Loose fill slopes are prevalent worldwide, and their failure during rainstorms is frequently documented. While existing studies have primarily focused on the initiation of such failures, the post-failure motion of rainfallinduced loose fill slope failures has rarely been explored. This study addresses this knowledge gap by investigating both the initiation and subsequent motion of rainfall-induced loose fill slope failures. To achieve this goal, a hydro-mechanical coupled MPM model was utilized to back-analyze the catastrophic 1976 Sau Mau Ping landslide in Hong Kong and conduct parametric studies. From an engineering perspective, the contractive behaviour of loose coarse-grained soil, which induces positive excess pore water pressure and leads to Bishop's stress reduction and a drop in strength, is a major factor contributing to this landslide. The entire failure process can be classified into three phases with different failure modes: local slide, global slide, and flow-like slide, closely related to the soil stress path. The computed results closely match the field measurements on various aspects, including the landslide zone, mobilized volume, and runout distance. The parametric studies reveal that the landslide zone, mobilized soil volume, and final runout distance decrease with a lower value of dilation angle and a smaller critical state plastic deviatoric strain. Conversely, in the case of a constant SWRC, there tends to be an overestimation of these parameters. It is therefore important to consider soil contraction and its influence on hydro-mechanical behaviour.

The research assesses the environmental impacts of waste management in Fez, Morocco, in line with the legal standards set by law 28-00 on waste management and law 12-03 on environmental impact assessment. Using the DPSIR framework (Drivers, Pressures, State, Impact, Response), 43 unregulated landfills were analyzed to assess their impacts on water, air, soil, biodiversity, and socio-economic activities. The results reveal medium to major impacts, predominantly local but continuous, affecting soil, water, air, and ecosystems. Human-related impacts include noise pollution and health risks, though there are also positive effects, such as job creation. While drought has lessened some water-related impacts, the overall disruption to ecosystems and communities is significant. The key message of this investigation is that unregulated waste management in Fez is causing ongoing environmental damage, particularly through illegal landfills. This research underscores the necessity of improving waste management strategies by integrating systematic evaluation methods like DPSIR. By providing a more systematic approach to understanding the complex interactions between waste and the environment, these findings are essential for shaping future waste management policies and promoting better environmental integration in urban planning.

Landfill failure threatens the safety of surrounding cities and causes soil and water pollution. High water levels can usually spur landfill failure. With the presence of earthquake, landfill instability is triggered in a greater possibility. However, the dynamic response and failure mechanism of landfills with high water level subjected to earthquakes are not yet clearly understood, and relevant experimental studies are quite scarce. This study includes a series of seismic centrifuge tests to investigate the seismic response of the landfill at different water levels. An improved method is proposed to prepare synthetic municipal solid wastes (MSWs) with similar staticdynamic properties to the actual MSWs. The failure and evolution mechanism of landfills with high water levels induced by the earthquake is revealed. Significant transitions are observed in the dynamic response of deformation, acceleration, and pore-water pressure as the water level changes. With the rise of water level, the settlement at the top of the landfill decreases first and then increases, while the horizontal displacement at the toe increases slowly, followed by a sudden drop; the acceleration amplification coefficient in the middle of the landfill increases first and then decreases; the dynamic pore-water pressure gradually decreases from positive to negative, but oscillates at the moderate water level. Three failure criteria and a hydro-earthquake coupled failure limit are proposed to demonstrate the combined effect of water level and earthquake on landfill stability. The test results provide a basis to establish seismic failure standards for landfills with different water levels and guide the seismic instability design of landfills with high water level.