Soil-rock interface landslides are common geological hazards in mountainous regions. While conventional cement-based micropiles are widely used for slope stabilization, their long curing time limits their application in emergency treatments. This study introduces polymer micropiles as a rapid-response alternative, leveraging the quick-setting and high tensile strength properties of polymer grouts. Field-scale tests and numerical simulations were performed to investigate the mechanical response and settlement deformation characteristics of the bedding slopes reinforced with polymer micropiles under loading. Results showed that polymer micropiles significantly improved slope bearing capacity, reduced crest settlement, and decreased surface displacement. Specifically, the bearing capacity of slopes reinforced with single and double rows of polymer micropiles increased by 111% and 211%, respectively, compared to the unreinforced slope. Settlement at the slope crest decreased by 76.9% and 90.4%, while lateral displacement at the slope toe was reduced by 77.8% and 92.8%. The final slope morphologies showed significant differences, with pronounced extrusion and soil detachment observed in the untreated slope, contrasted by only minor surface cracks in the polymer micropile reinforced slope. The simulations revealed that the micropiles fractured at the sliding plane when reaching the ultimate bearing capacity, indicating the compatibility of polymer micropile with the slope soils and the reinforcing effect of the micropiles. These findings demonstrate the feasibility and effectiveness of polymer micropiles for emergency landslide stabilization, offering a critical window for disaster response and permanent slope stabilization efforts.

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.