2026 Volume 5 Issue 1 Pages 49-56
This study aims to investigate the applicability of a lightweight soilbag filled with oyster shells, which have a lower specific gravity than soil particles, for the restoration of infrastructure such as bridge and road, etc. damaged by earthquakes that have occurred in recent years (e.g., Noto Peninsula Earthquake, 2024). For this reason, after determining the crushability of the oyster shells, compression tests were performed on the soilbag filled with the oyster shells, as well as on each soilbag filled with other comparison materials, i.e., waste roof tile and diatomaceous earth. The main conclusions obtained from this study were summarized as follows: (1) The uncrushed oyster shells in a mold were significantly crushed until reaching a predetermined static compressive load (=1.0 MN/m2), resulting in a substantial reduction in its volume. Even after exceeding the static compressive load, the oyster shells continued to be gradually crushed but the volume of the oyster shells confined within the mold showed little reduction. (2) The soilbag filled with the oyster shells crushed in the mold under a predetermined static load (>1.0 MN/m2) exhibited higher strength (or bearing capacity) than the soilbag filled with crushed oyster shells adjusted to predetermined particle sizes. (3) When waste roof tiles were used as filling materials for the soilbag, tension developed in the bag significantly contributed to improving the rigidity of the soilbag itself. On the other hand, when oyster shells or diatomaceous earth were used as filling materials, strength of the filling materials that had become denser during compaction themselves, in addition to the tension of the bag, affected the rigidity of the soilbag.
