Experimental studies and applications of fluidized solidified soil: Basic properties and benefit analysis

A large amount of excavated soil is generated during the construction of waterway engineering, and the resource utilization of such soil poses a great challenge. Fluidized solidified soil (FSS) provides an efficient resource disposal approach for this problem, while its engineering application still faces numerous difficulties. In this study, two types of canal waterway excavated soils were used to prepare FSS. The influence of water-solid ratio, cement content, and soil sample mixing ratio on the basic properties of FSS was systematically investigated. The key technical challenges in the engineering application of FSS were sorted out, and the field application practice of FSS was completed for three typical conditions in real waterway engineering. In addition, combined with actual engineering conditions, a systematic analysis of the carbon emission and cost characteristics of five conventional backfilling methods was carried out to clarify the engineering application benefits of FSS. The results show that the clay minerals in the soil samples reduce the fluidity of FSS. When the content of coarse-grained soil reaches 30%, benefiting from the optimization effect of particle gradation, the soil compactness is significantly improved, the strength increases correspondingly, and the water stability of FSS is also enhanced. Among them, the water stability coefficient of C10W0.3S40 reaches 99.09%, which is almost consistent with the strength of specimens under standard curing conditions. Before the engineering application of FSS, the characteristics of raw materials, mixing processes, and curing environments should be adequately considered, and a reasonable strength safety reserve should be reserved in the mix proportion design stage. Compared with another backfilling methods, FSS has significant advantages in terms of carbon emissions and costs, except for soil backfilling. It is recommended to be applied in backfilling projects with clear requirements for compactness.