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Engineered landfill covers are vital for environmental sustainability. This study investigates the shear behaviors of geocomposite drainage (GCD) and geomembrane (GM) interfaces—smooth (GMS), impinged texture (GMTI), and embossed texture (GMTE)—under 10, 30, and 50 kPa of normal stress and 0%, 50%, and 100% moisture levels using large-scale direct shear tests. All interfaces showed strain-softening behavior. At 50 kPa and 0% moisture, GCD–GMTI had the highest peak strength (28 kPa), whereas GCD–GMS had the lowest (10 kPa) at 100% moisture. Moisture and normal stress showed a coupling effect, reducing strength and friction angle. At a 0% moisture level, the strength of the GCD–GMS and GCD–GMTI interfaces under 50 kPa of normal stress was 500% and 250% of that at 10 kPa, respectively; at a 100% moisture level, these proportions decreased to 310% and 230%, respectively. For GCD–GMTE, the ratio slightly increased from 3.0 to 3.2, indicating better wet performance. Texture significantly affected strength: peak strength at 50 kPa was reduced by 41% (GCD–GMS), 16% (GCD–GMTI), and 26% (GCD–GMTE) as moisture increased from 0% to 100%. Large displacement (LD)-to-peak ratios were 0.8–0.9 (GCD–GMS), 0.7–0.8 (GCD–GMTI), and up to 1.0 (GCD–GMTE). Friction angles were reduced from 18° to 9°, 23° to 18°, and 18° to 14° for GCD–GMS, GCD–GMTI, and GCD–GMTE, respectively. Vertical deformation was <0.6 mm. Shear mechanisms depended on texture and moisture. Microscopic and 3D scans revealed moisture-induced GMTI smoothing, reducing interlocking and strength.

This paper aims to investigate the interfacial strength characteristics, particularly the residual strength, of a high-density polyethylene smooth geomembrane (GMB-S)/nonwoven geotextile (NW GTX) interface using a novel ring shear apparatus under high normal stresses and two specimen conditions. A total of eight normal stresses (from 50 kPa to 2308 kPa) and two specimen conditions (dry and submerged at ambient temperature) are considered in this study. The reliability of using the novel ring shear apparatus to study the strength characteristics of the GMB-S/NW GTX interface was demonstrated by conducting a series of direct shear experiments with a maximum shear displacement of 40 mm and ring shear experiments with a shear displacement of 10 m. The peak strength, post-peak strength development, and residual strength determination method of the GMB-S/NW GTX interface are explained. Three exponential equations suitable for characterizing the relationship between the post-peak friction angle and the residual friction angle of the GMB-S/NW GTX interface are established. This relationship can be used with the relevant apparatus (i.e., an apparatus with deficiencies in executing large shear displacement) in determining the residual friction angle of the high-density polyethylene smooth geomembrane/nonwoven geotextile interface.

Plasticized polyvinyl chloride (PVC-P) geomembranes (GMBs) are applied as anti-seepage materials in membrane-faced rockfill dams and pumped storage power stations. Assessing their lifetime to ensure durability during operation is crucial. This study conducted accelerated aging tests on three PVC-P GMBs immersed in water, along with axial tensile tests to investigate the degradation of mechanical properties. The degradation model was constructed using the Arrhenius equation, and the time to nominal failure (TNF) was predicted based on this model and failure criterion. The prediction model’s accuracy was verified using test data collected over 180 days at 20 °C. The results demonstrate that the TNF of PVC-P GMBs is influenced by water temperature, plasticizer content, and thickness of GMBs. Elevated temperatures accelerate the loss rate of plasticizers. Specifically, at 20 °C in a water environment, the estimated TNFs of Materials A and B with identical thicknesses were 49.05 and 153.76 years, respectively. This suggests that increasing the initial plasticizer content and enhancing its structural stability can significantly extend the TNF. Furthermore, Material C, which has a composition similar to Material B but with increased thickness, exhibited a predicted TNF of 181.30 years, indicating that greater thickness can effectively reduce the migration rate of plasticizers. The findings provide a theoretical basis for evaluating the TNF of PVC-P GMBs in reservoir bottom and below dead water level applications during operation.

