The rainfall erosion mechanism of high and steep slopes in loess tablelands based on experimental methods and optimized control measures

Abstract

The geological integrity of the Loess Plateau is extremely weak. Following the concept and goal of harmonious co-existence between the human race and geo-environment, first, the high and steep slopes of the loess tableland located in a typical ecological restoration area (in Yan’an city, northern Shanxi) were selected as the demonstration area for studying disaster prevention and control. The research adopted new loess curing agents combined with turf transplant techniques to modify and remediate a loess slope. Considering that indoor artificial rainfall tests have the advantages of controlled initial conditions and rainfall processes, this study carried out several physical experiments under different rainfall intensity conditions (60 mm/h, 120 mm/h, 150 mm/h, and 180 mm/h), revealing the dynamic evolution of loess tableland slope erosion, refining the response relation between subsurface physical and mechanical parameters (pore water pressure and moisture content), surface deformation, and rainfall intensity. Based on the perspective of water control, on the one hand, the experimental results showed that the application of improved loess and new technology can successfully decrease the erosion due to slope runoff. On the other hand, hypotonic materials slow down the vertical infiltration of surface water and prevent soil and water loss. Meanwhile, the practice of turf transplant achieves the goal of ecological restoration.