The existing opening was required to be enlarged by lowering the bottom steel to below ground level, creating a flush new opening.
With limited ground bearing capacity, the only suitable foundations were two piles caps previously installed for Castle Bridge to be founded on. A late design change to the bridge altered its location into the development, meaning the piles and pile caps were redundant. Limited suitable foundations constrained the temporary works design to provide support locations to the top steel in only two places.
A full 3D analysis of the cantilever RMD Superslim frame, supporting a total load of 500kN, was developed using CADS A3D Max then externally checked. Additional analysis was required on the existing beam as to calculate any anticipated deflection and reduce risk on cracking within the masonry.
The RMD Superslim solution provided suitable space for the demolition works, while also allowing reuse of the existing lower steel. Manually handling was kept to a minimum during installation with the use of mechanical hoists and cherry pickers.