Shotcrete is one of the common solutions for shallow sliding. It works by forming a protective layer with high strength and cementing the loose soil particles on the slope surface to prevent shallow sliding. However, the solidification time of conventional cement paste is long when shotcrete is used to treat cohesionless soil landslide. The idea of reinforcing slope with polyurethane solidified soil (i.e., mixture of polyurethane and sand) was proposed. Model tests and finite element analysis were carried out to study the effectiveness of the proposed new method on the emergency treatment of cohesionless soil landslide. Surcharge loading on the crest of the slope was applied step by step until landslide was triggered so as to test and compare the stability and bearing capacity of slope models with different conditions. The simulated slope displacements were relatively close to the measured results, and the simulated slope deformation characteristics were in good agreement with the observed phenomena, which verifies the accuracy of the numerical method. Under the condition of surcharge loading on the crest of the slope, the unreinforced slope slid when the surcharge loading exceeded 30 kPa, which presented a failure mode of local instability and collapse at the shallow layer of slope top. The reinforced slope remained stable even when the surcharge loading reached 48 kPa. The displacement of the reinforced slope was reduced by more than 95%. Overall, this study verifies the effectiveness of polyurethane in the emergency treatment of cohesionless soil landslide and should have broad application prospects in the field of geological disasters concerning the safety of people's live.

As one of the significant objects of remote sensing monitoring, landslides not only lead to huge economic losses, but also result in catastrophic environmental damage and human casualties. In the past few decades, piles are widely accepted and successfully applied in slope stabilization. Through numerical calculation based on limit equilibrium method, pile reinforcement effects on cohesive and cohesionless soil slopes are studied in this paper. The potential influencing factors are systematically analyzed, including cohesion, friction angle, pile truncation length, slope gradient, and soft band. A correlation was developed to predict the safety factor as a quadratic function of pile truncation length. The results show that pile reinforcement effect was related to the slope gradient and not to cohesion or friction angle. As the slope gradient increases, the pile reinforcement effect on the cohesive soil decreases, while that of the cohesionless soil increases. On the whole, the pile reinforcement effect of cohesive soil slope is better than that of cohesionless soil slope. For the slope with a soft band, the pile reinforcement effect gradually increases as the strength of soft band decreases. During the pile truncation process, the change in safety factor for slopes with a soft band can be divided into three phases: pile control phase, pile-soft band control phase, and soft band control phase. Piles are more suitable for reinforcing cohesive soil slopes containing soft bands, which can effectively improve the slope stability. The research results can provide reference for the rational use of piles and the reduction of geotechnical engineering hazards related to landslides.