West Island Line
Hong Kong

The HK$15.4B extension to the MTR West Island Line comprised 3km of tunnel and two 22.5m span underground station caverns.

Geo-Design contributed to the detailed design of the scheme, including the first properly urban caverns in Hong Kong.

Sector: Civils – transport caverns.

Optioneering
Development of design options and preparation of temporary support drawings for cavern complexes, including intersections and cross passages.
Value engineering
Change of design concept from undrained to drained. Risk reduction via repositioning caverns to avoid adverse ground conditions.

Ground investigation and modelling
Planning and specification of site investigation and testing, and development of detailed geological and rock mass models.
Detailed design
Rock engineering and structural design of two station caverns (22.5m span) with major 3D intersection components in variable, partially weathered rock mass conditions in urban locations.
Groundwater management
Impact assessments and mitigation design including for groundwater management, to establish approval for the first urban caverns in Hong Kong.