An Installation Of A Structural Health Monitoring System

Suspension bridges are able to work efficiently because of their cables, which are interesting from a mathematical perspective.

The first example of an external force is the static (dead) load, this refers to the gravitational forces acting on the bridge itself. Every structure has to be able to support the weight of its own materials in order for it not to collapse, this is before any live load is applied to it. Another example is dynamic (live) load which refers to traffic, from people or vehicles, which move across the bridge and apply additional weight to it increasing the magnitude of vertical forces acting on the bridge. But environmental factors such as changes in temperature, precipitation and winds can also create vertical and horizontal loads on the bridge. (Bagga

Furthermore, when the millennium bridge opened within the first weekend around 100,000 people had crossed the bridge. Due to such heavy traffic, this lead to something called resonance. Resonance is when the input vibrations frequency coincides with the natural frequency of the structure itself, causing large deflections to develop. The issue caused the bridge to undergo a swaying movement; hence led to its closure. After extensive research and analysis, it was found that the movement was caused by synchronized pedestrian footfall. To prevent this there were two options taken into account the lateral stiffening and the damping; both were used in order to increase the natural frequency of the structure so it did not match the footfall. In addition structures called fluid-viscous dampers and tuned mass dampers were installed to control both horizontal and vertical movements.

Several students are doing Science Fair projects at Woodstock Middle School and I am one of the seventh grade students. The topic I shall be doing is on how bridge structure affects the weight bearing capacity. I chose this specific topic to guide bridge builders in the right direction on what bridge is safest for public use. The key topics I plan to research on include the following: Beam, Warren Truss, suspension, cable-stayed, and arch bridges. I shall use the scientific method to guide me through this process.

In 1919, a study was begun to see if it would be possible to build a bridge across the Golden Gate. Michael O’Shaughnessy was the San Francisco city engineer. He was in charge of the rebuilding of the city after the devastating 1906 earthquake that destroyed much of the city. O’Shaughnessy knew the need for the city to have bridges. Most said it could not be done and others said it could be done but “it would cost about $100 million to build it” (Barter 23). O’Shaughnessy and Strauss, both wanting the same thing, got together. After the two consulted, they figured the only way to bridge the channel was to use a suspension bridge.

Bridges are structures that become very susceptible as time passes. In Oregon there have been many bridges being identified to be seismic vulnerable. In an article by Ed Jahn, he sates, “nearly sixty percent of state-identified lifeline bridges likely to collapse or be potentially taken out of use after a quake” (Jahn). Bridges are a whole different story because they aren’t easy to be re-evaluated when they are used constantly by people to get around. The problem with many of these structures, though is that more than half of these bridges were built before 1970 (Jahn). Because of this they aren’t reinforced with new building codes making them highly vulnerable to any disaster to the point of collapsing. It isn’t an easy thing to fix the problems with a bridge because many seem stable but are still at great risk. It is known that “Today, they're still building fracture critical bridges with the belief that they're not going to break,” (Rosenker). Even when a bridge is being identified to see if it’s stable a lot of the time they are thought to be ok, but are really in a bad condition. Because they aren’t fully evaluated, and if a disaster were to hit in a certain location it could cause the bridge to

Multi-story parking facilities have been proven to be problematic and very susceptible to collapse during an earthquake. Multi-story

Since the bridge is a "critical piece of infrastructure" connecting drivers traveling between Arizona and California, the goal of Caltrans was to speed up the design and construction of the bridge. Caltrans selected Accelerated Bridge Construction (ABC) methods to significantly

The west coast of North America is filled with many different environments and the various natural disasters present there. The effects of these disasters can be seen through the myriad bridge collapses we have had in the last 100 years. California is rife with earthquakes and they have caused many different bridges, such as the Antelope Valley Freeway Interchange or the Cypress Viaduct to collapse. Landslides and floods have also caused many different bridges to fall including the John Day River Bridge, the Tex Wash Bridge, and the Pfeiffer Bridge. Natural disasters are not the only thing that can take down a bridge; in fact, the Tacoma Narrows Bridge, the Skagit River Bridge, and the Peace River Bridge were taken down through human error.

On top of all this the proposed design would also need to be tested as it is not the same as the previous one which had been tested. A mathematical solution to be used for the designing of the bridge was not possible due to the fact that not much was known that has caused the collapse of the old bridge (Gimsing, 2011). While putting into consideration these conditions, the engineers opt to design the replacement and then add subject scale mockups to the design specifically constructed on a wind tunnel located in Washington

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).

As one looks across a gap in between two land masses, a thought of how one could cross comes to mind. When one thinks of this, a bridge comes to mind. Although they might now know what kind, a suspension bridge is the first idea. They picture something like the magnificent Golden Gate Bridge, one of the most recognizable structures in all of the world. Although suspension bridges now span over miles, they had very humble beginnings. The evolution and expansion of suspension bridges is a topic worthy of this very essay.

One of the most influential engineering discoveries in the past century was the ill-fated Tacoma Narrows Bridge. “Galloping Gertie” as she was known to local residents, the massive Washington state suspension bridge shook, rattled and rolled its way into the history books. Legendary in its time, the Tacoma Narrows Bridge held many records and drew tourists from around the world in its short life. However, the famous bridge is not known for its creative engineering or speedy construction, unfortunately the bridge was destined to fail. That failure in turn changed the way every building is constructed today as well as further man’s understanding of physics and the forces of nature. In this paper we

Using UHPC in the construction of new bridges and the renewal of existing highway bridge network can minimize maintenance requirement in the construction of new long life bridges resulting in low life cycle costs [3].

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.