BRIGHTON PIER

About This Project

Brighton Palace Pier (Grade II* listed building) opened in 1899. The pier stem and head total approximately 540m in length and the pier head itself comprises structure from three distinct time periods. The central core comprises Victorian cast iron piles. To the north east corner is an area approximately 35mx15m known as the boat deck built in the 1930’s. In the mid 1990’s the pier head was extended with new structure that surrounded the original pier head.

The 36 piles to the 1930’s boat deck are rolled steel joists (RSJ). The main group of piles is arranged on a 3×11 grid. The lines of 11 piles are spaced approximately 3m apart and the lines of 3 piles are spaced at approximately 3.5m and 6m apart. The outer row of 11 piles is inclined, the others are vertical. The piles are connected by three levels of horizontal steel beams, spaced approximately 3m apart. The top level supports a workshop and walkway over part of the piled area.

Above the boat deck area is an existing building. The building is single storey heavy steel frame with flat concrete roof. The buildings use is as a bar called “Horatios”. One end of the building has a higher level roof and a mezzanine floor storage area.

On conclusion of an annual condition survey of the structure it indicated the poor condition of the existing boat deck structure necessitates replacement.

As the existing building was to remain, the new structure under the pier had to be installed with the existing structure still in place. An existing workshop under the pier deck and above water level had to be removed.

The proposed new structure comprised of 24 new piles. These were circular hollow sections (CHS) and of 406mm diameter. To facilitate the pile installation, these were divided into short lengths and jointed together with bolted flange plates. The pile sections were filled with micro-concrete to form the core. Concrete scour protection that surrounds the piles at sea bed level were also constructed. The new piles were braced together with horizontal and diagonal CHS braces over 3 levels. To re- support the pier deck, floor and columns to the existing building, an assembly of new steel beams supported off the new piles was provided. These sections were arranged in a transverse (610×305×238 UB) and longitudinal (610×305×179 UB) direction on top of the piles.

Works Description

• Principal Contractor for the Scheme (NEC 3 option A)
• Install 24No, 406dia tubular piles in sections to complete tube length of 17.7m. Piles grouted from design/actual toe to form complete pile length of 28.5m. Installed by mini piling rig.
• Structural steel- install a network of primary steel bearing on new piles to form structural steel to accept load of existing building.
• Controlled synchronised jacking procedure to ensure gradual load transfer of building from old to new structure
• Scour jackets- CMP re-designed pre-cast scour formwork system to a simplified solution of reinforced fabric assembly, thus amounting to safer and faster diving installation time.