Field-scale testing and numerical simulation of polymer micropiles-reinforced soil-rock bedding slopes

Abstract

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.