ConstructioNews
Vol 32 No 5 (05-2023)
Tung Chung New Town Extension - Innovative Method of Reclamation
The Government has been planning to further develop Tung Chung New Town (TCNT) into a comprehensively planned new town with a larger population capacity and adequate local and regional community facilities.
The Planning Department and Civil Engineering and Development Department (CEDD) jointly commissioned the Planning and Engineering Study on the Remaining Development in Tung Chung – Feasibility Study (the P&E Study) in 2012 to review the remaining development potential of TCNT. A development proposal of Tung Chung New Town Extension (TCNTE) including the Recommended Outline Development Plan, the major development parameters and land uses were formulated in 2014.
The proposed TCNTE will cover areas on the eastern and western flanks of the existing TCNT. It will provide about 62,100 residential flats for a population of about 184,000. It will also provide about 500,000 square metres gross floor area (GFA) for office use, 327,000 square metres GFA for retail use and 50,000 square metres GFA for hotel use.
Land has been reserved in the extension area for recreational educational and community uses such as sports ground, and post-secondary institution. At Tung Chung West, a channelized section of Tung Chung River at the northeast of Shek Lau Po together with the immediate upstream section up to Shek Mun Kap Road will be revitalized into a river park for recreational use with a view to enhancing and promoting water-friendly culture. Upon completion of the proposed TCNTE, the total population of Tung Chung will increase to about 269,500. The first population intake is targeted in 2024.
Ongoing Works Contracts & Works Progress
Reclamation and Advance Works (Contract No.: NL/2017/03)
Project commenced in end December 2017 for completion in 2023. The main objective
of the works is to provide land in phases. The contract mainly comprises reclamation of the seabed at Tung Chung East by a non-dredged method to form a total of about 130 hectares of land; construction of seawalls with eco-shorelines; construction of a multi-cell drainage box culvert; provision of infrastructure for Tung Chung Area 58; and implementation of the associated environmental mitigation measures.
The reclamation works adopted non-dredged reclamation technology methods for reclamation and construction of seawalls. This project does not involve the removal of soft marine deposit. To strengthen the soft marine deposit and to enhance the stability of the seawall foundation, the project team introduces the non-dredged “Deep Cement Mixing” (DCM) method for stabilisation of ground. It is the first public works project using this technology.
The principle of DCM is to inject cement slurry into the marine deposit and mix them mechanically to form a cement mixing column. These cement mixing column clusters will form a DCM treatment area, to stabilise the seabed underneath the seawall before the construction of the seawall and reclamation works.
Traditional dredged reclamation technology requires transportation and deposition of marine deposit. Its impact in water quality and marine ecology is larger. As DCM does not require dredging, it is more environmentally friendly than the traditional dredged method by causing less impact to water quality and marine ecology.
Furthermore, in the course of the works, the project adopts the latest “Digital Twin” technology to create a smart management platform. The platform utilises the “Digital Twin” technology to collect and consolidate various kinds of site construction data and records through Internet of Things (IoT) sensors. Such data and records are then sent to a smart platform adopting Building Information Modelling (BIM) technology to simulate operations of the construction site, creating a real-time “Digital Twin” of the site in the virtual space. This enables the project team to monitor the entire construction site in real time, allowing quick and accurate decision-making, as well as facilitating day-to-day site management and collaboration in the project team.
With the adoption of the above innovative technology, the reclamation works have been implemented in an effective, environmentally-friendly and sustainable manner. From its commencement in December 2017, it has taken only 27 months for the completion of the first piece of land which was subsequently handed over to the Housing Authority in March 2020 for public housing development. The remaining works under the reclamation project and the associated eco-shoreline are to complete within 2023.
The construction of Tung Chung New Town Extension – Salt Water Supply System (Contract No.: NL/2020/02)
It has been launched in June 2021 and is anticipated to be completed by late 2024. The works mainly include the construction of Tung Chung Salt Water Pumping Station at the Tung Chung East reclamation area, construction of Tung Chung Salt Water Service Reservoir near Chek Lap Kok New Village, laying of about 2,600 metres long salt watermains and about 1,500 metres long fresh watermains.
Salt Water Supply System comprises the construction of two new 0.7 metre diameter watermains of approximately 350 metres long between Tung Chung Road and the proposed Salt Water Service Reservoir across a hill, in which a trenchless main laying technology “Horizontal Directional Drilling” is adopted, in order to eliminate the excavation works at the hill, hence minimizing the impacts on the nearby residents and environment. The drilling works commenced in December 2022 and it is anticipated to be completed in the 4th quarter of 2023. The project team is closely monitoring the drilling works to ensure the impact on the environment is minimized.
Major Infrastructure Works in Tung Chung East (Contract No.: NL/2020/03)
Works mainly comprise construction of engineering infrastructure including drainage
works, sewerage works, waterworks, roadworks, common utility tunnels and landscaping works; and construction of associated environmental mitigation works
including noise barriers and low-noise road surfacing.
