Recently, there have been various lifeline installations constructed in the underground space of urban area due to the effective use of land. For newly installed lifelines or the management of the installed lifelines, many construction activities of excavation and backfilling are observed. Around these area, there are possibilities of collapse or excessive settlement due to the leaking of the pipe or unsatisfactory compaction of backfill material. Besides, construction costs can be saved since the on-site soils are used. The application of this liquidity filling material is not only to the lifeline installation but also to underpin the foundation under the vibrating machinery. On the evaluation of the applicability of this method to this circumstance, the strength should be investigated against the static load from the machine load as well as the vibration load from the activation of the machine. In this study, the applicability of the liquidity fill material on the foundation under the vibrating machinery is assessed via uniaxial compression and resonant column tests. The liquidity filling material consisting of the on-site soils with loess and kaolinite are tested to investigate the static and dynamic characteristics. Furthermore, the applicability of the reclaimed ash categorized as an industrial waste is evaluated for the recycle of the waste to the construction materials. The experimental results show that the shear modulus and 7 day uniaxial strength of the liquidity filling material mixed with reclaimed ash show higher than those with the on-site soils. However, the damping ratio does not show any tendency on the mixed materials.

In general, reclamation with dredged soils requires a lot of time and cost. Few methods have been proposed to save these two factors. Using coal ash which is a co-product of thermal power generation has brought a great attention to researchers and engineers. Field tests were conducted and the results were analyzed to figure out the applicability of an artificial soil mixture with coal ash as a reclamation material. The ground composed of dredged soils and coal ash has a similar particle distribution to sand, and more cohesive and internal frictional angle than that with dredged soil only. In addition, the coefficients of horizontal consolidation and permeability were improved as well, which means the consolidation of the mixed ground could be accelerated.