The study looked at how rainfall affects the stability of carbonaceous mudstone embankment slopes. By using indoor experiments and rainfall data, the researchers found that heavy rainfall and longer duration can make the slopes less stable. The permeability of the soil also plays a role in how much water infiltrates the slope. Regardless of the slope's steepness, the safety of the embankment decreases under rainfall. Slope failure is mainly caused by the loss of water pressure and increased moisture content in the soil.