For the proposed common utility tunnel with total length of approximately 1.7 kilometres at the new reclamation area, the excavation and lateral support installation are in progress and the reinforced concrete works were commenced in end September 2022.
Siu Ho Wan Fresh Water Service Reservoir and Associated Mainlaying Works (Contract No.: NL/2020/04)
Project comprises construction of Siu Ho Wan Fresh Water Service Reservoir; construction of an access road from Siu Ho Wan Water Treatment Works to Siu Ho Wan Fresh Water Service Reservoir; and laying of fresh watermains.
Construction of the Siu Ho Wan Fresh Water Service Reservoir including the foundation and watermains laying works are in progress.
Site Formation and Infrastructure Works at Ma Wan Chung (Contract No.: NL/2020/05)
Works comprise widening of Tung Chung Road North; re-provisioning of existing Tung Chung Community Services Complex and site formation works at Tung Chung Area 23; construction of open space at Tung Chung Area 29A and coastal pedestrian access; promenade improvement works; construction of car park at Ma Wan Chung; and road improvement works and drainage works at Chung Yan Road.
Widening works of Tung Chung Road North are on-going. Excavation works for retaining wall construction are in progress.
Site Formation and Infrastructure Works at Tung Chung Valley, Phase 1 (Contract No.: NL/2020/06)
Project comprises construction of roads and road improvement of Chung Mun Road and Shek Mun Kap Road; site formation works for Tung Chung Areas 42 and 46; construction of common utility tunnel and sustainable urban drainage system; dechannelisation of existing channelized Tung Chung Stream and construction of the first phase of the River Park; and compensatory woodland planting.
Sheet piling works near Shek Lau Po Village are in progress for the temporary diversion of Tung Chung Stream.
Tai Ho Interchange (Contract No.: NL/2020/07)
Project commenced in Oct 2021, it comprises the construction of Tai Ho Interchange, Road P1 (Tung Chung East to Tai Ho section) and the extension of Pak Mong Subway.
Apart from the construction works of roads and bridges, the “Tai Ho Interchange” project also includes the laying works of fresh watermains, salt watermains and sewage rising mains. The proposed watermains and rising mains will run between Tung Chung East Reclamation area and Cheung Tung Road, via seafront of Siu Ho Wan Depot and with a total length of about four kilometres.
Excavation and lateral support works for retaining wall construction near MTR Siu Ho Wan Depot along North Lantau Highways are in progress. Other ongoing construction activities include laying of fresh watermains and sewage rising mains along Cheung Tung Road and Sham Shui Kok Drive, modification of Pak Mong Subway and foundation works for Pak Mong Channel Bridge.
Source of Information: Website of Civil Engineering and Development Department and Civil Service Bureau
Source of Picture: Website of Civil Service Bureau
The Planning Department and Civil Engineering and Development Department (CEDD) jointly commissioned the Planning and Engineering Study on the Remaining Development in Tung Chung – Feasibility Study (the P&E Study) in 2012 to review the remaining development potential of TCNT. A development proposal of Tung Chung New Town Extension (TCNTE) including the Recommended Outline Development Plan, the major development parameters and land uses were formulated in 2014.
The proposed TCNTE will cover areas on the eastern and western flanks of the existing TCNT. It will provide about 62,100 residential flats for a population of about 184,000. It will also provide about 500,000 square metres gross floor area (GFA) for office use, 327,000 square metres GFA for retail use and 50,000 square metres GFA for hotel use.
Land has been reserved in the extension area for recreational educational and community uses such as sports ground, and post-secondary institution. At Tung Chung West, a channelized section of Tung Chung River at the northeast of Shek Lau Po together with the immediate upstream section up to Shek Mun Kap Road will be revitalized into a river park for recreational use with a view to enhancing and promoting water-friendly culture. Upon completion of the proposed TCNTE, the total population of Tung Chung will increase to about 269,500. The first population intake is targeted in 2024.
Ongoing Works Contracts & Works Progress
Reclamation and Advance Works (Contract No.: NL/2017/03)
Project commenced in end December 2017 for completion in 2023. The main objective
of the works is to provide land in phases. The contract mainly comprises reclamation of the seabed at Tung Chung East by a non-dredged method to form a total of about 130 hectares of land; construction of seawalls with eco-shorelines; construction of a multi-cell drainage box culvert; provision of infrastructure for Tung Chung Area 58; and implementation of the associated environmental mitigation measures.
The reclamation works adopted non-dredged reclamation technology methods for reclamation and construction of seawalls. This project does not involve the removal of soft marine deposit. To strengthen the soft marine deposit and to enhance the stability of the seawall foundation, the project team introduces the non-dredged “Deep Cement Mixing” (DCM) method for stabilisation of ground. It is the first public works project using this technology.
The principle of DCM is to inject cement slurry into the marine deposit and mix them mechanically to form a cement mixing column. These cement mixing column clusters will form a DCM treatment area, to stabilise the seabed underneath the seawall before the construction of the seawall and reclamation works.
Traditional dredged reclamation technology requires transportation and deposition of marine deposit. Its impact in water quality and marine ecology is larger. As DCM does not require dredging, it is more environmentally friendly than the traditional dredged method by causing less impact to water quality and marine ecology.
