civil engineering breakthrough 2013

Finally, the drill is shut, and the fracking fluid is pumped into the underground layers and sealed there.

Steel frame structures are made as the name suggest from steel, the material is strong and flexible. When weight is added it bends without cracking. Another characteristic of steel is that its plasticity or ductility, meaning that when force is added it won’t crack however it will lose shape therefore giving warning for people to evacuate the building. A disadvantage of steel is that is loses strength when subject to fire. Studies have shown that it can loose up- to half its strength when subject to fire, therefore making it imperative to cover the steel with boards or spray on.

Once the well reaches the right depth, it turns right or left and becomes horizontal. This is called the kick off point. The horizontal section can span anywhere from 1,000 to 6,000 feet. The drill is removed but the surrounding steel casing remains. These steel casings are meant to protect the groundwater and the surrounding area from any potential leakage during the fracking process. Down at the horizontal section of the well, little holes are punctured through the steel in thousands of spots. Then, a water solution is pumped at a extremely high pressure down the well. This causes tons of cracks and fissures in the rock. Additives and sand in the water mixture hold the cracks open, allowing oil to escape and be brought up to the surface.

The earthquake was felt from southern Oregon to south of Los Angeles and inland as far as central Nevada, an area of approximately 200,000 square miles. The ground motion caused by the earthquake source is recorded by instruments called seismographs. The zigzag trace made by a seismograph, called a "seismogram," reflects the changing amplitude and frequency content of the ground shaking beneath the instrument (usgs.gov). Using seismograms, scientists can determine the time, the epicenter, the depth, and the type of faulting of an earthquake as well as estimate how much energy was released by it.

DePaolo, Edward, and Thomas, all professors and researchers of geology study hotspot volcanoes, and their impact on Hawaii. Their study is based on a major drilling project based in Hawaii. Drilling is a crucial aspect of gaining insight on volcanoes, because it provides samples of lava, which then provides information about Earth’s mantle. Scientists can then retrieve information from the mantle, such as the age of the volcano and its temperature. Experts say that drilling could be valuable for collecting information about other volcanoes and their mantles.

As Professor Farquharson’s studies progressed, modifications on the bridge continued. Tie-down cables were positioned on the bridge’s sides and wires were stretched diagonally across the bridge’s deck and main cables. Thus, the problem was believed to be solved. However, one of the reinforcing tie-down cables, placed only a month prior, snapped due to high speed winds on November 1. The date of this malfunction marks the start of a week-long series of unfortunate events ultimately leading to the bridge’s collapse on November 7.

In order to create a column-free space, designers and engineers opted to use free spanning composite glue-laminated (glulam) wood-steel arches supported by inclined concrete buttresses (Chodikoff, 2009). For the arches, the glulam slabs were made from engineered timbers consisting of wood laminations bonded together with strong, waterproof adhesives, resulting in a structural component as strong as steel. To increase the lateral stiffness, and assist in carrying the bending stresses from unbalanced snow loading, each arch has steel components anchoring the glulam slabs – resulting in a composite glulam wood-steel arch (Gregory, 2010). The use of glulam for the arches allowed for the roof’s large 100-metre span and curved element to be produced (Dietsch, 2011).

In the quake zone the Forbidden city in Beijing has stood for centuries past and in the documentary, Secrets of Chinas Forbidden City, the secret to the structural survival where unveiled. To determine the quake level that the Forbidden city building structure can withstand, a 1/5 scale model was constructed from the timber frame that is used in the palace of longevity and health. The construction method that was used is that of the traditional carpentry tools and techniques. Due to the simple joint connection that allow mobility during the earthquakes the forbidden city has lasted for centuries. The columns that holds the weight of the building are not connected to the stone bases, which allow the building to move freely and enabling the flexibility

Springs and other building materials are used to help save lives in earthquake prone areas. Scientist use a variety of different materials spanning from shock absorbers to springs. Scientists put springs under building that allow the buildings to sway but not topple over. Scientist tell builders to put steel bracing supports around or in the walls of buildings in between these are shock absorbers which stop the vibrating from going up the building. These are made of steel which are strong and don’t move a lot. Building materials need to be strong and flexible so that when an earthquake occures it won’t break. Steel ball bearings will move the platform and themselves but they will not move the house this helps the house

There are other ways to improve buildings to reduce the impact of earthquakes. In some Japanese buildings, there’s a base isolation built. The “Base Isolation” is a system that is made of steel disks. These steel disks are made of soft materials to soften the transmission of seismic movement from the ground

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).

Although these problems were corrected and the idea of building a skyscraper became a feasible task, there were many conditions that had to be taken into account, that did not need consideration when building a structure less than 40 stories tall. Four story buildings are supported by their own walls; however a new method needed to be created for skyscrapers since the previous building method would not provide enough support. Metal skeletal frames made of columns and beams were then developed to provide the support and strength needed for the skyscrapers. As the buildings grew taller, their structural design was made lighter and stiffer. Also, as the buildings grew taller, wind became an important issue. Normally, the force that acts on the skyscraper pushes directly downward towards the ground that would then counter balance that push. However, when an additional force acts on it, such as wind, the forces would act differently on the skyscraper. With a lateral force acting on the building, the steel columns of the frame on the windy side would stretch apart slightly while the columns on the other side would compress. Therefore, the skeletal frame built had to be made so that the structure would be free to move slightly with the wind and, at the same time, remain sturdy.

0 The foundation should safely sustain and transmit to the ground the combined dead and imposed loads of the building without resulting in any settlement or other movement of the building or any adjoining works.

Superstructure bears the load that is being passed over the bridge and it transmits the forces caused by the same to substructure. Load received from the decking is transferred on to the substructure by Bearings. They also distribute the load evenly over the substructure material as it may not have sufficient strength to bear the superstructure load directly. Piers and Abutments are the vertical substructures which transfer the load to the earth in the foundation. Wing walls and returns are constructed as the extension of

The subsea high-pressure wellhead housing (typically 18¾ in. (476.25mm)) is, effectively, a unitized wellhead with no annulus access. It provides an interface between the subsea BOP stack and the subsea well. The subsea wellhead is the male member to a large-bore connection, as shown in (the female counterpart is the wellhead connector on the bottom of the BOP stack), that will be made up in a remote subsea, ocean-floor environment. The 18¾-in (476.25mm) wellhead will house and support each casing string by way of a mandrel-type casing hanger. The internal diameter of the 18¾-in (476.25mm) wellhead provides a metal-to-metal sealing surface for the seal assembly, when it is energized around the casing hanger. The wellhead provides a primary landing shoulder in the bottom ID area to support the combined casing loads, and will typically accommodate two or three casing hangers and a tubing hanger. The minimum ID of the wellhead is designed to let a 17½-in (438.15mm) drilling bit pass through. (Petrowiki)