Discover how Tung Chung East New Town extension redefines reclamation with non-dredging, deep cement mixing, and eco-shorelines, significantly enhancing local biodiversity and reducing environmental impact.
The Tung Chung East (TCE) reclamation project incorporates many sustainable measures, including non-dredged methods for reclamation and use of the deep cement mixing (DCM) method. Eco-shorelines are planned along the seawalls to enhance biodiversity. Additionally, construction and demolition (C&D) materials are being utilized as the major source for reclamation filling material.
Key features demonstrating the sustainability performance:
- Sustainable reclamation through the use of advanced deep cement mixing method
- Recycling of C&D materials for reclamation and the use of by-product Ground Granulated Blast Furnace Slag (GGBS)
- Eco-Shoreline adds resilient edge and serves as guardian of coastal biodiversity
“We crafted a climate-resilient site and a future-ready living environment with an eco-shoreline, which will bring a unique and incredible experience to the local community.”
Stanley CHENG, Chief Engineer/Lantau 1, Civil Engineering and Development Department,
The Government of the HKSAR
The TCE reclamation is the first public works project in Hong Kong to use DCM method to speed up the reclamation process. DCM more efficiently solidifies the ground, enabling the reclamation to be completed approximately six months earlier than using the conventional method. The works contract commenced at the end of 2017 and with the use of DCM, the first parcel of land was delivered for public housing development in just 27 months. Furthermore, the demand for fill material to replenish settlement was reduced by around six million tonnes. This in turn reduced the number of vessel trips and thus the project’s carbon footprint.
Ground Granulated Blast Furnace Slag (GGBS) is a by-product of the steel industry. Its reuse for reclamation projects is not only more environmentally friendly but also enhances overall durability, improving end-product resistance to alkali-silica, sulphate and chloride reactions. The use of GGBS as a cement substitute has reduced cement consumption by 60% in this project, and achieved a significant reduction of some 600,000 tonnes in greenhouse gas emissions, specifically carbon dioxide.
The reclamation maximizes the use of “waste” C&D materials comprising rocks, concrete, asphalt, rubble, bricks, stones and earth generated from other sites, and accounting for over 70% of the total. The remaining portion consists of mechanical sand, a by-product of quarrying which has proved to be an effective substitute for marine sand, serving as the sand blanket.
Eco-shorelines are being adopted as a nature-based solution to enhance biodiversity. Environments have been created that closely mimic the physical conditions of natural habitats, thereby supporting marine life while offering effective shoreline protection. The eco-shorelines are of three different types, namely rocky, mangrove and vertical (Figures A to C).
Rocky eco-shorelines are provided in locations that are relatively susceptible to wave actions or have insufficient sunlight. Bio-blocks with varying levels and sizes of cavities are designed and constructed at inter-tidal zones to retain seawater during low-tide conditions, with the aim of creating suitable habitats and shelters for marine species. Mangrove eco-shorelines are provided at inter-tidal zones along seashores that are less susceptible to sea waves. Vertical eco-shorelines incorporate pots, cavities, eco-tiles and similar features to enhance the growth of tiny marine organisms. Nowadays, eco-shorelines become habitats for over 30 types of marine species.