Compression behavior of cement-treated marine dredged clay in Dalian Bay

There exists large volume of marine dredged clay generated worldwide to potentially compromise to ocean environment. Efficient resource utilization of dredged clay is crucial to sustainable development of offshore works. In this study, cement-treated marine dredged clay is suggested as filling materials for the construction of artificial islands in Dalian Bay, China. To evaluate influence of cement addition on compressibility, a series of oedometer tests were performed on reconstituted and cement-treated dredged clay. The effects of initial water content, cement content and curing time were examined. In addition, the pore fluid salinity effect on reconstituted and cemented dredged clay was explored by desalination treatment, respectively. The testing results show that the vertical yield stress of cemented dredged clay is governed by initial water content while the compressibility in post-yield state is determined by cement content. The influence of curing time is more significant for the specimens with higher initial water content. The compressibility of reconstituted dredged clay decreases when increasing salinity of pore fluid, but pore salt accelerates the degradation of artificial structure of cemented clay. Moreover, a practical predicting method was presented based on the experimental data. Both the pre-yield compression index Cs and post-yield compression index Cc are correlated with the yielding point. The proposed method enables to more quickly capture the compression curves of cement-treated dredged clay in practice.

Automated summary

Efficient resource utilization of marine dredged clay is crucial to sustainable offshore works. Cement-treated dredged clay can be utilized for the construction of artificial islands, with the influence of cement addition on compressibility being examined. The compressibility of cemented dredged clay is determined by initial water content and cement content, with curing time having a significant impact on higher initial water content specimens.