Silt is widely utilized as a filling material in transportation construction, However, it frequently suffers from problems, such as excess pore water pressure buildup, settlement, and mud pumping. Wicking geotextiles have emerged as a sustainable solution by improving both drainage and reinforcement capacities, yet their optimal design parameters remain unclear. To address this gap, a series of tests were performed to investigate the effects of compaction degree, reinforcement configuration (number, spacing, position), and specimen geometry on the mechanical and consolidation of silt reinforced with wicking geotextiles. The results reveal that the failure mechanism of reinforced silt progresses through four distinct stages, which the wicking geotextile improved interparticle contact, delays crack initiation, and improves post-peak stability. Wicking geotextiles significantly improve strength, particularly at lower compaction degrees, by restraining crack propagation and promoting uniform stress distribution. Optimal mechanical performance was achieved with three reinforcement layers and compaction degrees of 93-95 %. Mid-depth placement of a single layer or uniform spacing of multiple layers produced the best outcomes. Although non-uniform spacing provided advantages at early deformation stages, it ultimately induced premature failure, whereas uniform spacing (= 1.27 exhibited improved ductility, while larger specimens with multiple layers demonstrated improved post-peak stability. Wicking geotextiles accelerated drainage and void ratio reduction but concurrently decreased the compression modulus. These findings contribute to a more comprehensive understanding of the mechanical and hydraulic responses of wicking geotextile-reinforced silt and provide practical insights for the design and optimization of reinforced subgrades.

Roadbed engineering in alpine tundra environment is prone to frost heave and thaw settlement, cracking of pavement, uneven settlement, and other challenges under the action of seasonal freeze-thaw cycle. Wicking geotextile has important application value in frost damage control of roadbeds, but solar radiation, especially ultraviolet radiation, is one of the main factors leading to premature failure of wicking geotextile. In this study, different kinds of ultraviolet-resistant wicking fibers were developed by blending modification technology, and the various types of fibers were compared with each other in terms of their physical and mechanical properties, so as to obtain the optimal modified wicking fibers with the content of 2 % UV-1164 + 0.3 % B900 addition. Subsequently, a 20-day accelerated aging test was conducted on modified wicking geotextiles. The inhibitory effect of the modification treatment on the wicking geotextile indicating photo-oxidative aging was characterized by scanning electron microscope, and the effect on the mechanical properties maintenance of the wicking geotextile was characterized by tensile strength and top-breaking strength tests. Finally, a soil column drainage test was designed and carried out, based on which the horizontal hydraulic conductivity rate and 120-h drainage volume of wicking geotextiles before and after the modified treatment were predicted under the aging cycle of 40 d. The test and prediction dates showed that the hydraulic conductivity was deteriorated with the aging time, but the modification treatment could obviously inhibit the deterioration degree. Compared with the control group, the hydraulic conductivity of the modified wicking geotextile increased by about 0.35E-5 g/s, and the drainage capacity increased by 0.76 % at 200 h.

Active moisture control of wicking geotextiles is an effective way to prevent roadbed frost heave diseases. The performance of water conducting fibers determines the drainage function of the wicking geotextile. This study proposes a design method of the cross-sectional structure that synergistically consider drainage and mechanical properties in fibers. The circular or elliptical fiber profile and semicircular groove shape are first determined based on the maximization of the fiber cross-sectional specific surface area. Then, numerical simulation orthogonal experiments are conducted using COMSOL Multiphysics software to investigate the water conductivity and uniaxial tension of irregular fibers. The CRITIC weighted indicator of water conductivity to fiber volume ratio, tensile stress peak and fracture elongation is used as the analysis objects. The influence weights of fiber contour morphology, fiber size, groove number and groove area ratio on the weighted indicators are analyzed, and their optimal values are determined. The optimal M-shaped fiber is obtained, and the effectiveness of optimization design is verified through scanning electron microscopy and uniaxial tensile test. The M-shaped fiber is woven into the wicking geotextile, and geotextiles water conversion corporation test and drainage test of silty clay soil column is carried out. The test find that mass moisture content of the soil sample decreased by 4.73% within 8 days, which is 2.24% more than that of the staple fibers needling geotextile. This proves the effectiveness of M-shaped fibers and wicking geotextiles woven into them.

An enhanced geosynthetic material, PVF-wicking geosynthetic (PWG), was developed to improve the performance of the wicking geosynthetic product family, e.g., the wicking geotextile (WG). The PWG was made by coating deep-grooved wicking yarns and reinforcement with the layered polyvinyl alcohol formaldehyde (PVF) high-absorbent materials. The drainage performance of PWG was assessed through beaker drainage tests and soil column tests. The results of the beaker drainage test and SEM images indicate that PVF does not obstruct the deep-grooved yarns. It is found that, by facilitating efficient water absorption, storage, and transfer as a transit layer between the subgrade and wicking yarns, PVF plays a crucial role in enhancing the drainage capabilities of the geosynthetic material. PWG outperforms WG in terms of drainage efficiency under both static and cyclic loading conditions. The mechanism of the drainage improvement by PWG under cyclic loading is that the excess pore pressure within the PVF layer accelerates the water transfer from the pores of the PVF into the grooves of yarns. PWG, included with reinforcement, exhibited comparable interface characteristics to WG, with the potential to meet the requirements of soil stabilization. The remarkable drainage efficiency of PWG underscores its potential for practical applications.