Abstract: Geotextile tubes have broad application prospects in the treatment and reinforcement of fine-grained tailings dams. To investigate the shear characteristics of geotextile tubes filled with fine�grained tailings during the consolidation process，field-scale consolidation tests were conducted. Two types of tailings and four types of woven geotextiles with different specifications were selected to prepare geotextile tubes. Direct shear tests were performed to analyze the evolution of tailings dry density as well as the shear strength of both tailings and geotextile tubes under different consolidation durations. The influ⁃ ence mechanisms of tailings properties，geotextile parameters，and consolidation time on the mechanical behavior of geotextile tubes were revealed. The results show that with increasing consolidation time，the dry density of tailings increases following a quadratic function and gradually stabilizes，with an increase of more than 30% after 40 days of consolidation. The permeability and mechanical properties of geotextiles have significant effects on the consolidation efficiency and shear strength. A higher permeability coefficient leads to a higher degree of consolidation，while greater tensile strength of geotextiles results in more pro⁃ nounced strength improvement of the geotextile tubes. Compared with pure tailings，the cohesion of geotex⁃ tile tubes increases by 4~7 times，whereas the increase in internal friction angle is relatively limited. A sig⁃ nificant quadratic relationship exists between tailings dry density and shear strength parameters，allowing the prediction of strength indicators based on easily measurable dry density parameters. The findings pro⁃ vide a theoretical basis and engineering reference for the stability analysis of geotextile tubes and the selec⁃ tion of geotextiles in tailings dam engineering.

Key words: fine tailings, geotextile tube, consolidation test, shear properties, dry density