Palm Jumeirah Vehicular Tunnel Project

Action engineered a floating station that provided 300 m of deck area on which the pump spread was floated over the middle of the cofferdam. Due to the critical nature of the pumping works Action monitored the discharge and drawdown 24 hours a day for the duration of the works, collecting data from an integrated instrumentation solution. These monitoring systems were an integral part of the early warning system implemented on site. Action followed the dewatering of the cofferdam with the design, installation and operation of a temporary Ground Water Control system to manage water seepage through the sheet-pile along with natural water in-flows. A maximum excavation of -28 m below the Mean Sea Level was maintained during 18 month construction period. The temporary dewatering system was engineered using the aid of Finite Element Analysis, the results of hich were interpreted in conjunction with Action's extensive local experience, and correlated data from the Phase 1 works. The solution was engineered in compliance with Nakheel's environmental guidelines. The final solution consisted of installations around the site perimeter operated from two Pumping stations located on the East and West embankments. Controlled flooding of the construction site was the final phase of the dewatering scope. Initially water was allowed to ingress in order to test the structure for leakage. This was followed with a accelerated flooding schedule, which reinstated the water table to it’s original level within a period of 21 days.