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Wednesday, October 30, 2019

Cause of the collapse of Heathrow rail tunnel in 1999 and what should Essay

Cause of the collapse of Heathrow rail tunnel in 1999 and what should have been done to prevent the collapse - Essay Example NATM was implementing one of the firsts in almost everything. The technology of the method involves spraying shotcrete around the surrounding of the tunnel. This process leads to the formation of the supportive crust though temporarily. It was the first time that the project was used in London clay and the method being new most of the people working in the tunnel were not familiar with some of its aspects. In addition, the New Austrian Tunnelling Method (NATM) applied the self-certification method for the first time at the London Heathrow Airport site (Muir, 2000, p. 19). This method requires that contractors be charged with the responsibility of certifying their work. This method offers no opportunities for oversight management. The case resulted in Balfour Beatty receiving a heavy fine of one point two million pounds while the same court slammed Geoconsult with a five hundred thousand pounds fine for its less capable role. The collapse The collapse occurred on the night twentieth a nd twenty-first of October in nineteen ninety-four. There were no casualties but the cost of recovery amounted to one hundred and fifty million pounds. The project stalled for six more months and disruption of the underground Jubilee Line Extension. However, there were no casualties, the Health and Safety Executive (HSE) successfully filed a petition that resulted heavy fines of one million and two hundred pounds o both Balfour Beatty and Geoconsult with legal costs amounting to two hundred thousand pounds. Causes of the collapse Balfour Beatty and Geo consult implemented the New Austrian Tunnelling Method despite the method having reservations that were grave. This resulted in one of the worst civil engineering disasters in the last century bearing in mind the fact that the Heathrow accident occurred one month after the Munich disaster. The Health and Safety Executive (HSE) took the initiative to warn the two contractors about being cautionary in their approach but contractors fail ed to heed the advice. Among other general failures, the case proved that there was flawed workmanship, which included serious flaws in the management of construction procedures and contract arrangements that failed to meet the standard requirements. The New Austrian Tunnelling Method (NATM) operated as UK-NATM and had serious failures. To begin with, the method was appropriate for primary lining. This should only apply to temporary works (Feld and Carper, 1997. P. 33). The method does not put into consideration the primary lining while designing the secondary lining. The method takes these steps while it is normal that secondary lining is the second phase and its design should follow the design of the primary lining. The main cause of the problem in the process employed by NATM is that it designs both linings simultaneously. The right process requires that the design should be subsequent. This means that the design of primary lining should come before the design of the secondary li ning. The design process should be design as you go. The UK-NATM method allows little room for convergence under the buildings and works concurrently with grouting. The method does not have oversight supervisors and this denies the opportunity for monitoring the appropriateness of the design and gives information regarding compensation grouting. Construction of Heathrow using this method denied the project oversight management hence corrective measures could not

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