Feasibility study of using microbially stabilized dredged marine clay as fill materials for sustainable land reclamation in Hong Kong

Dr Kwok, Chung Yee   (Principal Investigator (PI))

Mr Fong Michael   (Co-Investigator)

Professor Shih Kaimin   (Co-Investigator)

Mr Ho Ken   (Co-Investigator)

24

2022-12-28

500000

Feasibility study of using microbially stabilized dredged marine clay as fill materials for sustainable land reclamation in Hong Kong

Feasibility study, fill materials, microbially induced calcite precipitation, stabilized dredged marine clay, sustainable land reclamation in Hong Kong

Building and Construction

Engineering (E)

ECF Project 156/2021

Environment and Conservation Fund

2021

On-going

Dredged marine clay is a significant source of solid wastes in Hong Kong and is normally dumped in open water which is costly and environmentally unfriendly. Exploring the reusability of the dredged marine clay is meaningful in two aspects, minimizing the need of dumping and meanwhile relieving the fill materials shortage situation for large scale reclamation. In this proposal, the feasibility of using stabilized dredged marine clay as fill materials for sustainable reclamation will be thoroughly explored. A new microbially induced struvite precipitation (MISP) method will be adopted, instead of cement, to stabilize the dredged marine clay, which has low carbon emission and is non-energy intensive. The aim is to obtain optimum design mixes, considering the bacterial density, cementation solution concentration, curing duration and medium by carrying out a series of uniaxial compression tests; then oedometer and triaxial tests will be conducted to characterize the compression and shearing behaviour of the stabilized marine clay at the optimum mixes; finally, an examination of microstructure characteristics of the stabilized marine clay will be performed to identify those microscopic parameters of the struvite that govern the macro physical and mechanical responses of the stabilized marine clay.