By Samer Skaik
In complex high rise projects, employers tend to fast track works where construction can begin while design is still incomplete following three main phases of procurement. Shoring system and piling are firstly procured and awarded to an enabling contractor. Upon completion of enabling works, main design and traditional tendering of the second phase can be concluded in order for main construction works to commence on site. While main work is progressing, design of specialist packages will be completed and nominated subcontractors are appointed in a timely manner shaping the third phase of procurement. Such common phased construction usually results in substantial time saving in project life cycle. However, many fast track projects suffer time and cost overruns due to inherent risks of fast tracking such as design deficiencies and ambiguities in risk allocation between involved parties. This paper aims to investigate pros and cons of fast track procurement approach for complex high rise projects and examine how relevant risks are allocated among enabling contractors, main contractors, nominated subcontractors and project consultants in theory and practice.
The paper will demonstrate an interesting case study of a fast track overseas super high rise building where an Australian firm was appointed by the employer as a technical expert to provide a detailed report on the failure of shoring system while the construction of five basements had just started next to marina. There were two different failures that the Australian expert was supposed to assess their causes. First, a major deflection was observed on neighbor’s shoring wall towards building plot which put a major area within the plot on hold by local municipality for safety precautions. Second, water seepage started to show signals on the sides of the lift pit at the center of plot despite the existence of running dewatering system. Then, seepage rapidly developed to a major flood filling the excavated pit of 25 meters depth with water. The case study will also demonstrate another problem associated with subcontract nomination which is another fast tracking approach in high rise buildings and will discuss the taken measures by the project management team to redress problems and mitigate risks during construction. In conclusion, lessons learnt from the case study will be summarized with recommendations to have better practice of fast tracking approach in complex high rise buildings.
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