A Sustainable Approach to Marine Reclamations Using Local Dredged Marine Soils and Wastes: Soft Soil Improvement, Physical Modelling Study, and Settlement Prediction-control

Housing is currently one of the burning social issues in Hong Kong. There is an urgent need for providing large areas of suitable lands for residential houses and other infrastructures. In 2018, the Hong Kong Government proposed a major reclamation project in Hong Kong waters, i.e., “Lantau Tomorrow” vision, the main concerns of which are the short supply of fill materials, long construction time, and high cost. To tackle these concerns, the authors have proposed to use local 4dredged Hong Kong Marine Deposits (HKMD) and construction wastes to fill a reclaimed area on the seabed in a major Research Impact Fund project in 2019 with HK$15M funding. The use of local HKMD and construction wastes can significantly save the costs for fill material and shorten the construction time. In this paper, successful reclamation projects using soft soils will be briefly reviewed. The state-of-the-art research findings in PolyU, including the results from two ongoing physical model tests, turning construction wastes into the competent filling materials, and a well-verified new simplified Hypothesis B method for predicting soft soil settlements will be presented. Lastly, the methodologies for controlling the post-construction settlement will be discussed.