Bridge Building and Beam Bridges - Essay Example

College Task Beam bridges A beam bridge is the simplest type of bridge that can be constructed. Its main composition is a crevice that is span by a beam that is solid in structure. The beam has support given o it by piers that are positioned on both sides of the opening. Sometimes these piers rest directly on the ground. Typically, a beam bridge will span a distance less than 250 feet. These make them the best option for footbridges and overpasses. When constructing a beam bridge, supports are installed on both sides of the bridge to help support the entire weight of the completed bridge. However, some simple bridges are set on the ground without first installation of the supporting systems it is of importance to note that when this is done underground preparation has to be done. Every edge of the bridge is always tested to make sure that there is stability. Shoring and underpinning techniques are important to ensure that we come up with a stable bridge. For more stability, excavation of the soil as well as the backfilling of the soil is important however, it is not necessary. Piers are always laced vertically on the edges of the bridge to make sure that the bridge gets the correct support. To make these piers, we can use a range of materials ranging from masonry, steel, or concrete and to ensure that the base is stable, we have to embed it with concrete. Building the bridge When building a beam bridge, the bridge span is always made at a different place and then transported to the area where the bridge is to be made. The bridge is made by bringing together two concrete or steel girders that get support from some decking materials. To add weight, the bridges are made with grudges, which comprise solid beams and built with trusses that are webbed to provide support. A crane is then used to lift the bridge to the supports then it is welded to ensure that the bridge is firm. The main materials used to construct the bridge is pre stressed concrete. This is very important in ensuring that the bridge is able to withstand the forces that are combined at each of the edges of the bridge. Since the top of the bridge is subject to compressive forces, and the bottom of the bridge is subject to tensile forces, they are left to overcome each other. In a well made beam bridge, the forces do not exist. The main risk that may be found here is the accidental collapse of the bridge in case the bridge is not correctly placed on the supports, this leads to the bridge collapsing on the ground due to lack of support. To prevent this, ground engineers are useful in ensuring that the bridge is correctly placed on the supports. There are a number of considerations that have to be put in place to ensure that the construction is economically feasible as well as being environmentally friendly. First the bridge has to be made of materials that are not soluble in water since some of these bridges are placed above water channels and if the materials are water soluble then it will pollute the water below. We also have to weigh the costs of the materials to ensure that we use the cheapest materials that are available in the market. And all in all the workers have to know the right proportions of the materials that they are using so that there is no wastage that occurs in the making of the bridges. Bolting The best bolting technique for this particular bridge is the shear connection method. In this type of bolting, a central plate is made to align with the central beam so that a hole is drilled inside it for the bolt to b able to get into it. To attach the shear connection, we use standard bolts shear bolts. Arch bridges Construction Construction of the arch bridge starts with the designing of the bridge. When designing, you have to have the arch and the roadway in the mind. Most of the known arches are found under the road, however it is important to know that some arches exists such that roads pass through them. All these have to be kept in mind during the design method. After the design, we have to prepare and excavate the banks that we are supposed to use so that they can pave way for the road to pass through. In this stage, the bedrocks are excavated so that the ends of the bridge can be placed. After the banks have been cleared, we now have to construct the arch bridge from both sides of the banks. It is important to know that when this is taking place, then the banks will remain unstable until the two arch meet at the centre. So we have to start the two arches together and make sure that they meet at the centre. The material chosen for building the two arches is a combination of steel and concrete since these two can very well support the compression that happens when the two arch meet. It is useful to measure the progression of the bridge very carefully. Without careful measure, then the two bridges might not end up meeting at the centre and this is not good for the support of the bridge. As a result of wrong measurement, we can end up with very expensive losses since the bridge will not be able to withstand the stress that will be laid on it. The next step is to connect the two arches together from the top of their meeting and while this is happening, we have to slowly remove the bracing that was temporarily placed there. A lot of care should be taken to ensure that no injury comes from this and that the shaft does not fall on someone. After the two arches have been connected, then the next step is to make a roadway that is from the bottom of the arch or sometimes it is good to suspend it from the arch but this depends on the kind of design that is needed. The next step is to pave the new arch bridge and enjoy the roadway. Remember to always use steel and concrete since they are environmentally friendly, they are strong and lastly they are economically feasible and are easily available. The best bolting technique for this particular bridge is the shear connection method. In this type of bolting, a central plate is made to align with the central beam so that a hole is drilled inside it for the bolt to b able to get into it. To attach the shear connection, we use standard bolts shear bolts. Suspension bridges When building the suspension bridges, the first thing to do is to sedan anchor for the cables. This is because they are the ones that bear a lot of weight. This has to be done on solid bedrock or a concrete that is enormous enough to support the existence of the bridge. To distribute the weight, spread the cables into the rocks to facilitate evenly distribution of the cables. Next you have to slowly pour the concrete footing for the pillar. Make sure that the forms are placed on the waterway. After this use a pump to pump out the water from the concrete then excavate this to a base that is solid and then at this moment pour the footings inside. Build the bridges suspension towers at the footings of the concrete. This will allow the cable to