Loads and Forces on Buildings - Example

LOADS AND FORCES ON BUILDINGS Student Name: Student P number: Module: Module code: Submission deadline: Introduction A structure is an architectural piece of construction that can be either temporary or permanent. In addition, architectural structures might pose several characteristics such as freestanding, immobile and or outdoor. Architectural structures consist of either buildings or non-buildings structures. Houses, skyscrapers and shopping malls, to mention, but a few fall under the category of buildings whereas non-building structures include bridges, dams and lookout towers to mention but a few. This portfolio will focus on bridges and the architectural concepts behind their construction. A description of understanding of the construction process of bridges will be included in this portfolio as well. I will discuss the properties of construction materials and how these materials affect their usage in the construction (Bennett, 1997). Bridges are non-buildings structures. Their sole purpose is to span physical obstacles such as a valley, body water or a road. Bridges can be categorized in numerous ways. Most commonly, bridges are categorized based on the type of structural elements. Secondly, bridges can be categorized by what they will carry, whether or not the bridges are fixed or movable. Finally, yet importantly is the materials used to build the bridge. All these mention aspects can and are used when categorizing bridges (Das, Frangopol, & Nowak, 2001). Types of Bridges Structural Type: In any bridge that is, constructed forces are eminent. These forces that act against the bridge can be either, bending forces, shear forces, compression forces, tension forces and or torsion forces. These forces are always distributed throughout the structure (bridge). It is common for bridges to have all the above principle forces. However, the employment of these forces is to a degree despite the fact that only a few of these forces will predominate. It is common to have a clear separation of forces. Movable or Fixed: In most cases, bridges are fixed (not movable). This implies that the bridges have no parts that can move or ultimately the bridge cannot be moved. These bridges are bound to remain in the same place until they are demolished or they fail short in serving their purpose. On the other, there are temporary bridges that can be assembled upon deployment, disassembled, and used elsewhere. In addition, these temporary bridges are mostly reusable. They, the temporary bridges are common in military engineering (Whitney, 2003). Bridges Types by Use: in the categorization of bridges, the type of load the bridges are designed to carry. Bridges can be used to carry pedestrians, trains, automobiles, waterways or pipelines, and or water transport to mention but a few. Some bridges can be used to carry trains, automobile and pedestrians. In addition, these bridges can be used to host pipelines that transport other commodities. Bridged Types by Materials: Other than just build the bridges, the materials used in the construction are also used in the categorization on these bridges. Unlike in the earlier days when bridges were built either with stones, timber and or masonry. Fiber, concrete and steel to mention but a few are among the materials used to build modern bridges. Types of Loads on Bridges Weight, environment and type of loads are among the major factors that engineers have to consider when building bridges. These considerations are presumed over the bridge for the expected life span of the bridge. Furthermore, the types of materials to be used for the bridge are determined by the above mention factors. The type of load is the most vital aspect to consider. The structural consideration is for the bridge to be able to withstand the load expected to be carried. Dead Load: This is the forces and weight of the bridge itself. Dead load is comprised of all the materials and or parts used to build the bridge. All components that are in place to ensure the bridge stands all add up to the dead load. The concrete, beams, steel and or cement and in addition to any other components that might be used to make the bridge all total up to the dead weight of the bridge. As compared to the live load (to be discussed next), the dead load usually carried less weight. This case is only valid for short spans only. However, in long spans, the live load is usually smaller than the dead load. Proper engineering is needed in longer spans to ensure that the dead load is minimized as much as possible (Das, Frangopol, & Nowak, 2001). Live Load: Any load that the bridge will support load that move across the bridge is called live load. Primarily, the live load is greatly dependent on the traffic pattern the bridge will experience. Live load includes automobiles, pedestrians and other things that will travel across the bridge at any given time. In addition, things like collected rainwater, snore and or debris are calculated in to the total live weight. In addition, called imposed loads, these loads are temporary or moving and can contain dynamic load (Bennett, 1997). Dynamic Load: These types of bridge loads cannot be accurately measured. In most cases, weather conditions and earth activities contribute to these dynamic loads. Snore, water, vibrations and extreme weather line wind are the common forms of dynamic loads. During construction, a