An incredibly challenging project, the room sits approximately 6m underground. The room is designed to contain an electronic signalling box that aids to control the flow of trains running through the station. The room construction comprised of a reinforced concrete floor and walls, there was also brickwork built approximately 100mm on the inner face of the r/c wall and single skin brickwork separating the room from the other areas within the station. This meant there was a non-serviceable cavity on those two walls.
This internally built brickwork wall could not be removed due to operational restrictions and H + S practices so TFL engineers proposed works should be carried out to the brickwork face. There was evidence of dampness to the soffit and slab, however we must assume that moisture would be present inside the cavity and allowances should be made to drain any potential moisture build up.
With regards to draining any moisture build up in the cavity, it was agreed that holes were drilled into the cavity at regular intervals and Koster Superpacker inserted so that in normal operation this would provide a seal however could be removed during maintenance to relieve any moisture build up.
During the design they wanted to have a Unistrut system mechanically fixed to the walls and ceiling which would have broken the waterproofing system and caused weakness. We proposed a solution whereby we could retro fit the anchor sleeves without compromising the integrity of the finished waterproofing solution.
Moorgate Station SER