Study On Key Technology For Zhuhai-macao Port Artificial Island Formation

With the rapid expansion of coastal cities, land and shoreline are becoming depleted.Marine land reclamation has become a major way to alleviate the dispaties betweencurrent land shortage and construction demands so as to expand the socialdevelopment space. Artificial island, as an effective approach for ocean utilizing, is infull swing around the world, whose investment and construction scale are gettingbigger. However, besides the poor nature condition, complex technology, resoucelimits and construction difficilties, each construction of an artificial island still need tofully consider the ecological environment protection. Therefore, it is necessary todiscuss/study deeply the key technical issues of designing large artificial island.The study is carried out in this dissertation, relying on Hong Kong-Zhuhai-MacauBridge Zhuhai-Macau Frontier Port Artificial Island Project. Focusing on the researchand design procedures considered in the construction of the artificial island, analysesare given in this paper, including the natural environment of the site ofZhuhai-Macau Frontier Port Artificial Island, comparing several key technologiessuch as general layout and planning, land formation and ground improvementprogram, hydraulic revetment structure type and construction methods and schedule,also studying the local ecology and environmental protection measures, finally arelatively complete reasonable set of method for the construcition of offshoreartificial island is derived.The paper’s main innovations are as follows:1) It is proposed to separate the Zhuhai connecting artificial island from the mainisland in the general layout, so as to reduce tide change, coastal evolution andwater blocking rate after the implementation of the project. Meanwhile, lessen thecost and difficulty of the construction of Zhuhai connecting artificial island.2) A reasonable overtopping standard has been determined based on the deepanalysis on local hydrological, overtopping test results and access restrictionsduring Bridge operations, so as to lower the top elevation of crown wall, whichresult in a fantastic sight viewing for tourist. Meanwhile, either the traffic safety orstructure safety will be assured during the typhoon.3) Cosidering the natural conditions of the project site, analysis and research have been carried out to study the possibility of using different type of marine structuresin eastern、southern seawall and western、northern seawall, which can satisfy thelandscape requirement. Through structural comparison, the scheme of slope-stylerubble mound structure plus removing soft silt is adopted for eastern/southernseawall, which is safe and reliable with a strong ability against typhoon; while forwestern/northern seawall, the scheme of half vertical type embankment plusvacuum-surcharge preloading is used to reduce dredging and protect environment,creating a beautiful landscape.4) Considering that the sea zone close to the prosperous areas of Zhuhai and Macau,sea sand backfill is proposed in land-formation, avoiding strong pollution duringthe dredging and backfilling. Moreover, preloading surcharge plus dewateringmethod is adopted for ground improvement so as to reduce the total amount ofsand requirement and save the cost.5) Making environmental protection measures to minimize the negative impact onsea as well as the ecological environment through the use of appropriateconstruction methods, especially for the protection of Chinese White Dolphins.The research results have been successfully applied to the artificial island ofZhuhai-Macau Frontier Port. It is believed that the research methods, design andconstruction achievements can provide effective reference for future similar projects.