Facade Jacking: Oxford House
Cantillon recently completed the demolition and enabling works package at 73-89 Oxford Street for our client Great Portland Estates and Multiplex.
The demolition package was delivered on one the busiest shopping street's in Europe with access to the project and waste removal restricted in the main to a tower crane operation within a pit lane formed on the highway on Oxford Street.
Demolition was completed some time ago but the Cantillon team recently returned to jack the retained brick and terracotta facade on Dean Street. The facade was retained internally due to the proximity of the Cross rail development next door. The retention system was founded 3m below the existing basement to avoid clashing with the new structure. The facade was retained by over 100t of steel and stood 5 stories above ground level.
Due to the proposed floor levels of the new structure, the façade required jacking 890mm.The façade retention system was designed with vertical guide rails between the retention towers and the clamping frame around the façade. These were separated by greased skates and retained in position with steel rollers to allow vertical movement when jacked. The façade was jacked from the underside of the 1st floor beam using 36 single stroke hydraulic jacks set in pairs perpendicular to the beam. The lift was completed over 2 night shifts due to the complexity of the operation with minimal impact to neighbouring businesses and construction sites.
Strict movement criteria were set during the lift and a continuous surveying and measuring operation was undertaken to ensure the lift was progressing as planned within the limits. The façade was lifted at a rate of approximately 10mm per minute and completed on schedule and handed back to Multiplex to continue with the superstructure construction.