Search Results (180)

Urban subsurface pipeline bursts can induce catastrophic cascading effects, including ground collapse, infrastructure failure, and socioeconomic losses. However, stratum responses during the erosion cavity expansion phase and corresponding disaster mitigation strategies have rarely been researched. In this study, a numerical model validated through experimental tests was employed to investigate the effects of internal water pressures, burial depths, and different geotextile-based disaster mitigation strategies. It was revealed that a burial depth-dependent critical internal water pressure governed the erosion cavity expansion, and a predictive equation was derived based on the limit equilibrium theory. Higher internal water pressure accelerated the erosion cavity expansion and amplified the stratum stress within a range of twice the diameter D. Increased burial depth $d$ reduced peak ground heave but linearly expanded the heave zone range, concurrently elevating the overall stratum stress level and generating larger stress reduction zones (i.e., when $d/D$ = 3.0, the range of the stress reduction zone was 8.0D). All geotextile layout configurations exhibited different disaster mitigation effects (the peak ground heave was reduced by at least 15%). The semi-circular closely fitted configuration (SCCF) optimally restricted the expansion of the erosion cavity, reduced the stratum displacement (i.e., 39% reduction in the peak ground heave), and avoided stress concentration. Comprehensive analysis indicated that SCCF was suited for low-pressure pipelines in deformation-sensitive stratum and semi-circular configuration (SC) was suitable for deformation-insensitive pipeline sections. These findings provide actionable insights for tailoring mitigation strategies to specific operational risks. Full article

In response to the dual challenges of the mechanical behavior of steel sheet pile cofferdam and sediment control in urban water intake projects, a multi-method integrated study was conducted based on the Nenjiang Project. The results show that the peak stress of FSP-IV steel sheet piles (64.3 MPa) is located at a depth of 5.5–8.0 m in the center of the foundation pit, and that the maximum horizontal displacement (6.96 mm) occurs at the middle of the side span of the F pile. The internal support stress increases with depth, reaching 87.2 MPa at the bottom, with significant stress concentration at the connection of the surrounding girder. The lack of support or excessively large spacing leads to insufficient stiffness at the side span (5.3 mm displacement at the F point) and right-angle area (B/H point). The simultaneously developed sediment control integrated system, through double-line water intake, layered placement of the geotextile filter, and the collaborative construction of the water intake hole–filter layer system, achieves a 75% reduction in sediment content and a decrease in standard deviation. This approach ensures stable water quality and continuous water supply, ultimately forming a systematic solution for water intake in high-sediment rivers. Full article

Green roofs are increasingly being adopted as sustainable, nature-based solutions for managing urban stormwater, mitigating the urban heat island effect, and saving energy in buildings. However, the long-term performance of their individual components—particularly filter geotextiles—remains understudied, despite their critical role in maintaining system functionality. The filter layer, responsible for preventing clogging of the drainage layer with fine substrate particles, directly affects the hydrological performance and service life of green roofs. While most existing studies focus on the initial material properties, there is a clear gap in understanding how geotextile filters behave after prolonged exposure to real-world environmental conditions. This study addresses this gap by assessing the mechanical and structural integrity of geotextile filters after five years of use in both extensive and intensive green roof systems. By analyzing changes in surface morphology, microstructure, and porosity through tensile strength tests, digital imaging, and scanning electron microscopy, this research offers new insights into the long-term performance of geotextiles. Results showed significant retention of tensile strength, particularly in the machine direction (MD), and a 56% reduction in porosity, which may affect filtration efficiency. Although material degradation occurs, some geotextiles retain their structural integrity over time, highlighting their potential for long-term use in green infrastructure applications. This research emphasizes the importance of material selection, long-term monitoring, and standardized evaluation techniques to ensure the ecological and functional resilience of green roofs. Furthermore, the findings contribute to advancing knowledge on the durability and life-cycle performance of filter materials, promoting sustainability and longevity in urban green infrastructure. Full article

This study applies the concept of the circular economy by using poultry feather waste to produce biodegradable geotextiles for environmental applications. The main goal was to assess their biodegradability, effect on soil properties, and usefulness in supporting plant growth. Three types of feather-based nonwoven fabrics were manufactured using a needle-punching method and tested under laboratory and field conditions over a 23-month period. Laboratory tests confirmed high biodegradability: Nonwoven I and III lost over 91% of their mass within 24 weeks. In field trials, plots covered with biodegradable geotextiles showed up to 266% more seedlings compared to bare soil, and plant height increased by 90% on average. The materials also improved soil moisture retention and supported microbial activity. After use, the nonwovens did not require removal and decomposed naturally, enriching the soil. The results demonstrate that feather-based geotextiles are a sustainable, effective, and locally available solution for soil protection and vegetation in difficult terrain. Full article

