Geotechnical Analysis and Design

CGL, through its structural engineering partner, Walsh, worked collaboratively with the broader Mace project team and supply chain wave to deliver the detailed design solution. This included a temporary platform over the excavated area to facilitate safely advanced construction of the lift shaft overhead to mitigate programme delays.

CGL combined advanced geotechnical analysis using PLAXIS FE Soil-Structure Interaction modelling with their knowledge of leading innovative and advanced concrete coring/sawing techniques to specify, plan and sequence the excavation of the new pit location as a workable solution. The collaboration between structural engineers and geotechnical engineers allowed the residual raft strength to be matched to the dewatering and licensed discharge to drains.

The watertight pit construction was built-out and structurally tied to the existing raft reinforcement. This allowed the dewatering to be decommissioned without ever having to utilise tankerage and maintaining the raft integrity as a water barrier.