Volker Stevin Ltd. was awarded the contract of the Vessel Relocation works for the Thames Tideway Tunnel scheme. These works involve the relocation of 2 ships (HMS President and PS Tattershall Castle) which are permanently moored on the Thames and the provision of a new pier pontoon for the Thames ferry and leisure vessels.
Geobest performed drivability and vibration analyses for all parts of the project. This included large diameter steel tubular piles and several sheet pile structures. All steel piles had to be driven in very stiff to hard London Clay. The Soil Resistance during Driving (SRD) was established based on an extensive soil Investigation programme and was adapted during the project based on the result of the first installed (sheet) piles.
Special focus was put on the influence of the pile driving works on the surrounding objects, which included several underground services, the existing Blackfriars Railway bridge and the old Victorian River wall. During the execution of the piling works, vibration measurements were carried out to check the vibration prognoses. Piling works were executed without damage to the above mentioned structures.