Three‐dimensional finite element method analysis on the tunnel‐soil‐underground pipeline was carried out based on the ABAQUS program. PSI element was applied to simulate the interaction between the pipelines and soil. Parameters such as an elastic modulus of soil, stress release rate, at‐rest lateral pressure coefficients, an elastic modulus of pipelines, and buried depths of tunnels were analyzed. The effects of tunnel excavation on the displacement of existing pipelines were investigated, and the settlement relationships were obtained. The relationship between each parameter and surface settlement was determined by the grey relational analysis method to analyze each parameter’s sensitivity to the settlement of the pipeline, which can provide a reference for emphasis and methods of shield tunneling support. Finally, a formula of the settlement relationship between the maximum surface settlement and pipelines deformation was proposed for different pipe‐soil relative stiffness. The formula was applied in the practical case. Compared with the field monitoring results and FEM computer results, it has been found that the proposed normalized formula is consistent with the measured results and numerical simulation of the pipeline settlement.

This study aimed to investigate the sustainable use of recycled plastics, specifically polypropylene (PP) and high-density polyethylene (HDPE), in the manufacture of geogrids for geotechnical and civil engineering applications. Plastics were collected from a recycling center, specifically targeting containers used for food, cleaning products, and other domestic packaging items. These plastics were sorted according to the Möbius triangle classification system, with HDPE (#2) and PP (#5) being the primary categories of interest. The research methodologically evaluates the mechanical properties of PP/HDPE (0/100, 25/75, 50/50, 75/25 and 100/0% w/w) composites through tensile and flexural tests, exploring various compositions and configurations of geogrids. The results highlight the superiority of pure recycled HDPE processed into 1.3 mm thick laminated yarns and hot air welded for 20 to 30 s, exhibiting a deformation exceeding 60% in comparison to the PP/HDPE composites. Through SolidWorks^® Simulation, it was shown that the adoption of a trigonal geogrid geometry optimizes force distribution and tensile strength, significantly improving slope stabilization efficiency. Based on the results obtained, a laboratory-scale prototype geogrid was developed using an extrusion process. The results underscore the importance of careful composite design and yarn configuration selection to achieve the desired mechanical properties and performance in geogrid applications. It emphasizes the potential of recycled plastics as a viable and environmentally friendly solution for stabilizing slopes, contributing to the reduction in plastic waste and promoting sustainable construction practices.

Slope instability in mountainous regions poses serious challenges to infrastructure resilience, particularly under anthropogenic pressures and climatic variability. This study evaluates the mechanical reinforcement provided by Vetiver (Chrysopogon zizanioides) to stabilize slopes in seven representative soils of the Quillollaco Formation, southern Ecuador. Direct shear tests on soil–root composites were used to quantify root-induced improvements in cohesion (c′) and internal friction angle (ϕ′), and slope stability was analyzed with the Spencer limit equilibrium method for heights of 5, 10, and 15 m under dry conditions. Results demonstrated significant reinforcement effects, with Vetiver increasing shear strength parameters at all depths and maintaining safety factors above 1.10 in every scenario. The highest gains, up to 16%, were observed in high-plasticity soils (CH and MH). Sensitivity and inferential statistical analyses confirmed the robustness of these improvements, with over 95% of paired t-tests yielding p < 0.05. These findings highlight Vetiver as a reliable nature-based solution for slope stabilization in tropical mountain environments, offering a sustainable and transferable alternative to conventional geotechnical methods.

Landslides are a recurrent geohazard in Andean urban environments, where weak soils, intense seasonal rainfall, and unplanned urban expansion combine to increase slope vulnerability. In such settings, sustainable hillside management requires stabilization strategies that are both technically effective and environmentally compatible. This study evaluates the effect of root reinforcement by vetiver grass (Chrysopogon zizanioides) on slope stability in two representative soils from Loja, Ecuador: sandy silt (SM) and sandy clay (SC). A reduced-scale physical model with 30 days of root development was established, and consolidated–drained direct shear tests (ASTM D3080/D3080M-23) were performed to determine the shear strength parameters under bare and vetiver-reinforced conditions. These parameters were then incorporated into numerical slope stability analyses using Slide and PLAXIS 2D, considering three slope angles (30°, 45°, and 50°), six root-positioning configurations, and hydraulic conditions with and without a water table. Vetiver increased effective cohesion by 22.7% in sandy silt and 19.0% in sandy clay, while the internal friction angle increased by 21.8% and 12.2%, respectively. Across all modeled scenarios, vetiver produced a consistent improvement in the factor of safety. The most critical case, corresponding to sandy silt at 45° with a water table, increased from FS = 0.841 in the control condition to FS = 1.309 under the full-coverage configuration. Parametric sensitivity analysis yielded coefficients of variation between 4.97% and 7.03%, indicating a stable model response under controlled parameter perturbations. These findings support vetiver as an experimentally grounded and environmentally sustainable Nature-based Solution for slope stabilization and provide relevant evidence for sustainable management of hazard-prone urban hillsides in vulnerable Andean settings.

In this article, we study an optimized radiative cooling geometry for ion projection lithography masks. In this design, a polished infrared mirror guides radiation from the mask to a high-emissivity cooled-cylinder positioned about 0.5 m away. Previous finite element modeling of this system predicts thermal distortion below 1 nm for practical mask designs. This is the first experimental study of the design. We show, by measuring the mean mask stress as a function of cooled cylinder temperature, that radiative cooling balances beam heating, with a power density of $\text{2.15\hspace{0.5em}}{\mathrm{mW/cm}}^2,$ when the cooled cylinder is held at $\text{15\hspace{0.05em}°}\mathrm{C}$ and the temperature of the mirror and mask frame are at $\text{25\hspace{0.05em}°}\mathrm{C}.$ The results agree with finite element modeling.