Case Study: Golder Associates achieves optimized subsea tunnel design, $16M cost savings and 1,500‑ton CO2 reduction with Bentley

Golder and Associates Strengthen One of the World’s Largest Subsea TBM Tunnels in Newly Reclaimed Land

Golder Associates was the geotechnical designer for the Tuen Mun–Chek Lap Kok Link (TMCLKL), a 4.1 km, dual two‑lane subsea tunnel up to 55 m below the sea in newly reclaimed land. Facing complex ground conditions (soft marine deposits, alluvium, decomposed granite, high groundwater pressures), tight deformation limits over a 120‑year design life, and the need to support record‑sized TBMs, Golder turned to Bentley’s geotechnical applications — including PLAXIS 2D, PLAXIS 3D, gINT, HoleBASE, and MicroStation — to analyze and manage the data and designs.

Using Bentley’s PLAXIS models and Bentley’s information‑management tools, Golder optimized soil models, tunnel excavation sequences, and support barrettes; PLAXIS 3D sensitivity analyses reduced barrettes from 158 to 106 (46 were shortened), saving about two months of construction, USD 16 million, and roughly 1,500 tonnes of CO2. Bentley’s tools produced realistic settlement and lining‑deformation predictions that matched monitoring (volume loss generally <1%), helping the TMCLKL open on schedule and cut travel time between the Northwest New Territories and the airport from 30 to 10 minutes.

Golder Associates

Lee Siew Wei

Principal, Golder Associates