Salt farming has been a hereditary occupation in the coastal communities of Madura Island; however, salt productivity in this area is still relatively low. The government has introduced a new production technology, called a geomembrane, as part of their efforts. The application of the latest technological innovations has been promoted worldwide to increase farm productivity, including in salt farming. This research aims to determine the determinants of adoption decisions for salt production technology and estimate the adoption impact on technical efficiency. The data in this study are cross-sectional from 215 small-scale salt farmers on Madura Island, East Java, Indonesia. The data were analyzed using logistic regression to identify which factors influenced farmers’ decisions to use geomembranes. The influence of adoption on farmers’ technical efficiency was then assessed using propensity score matching (PSM) and data envelopment analysis (DEA). The findings indicate that age and the dummy variables of gender, land ownership, profit-sharing involvement, and membership in the People’s Salt Business Group (KUGAR) all had a significant impact on adoption rates. The findings of controlling matched samples using the PSM process reveal that geomembrane application improves and greatly increases farmers’ technical efficiency. Those who used geomembranes displayed greater technical efficiency than those who did not. These findings imply that salt production technology should be promoted more to increase productivity, especially geomembrane adoption, through outreach and dissemination of information, including for landowners involved in the profit-sharing system. The government should keep supporting salt farmers and motivate them to adopt geomembrane technology to ensure the sustainability of salt production in the coastal communities on Madura Island.

In the past thirty years many mining projects in Chile and Peru have used: (i) polymeric geomembranes and (ii) design-and-build cutoff trenches, plastic concrete slurry walls, and grout curtain systems to control seepage at tailings storage facilities (TSFs). Geosynthetics are a viable alternative at a TSF dam for clay cores or impermeable materials, mainly because of their marked advantages in cost, installation, and construction time. This article describes the use of geosynthetics liners and cutoff trench–plastic concrete slurry walls–grout curtain systems in TSF dams in Chile and Peru mining, with the objective to decrease seepage to the environment, considering different dam material cases such as: cycloned tailings sand dams, borrow dams, and mine waste rock dams. Finally, this article discusses aspects of geosynthetic technology acceptance in the local regulatory frameworks, lessons learned, and advances. It focuses on the use and implementation of geosynthetics in TSFs in Chile and Peru, which have some of the highest TSF dams in the world, as well as a wet environment, dry environment, extreme topography, and severe seismic conditions. These conditions constitute a challenge for manufacturers, engineers, and contractors, who must achieve optimal technical solutions, while being environmentally aware and economic.

Geomembrane relaxation can effectively prevent the geomembrane from being damaged by tensile stresses caused by temperature changes and uneven settlement of the foundation. Existing and commonly used reservation methods, such as wave-shaped, groove-shaped, and Z-shaped techniques, are unidirectional and cannot resist multidirectional tensile stresses in geomembranes. Therefore, we propose three methods for reserving bidirectional geomembranes, including the cross-groove-shaped, cross-Z-shaped, and combined Z- and groove-shaped techniques. Additionally, we investigate the key issues of these methods and their practicality through field tests and theoretical analyses. The results of the study show that the cross-groove-shaped technique is prone to geomembrane folding at the corners of the cross-intersection, and it is necessary to set a wiping angle of approximately 35° to solve the problem. The cross-Z-shaped technique does not require grooving and reduces the amount of civil construction performed. However, the neoprene rods cannot be folded 180° or restored after being separated once. The combined Z- and groove-shaped technique has no folding phenomenon and does not require 180° of folding. With a lack of folding, including 180° folding, the number of grooves can be reduced by half, but the cross-Z-shaped specimen cannot be restored after separation. In practical applications, it is recommended to use the cross-groove-shaped method or to choose a suitable bidirectional reservation method according to the actual requirements.

