Numerical assessment of the pull-out behaviour of a GFRP nail

Glass fibre-reinforced polymer (GFRP) bars have emerged as a promising alternative to steel reinforcements in soil nailing, owing to their corrosion resistance and favourable strength-to-weight ratio. Despite these advantages, limited studies have evaluated the pull-out performance of GFRP bars compared to conventional steel bars. This study presents a numerical assessment of the sand–GFRP nail interaction using the finite element software Midas GTS NX. The numerical results are validated against experimental data, and the influence of key parameters, including nail geometry, overburden pressure, and soil friction angle, is examined. Comparative analyses with the ribbed steel nail are also provided. Results show that although GFRP nail generally exhibits lower pull-out capacity than steel nail, optimised design conditions can yield comparable performance, highlighting their potential suitability for specific geotechnical applications.