An attempt was made to simulate the conditions prevailing in an agricultural crop to investigate whether and how geotextile microplastics alter the movement and accumulation of heavy metals in plants. For this purpose, a pot experiment, lasting 149 days, was carried out on soil obtained from a rural area, where pieces of a geotextile in mesoplastic dimensions, of the same chemical composition as that used by farmers in the Greek countryside, were added. Furthermore, metal solutions (Cu, Zn, Cd) were incorporated in the pots at two levels, and incubation prior to planting was carried out for two weeks. Then, industrial hemp was cultivated, while continuous measurements of its horticultural characteristics and of the levels of metals moved from the soil to the plant were made. The plants appeared to be highly resistant to the rather harsh growing conditions, and furthermore, it was observed that the cumulative metal capacity of cannabis was enhanced in most cases. The simultaneous presence of metals and geotextile (plastic) fragments enhanced the amount of Zn and Cd transfer into the soil-to-plant system. Hemp plants exhibited strong resilience abilities in the particularly stressful soil environment, possibly developing defense mechanisms. The experiments are particularly encouraging as they prove that simple and habitual practices in cultivated soils that lead to post-weather erosion of the geotextile may contribute positively in terms of remediation methods for heavy-metal-laden soils, as they indirectly help the plant to remove larger amounts of metal elements. The experiments should be intensified on a wider range of soils of different soil reactions and particle sizes and, of course, should be carried out under real field conditions in Mediterranean soil environments. Full article

This study examines the tensile behavior of both plain and seamed geotextiles. Samples were taken from two geotextile tube test beds, one made of composite materials and the other of woven materials, constructed in 2013 and 2016, respectively, in the Saemangeum reclaimed area. These test tubes have been exposed to marine conditions and sunlight for 10 and 8 years, respectively. Based on sunlight exposure, samples of plain and seamed geotextiles were collected from both exposed (top) and non-exposed (bottom) locations. The tensile strength–strain curves, strength degradation, and seam efficiencies of the original samples were compared with those exposed to marine environments and sunlight for 8–10 years. Geotextile tubes have been found to function normally even after being exposed to seawater and sunlight for 8–10 years, with sunlight being identified as the most significant factor affecting long-term tensile strength. The influence of seawater on tensile behavior is minimal, and it was observed that the tensile strength of the seam after 8–10 years is only about 10–19% of the initial plain tensile strength. Nevertheless, the tubes operate without failure, suggesting that the earth pressure acting on stabilized geotextile tubes is relatively low. These findings offer valuable insight into the long-term durability of geotextiles tubes under harsh environmental conditions and serve as a reference for future applications. Full article

Geotextile bags are widely used in revetment engineering due to their simple fabrication and cost-effectiveness. However, prolonged exposure to natural environments can lead to aging and damage, compromising their performance. To enhance the durability of geotextile bags in practical applications, this study conducted microscopic examinations and strength tests, employing a slurry spraying method to form a protective surface layer. Adhesion tests and orthogonal experiments were performed to evaluate the impact of spraying parameters on performance. The optimal parameter combination was determined through range analysis, variance analysis, and projection pursuit regression (PPR) analysis, with the durability improvement verified by accelerated aging tests. Results demonstrated that sediment significantly reinforced the internal fibers and mechanical properties of the geotextile. Artificial slurry spraying effectively adhered to the geotextile surface, with clay slurry exhibiting the strongest adhesion. By integrating range analysis, variance analysis, and PPR analysis, the key influencing factors were identified as spraying thickness, geotextile thickness, and clay content. The optimal parameter combination was selected for accelerated aging tests and electron microscopy observation, revealing that the spraying treatment significantly improved the geotextile’s strength retention rate, delayed performance degradation under UV and high-temperature conditions, and protected the fiber structure. These findings provide valuable insights in terms of enhancing the durability of geotextile bags. Full article

Geotextiles are widely used for separation, drainage, filtration, and erosion control, as well as for enhancing plant growth conditions. The objective of this study was to evaluate the impact of incorporating poultry feathers on the biodegradation rate of nonwoven geotextiles in arable soil. The research was conducted under laboratory conditions, with biodegradation assessed based on mass loss. The findings confirmed that the presence of keratin-rich waste positively influenced the biodegradation rate of the tested materials. Additionally, the potential ecotoxicological effects of biodegradation were examined, revealing no adverse impact on microbiological activity. Statistical analysis demonstrated a correlation between material composition and biodegradation time. This study represents a significant step toward the sustainable management of poultry feather waste in agricultural applications. The tested materials could serve as an environmentally viable alternative for long-term applications, aligning with ecological sustainability principles by simultaneously enriching soil with essential nutrients and promoting waste valorization. Full article

