The envisioned transformation of the former MI5 headquarters involves a plan to excavate three additional basement levels. However, this undertaking brings with it the potential for ground movements that could impact neighboring properties. In order to secure planning approval, it became imperative to showcase that both temporary and permanent support measures for the basements would effectively mitigate any excessive movements.

To meet this requirement, an intricate 3D Finite Element Analysis (FEA) model was meticulously crafted. This comprehensive model not only encompassed the proposed development but also considered the existing adjacent structures and the surrounding terrain. Through rigorous analysis, this model accurately forecasted ground movements, ensuring that they remained within permissible thresholds.

By demonstrating the efficacy of the devised support strategies through the FEA model's predictions, the concerns of potential adverse effects on the neighboring properties were allayed.

Highlights

• A study of sub-structure details for Leconfield House and adjacent buildings to assess their sensitivity to ground movement.

• 3D FEA model of Leconfield House and adjacent sub-structures (basements and foundations).

• Simulation of construction of 3 basement floors and prediction of resulting ground movement.

• Damage assessment for adjacent buildings found to be within acceptable levels.

• Planning permission for the development granted.