How to make use of Underground Space How to make use of Underground Space
to develop more land to develop more land
Becky L S LUI, Senior Geotechnical Engineer
Geotechnical Engineering Office
Civil Engineering & Development Department
Norway – Water Treatment Plant
Singapore – Petrol Storage Area
“to launch strategic planning and technical studies to facilitate the development of underground space and promote use of rock caverns as part of Hong Kong’s pursuit of sustainable development….”
Background
Background - - Policy Address 2009 Policy Address 2009
The use of rock cavern has been identified as one of the 6 enhancing land supply options:
Background
Background - - Enhancing Land Enhancing Land Supply
Supply
Background
Background – – The need! The need!
Background
Background - - Definition Definition
Underground space 地下空間 :
Large basement-type
excavations formed by cut and cover methods 地下室
Purpose-built rock caverns 岩洞
Singapore – Petrol Storage Area MTR
Stations
Flood storage tank at Tai Hang Tung
Background
Background – – Examples of Examples of basements in Hong Kong
basements in Hong Kong
Shopping Mall
Norway – Water Treatment Plant
Singapore – Petrol Storage Area
Background
Background – – Examples of Examples of Caverns in Hong Kong
Caverns in Hong Kong
Tai Koo MTR
Stations
Norway – Water Treatment Plant
Singapore – Petrol Storage Area
狗虱灣爆炸品倉庫 KauKau Shat Wan Explosives Shat Wan Explosives
Depot (1997) Depot (1997)
赤柱污水處理廠
Stanley Sewage Treatment Stanley Sewage Treatment
Works Works (1995) (1995) 西區海水配水庫
Western Salt Water Service Western Salt Water Service
Reservoirs (2009) Reservoirs (2009)
港鐵西港島線爆炸品倉庫 MTR West Island Line MTR West Island Line Explosive Magazine (2010) Explosive Magazine (2010)
Background
Background – – Examples of Caverns in Hong Kong Examples of Caverns in Hong Kong
土木工程拓展署 土力工程處
Background – Foreign Examples
Norway – Water Treatment Plant Finland – Sewage Treatment
Plant • Capacity: 1000
Norway - Coliseum
• Capacity: 5,500
Background – Foreign Examples
Norway – Water Treatment Plant Finland – Swimming Pool
• Capacity: 1,000
Singapore – Petrol Storage Area
• 150 m3 Norway – National Registry
27 m
West Island Refuse Transfer Station
(1997) The Coliseum in Norway (1993)
61 m
(Norway has similar geology as HK) The widest cavern in HK
Background – Foreign
Examples
Natural Criteria for Developing Caverns
• Strong Granites and Volcanics
• Avoid fault zones
Hillside near the urban area
HK Geological Map
Cavern Suitability Map Cavern Suitability Map
Cavern Suitability Classes High to Medium (64%) Medium to low (30%) Not Suitable (6%)
Norway – Water Treatment Plant
Singapore – Petrol Storage Area
Selection of Potential Areas for Cavern Development
Suitability Criteria
Descriptions
Surface Land • Government land - suitable Underground
structures
• Away from existing tunnels and caverns
Geology • Granitic and volcanic rocks – highly suitable
• Away from faults and poor rock mass
• Areas with significant geotechnical constraints – not suitable
Topography • Upper elevations to allow for sufficient ground cover Landfill Areas • Not suitable
Reclamation Areas
• Not suitable
Country Parks • Suitable but portals need to be placed outside country parks
Reservoirs • Not suitable to avoid seepage
Norway – Water Treatment Plant
Singapore – Petrol Storage Area
Government Facilities
Stock-taking of all Government Facilities
Norway – Water Treatment Plant
Freshwater Service Reservoir Sports Centre Seawater Service Reservoir Sewage Treatment Works Freshwater Treatment
Works Civic Centre Refuse Transfer Columbarium Wholesale market Incinerator
Mortuary Slaughterhouse Warehouse
Total No.: 445
Total Area: 485 ha
Stock-taking of all Government Facilities
Norway – Water Treatment Plant
Singapore – Petrol Storage Area
Environmental • Benefits Economical • Nature
• Size
• Location
• Geological conditions
• Preceding case in Hong Kong / foreign countries
Social • Existing Location
Consideration of Relocation of
Government Facilities into Caverns
Norway – Water Treatment Plant
Singapore – Petrol Storage Area Shatin
Lion Rock Siu Ho Wan
Mount Davis Tuen Mun
• Greater than 20 hectares in size
• Able to accommodate multiple cavern sites
• Public benefit
• Relative ease of access
Strategic
Cavern Areas
Strategic Cavern Areas
Strategic Cavern Areas
Preliminary Feasibility Studies Preliminary Feasibility Studies
¾ Mount Davis and Kennedy Town Service Reservoir
¾ Shatin Sewage Treatment Plant
¾ Mui Wo Sewage Treatment Plant and Refuse Transfer Station
Preliminary feasibility studies for transferring the
following facilities into caverns had been carried out:
Norway – Water Treatment Plant
Singapore – Petrol Storage Area
Mount Davis and Kennedy Town Service Reservoir
9 2 ha of land can be released
9 Existing cavern facilities nearby successfully
completed
9 Future expansion can be provided for underground
Cross Section
Kennedy Town Service Reservoir Mount Davis
Service Reservoir
Kennedy Town Service Reservoir
Mount Davis Service Reservoir Tentative cavern site
Norway – Water Treatment Plant
Singapore – Petrol Storage Area
Shatin Sewage Treatment Plant
Sha Tin Sewage Treatment Works
Schematic cavern layout A Kung Kok
亞公角
Tentative cavern site
9 28 ha of prime waterfront land can be released
9 Known similar
underground sewage treatment plant
9 Visual and environmental impacts improved
9 Future expansion can be
provided for underground
Norway – Water Treatment Plant
Mui Wo Sewage Treatment Plant and Refuse Transfer Station
Not-in-my-backyard facilities including sewage treatment works, refuse
transfer station, bus depot, etc.
Mui Wo town centre
Tentative Integrated cavern site
Cavern Cross Section
9 2.5 ha of waterfront land
can be released 9 Revitalize 500 m of
waterfront area
9 Visual and environmental impacts improved
9 Future expansion can be
provided for underground
GEO, CEDD
