Sustainability in Proposed Bridge Construction - Essay Example

? Sustainability in Proposed Bridge Construction Sustainability in Proposed Bridge ConstructionIntroduction Engineering construction and sustainability of transportation infrastructure has become a broad attention to realize its impact on social and economical environmental achievements in the society. There is rapid growth in sustainable engineering, thus most authorities take sustainability as the driving force behind decision making, and policies used in constructions of bridges (Michael 2001). In bridge engineering and construction, sustainable infrastructure involves planning for the project, designing the structure of the bridge, constructing using the right materials, and maintaining the context sensitivity. In addition, one should considering the durability of the selected materials. In bridge engineering, the constructors have opportunity to make their decisions and provide solutions that will give a balance between the environments, social impact, and economical guidelines of sustainability. The bridge to be constructed is a unique one in nature since it will be capable of opening from the middle to enable large ships and vessels to pass freely. This will require a lot of time to design, rating or assessment of materials to be used (Institution of Civil Engineers, 2001). The bridge professionals and transportation authorities should ensure that the right materials and construction techniques are used and presented in a consistent, systematic and credible way. This project will consider the development of bridge sustainability putting into consideration its three pillars, that is; social, environmental, and economical factors. The project will focus on the materials used in construction, but not limited to the following content: 1) What is the mentioned material? 2) Why it is a good material to be used in the construction of a bridge? 3) What are the advantages and disadvantages of it in constructing a bridge in this project? 4) How it could be good for the bridge in the long run, is it durable? 5) Comparison between the properties of the materials and how it could be improved Materials used in the bridge Materials and other resources to be used in sustainable bridge construction should be ensured to be the most appropriate materials for the site and the future maintenance in case of recycling of the structure. The constructor should include sustainable materials and should be in a position to answer several questions such as: are recycled materials used in bridge construction? What is the cost of the materials? Is the bridge designed with a complete life cycle analysis in place? The construction of the bridge in question will require the following materials (Steele, 2004): 1. Steel (frame, deck, and structure) 2. Timber 3. Concrete 4. Wire cables 5. Winches 6. Solar panels 7. Small Wind turbines The design and the innovation of this bridge project will be determined by the materials above. In addition, the materials selected will also address construction of lifelong maintained engineering motorway bridge. Individual materials Steel (frame, deck, and structure) Steel is iron materials made from iron ore. It is used in the construction of structures that require strong foundation and based. Steel will be used to strengthen the bridge. In order to make the bridge stronger still bar should be used to reinforce the concrete. Deck will be used to span the distance between the two ends of the bridge, since the bridge is suspended, deck will form the open truss structure to support the roadbed, preventing the bridge from collapsing. Rivets are used to join steel and the deck. Steel will form the Beams, plates, and rods shown in the proposed bridge picture (Parag, 1999). Advantages of steel Steel makes a strong foundation of the bridge. This is because steel is one of the strongest materials used in bridge constructions. It is also used to span distances that are cannot be spanned using other construction materials such as wood. It is stronger than concrete and weighs less thus easy to use and handle. Disadvantages Steel materials are susceptible to rust and corrosion and tend to require a lot of maintenance. This is because steel oxidizes to form rust, which is a porous corrosion product that exposes more metal to oxidation causing farther corrosion. In the construction of bridge it would be advisable to paint the steel in order to prevent corrosion and to improve on the appearance. Aluminum can be used in place of steel since it has anti-corrosive properties. Timber Timber also referred to as wood is mainly used for extension. Timber will be used in relatively simple structures constructed on the bridge. However, wood is not very reliable as compared to other construction materials since they are weak. Advantages The materials are cheap and more affordable as bridge construction materials. In addition, it is easy to work with using basic tools and equipments to be used in construction. The materials also add more beauty and are therefore primarily preferred and chosen in most of the construction involving pedestrian’s access or light weight vehicles. Timber is appropriate materials for use since it is less affected by temperature, wind, and humidity and can therefore withstand the conditions of the bridge (Parag, 2001). Disadvantages Timber is prone to rotting and swelling when exposed to moisture especially rains, this will make the bridge to be weak. In addition, if not chemically treated pest such as ants will damage them. To increase the long life of timber, it is advisable to protect it from rain and employ chemical treatment to prevent damage from ants. Chemical treatment techniques such as oil based, water borne based, and solvent based preservatives. Concrete reinforce Concrete is a combination of two materials, cement and aggregate used in most of the constructions. Concrete is very popular for all types of bridges constructions because of its affordability and good strength. Concrete will be used in the reinforcement of the steel from the grounds and also the wood. The concrete will be formed according to the size of the steel and other metal used in the construction and it will form the foundations of the four structures of the bridge (the four corner pillars). Since the bridge will have longer spans, the engineers should use concrete to reinforce the still bars use and employ pre-stressing treatment to increase its strength. Advantages Concrete requires little or no maintenance in constructions. In addition, it can be easily formed and shaped according to the user’s desires. Disadvantages of using concrete Concrete is not good when used saltwater since it hold up poorly against it. It is also prone to erosion making the tendency to create weak foundation of the bridge. To increase its effectiveness to the bridge, the