Learning From Engineering Disaster - Coursework Example

LEARNING FROM ENGINEERING DISASTER (Student Name) (Course No.) (Lecturer) (University) (Date) Introduction Several disasters have in the past occurred because of engineering failure. From the engineering disasters, the engineers have learnt to correct the mistakes in the current designs and constructions to prevent future tragedies. Engineering can be well-defined as the presentation of science, technology and the practical knowledge of designing, inventing, constructing, maintaining and improving machines and structures (McEvily, 2013, 42). Disaster, in simple terms, can be defined as an occurrence that cause a widespread destruction of property and cause distress to people and other living things. For this reason, engineering disaster can, therefore, be defined as the failure of the engineer to construct matter according to the set standards and regulations leading to damage to property or loss of life. This research report looks into the engineering disaster of the collapse of two aerial walkways in the Kansas City Hyatt Regency Hotel in 1981 (Bruce and June, 2005, 217). Concept of ‘Man-Made’ Disaster/Engineering Failure To understand the engineering disasters, it is important to look at certain aspects of engineering that result in poor engineering choices and practices. The consideration of engineering failure to lead to an engineering disaster is the public perception of risk level. The main cause of engineering disasters can come from human factors resulting from ethical failure hence leading to the accident. In some cases, the resources used in the construction may fail to perform their functions hence leading to the downfall of the walkway and resulting to the accident. Human error in engineering disaster results from the deficiency of following engineering ethics (Caroline, 2011, 314). The same principles and assumptions apply to the collapse of two aerial walkways in the Kansas City Hyatt Regency Hotel at Kansas City in 1981. The incident, which took place during the “tea dance” raised questions about the integrity on the construction engineers in the city (Roth, 2007, 83). The disaster was among the major setback of the engineering accountability that happened to cause the loss of 114 people, with several others getting injuries. Therefore, it is important to analyse the actions that lead to the accident and to find a solution to prevent future occurrences. Concerning the incident, the first assumption that can be due to the failure of the architectural design to properly consider the central tendency in which the structure was to balance (Delatte, 2009, 127). Therefore, the collapse of the structure may have resulted due to errors in design. The other assumption is that the walkway might have exceeded the number of people it could support. The third assumption can be the fact that the walkway might not have been maintained from the time of construction. Structure Design and Construction Phase The development of the structure was carried out in the fast track methodology, which was the common procedure in the 1970s. The methodology involved the construction proceeded designs, structural design together with architectural design preceded. The structural designs and construction were considered to be lacking quality control and adequate time to carry out the construction. Another issue of concern was the exchanging of the construction and design personnel that saw people come with different construction standards (McEvily, 2013, 45). The design of the Hyatt Regency can be traced back to 1976. The structure was to consist of thirty-five stories and seven hundred and fifty guest rooms. Other areas considered in the structure were the kitchen, restaurant and offices that were all housed in four floors. The responsible construction engineers made some changes to the original structural design. The changes that were made in the design include the expansion of the joints that separated the structure of the roof between the hall and the from the concrete functioning block. The trusses crossing at 120 feet provided the main structural support. The slide bearing mounted on the concrete corbels provided the support for the end of the functioning block. The equilibrium between the functioning block and the restaurant floors were provided by the system walkways situated in the second, third and fourth floors (Roth, 2007, 167). To avoid loading of the first concrete floor, the sunscreen construction changed to the vertical truss that collected the weight from the roof of one chord and transferred them to the chord on the first floor. (Adams, 2007, 204). The design of the structure underwent several transformations between January to August in 1978. The major changes were done on the screen and the curtain wall on the western section of the atrium (Harris et al., 2014, 42). The change resulted in the alteration of the horizontal support structure in the walls without changing other elements such as the screen wall trusses hence creating an imbalance and lack of support for the column splices. The issue can be considered as one of the challenges that contributed to the collapse of the two aerial walkways (Delatte, 2009, 34). The challenge was contributed by lack of coordination between the project designers and the construction engineers. The junior engineers who came after the senior project designers and engineers carried out the alteration of the construction plan. The construction of the whole structure was uncoordinated throughout the process. By the time of issuing the new designs, the construction work was already done, and the changes could not be implemented. The foundation of the structure was complete, and the conduction was on the final floor (Wright & Valencia, 2000, 67). Moreover, the construction of the structure lacked quality control parameters hence became a challenge to the developer who contracted private contractors to carry out the inspection of the entire structure. The material that materials that were used to construct the atrium in 1978 was found to be below the required standard. This act can be said to be cost cutting by opting to go for cheaper materials that do not meet the fabrication requirements the construction work (Adams, 2007, 138). Materials and Structure Failure The fabricated atrium steel that was erected in summer 1978 was the first cause of material failure. The embedded plates that connected the beams to the concreted along the expansion lines were also not considered during the construction. The problem was realised by another contractor who tried to solve the problem (Roth, 2007, 136). The contractor managed to adjust the seat angles and using four expansion bolts but only managed to install two bolts. On the of the hit, rebar was left out with the engineer managing to install one of the web angles with three bolts. The imbalance in the construction and repairs created an imbalance of the force equilibrium of the whole structure since less than five of the fourteen bolts were correctly installed. The erection tolerance required the enlargement of the holes at the angles. The enlargement, which was done using a torch left an uneven surface. A beam and a cold snap at one corner of the atrium that has a faulty connation pulled out of the wall due to material failure and the imbalance weight (Harris et al., 2014, 79). The impact caused the edge of the beam to swing and hit the adjacent inner column. The impact of the hit caused the column to buckle and the sudden drop of two bays from the roof. Luckily, the first accident did not result to any casualty, and there was a rapid response to the construction failure. Despite the warning sign, the investor still maintained the engagement of independent