Case Study: SAIDEL Engineering achieves subway-operator approval and halves tunnel impact for Bucharest’s first residential building above subway tunnels with Bentley PLAXIS

SAIDEL Engineering Designs First Residential Building above Subway Tunnels in West Bucharest

SAIDEL Engineering was hired to deliver the structural and geotechnical design for the first residential building constructed above subway tunnels in West Bucharest, a EUR 2.5 million pioneer project with an irregular footprint that had been rejected and stalled for two years. The main challenge was proving to the conservative subway operator (Metrorex) that the foundation would impose minimal displacements and structural forces on the tunnels; to meet this challenge SAIDEL used Bentley’s PLAXIS geotechnical software (PLAXIS 3D) to develop a robust analysis and approval package.

Using Bentley’s PLAXIS, SAIDEL produced advanced 3D finite‑element models (including nonlinear soil behavior, hexagonal prisms for piles and rigid body pier loads) and proposed a 1.5 m raft on 37 piles (1,080 mm × 18 m). The PLAXIS-driven design earned Metrorex approval within three months, halved the building’s influence on tunnel lining in terms of displacement and structural forces, showed only ~6 mm uplift during excavation, led to reducing the building from 10 to 9 stories and cut raft thickness from 2 m to 1.5 m—saving concrete and reinforcement while unlocking future development over city tunnels.

SAIDEL Engineering

Șerban Nicolau

FEM Design Engineer