John Sisk and Son Ltd selected Coffey, A Tetra Tech Company, to provide geotechnical design services for temporary works for a 500-meter-long immersed tube tunnel beneath the River Shannon in Limerick, Ireland.
The project, which consisted of installing prefabricated tunnel segments underwater, required €14M of temporary works to retain excavations for the cut and cover sections at each end of the tunnel. Coffey conducted a detailed analysis of the behavior of each wall during construction. By applying our thorough understanding of the difficult ground conditions and the complex construction sequence we were able to manage the risks of overstressing the temporary structure.
