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Applied Research Impact Case 9

Beneficial Reuse of Marine Mud

Dr Dickson Yan, Faculty of Science and Technology

 

 

 

The Kai Tak Development is a huge project to turn the former airport site and its nearby districts such as Kowloon City, Wong Tai Sin, and Kwun Tong into a new sustainable community. The development has however, introduced along problems arising from the disposal of excavated marine mud. From the construction perspective, marine mud has little value for reuse owing to its high water content, soft and bouncy texture, as well as contamination. The disposal of marine mud also puts a burden on landfills or marine dumping sites and incurs significant transportation costs.

 

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Kai Tak Development Site

 

To solve the above problems, Dr Dickson Yan was appointed as a consultant to study the feasibility of reusing marine mud excavated from the Kai Tak Cable Tunnel. He considered the potential on-site application of marine mud and proposed reusing it to fill up the trenches after excavation, i.e. as backfill material. As a common practice, sand and rocks found around a construction site (native soil) are used as backfill materials. If native soil is not available, backfill materials must be purchased and transported from other places. Investigations have been carried out to use local marine mud as an alternative backfill material. It is found that by mixing marine mud with the right proportion of native sand and cement, the mud can increase its strength significantly to meet the requirements for backfill application.

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Marine Mud

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Compressed mud cube between compressor

 

This project provides an eco-friendly approach to handle excavated waste. It does not only reduce the transportation cost of disposal, but also minimizes the cost of purchasing backfill materials. The findings were published in international journals such as Journal of Construction and Building Materials and Journal of Environmental Engineering and Landscape Management. Moreover, the project has been used as a case study in countries like Korea, China, the USA, and France.