be expanded over a longer distance. To know more ensure that you know the exact length that the bridge is expected to span since the longer the span the higher the towers will be expected to be made. Next we have to stretch the cable past the towers and after this let them be in the anchors that have been prepared. We have to make the cable from twisted steel. This is because steel is very strong and can be able to withstand the forces that it will be exposed to over a longer time than any other material that can be used. Second the steel is readily available and is not corroded with water a factor that makes it environmentally friendly. After this has been done, trusses have to be attached to the main cable called the suspenders. These are attached to the trusses to ensure that it does not bend in the air. Next we have to apply decking of the bridge to the trusses. This can be done from a number of materials but aluminum is the best material to use here. When choosing the material, its corrosion ability has to be considered so that it does not result in corrosion of the water. After this, the bridge is complete and can be used after it has been inspected with the various engineers’ body. Task 2 Steel frame structures Construction using steel is a very complex process; first it varies in size and can be used to make very small structures to huge structures that support millions of tones of weight. Calculations and engineering methods are very important in the building process and can result in very complex and well structured buildings. To ensure that this is achieved, we have to ensure that a lot of preparations which included various calculations are made so that the structures are affected. Most steel structures get support from the steel frame which is smaller boxes in a bigger box. Steel loads are majorly dead loads which happen to be the weight of the steel itself. Concrete frame structures Concrete structures are able to support a lot of weight and have more dead load than steel structures. They however offer security on structures as they are hard to break through. They are also stable and can withstand a lot of circumstances such as storms. Two methods of making concrete structures generally exist, these are erection of precast concrete and the second method is by forming walls individually and then taking them to the required sites. This is done if a particular person wants the structure and they order for it. The constructions coming from concrete Aare always permanent and can stay for a longer period of time than many other forms of structures. The concrete structured should not be done in places where the soil shifts as this will lead to damages unless; a foundation which is floating is made. Portal frames In order to solve the problem of cost, portal farms became the answer to World War II. They are mainly used in warehouses and other large industrial buildings. Most of them are constructed from steel and contains solid webs that are very important in the constructions. Their main advantage that they offer to the building industry is cost effectiveness. They are very cost effective and most of the people who chose to use it do so because of their cost. They are lightweight and are easily constructed from hot rolled angle sections. The materials are very flexible and can offer a great degree in their construction. Constructions are the main challenges in their design since for stability to be maximized; the calculations have to be exact. The materials also have a very poor resistance to fire and so can be easily destroyed by fire. Therefore, during the calculations processes it is also important to consider the maximum temperatures that the entire structure can withstand and how to prevent fires from taking effect. Task 3 Types of roads Roads can be classified based on the type of material in their surfaces. We can classify the roads as metallic, asphalt, concrete, composite surfaces. This is in reference to the type of materials that is laid down. Metallic roads are made from broken stones as well as cinder. This type of road was very common with the roman soldiers. However, the Brazilians also used the limestone roads in the past. This type of road is permanent and is able to withstand a lot of stress. Tarmac is the main type of material that is currently in use. The other type of road is asphalt. These roads are made from concrete that comes from asphalt. Bitumen is used in the making of these types of roads. Finally, concrete surfaces, these are made from portal and cement. To increase workability, various mixtures are useful in the making of the cement. There are various methods of road construction these are asphalt paving for making asphalt roads. In this type of road making, liquid asphalt is used to spray the aggregate is then heated and the binder evenly sprays it in the road that is to be made. This hot combination is what is known as blacktop. Cement concrete paving, is another type of method that is used in making concrete roads. The main binding agent here is the Portland cement and water mixed with sand. To form a solid thick layer, we have to apply thick layers of aggregate on the road so that it can get to be stable. The main materials used here are steel tarmac and broken stones. Portland cement is also important in the construction process. Steel is used to make the road be able to withstand stress when exposed to it. This is affected by the use of concrete to build the road, which will end up being very stable tar is used in the stabilizing of the steel on the ground. Tar is also used to join the gravels together and to make them closely packed to each other. During the paving process, the tar is very useful in making the road have a strong foundation. When designing and constructing roads, we have to have in mind the drainage patterns of the road. This is one of the mistakes that the designers have in mind. This will mean that we have to design the road such that the drainage system is found under the road. This is very important in ensuring that the water does not damage the road as it rains. Otherwise, the whole road will be swept after a while. The water also should be directed away from homes and public structures so that there is no damage that is directed to the public. Bibliography BLACK, F., & HOLLENBECK, M. (1976). Road construction. [Fullerton], Utah State Historical Society and California State University, Fullerton, Oral History Program. WULFF, S., & BALL, R. E. (1994). Road construction. Scarborough, Ont, Quality Special Products. HUGHES, G., & JAMES, A. (1994). Road construction. Plymouth, MN, Distributed by Simitar Entertainment. RAND MCNALLY AND COMPANY. (1990). Road construction. [Chicago], Rand McNally and Co. GENAT, R. (1995). Road construction. Osceola, WI, Motorbooks International Publishers & Wholesalers. GENAT, R. (1995). Road construction. Osceola, WI, Motorbooks International Publishers & Wholesalers. Read More