We undertook the geotechnical challenge for the primary interchange station on the new HK$18 billion West Rail line, which extends up the west side of the Hong Kong mainland from Kowloon to Tuen Mun. Nam Cheong Station caters for the Airport Express and western MTR lines, and the West Kowloon Expressway.
These rail lines were all operational before design and construction of Nam Cheong Station began. This posed one of the key project challenges - to design the new station so that it could be constructed around and beneath the existing lines in a way that did not interrupt their operation or adversely affect existing structures.
We worked with Hong Kong-based design engineer RBA, as part of a design-construct team that included Balfour Beatty Construction, between 1999 and 2001. Our contribution included development of all project geotechnical design parameters, challenging locally accepted materials criteria, and design of all of the geotechnical elements.
These included deep foundations, temporary excavation support and de-watering systems, and all monitoring and ground related impact assessments. We followed this with provision of construction phase support for troubleshooting, NCR resolution, geotechnical related construction advice, and as-built reporting.
- Geotechnical interpretation and assessment
- Design of large-diameter, deep bored pile and shaft-grouted friction barrette foundations
- Design of mini-piles and driven steel H-pile foundations
- Modelling of the soil-structure interaction effects on the:
- existing at-grade high speed rail
- elevated expressway viaducts
- other adjacent structures
- floating piles/barrette foundations
- Deep well dewatering and temporary sheet pile excavation design for underground portions of the station
- Large-diameter pipe jacking assessment and settlement analysis
- Geotechnical monitoring review
- Design and construction observation and design support.