2026 Volume 75 Issue 1 Pages 37-44
The authors have developed a technology that involves driving biomass mixed materials into the ground as infill material using the sand compaction pile (SCP) method, thereby preventing liquefaction while storing carbon in the ground. The biomass material selected was bamboo crushed into chips, which also serves to effectively utilize abandoned bamboo forests that are causing bamboo problems (phenomenon in which bamboo proliferates abnormally, adversely affecting the natural environment and human life) in various areas. A biomass mixed material is used, which is a mixture of recycled crushed stone made from bamboo chips and concrete waste. Sand, crushed stone, and recycled gravel, which are conventional SCP infill materials, have a long history of use. However, biomass mixed materials have no history of use, and their material characteristics as SCP infill materials are unknown. Therefore, indoor tests were conducted to confirm the compaction characteristics of the biomass mixed material, its strength characteristics through CBR tests, and its liquefaction strength through repeated triaxial tests. At the same time, tests using actual equipment were conducted to confirm workability and quality (completed pile diameter, N-value at pile center) as well as improvement effects (N-value in-between piles). In addition, estimates of CO2 emissions from construction using the infill material used in this project showed that the use of biomass mixed materials resulted in a reduction of approximately 600% compared to conventional sand piles.
