Rainfall has been identified as one of the main causes for slope failures in areas where high annual rainfall is experienced. The slope angle is important for its stability during rainfall. This paper aimed to determine the impact of the angle of soil slope on the migration of wetting front in rainfall. The results proved that under the same rainfall condition, more runoff was generated with the increase of slope angle, which resulted in more serious erosion of the soil and the ascent of wetting front. A modified Green-Ampt (GA) model of wetting front was also proposed considering the seepage in the saturated zone and the slope angle. These findings will provide insights into the rainfall-induced failure of soil slopes in terms of angle.

The risk of tailings dam-break disaster is dependent on the type of slurry and its flow characteristics. The flow characteristics of slurry surging from tailings dams collapse are directly influenced by grain size, breach width, slurry concentration, and surface roughness of the gully. Among these parameters, slurry concentration plays the most critical role, but there are few studies on it. This paper focuses on the flow characteristics of slurry with different concentrations, and a series of flume experiments were carried out to obtain the flow characteristics of inundated height, impact force, and velocity in 30%, 40%, 50%, and 60% concentrations. The study confirms that the concentration of slurry has a significant influence on the flow characteristics. Through the experimental study, it is observed that, with the decreasing of slurry concentration, the impact force and velocity of slurry increased in varying degrees; on the contrary, the flow height elevated with the slurry concentration decreasing. The main reason is that the higher the slurry concentration, the higher the static yield stress and viscosity—in varying degrees. The results can provide a detailed understanding of the slurry concentration influence on the flow characteristics, which guides the evacuation time and height downstream.

Glass fiber is a kind of polymer, which can effectively improve the mechanical properties of sand. However, the improvement effect of glass fibers with a reticular structure is different from that of ordinary fibers. At the same time, the sandy soil structure is diversified and part of the soil is layered, such as the lenticle in tailings dam, which often forms layered sandy soil with nearby tailings sand. The existence of the lenticle has adverse effects on the stability of the tailings dam. In order to study the reinforcement effects of reticular glass fibers on tailing sand with the lenticle (layered sand), a series of triaxial shear tests were carried out on the tailings sand by changing the layers of reticular glass fibers and the position of reinforcement. The results demonstrated the following five main points: (1) the shear strength of the tailings with the lenticle is significantly lower than the shear strength of the tailings fine sand, and the influence of the lenticle on the shear strength of the tailings is mainly concentrated on the cohesion. (2) When the reticular fiber is added to the tailings with the lenticle, the cohesion of the sample increases nonlinearly with the increase of the number of fiber layers, while the internal friction angle is basically unchanged. (3) The improvement effect of the reticular fiber on the shear strength of the sample varies with the position of the reinforcement, which is represented as the interface > tailings fine sand > lenticle. (4) Only when the axial strain develops to a certain extent, the reinforcement of the reticular fibers is reflected. (5) The reinforcement effects of reticulated fibers are determined by the interaction of forces at the interface between fibers and sand. The research results can not only provide a scientific basis for the construction of reinforced tailings dam, but also play a guiding role in disaster prevention and mitigation work of reinforced slopes with a weak zone, and even provide the reference for the reinforcement research of layered structures.

