THE SCHEME
When complete, Water Street Bridge will provide a road and pedestrian link between the new Wood Wharf development and Montgomery Square, a span of 150m which includes a 25m bascule bridge across the southern end of the Bellmouth Passage.
DESIGN AND ENABLING WORKS
Bachy Soletanche was appointed by Canary Wharf Contractors to install marine piles and mini-piles to provide support for construction of the deck and bridge structure. The scheme was designed by consulting engineers, COWI. Prior to commencing the main geotechnical elements, the team undertook enabling works including obstruction removal and unexploded ordnance probing.
CONSTRUCTION
Water Street Bridge was divided into two elements, marine piling and land-based mini-piling. In total, 64 marine piles were constructed, with the split being 52 at 900mm diameter and 12 at 1200mm diameter. All the marine piles were bored to a depth of 29m and constructed under polymer. The land-based mini-piling involved the construction of six mini-piles, with a diameter for 450mm and bored to a depth of 24.5m.
Bachy Soletanche contracted Red7Marine to provide the marine support with tension leg and spud leg barges to complement BSL in-house designed and fabricated bespoke tooling to ensure an efficient installation process. The marine piles and reinforcement were delivered directly to the site by barges.
The team also faced an additional challenge by having to operate within a restricted excavation period (1am to 4am) to comply with London Underground regulations. This was achieved through detailed logistical and programme planning.
