High groundwater flow velocity is a major challenge in many artificial ground freezing (AGF) projects, especially in groundwater control projects. That condition may be unfavorable for the formation of a frozen body. This study aims to understand the effect of seepage flow on the heat transfer behavior and hydraulic conductivity variation of sand during the freezing process in AGF projects by using a vertically buried freezing pipe. The authors conducted a small-scale laboratory experiment that combined a flow test, freezing process, and infrared thermograph observations of thermal distribution. The authors prepared saturated Toyoura sand and a Toyoura-silica sand layer combination as the heat-transfer medium. The thermal distribution and hydraulic conductivity behavior were investigated by two series of freezing experiments with different sand layers and flow scenarios. Infrared thermograph observation results showed how water affects the thermal distribution characteristic, whereas flow test results showed the relation between hydraulic conductivity and frozen-body development.

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Expansive soil is one of the factors that cause road damage in Indonesia. Its behavior is influenced by moisture content. At high moisture content, expansive clay has a very low bearing capacity and high swelling and shrinkage rate compared to other soil types. This soil expansion causes a heave force on the road pavement. When the force exceeds the strength of the pavement, the pavement will deform and break as the initial damage is created. Therefore, it is critical to investigate the effect of moisture content on the swelling-shrinkage behavior of expansive soil. In this study, soil expansion is numerically predicted using the finite element approach on ABAQUS compared to the laboratory expansion index test. The geometric shape and loading of the soil model are the same as the sample shape and loading of a laboratory expansion index test. The Mohr-Coulomb soil constitutive model with sorption is used to simulate water absorption in partially saturated soils. Coupled wetting liquid flow and porous medium stress analysis are used to simulate swelling and shrinkage. The simulation is divided into two types: geostatic, which simulates soil model loading, and coupled pore fluid, which simulates changes in water content. The simulation is then compared to the laboratory test for validation. The numerical analysis results show that the model's accuracy depends highly on the constitutive soil model, whereas the Mohr-Coulomb model shows a limitation in accuracy with the maximum swelling in the simulation is 21.704%, while the average maximum swelling in laboratory testing is 15.515%.

On January 14, 2021, several villages in Majene Regency suffered landslides triggered by a M6.2 earthquake. The study’s aim is to use the Index Storie model approach, remote sensing data, and Geographic Information Systems (GIS) to map the distribution of landslide-prone areas as a mitigation basis in Majene Regency to reduce the potential for future landslide disasters. The level of landslide potential was determined based on slope conditions, soil types, rainfall, land use types, and potential earthquake risk. In general, morphological conditions in Majene Regency are dominated by slopes that are still covered in forests and receive relatively low rainfall, resulting in low landslide potential if seismic potential factors are not taken into account. Based on the results of an analysis that considers slope factors and potential seismic risks, the results of a map that illustrates the risk of landslide are quite high in several areas, are Malunda District, Ulumanda District, and Tubo Sendana District.