wires spirally bound to form a rope (O'Connor, 1971, p. 372). Vertical cable suspenders that are fastened to the main cables hang the actual roadway. Stiffening girders and trusses are along the side of the bridge to distribute concentrated loads and help to keep the motion of the bridge at a minimum (Troitsky, 1994, p115).

Because of advancements in today’s technology in construction field, many types of bridges are being constructed depending on the requirement and their suitability for the situations.