Application of Observational Method in Dubai Metro Underground Excavations

摘要

This paper presents the development and application of the Observational Method in the constructionrnof the underground stations and cut and cover tunnels in Dubai Metro Project which was the firstrnmetro project in the Middle East involving the construction of 75.9 km long urban metro line. The cutrnand cover station boxes and tunnels involved the use of top down construction method and permanentrndiaphragm walls to support up to 25m deep excavations in densely developed urban area. Thernapplication of observational method with close collaboration between the Designer, the Contractor andrnthe Employer led to substantial cost and time savings including eliminating the need of 50% heavyrntemporary struts. The project background, appraisal of ground conditions and development &rnsuccessful implementation of the observational methods are described in this paper.