Under the background of global energy low-carbon transformation, coalbed methane (CBM) reserves in soft coal-rich areas such as China’s Shanxi Qinshui Basin account for over 30% of the national total, yet the extraction efficiency has long been below 35%. The core bottleneck lies in insufficient understanding of the mechanisms by which multiple factors (e.g., temperature, moisture content, particle size, and initial pressure) regulate gas desorption, coupled with the lack of quantitative comparison and priority ranking. Taking soft coal from a coal mine in Shanxi Province, China, as the research object, this study conducted 16 groups of single-factor experiments (temperature: 10–40 °C, moisture content: 2%–8%, particle size: 0.3–4.0 mm, initial pressure: 1–4 MPa). Combined with high-precision monitoring and a quantitative evaluation system of “curve separation degree-peak rate range-attenuation constant range”, the regulation laws, mechanisms, and priority order were revealed. Results show that initial pressure is the absolute dominant factor: the cumulative desorption amount at 4 MPa is 5.5 times that at 1 MPa, with a 6-fold difference in peak desorption rate. It determines gas reserves and desorption driving force through Langmuir adsorption equilibrium and pressure difference. Moisture content is a key inhibitory factor: the desorption amount at 8% decreases by 68.55% compared to 2%, showing a sharp decline in the 2%–4% range and a slow decline in the 4%–8% range, attributed to pore blockage and adsorption competition. Temperature is an auxiliary promoting factor: the desorption amount at 40 °C increases by 40% compared to 10 °C, regulating desorption by breaking adsorption equilibrium via Le Chatelier’s principle and accelerating molecular thermal motion, but is constrained by moisture content. Particle size has the weakest impact: the difference in final desorption amount between coal samples of 0.3–0.5 mm and 2.0–4.0 mm is less than 5%, only assisting in regulating the initial rate. Quantitative comparison establishes the priority order: initial pressure > moisture content > temperature > particle size. This study fills the gap in quantitative comparison of multifactor effects, provides support for precise gas control strategies of ″pre-extraction pressure control-drainage dehumidification-temperature control assistance-local coal fragmentation”, and is of great significance for improving CBM development efficiency and preventing gas disasters.

As global climate change continues, extreme rainfall events occur more frequently, exacerbating water-related damage to reinforced embankments. To solve this problem, 16 groups of reinforced embankment failure model tests were carried out using a self-developed model test device under multi-factor coupling, with rainfall intensity, gradient, and number of reinforcement layers used as variables. The distribution and evolution laws of pore water pressure and soil pressure were systematically analyzed, and the failure process of reinforced embankments was visualized. The failure mode, mechanism, and characteristics of the reinforced embankment were revealed, and the evolution of the failure process was determined. Finally, sensitivity analysis was conducted on rainfall intensity, slope, and number of reinforcement layers. The results show that both pore water pressure and earth pressure have obvious burial depth and near slope effects, but the burial depth effect on pore water pressure is opposite to that of earth pressure. Unlike traditional soil slopes, which fail through circular arc or broken-line slip, reinforced embankments exhibit progressive erosion failure under "hydro-mechanical coupling effect". The failure evolution of the reinforced embankment follows the sequence of water infiltration → soil softening → gully expansion → local failure → "pore erosion" failure → overall instability. The primary factor driving failure is the deterioration in soil strength caused by the decrease in matrix suction, rather than a sudden increase in pore water pressure. The results of this study have important theoretical value for reinforced embankments.

Quartz-rich tailings are potential secondary silica resources, but bulk SiO₂ content alone does not establish their upgrading potential. Previous comminution, separation, dewatering, and storage modify particle size distributions, mineral liberation, mineral associations, and surface conditions, affecting subsequent beneficiation and purification. This review examines studies published up to September 2026 on quartz-rich tailings and related mineral processing residues, prioritizing actual tailings studies that report feed characteristics, processing conditions, product quality, or recovery. The reviewed results indicate that flowsheet selection depends primarily on how the impurities occur and whether they can be liberated, exposed, or selectively removed. Surface coatings, slimes, and liberated impurity minerals can generally be removed by conventional beneficiation, whereas intergrowths may require controlled liberation followed by appropriate separation. Deep purification is justified only when the residual impurities can be effectively exposed or removed by the selected treatment. Final SiO₂ grade is reported more consistently than mass yield, SiO₂ recovery, saleable size yield, and impurity deportment, limiting comparisons of overall flowsheet performance. Moreover, high chemical purity alone does not establish suitability for a specific application. The treatment endpoint should therefore be the consistent production of quartz meeting its intended specification at acceptable recovery and within the required product size range, rather than the maximum purity obtained from a small fraction of the tailings.