engineers to carry out an inspection of the atrium and the design of the structure. Although the rods were in accordance with the specification, the engineer inspectors still could not realise that the drafting error that was made by the junior in the design of the structure (Mohamed, 2008, 78). Technically, the structural design of the hanger rods was not to the standards of the Kansas City building. Therefore, there emerged a connection failure unavoidable to the service load and was contributed to the redundancy of the engineers. If the situation had been resolved by time, the failure of the rod would have not resulted in the collapse of the walkway. Thus, the collapse of the walkway is contributed to the lack of well organised procedures in the design stage and lack or responsibility and integrity of the engineers that made the changes to the designs without correcting other sections (Caroline, 2011, 318). From the technical viewpoint, the joint that resulted in the collapse of the walk was caused by the joints that ran along the box beams. The box beams were in turn suspended from the ceiling using long and thin hanger rods. The wide flange beams with 16-inch depth (W16x26) that were used on both sides of the walkway were hung from the box beam that was made from two MC8x8.5 rectangular channels that are joined together. The clip angle joint and the box beam that were welded to together are the main structures that caused the failure. The clip angle joint did not carry any weight hence putting more weight on the fixed hinge plate at the end of the walkway. The different weight distribution, therefore, caused an imbalance of the hanger rod that provided the support (Harris et al., 2014, 86). The additional of another rod, there was a weight increase on the fourth floor and with more people in the walkway, the weight increase further causing the collapse of the walkways. Engineering mechanics The instability of the rail foundation that was not in accordance to the original design was not meant to resist the horizontal load. To prevent disasters, the engineers are expected to design a suitable structures that can contain the load of the building and additional weight that will be added. From the original design of the suspension rods, the vertical load was to be resisted by the vertical piles so that the inclined piles to support the walkways be resisted by the horizontal loads. The analysis of the raking piles is as follows. Assuming that point QA, QB, and QC are receiving the axial forces. The pin joints in both ends give the possibility of determining the line action of the action of the suspension rods. The lines show the force and the direction of the force. Therefore, QA, QB and QC are the force per unit length from the structural foundation from the imaginary piles. The subsequent force from QB and QC is at R, which have to pass through ‘a’, which is the point of intersection of R (the load) and QA. The force polygon below explain the force equilibrium. In set A, the axis force equilibrium is calculated as; QPA = QA / nA Whereby nA is the number of piles in set A. To get the determine the axis load for each pile of the walkway in set B and C, the formula is; QPB = QB / nB and QPC = QC/nC Investigative Bodies Investigations of the incident were carried out by National Bureau of Standards, which is currently operating as National Institute of Standards and technology to tray and establish the cause of the collapse. According to the inspection body, the cause of the collapse was that the hunger rod that pulled through the box beam. The imbalance of the structure, therefore, resulted to the falling of the walkway on the fourth floor. The suggestion that was brought by the investigating official was that the structural system would have been made with alternative load paths (Adams, 2007, 45). The alternative paths would have made the other hangers rods to be held in position hence supporting the weight of the floor and the people present. The absence of redundancy, the structural failure resulted in the collapse of the entire walkways. According to the original plan, the second and fourth floor were supposedly to be suspended using the same rod and firmly held by nuts. The second investigation body was the Havens Steel Company. The company is responsible and was responsible for the manufacture of the steel rods that were used in the construction. The finding of the investigation was addressed to the have resulted due to the alteration of the construction plan without proper coordination (Wright & Valencia, 2000, 95). According to the National Bureau of Standards, the specification for the walkway met the required standards. However, the database for the walkway was extremely limited and did not have a tendency towards the upper boundary of the 95% confidence of the NBS database band. Therefore, the walkway box beams had a heavier cross-section that was expected to increase lead resistant slightly. From the investigations by the NBS, it became clear that the walkway collapse due to the action of the lead that was substantially less than the design loads that are specific according to the Kansas City Building Code (Mohamed, 2008, 193). Considering the destruction of the structural components, the failure of the walkway system showed some signs of failure in the box beam hanger rod connections at the eastern end of the centre box beam in the fourth floor walkway. The alterations that were done on the arrangement of the hanger rod from continuous to interrupted rods also contributed to the increase in load that was being transferred by the box beam hanger rod connections on the fourth floor. Therefore, there was a complete imbalance of the walkway structure and with the additional traffic; the support rods could not contain the weight of the structure (Bruce and June, 2005, 361). Conclusion The collapse of the aerial walkways of the Hyatt Regency Hotel was a pure “man-made” due to negligence to adopt the City construction guidelines, altering the building design and choice of wrong materials. For example, the section that led to the collapsed structure failure was never designed. Therefore, the architectural designers and the engineers must work together to prevent structural failures (Bruce and June, 2005, 281). Lessons learnt from the accident has prompted an evolution into the engineering practices. The engineers should, therefore, follow the guidelines stated in the existing construction ethics. The investigative bodies should also follow the strict guidelines of the construction ethics. Hiring of private investigators can be influenced by stakeholders decision hence should not be given priority. References Adams, D., 2007. Structural engineer's professional training manual. Maidenhead, McGraw-Hill Professional. Bruce E., and June K., 2005. Structural Safety and Its Quality Assurance. ASCE Publications. Caroline Whitbeck, 2011. Ethics in Engineering Practice and Research, Cambridge University Press Delatte, N. J., 2009. Beyond failure forensic case studies for civil engineers. Reston, Va, ASCE Press. Harris, C., Pritchard, M., Robins, M., James, R., & Englehardt, E., 2014. Engineering ethics: concepts and cases. Boston, MA: Wadsworth Cengage Learning. McEvily, A. J., 2013. Metal failures: mechanisms, analysis, prevention. Hoboken, New Jersey: John Wiley & Sons, Inc. Source: http://www.books24x7.com/marc.asp?bookid=52804. Mohamed G. H., 2008. Large-Scale Disasters: Prediction, Control, and Mitigation, Cambridge University Press. Roth, L. M., 2007. Understanding architecture: its elements, history and meaning. Boulder, Colo, Westview. Wright, K. R., & Valencia Zegarra, A., 2000. Machu Picchu a civil engineering marvel. Reston, VA, American Society of Civil Engineers. Read More

