One Nine Elms will be a mixed-use (hotel & residential) development on the south bank of the River Thames with a total project value of approx £300 million.
SOLVE were commissioned by the Concrete contractor, Careys Civil Engineering, to complete the 3D RC detailing package of the 3 storey basement structure, up to and including ground floor level, which was to be built using top down construction.
What were the challenges and what made the project successful.
Carey's very quickly identified the benefits of our 3D models and were instrumental in pushing this technology to other members of the design team for greater collaboration and detail development. The benefits of using 3D models were specifically highlighted during the detailing of one of the core base rafts that was 2 storeys below ground, requiring all plant and materials to be supplied through small mole holes and constructed in tight conditions.
This raft itself, was 4.7m at its deepest point, containing 12 layers of H40 bars just in the bottom, and with a total rebar weight of approx 1400 tonnes. Straight away the 3D rebar model highlighted problems with the buildability of this raft, highlighting areas of heavy congestion and severe bar clashes that could potentially have caused very costly delays.
A working solution was then developed over many weeks through online skype sessions and meetings based around the 3D models. This raft has now been completely installed with the assistance of 3D models viewed on tablet devices via Trimble Connect, and was the second largest continuous concrete pour in London.
What benefits utilizing BIM and Tekla Software brought to the project.
The design of the reinforcement elements was extremely complex, but our 3D rebar models helped the Carey's site team visualise any potential problems very early on in the project. These preliminary models were then used extensively for the design development of the reinforcement before we completed the final detailed construction drawings and schedules. This allowed the final reinforcement layouts to take into account Carey's construction methods, sequences and fixing preferences while still achieving the main consultant's design intent requirements.
This process ensured the rebar would fit as planned and reduced the amount of cutting and changes that would normally be expected on a project of this complexity, therefore minimising delays and costs and maintaining a very high level of health and safety. 3D models were issued alongside every 2D drawing and made available to all parties involved.
The project in numbers
Basement structure only: Over 4000 tonnes of reinforcement in the basement structure. 30,000m3 of concrete, project time scale 97 wks.