The first project of the Grosvenor Estates Framework, this will be a big test of logistics, planning and erection. Located in central London, the structure will consist of two existing retained buildings and a new steel frame erected between them. Stregthening works will take place in the retained structure fronting onto Grosvenor Street in what is known as "Phase 2", whilst the frame in the central courtyard area will be a completely independent steel frame.
Ordinarily a structure like this would be quite simple to construct, however due to the constraint of access into the site, this project jumps considerably in difficulty. Everything must fit through a 2m high by 2m wide opening in the existing structure and be manhandled into position.
The pre-site works are well underway, with completion of all fabrication drawings, GAs, connection details and surveys due weeks before erection begins on site. This has been made possible by an excellent flow of information from the main contractor and design team as well as meetings which compare our own 3D model with the engineer's 3D model.
Connection details for the "new frame" in the central courtyard have been simplified as much as practical, and when combined with positive lifting points and "pinkies", will result in very quick erection of the new steel frame.
The most complicated part of the pre-site works however has involved an extensive look into the constructability of the steel frame. Approximately 2 months have been spent working out the logistics and feasibility of installing the whole central steel frame, from basement to roof level, in one continuous visit from the basement slab level, and we are pleased to say that we have managed to find a way.
Due to the simplicity of the connection details and the steel frame designed by the engineer, the fabrication of the frame has been exceptionally simple. Sockets to accept leading edge protection have been fixed to the top flange of the appropriate members, and in the majority of the cases, this is the most complicated fabrication required!
Inutmescent paint is required on the new steelwork, the majority of which will be painted on-site, however the inaccessible flanges of the new steel will be painted off-site in our factory to ensure that the new steelwork is correctly fire rated.
With erection of the new steel frame well underway on site, the extensive time spent planning the construction of the project has paid off dividends. Considerations regarding the size of crane and access equipment has meant that the site is even more crowded in the work area than envisaged pre-site, however this has not hampered the erection of the frame, and the use of positive lifting points has proved to be a major time saver.
Major deliveries of steelwork and decking to site occur at the weekend to minimise impact to the erection of the steel frame, with smaller deliveries of easily handable steelwork are undertaken during the week to ensure continuation of work for our operatives.
The structural steel works within the retained building on Grosvenor Street have been completed, and the steelwork went in with very few issues.
Yet again this is down to the extensive planning undertaken both internally and externally with the Main Contractor to ensure that the scaffold access platforms provided did not clash with the new steelwork.
Overall the project has been a major success for Becro, and the experience gained on site has been invaluable.