In this study, several composting strategies such as the use of semipermeable geotextile covers and biochar as an additive were investigated to improve olive mill wastewater (OMW) biodegradability and mitigate greenhouse gas (GHG) emissions during industrial-scale composting. In addition, the final characteristics of the compost obtained and its marketable value were also assessed. For this purpose, four different co-composting mixtures were prepared with OMW as the main ingredient, and two types of manure (cattle and goat manure) and bulking agents (almond pruning and vineyard pruning waste) as N and C sources. The results showed that exothermic behavior and biodegradability were more influenced by the co-composting strategy. The use of biochar as an additive showed a reduction in N losses (−14%) via GHG emissions and a significant improvement in cation exchange capacity (+35%) or the content of humic substances (+10%) in the final product. Lastly, the use of a geotextile cover was shown to be the worst cost-effective strategy, as it did not improve compost quality and showed no effect on GHG emissions. Full article

The reclamation of illegal landfills poses a significant threat to the environment. An example of such a case is Łomianki near Warsaw, where an illegal landfill contained alarming levels of arsenic and chromium, posing a potential risk to the health of local residents due to the possibility of these metals contaminating a nearby drinking water source. Initial geochemical tests revealed high concentrations of these metals, with chromium reaching up to 24,660 mg/kg and arsenic up to 10,350 mg/kg, well above international environmental standards. This study presents effective reclamation strategies that can be used in similar situations worldwide. The reclamation allowed this land to be used for the construction of the M1 shopping center while minimizing environmental hazards. The study is based on a case study of the reclamation of this illegal landfill. The methods used in this project included the relocation of approximately 130,000 m³ of hazardous waste to a nearby site previously used for sand mining. Bentonite mats and geotextiles were used to prevent the migration of contaminants into the groundwater. The waste was layered with sand to assist in the structural stabilization of the site. In addition, proper waste segregation and drainage systems were implemented to manage water and prevent contamination. Eight years after the reclamation, post-remediation soil surveys showed significant improvements in soil quality and structural stability. Specifically, the Proctor Compaction Index (I_S) increased from an estimated 0.5–0.7 (for uncontrolled slope) to 0.98, indicating a high degree of compaction and soil stability, while arsenic and chromium levels were reduced by 98.4% and 98.1%, respectively. Reclamation also significantly reduced permeability and settlement rates, further improving the site’s suitability for construction. The cost-benefit analysis showed a cost saving of 37.7% through local waste relocation compared to off-site disposal, highlighting the economic efficiency and environmental benefits. The main conclusions of this study are that land reclamation effectively reduced environmental hazards; innovative solutions, such as bentonite mats, advanced waste sorting, geotextiles, and drainage systems, improved environmental quality; and the Łomianki case serves as a model for sustainable waste management practices. Full article

The ongoing changes in natural and urban ecosystems, driven by climate change, population growth, and other anthropogenic factors, necessitate the implementation of green infrastructure, such as green roofs and walls. The functional value of these systems is demonstrated through their alignment with the Sustainable Development Goals, particularly Goal 11 (Sustainable Cities and Communities) and Goal 3 (Good Health and Well-Being), which are directly related to the implementation and development of sustainable strategies in buildings and urban environments. By leveraging the ecosystem services they provide, green infrastructure contributes to life on land, enhancing biodiversity—especially for flora, fauna, and pollinators. Additionally, their potential for visual appeal and esthetic value, often emphasized during installation, can enrich the cultural and landscape value of urban spaces, ultimately promoting good health and well-being for urban residents. This study aims to incorporate native vegetation into the design of intensive (walls) and extensive (roofs) green infrastructure within a neotropical mountainous climate. To achieve this, an experimental module was developed, integrating native and non-native vegetation selected based on criteria such as relative growth rate (RGR), measured by species size in relation to geotextile mesh coverage and visual survival status. Additional criteria, including stress (SP), esthetic (AP), and coexistence (CP) metrics, inform design strategies aimed at enhancing biodiversity through the use of native vegetation, while maintaining the esthetic integrity of the design. While further evaluation of a broader range of vegetation is necessary to establish more comprehensive parameters, this study has yielded promising results. It demonstrates that the interaction between certain non-native species and native species can positively influence the survival of the latter, while also supporting the survival of native vegetation with significant esthetic value. Full article