This study analyzed sea salt production and compared the technical efficiency level and the technology gap between traditional technology and High-Density Polyethylene Geomembranes (HDPE GMB) technology in the Phetchaburi province using a copula-based meta-stochastic frontier technique. A total sample size of 250 was chosen, comprising 195 traditional farmers and 55 HDPE GMBs farmers. Several copula families were used to analyze the dependence structure of the two error components and the best-fit copula-based meta-frontier model used Gaussian copulas. Land, labor, and fuel energy are the most significant input variables in the Gaussian copula-based meta-frontier model with a translog production function. Compared to meta-frontier production, the average technological gap between traditional technology production and HDPE GMB technology production was 0.69 and 0.77, respectively, meaning HDPE GMB technology is more technically efficient than traditional technology. The study identified that land, market price, sex, and experience were the contributing technical inefficiency factors for traditional technology production. For HDPE GMB technology production, land, sex, and experience were found to be contributing factors. The performance of HDPE GMB technology in salt farming in the Phetchaburi province suggests that public and private sector agencies should promote greater access to this technology for salt farmers.

The tailings from gold beneficiation can cause various negative impacts, necessitating measures to prevent their transport and environmental contamination. Geomembranes serve as hydraulic barriers in mining tailings reservoirs, thereby supporting the Sustainable Development Goals (SDGs). To ensure that the geomembrane effectively mitigates environmental impact, it is essential to study its durability when applied in the field. This article examines the long-term performance of an HDPE geomembrane exposed for 7 and 11 years at a gold mining tailing site in Brazil. Samples were exhumed from different locations at the dam, and their properties were evaluated. Non-parametric statistics were employed using the Kernel Density Estimator (KDE). For the 11-year-old geomembranes, the probability of the geomembrane reaching nominal failure in terms of tensile strength was 0.4%. The peel separation values exceeded the maximum allowable by the GRI GM13 standard. Although the geomembranes showed significant antioxidant depletion, suggesting they were close to or had already reached their residual stages, they approached nominal failure based on their stress crack resistance but did not rupture. The environmental analysis indicated no significant contamination in the area, corroborating that the geomembrane is fulfilling its function. The non-parametric methodology proved promising for durability analysis and could be applied to other engineering projects with geosynthetics, thereby adding reliability to decision-making in alignment with sustainable development.

This study presents a novel approach for monitoring waste substrate digestion under high-density polyethylene (HDPE) geomembranes in sewage treatment plants. The method integrates infrared thermal imaging with a clustering algorithm to predict the distribution of various substrates beneath Traditional outdoor large-scale opaque geomembranes, using solar radiation as an excitation source. The technique leverages ambient weather conditions to assess the thermal responses of HDPE covers. Cooling constants are used to reconstruct thermal images, and clustering algorithms are explored to segment and identify different material states beneath the covers. Laboratory experiments have validated the algorithm’s effectiveness in accurately classifying varied regions by analyzing transient temperature variations caused by natural excitations. This method provides critical insights into scum characteristics and biogas collection processes, thereby enhancing decision-making in sewage treatment management. The methodology under development is anticipated to undergo rigorous evaluation across various floating covers at a large-scale sewage treatment facility in Melbourne. Subsequent to field validation, the implementation of an on-site, continuous thermography monitoring system is envisioned to be further advanced.

Plasticized polyvinyl chloride (PVC-P) geomembranes (GMBs) are susceptible to physical scratches due to improper construction in water conservancy projects. Axial tensile tests and permeability tests were carried out to investigate the mechanical properties and impermeability of PVC-P GMBs with scratches under various combinations of scratch angles, lengths, and depths. This was achieved by evaluating the break strength, break elongation, Young’s modulus, and permeability coefficient. The results demonstrated that physical scratches weaken the mechanical properties of PVC-P GMBs, and interactions among the influencing factors were observed. The influence of scratches on the break elongation and break strength outweighed that on Young’s modulus, with scratch depth exerting the most significant effect on the mechanical properties under identical conditions. The scratches on PVC-P GMBs should be minimized in practice, while those without penetrating cracks along the thickness direction and tensile deformation have negligible effects on impermeability. The failure threshold of PVC-P GMBs with scratches was determined, along with the scratch depths, angles, and lengths affecting the operation of the project. This provides a reference for assessing whether PVC-P GMBs with scratches jeopardize the safety of projects.