concept dubbed ‘breathing room’ is adapted. This implies that the bridge is designed to accommodate these dynamic loads without succumbing to their breaking or collapse form. Other Loads: Bridges are built in various places. These places have different terrains, therefore, when laying down the foundation for the bridge loads that are specific to different terrains ought to be considered. Detailed load bearing loads are calculated during the design phase. These load bearing are because of considering environmental patterns and weather patterns. Conclusively, the best design for strength is determined by the load expectation of the bridge. In addition, this ensures longevity of the bridge despite the terrain it is built on. Types of Forces on bridges Forces are eminent in any bridge. During the design phase, engineers are expected to make designs that will anticipate and withstand these forces. Compression and tension forces are the common types of forces on bridges. Pushing and pulling are also other types of forces on bridges. Shear and tension forces are that have to c=be considered when designing and building of bridges (Ryall, 2007). Compression Forces: Also known as pushing force compression forces are greater in smaller objects or rather shorter bridges. The shorter the bridge, the more compression force it can handle. Unlike longer bridges, their capacity to withstand compression forces is small. The effects of the compression force are evident when one attempts to compress a long piece of wood. The piece of wood easily bends as opposed to a shorter piece of wood. Failure from buckling is the result of a piece of wood or bridge breaking from compression forces. It is common for top chords of bridges to be in compression. Truss designs are eminent in ensuring that the compression force is distributed. This implies that various internal parts of the bridges will be in compression as well (Chen, 2010). Tension Forces: These forces are also known as pulling forces. Rigid structures such as wood have a higher resistance to these forces. Tension forces always act on end in a pulling motion. It is rather difficult to break a piece of wood by pulling on both ends. There are two types of tension forces, perpendicular tension forces and parallel tension forces. A bridge can easily with stand parallel tension forces, as opposed to perpendicular tension forces. However, it is keen to note that despite the length of a bridge, the level of tension force that a bridge can hold is the same. Torsion Forces: Torsion forces are also known as twist forces. These forces are common when one is wringing a piece of cloth to drain water from the cloth. Weak structures easily break under these torsion forces. This result is in contrast with a hard object. For instance, a baseball bat will not easily break or shatter due to torsion force. Thirdly, consider twisting (applying torsion force) to a piece of licorice and it will twist around severally before it breaks. The above materials react different under torsion forces. When designing bridges, engineers should ensure that they reduce the torsion force as much as possible. Shear Forces: These forces are because of two forces acting on an object but in different directions. When one holds a piece of wood and push both up and down with both hands it is said that, you are applying shear forces on the block of wood. As for the bridge, it is vital to design bridges that can with stand these forces. Despite these forces not having much impact when exerted, their effects can be catastrophic if the pressure on either side different (Ryall, 2007). Shear force is usually exerted in a horizontal manner and not in a vertical manner. Conclusion Designing and constructing of bridges is a challenging task. All the above mention facts have to be considered to ensure a quality product is delivered. Both the load and forces are crucial consideration when designing and building of bridges. It is eminent to note that, load aspects have to be considered first. By so doing, one can establish or rather comprise the most appropriate list of material to be used for the bridge. Furthermore, the materials used in the construction of the bridge will have major roles in determining its durability, stability and longevity of the bridge. Forces enacted or rather expected of a given bridge are dependent on the type of materials the bridges is. The weaker the material, the easier it is for the bridge to collapse. The harder the bridge, the more rigid it is hence a fracture will result in the bridge breaking. The bottom line is all loads, forces and building materials have to be properly analyzed before used to build a bridge. Finally, yet importantly, the terrain in which the bridge is to be built has to be considered as well (Chen, 2010). References Bennett, D. (1997). The Architecture of Bridge Design. London, Telford. Chen, G. (2010). Architectural Practice Simplified A Survival Guide And Checklists For Building Construction And Site Improvements As Well As Tips On Architecture, Building Design, Construction And Project Management. Denver, Colo, Outskirts Press. Das, P. C., Frangopol, D. M., & Nowak, A. S. (2001). 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 2001. London, Telford. Ryall, M. (2007). Manual of Bridge Engineering. Whitney, C. S. (2003). Bridges of the World: Their Design and Construction. Mineola, NY, Dover Publications. Read More