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Serious computational instability problems are usually encountered in solving the sedimentation-consolidation model based on an interaction coefficient (SCMIC). In this study, the computational instability behavior of SCMIC is investigated with given upwind finite difference scheme. Results show that significant numerical errors occur when low grid density is used. By analyzing the variations of governing equation coefficients with time, it is found that the computational instability is due to the highly nonlinear variation of d σ ′ d e with e ( σ ′ is effective stress and e is void ratio), which causes significant errors in calculating the average value of d σ ′ d e. By eliminating the effect of the high nonlinearity of d σ ′ d e , the computational instability of SCMIC can be completely resolved. Such a resolution method for the computational instability overcomes the restriction of grid density, which can facilitate the simulation of simultaneous sedimentation and consolidation in the geotechnical engineering field. [ABSTRACT FROM AUTHOR]

Cement-based treatment is a well-established technology for converting unwanted marine dredged clay (MDC) to qualified filling materials. However, a basic understanding of the strength development of cement-treated MDC is still lacking. In this study, we attempt to characterize the strength variation of cement-treated MDC under a wide range of water-to-cement ratios (w/c). The dominant influencing factors such as initial water content, cement content, curing time and pore salinity are examined through a series of laboratory tests. The results indicate that the strength of cement-treated MDC decreases exponentially with the initial water content. The strength approaches zero when the initial water content increases to 3.5–4.0 times the liquid limit, even with a high content of cement. The effect of pore salinity depends significantly on the cement content and curing time. Owing to the wide range of w/c, the extensively used Abrams' law fails to characterize the strength variation of cement-treated MDC precisely. To this end, a new strength prediction model is proposed based on the concept of minimum cement content. The volume ratio is found to be inferior to the mass ratio in defining the minimum cement content, which remains approximately constant even for a wide range of w/c. [ABSTRACT FROM AUTHOR]