The issue of water-enriched surrounding rock induced by excavation disturbances in loess tunnels represents a significant challenge for the construction of loess tunnel projects. Based on the concepts of lime sac water absorption, expansion, and compaction, consolidation, and drainage of surrounding rock and soil, as well as active reinforcement, a tandem water-absorbing and compaction anchor with heat-expansion and compaction consolidation functionality has been developed. To facilitate the engineering design and application of this novel anchor, a consolidation equation for cylindrical heat source-consolidated soil was derived under conditions of equal strain and continuous seepage. Considering the impact of temperature in the thermal consolidation zone on soil permeability, an analytical solution for the average degree of consolidation of the surrounding soil after support with the water-absorbing and compaction anchor was provided. The correctness of the solution was verified through engineering examples, demonstrating the reasonableness of the theoretical calculation method used in this study. The analysis of consolidation effects in engineering examples demonstrates that the excess pore water pressure in the borehole wall area dissipates rapidly after reaming, exhibiting an exponential decay over time. By the 100th time step, the pore pressure decreases from 100 kPa to 63.2 kPa. As consolidation continues, by the 1000th time step, the pore pressure further reduces to 21.6 kPa. The region with significant changes in pore pressure amplitude is primarily located within the plastic zone of the reamed hole, while the rate of pore pressure change in the more distal elastic zone is generally lower. The consolidation process effectively dissipates the excess pore water pressure and converts it into effective stress in the soil, indicating a notable active reinforcement effect of the water-absorbing compaction anchor. Within the plastic zone, the attenuation rate of excess pore water pressure is 85%. Under different drainage conditions at the borehole wall, the dissipation rate of excess pore pressure in Model 1 (Assuming drainage conditions around the water absorbing anchor rod) is greater than that in Model 2 (Assuming that there is no drainage around the water absorbing anchor rod), with the average degree of consolidation in Model 1 being 22% higher than in Model 2. Under the conditions of Model 1, the active reinforcement effect of the water-absorbing compaction anchor is more pronounced, providing better reinforcement for the surrounding rock and soil. To ensure the reinforcement effect, the theoretical design should consider a certain surplus in the filling quality of the lime water-absorbing medium. The research findings are of significant importance for advancing the theoretical structural design and engineering practical application of this new type of anchor.

Torrential rainfall is one of the significant factors contributing to shallow slope failures. This study discusses the effect of the different filter gabion sizes against slope instability due to torrential rainfall numerically. The experimental investigation of effects of different filter gabion sizes was extensively investigated. The investigations were carried out in a two-dimensional domain using the saturated-unsaturated consolidation analysis method with an elastoplastic model for unsaturated soils considering two suction effects. Four different sizes of filter gabion were used in this investigation. The results of numerical simulations of slope model tests showed that, as rainwater accumulated at the slope toe, the pore water pressures (PWPs) near the slope toe increased to be positive or larger than the surface soil's air entry PWP. The phreatic surface that appeared on the slope surface as the positive PWPs increased with the elapsed time. In the simulations, large displacement, considered surface failure, started once the phreatic surface reached the slope surface. The simulated phreatic surface appearance time on the slope surface extended as the filter gabion size became larger. Nevertheless, the results showed that the applied analysis method is powerful and reliable for simulating slope failure behaviours and their proper countermeasures under torrential rainfall.