Therefore, the collapse of the structure may have resulted due to errors in design. The other assumption is that the walkway might have exceeded the number of people it could support. The third assumption can be the fact that the walkway might not have been maintained from the time of construction. Structure Design and Construction Phase The development of the structure was carried out in the fast track methodology, which was the common procedure in the 1970s. The methodology involved the construction proceeded designs, structural design together with architectural design preceded.

The structural designs and construction were considered to be lacking quality control and adequate time to carry out the construction. Another issue of concern was the exchanging of the construction and design personnel that saw people come with different construction standards (McEvily, 2013, 45). The design of the Hyatt Regency can be traced back to 1976. The structure was to consist of thirty-five stories and seven hundred and fifty guest rooms. Other areas considered in the structure were the kitchen, restaurant and offices that were all housed in four floors.

The responsible construction engineers made some changes to the original structural design. The changes that were made in the design include the expansion of the joints that separated the structure of the roof between the hall and the from the concrete functioning block. The trusses crossing at 120 feet provided the main structural support. The slide bearing mounted on the concrete corbels provided the support for the end of the functioning block. The equilibrium between the functioning block and the restaurant floors were provided by the system walkways situated in the second, third and fourth floors (Roth, 2007, 167).

To avoid loading of the first concrete floor, the sunscreen construction changed to the vertical truss that collected the weight from the roof of one chord and transferred them to the chord on the first floor. (Adams, 2007, 204). The design of the structure underwent several transformations between January to August in 1978. The major changes were done on the screen and the curtain wall on the western section of the atrium (Harris et al., 2014, 42). The change resulted in the alteration of the horizontal support structure in the walls without changing other elements such as the screen wall trusses hence creating an imbalance and lack of support for the column splices.

The issue can be considered as one of the challenges that contributed to the collapse of the two aerial walkways (Delatte, 2009, 34). The challenge was contributed by lack of coordination between the project designers and the construction engineers. The junior engineers who came after the senior project designers and engineers carried out the alteration of the construction plan. The construction of the whole structure was uncoordinated throughout the process. By the time of issuing the new designs, the construction work was already done, and the changes could not be implemented.

The foundation of the structure was complete, and the conduction was on the final floor (Wright & Valencia, 2000, 67). Moreover, the construction of the structure lacked quality control parameters hence became a challenge to the developer who contracted private contractors to carry out the inspection of the entire structure. The material that materials that were used to construct the atrium in 1978 was found to be below the required standard. This act can be said to be cost cutting by opting to go for cheaper materials that do not meet the fabrication requirements the construction work (Adams, 2007, 138).

Materials and Structure Failure The fabricated atrium steel that was erected in summer 1978 was the first cause of material failure. The embedded plates that connected the beams to the concreted along the expansion lines were also not considered during the construction. The problem was realised by another contractor who tried to solve the problem (Roth, 2007, 136).

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