construction engineer should make sure that pre-stressing treatment is done during the construction so that its strength is improved. Concrete is durable and is recommendable to be used in this project Wire cables Wire cables are made from multiple strands of wire. The wire cables are of great importance to this construction since they will be used in suspension of the bridge. The cables can be made from chains or linked bars such as the ones used in the older bridges. However, since the bridge requires being strong, it is recommended to use multiple strands cable wires. Advantages The cables can be prepared in large in mid-air from a temporary walkway. This makes the work of construction to be easy. Disadvantages The engineers will have problems when lifting large chains or wire cables into the refigured position. On the other hand, failure of a single eye bar on the cable wire can cause collapse of the whole bridge. The engineers will need to make sure that there are no bad links on the wire cables to avoid failure of the entire bridge. The length of the cable wires will be determined by the length of the deck in the bridge. Cable wire strength used should be proportional to the length of the deck which is 112.99 m. The suspended cables will be anchored at each end of the bridge. This is because any load that will be applied on the bridge will be transformed into tension in the main cable. The main cable wire will be anchored and run beyond the pillars to deck level and continue connecting with anchors in the ground for support. Cables will be used to hold the deck and to pull it up as shown in the figure below: Winches Winches are form of pins that are used in the strengthening of the bridge. They are mainly used in reinforcement and concreting of the materials like deck and steel used in the construction. The pins can be also used in to hold the cable wire holding the deck on the air-way. They are used together with the cables wires to hold the deck. Advantages The winches are easy and cheaper to use. The winches may be either manually or electrically driven. The electrical winches are the most preferred. Disadvantages Winches are very heavy and need cranes for them to be put in place. However, when they are not handled with care they can cause death. The weight of a winch is estimated to be around 7,000 pounds making it more difficult to work with. People building the bridge should be very keen whenever dealing with winches and the cranes. This is because a number of death cases has being reported where the crane fail due to poor operations, causing the winch to fall down striking the workers unexpectedly. However, it will increase the strength of the deck when used appropriately (Institution of Civil Engineers, 2001). Solar panel Since the bridge will be capable of opening from the middle to allow big ships and vessels there is need to have a solar panel placed around the bridge. Solar panels will be used to supply the electricity needs of the bridge. The bridge will have a hydraulic system to aid in the open and closing of the bridge from the middle. Electricity will be used as the sources of power. However, the bridge can use natural resources such as sun to generate electricity (Patrizia, 2004). The engineers can use solar cells to convert sunlight to electricity using the process of photovoltaic (electricity from light). Advantages Solar panel can be used to tap electricity that can be used in future. Excess power collected from natural sources can be stored for future use. It can be used to burn the fossil fuel which causes no noise and pollution to the environment. On the other hand, the fuel used makes the bridge to operate automatically (opening and closing on the middle) Disadvantages Expensive to install the full system and it requires skilled personnel. The importance of the solar panels is that, the PV will automatically control the system without any human interventions thus making the operation of the proposed bridge more effective. Small wind turbines Turbines are used to generate power. The turbines will act as a supplement for solar panel. The space between the viaducts can be used for the installation of wind turbines which would produce around 25 million kilowatts hours of electricity per year. Advantages The turbines will be used to generate electricity which will be a source of revenue to the company and a source of power to the system. Electricity generated can be used to light homes, and companies around. In addition, this will act as a source of renewable source company. Disadvantages The system may be expensive to install. Conclusion Sustainability will be the key issue to be considered in the bridge construction. The engineer should address the issue of bridge design, construction, and the lifelong maintenance. This issue will be determined by the type of materials to be used. In addition, the three pillars of sustainability should form the key element before the construction of the proposed bridge (Christopher, 2012). The future sustainable issues should be considered; the impact of the form of the bridge, the maintenance of the bridge, the repair cost and replacement strategies should be noted before the bridge is constructed. Lastly, the durability of the materials used should be tested and assessed to avoid incurring extra cost in future. Innovative structure of the bridge should be given for criticism before the actual contraction. References (Britain), Institution of Civil Engineers (Great. Current and future trends in bridge design, construction and maintenance 2: safety, economy, sustainability and aesthetics ; proceedings of the international conference organized by the Institution of Civil Engineers and held in Hong Kong on 25-26 April . Telford, 2001. Michael Bauer, Peter Meosle, Michael Schwarz. Green Building: Guidebook for Sustainable Architecture. Springer, 2010. Parag C. Das, Dan M. Frangopol, Andrzej S. Nowak, Institution of Civil Engineers (Gran Bretana). Current and Future Trends in Bridge Desing Construction and Maintenance: Safety, Economy, Sustainability and Aesthetics. Thomas Telford, 1999. Parag C. Das, Dan M. Frangopol, Andrzej S. Nowak, Institution of Civil Engineers. Current and Future Trends in Bridge Design, Construction and Maintenance 2: Safety, Economy, Sustainability and Aesthetics. Thomas Telford, 2001. Steele, Kristian. Environmental Sustainability in Bridge Management. Construction Research Communications Limited, 2004. Vicenzo Bentivegna, P.S. Brandon, Patrizia Lombardi. Evaluation of the Built Environment for Sustainability. Taylor & Francis, 2004. Wai Kiong Oswald Chong, Christopher Hermreck. ICSDC 2011: Integrating Sustainability Practices in the Construction Industry : Proceedings of the 2011 International Conference on Sustainable Design and Construction, March 23-25, 2011, Kansas City, Missouri. ASCE Publications, 2012. Read More