GEA has been appointed by London Square to provide geotechnical and geoenvironmental consultancy services for a new high-rise residential development in Lewisham, London.

The commission included reviewing an existing desk study, designing and undertaking a ground investigation, and preparing an interpretive report and remediation method statement to support the proposed development.

The site was previously occupied by a large retail development and included a former petrol filling station, presenting a number of geoenvironmental considerations.

With active demolition works taking place during the ground investigation, GEA worked closely with the client and principal contractor to coordinate fieldwork around site restrictions and the project’s critical programme.

The ground conditions comprised London Clay overlying the Lambeth Group and Thanet Formation, with numerous groundwater strikes encountered. Significant borehole depths were also required to provide the information necessary for the proposed piled foundation design.

Drawing on its experience of the local geology, GEA selected a dual-head rotary-sonic drilling methodology. This enabled faster drilling compared with conventional methods while minimising sample disturbance within the variable Lambeth Group horizons, allowing improved geological logging and more detailed groundwater observations.

Following completion of the ground investigation, GEA prepared an interpretive report providing detailed advice on piled foundations and enabling works.

The team also developed a contamination risk assessment and remediation strategy addressing both sitewide contamination and the former petrol filling station.

GEA looks forward to continuing its involvement as the development progresses.