Salt marshes, which provide vital ecosystem services and play a key role in coastal protection, require innovative restoration strategies to enhance their resilience to sea level rise (SLR) in the context of ongoing climate change. This study evaluated the effectiveness of various eco-engineering structures in promoting sediment accretion within a temperate estuary (Mondego estuary, Portugal). Five experimental cells were tested: (1) a control cell with bare soil, (2) a cell with autochthonous vegetation, (3) a cell with a wooden palisade, (4) a cell with geotextile fabric, and (5) a cell with geotextile bags filled with sand. Sediment accretion was measured seasonally from 2019 to 2022, and sedimentation rates and patterns were compared across the different structures. Environmental variables, including precipitation and tidal flow, were also monitored to assess their influence on sediment dynamics. Results indicated that eco-engineering structures enhanced sedimentation compared to the control. The highest accumulation was observed near the wooden palisades and geotextile bags, particularly in areas aligned with the river flow. This study underscores the potential of eco-engineering approaches to promote localized sediment stabilization and enhance marsh resilience. However, long-term monitoring and adaptive management are essential to address challenges associated with SLR and hydrodynamic variability. The findings provide valuable insights for designing effective and targeted restoration strategies in estuarine environments. Full article

Geotextiles are a commonly used green material which can improve the water holding capacity of soil. However, the effects of density on evaporation and cracking of geotextile–soil composites are still unclear. The results indicate that the addition of geotextiles divides the soil water evaporation into five stages: constant loss stage, rapid deceleration stage, secondary deceleration stage, tertiary deceleration stage, and residual loss stage. When the geotextile density was 0, 200, 400 and 600 g/m², the deceleration stage accounted for 55.7%, 64.3%, 70.4% and 74.8%, respectively, of the total evaporation time of water in the soil. Compared with soil without geotextiles when the geotextile density was 200, 400 and 600 g/m², the soil average residual water content rose by 34.8%, 127.1% and 247.0%, respectively. When the geotextile density was 600 g/m², the crack rate and fractal dimension were reduced by 44.44% and 18.39%, respectively. Geotextiles can provide fiber interleaving points and pore spaces, and high-density geotextiles can effectively prevent the movement of fine particles and form a thicker layer of fine particles to enhance the water retention and crack resistance of the soil, so that the geological environment contributes to sustainable development. The application of geotextile–soil composites can achieve long-term sustainable protection against soil evaporation and cracking. Full article

A capillary barrier cover (CBC) is a geotechnical structure which a coarse-grained soil layer covered by a fine-grained soil layer. A CBC can retain downward water infiltration, increase water storage capacity and lateral diversion, and prevent capillary rise. Geotextiles are usually set up as isolation layers between fine-grained and coarse-grained layers to prevent fine particles entering the coarse-grained layer, resulting in a decrease in downward water infiltration and water storage capacity. However, crustal stress, farming, animal, plant activities, and other factors may cause damage to the isolation layer. At present, there is no reliable and accurate method to determine the location and degree of damage to the isolation layer. The existing methods search for the damage location by excavating the whole fine layer, which incurs high maintenance costs. If the damaged position of the CBC isolation layer can be accurately obtained, it can reduce maintenance costs. Therefore, this study investigated the influence of a coarse-grained layer mixed with different particle sizes and proportions of fine particles on water storage capacity through laboratory soil column experiments. The results are as follows: (1) Fine particle mixing into the coarse-grained layer will reduce water storage capacity, and there is a worse admixture ratio that minimizes water storage capacity. (2) The CBC enhances the fine-grained layer volumetric water content (VWC), but the enhancement degree decreases as the distance from the fine–coarse interface increases. (3) A method has been proposed to determine the location and degree of damage to the isolation layer. When the VWC at the fine–coarse interface reaches a stable level during breakthrough, the CBC effect exists, the higher the VWC at the fine–coarse interface, the stronger the CBC; when the VWC at the fine–coarse interface is unstable during breakthrough, the CBC effect disappears, and the median diameter of the fine particles mixed into the coarse-grained layer is finer than or equal to the fine-grained particles’ median diameter. Full article

The application of geotextiles as filter materials in various systems, such as biofilters, wetlands, and wastewater treatment plants, has grown significantly in recent years. The ability of these materials to support biofilm growth makes them ideal for the removal of organic and inorganic contaminants present in wastewater. The objective of this research was to analyze clogging through variations in permeability, using column tests for 80 days with two types of nonwoven geotextiles with different grammages (GT120 and GT300), as well as to study the efficiency in the removal of organic matter. A synthetic wastewater was used, allowing the specific observation of biological clogging and the treatment carried out exclusively by microorganisms. The results indicated that bioclogging was not a significant factor within the experimental period. Through the mass test, a continuous increase in biofilm growth over time was observed for both geotextiles. For scanning electron microscopic (SEM) images, GT300 presented a larger biofilm area. A higher removal of COD (80%), N (52%), and P (36%) by microorganisms present in GT300 was found, which appears to be associated with its greater thickness and weight. The higher mesh density provides a larger area for the growth of microorganisms, allowing a greater amount of biomass to establish itself and contributing to the efficient removal of pollutants. These findings highlight the potential of using geotextile filters in wastewater treatment applications, where biofilm growth can positively contribute to contaminant removal without immediately compromising permeability. Full article