Furthermore, in the course of the works, the project adopts the latest “Digital Twin” technology to create a smart management platform. The platform utilises the “Digital Twin” technology to collect and consolidate various kinds of site construction data and records through Internet of Things (IoT) sensors. Such data and records are then sent to a smart platform adopting Building Information Modelling (BIM) technology to simulate operations of the construction site, creating a real-time “Digital Twin” of the site in the virtual space. This enables the project team to monitor the entire construction site in real time, allowing quick and accurate decision-making, as well as facilitating day-to-day site management and collaboration in the project team.
With the adoption of the above innovative technology, the reclamation works have been implemented in an effective, environmentally-friendly and sustainable manner. From its commencement in December 2017, it has taken only 27 months for the completion of the first piece of land which was subsequently handed over to the Housing Authority in March 2020 for public housing development. The remaining works under the reclamation project and the associated eco-shoreline are to complete within 2023.
The construction of Tung Chung New Town Extension – Salt Water Supply System (Contract No.: NL/2020/02)
It has been launched in June 2021 and is anticipated to be completed by late 2024. The works mainly include the construction of Tung Chung Salt Water Pumping Station at the Tung Chung East reclamation area, construction of Tung Chung Salt Water Service Reservoir near Chek Lap Kok New Village, laying of about 2,600 metres long salt watermains and about 1,500 metres long fresh watermains.
Salt Water Supply System comprises the construction of two new 0.7 metre diameter watermains of approximately 350 metres long between Tung Chung Road and the proposed Salt Water Service Reservoir across a hill, in which a trenchless main laying technology “Horizontal Directional Drilling” is adopted, in order to eliminate the excavation works at the hill, hence minimizing the impacts on the nearby residents and environment. The drilling works commenced in December 2022 and it is anticipated to be completed in the 4th quarter of 2023. The project team is closely monitoring the drilling works to ensure the impact on the environment is minimized.
Major Infrastructure Works in Tung Chung East (Contract No.: NL/2020/03)
Works mainly comprise construction of engineering infrastructure including drainage
works, sewerage works, waterworks, roadworks, common utility tunnels and landscaping works; and construction of associated environmental mitigation works
including noise barriers and low-noise road surfacing.
For the proposed common utility tunnel with total length of approximately 1.7 kilometres at the new reclamation area, the excavation and lateral support installation are in progress and the reinforced concrete works were commenced in end September 2022.
Siu Ho Wan Fresh Water Service Reservoir and Associated Mainlaying Works (Contract No.: NL/2020/04)
Project comprises construction of Siu Ho Wan Fresh Water Service Reservoir; construction of an access road from Siu Ho Wan Water Treatment Works to Siu Ho Wan Fresh Water Service Reservoir; and laying of fresh watermains.
Construction of the Siu Ho Wan Fresh Water Service Reservoir including the foundation and watermains laying works are in progress.
Site Formation and Infrastructure Works at Ma Wan Chung (Contract No.: NL/2020/05)
Works comprise widening of Tung Chung Road North; re-provisioning of existing Tung Chung Community Services Complex and site formation works at Tung Chung Area 23; construction of open space at Tung Chung Area 29A and coastal pedestrian access; promenade improvement works; construction of car park at Ma Wan Chung; and road improvement works and drainage works at Chung Yan Road.
Widening works of Tung Chung Road North are on-going. Excavation works for retaining wall construction are in progress.
Site Formation and Infrastructure Works at Tung Chung Valley, Phase 1 (Contract No.: NL/2020/06)
Project comprises construction of roads and road improvement of Chung Mun Road and Shek Mun Kap Road; site formation works for Tung Chung Areas 42 and 46; construction of common utility tunnel and sustainable urban drainage system; dechannelisation of existing channelized Tung Chung Stream and construction of the first phase of the River Park; and compensatory woodland planting.
Sheet piling works near Shek Lau Po Village are in progress for the temporary diversion of Tung Chung Stream.
Tai Ho Interchange (Contract No.: NL/2020/07)
Project commenced in Oct 2021, it comprises the construction of Tai Ho Interchange, Road P1 (Tung Chung East to Tai Ho section) and the extension of Pak Mong Subway.
Apart from the construction works of roads and bridges, the “Tai Ho Interchange” project also includes the laying works of fresh watermains, salt watermains and sewage rising mains. The proposed watermains and rising mains will run between Tung Chung East Reclamation area and Cheung Tung Road, via seafront of Siu Ho Wan Depot and with a total length of about four kilometres.
Excavation and lateral support works for retaining wall construction near MTR Siu Ho Wan Depot along North Lantau Highways are in progress. Other ongoing construction activities include laying of fresh watermains and sewage rising mains along Cheung Tung Road and Sham Shui Kok Drive, modification of Pak Mong Subway and foundation works for Pak Mong Channel Bridge.
Source of Information: Website of Civil Engineering and Development Department and Civil Service Bureau
Source of Picture: Website of Civil Service Bureau