Soil improvement using agar gum polymer for seismic liquefaction mitigation

Abstract

Liquefaction can cause ground subsidence and structural collapses, which could result in considerable damage. While numerous preventive methods have been proposed to prevent such liquefaction, most of these methods involve cement-based reinforcements, thus potentially introducing other environmental problems, such as groundwater contamination and increased carbon dioxide emissions. Therefore, it is essential to develop and use eco-friendly, ground-reinforcement materials. Agar gum is an eco-friendly biopolymer extracted as a result of the biological activities of microorganisms. Ground-reinforcement of agar gum enhances its effectiveness in improving the unconfined compressive and shear strengths, thus making it a suitable, eco-friendly, ground-reinforcement material. However, while the use of agar gum could (logically) increase the strength of lique-faction resistance, there is insufficient research to support this assumption. Therefore, in this study, the viscosity, unconfined compressive strength, and hardness of agar gum were quantified, and the liquefaction resistance strength was evaluated based on cyclic triaxial tests using agar-gum-treated samples. The hardness, unconfined compressive strength, and liquefaction resistance strength increased with increasing agar gum concentrations, and the change based on a curing time was relatively constant. In addition, the effect of enhancing the lique-faction resistance strength using agar gum was confirmed based on a comparison with previous studies using untreated samples and other reinforcing materials.