Central London Bank
Deconstruction Scheme
Specialist Scaffold Access Systems,
Demolition
RDG was contracted to design a scheme to enable the deconstruction of two link bridges connecting two office buildings. The site was bound by high security requiring full hoarding protection to ensure that the site was not visible from the outside.
The link bridges spanned 16m and were located at the North and South ends of the two buildings, extending from ground level to the roof. The land occupied a heritage site with part of the London Wall beneath. This created loading constraints with a maximum reaction force of 10kN point load or 10kN per square meter.
Site access for materials was limited due to a highly controlled service road on the north side and a pedestrian shopping area on the south side. This required that the materials being manoeuvred were piece small.
The deconstruction required craneage facilities above each link bridge with a capacity of 10t safe working load, split between two 5t hoists. The steel column within the building was utilised as a strong point, transferring the crane loads into the foundations of the building. This avoided physical contact with the building fabric, as requested by the client.
Conventional crane facilities usually run on steel. However, this was not a viable option due to the 16m span between the two buildings and the site access constraints. The solution was to design a series of aluminium lattice beams to create a lattice girder. A tubular tracking system was placed on top of the aluminium lattice beams. The maximum length of each crane section was 2.7m, resulting in a splice joint in the middle.
The deconstruction required craneage facilities above each link bridge with a capacity of 10t safe working load, split between two 5t hoists. The steel column within the building was utilised as a strong point, transferring the crane loads into the foundations of the building. This avoided physical contact with the building fabric, as requested by the client.
Conventional crane facilities usually run on steel. However, this was not a viable option due to the 16m span between the two buildings and the site access constraints. The solution was to design a series of aluminium lattice beams to create a lattice girder. A tubular tracking system was placed on top of the aluminium lattice beams. The maximum length of each crane section was 2.7m, resulting in a splice joint in the middle.
An access scaffold was erected on the outside of both link bridges to facilitate the removal of the link bridge windows. The scaffold could not be freestanding due to the 10kN point load constraints and could not be tied to the building fabric. A birdcage scaffold was designed to fill the void between the two link bridges to transfer the loading from the external access scaffold into a support frame. The birdcage allowed all horizontal and lateral loads to dissipate to ensure that the 10kN point load was not exceeded.
An access scaffold was erected on the outside of both link bridges to facilitate the removal of the link bridge windows. The scaffold could not be freestanding due to the 10kN point load constraints and could not be tied to the building fabric. A birdcage scaffold was designed to fill the void between the two link bridges to transfer the loading from the external access scaffold into a support frame. The birdcage allowed all horizontal and lateral loads to dissipate to ensure that the 10kN point load was not exceeded.
Skips were positioned on the North side. Materials from the South side were transferred via a tracking system. The materials being manoeuvred weighed considerably more than the permissible load. A transfer trolley system was designed to distribute the load into the ground such that the 10kN constraints were not exceeded.
Skips were positioned on the North side. Materials from the South side were transferred via a tracking system. The materials being manoeuvred weighed considerably more than the permissible load. A transfer trolley system was designed to distribute the load into the ground such that the 10kN constraints were not exceeded.
