Geosynthetics have been commonly used for the construction of civil engineering structures such as retaining wall, road and railways, coastal protection, soft ground improvement work, and landfill systems since the 1960s. In the past 40 years, the development of polymer materials has helped to prolong the life of geosynthetics. In terms of the practical use of geosynthetics, engineers must understand their appropriate application. The first part of this paper provides a basic description of geosynthetics, including their types, components, and functions. The second part deals with the geosynthetics used as filters. This part briefly presents the mechanism of filtration, the factors affecting the durability of geotextile filters, design concepts, laboratory tests, and case studies. The third part of the study covers the use of geosynthetics for stabilisation. Its mechanism was explained separately for geogrids and for geocells. Several examples of applications with geosynthetics intended for the stabilisation function are described in the last part of this paper.
This paper concerns a case study presenting one of the biggest landfills in Poland that required application of complex engineering works to extend the deposing capacity of the structure. The shear strength parameters of the subsoil and waste material used for analyses were based on geotechnical investigation and were then applied in slope stability analyses of the landfill. For the purpose of safety management of the new development and reclamation plan for the landfill, an observational method was applied to increase the geotechnical safety of the structure. The slope reinforcement methods mainly included the geogrid, geocomposite, and berms construction. However, much of the uncertainty associated with the stability of the geogrid-reinforced slope is related to the time-dependent deformation of geosynthetic materials. For the purpose of changes in the geogrid parameters with time, the samples were excavated from the landfill slope after 20 years of exploitation and analyzed in the laboratory. The tests allowed precise determination of the material properties, changing geometry, and mechanical properties like tensile strength and strain. Obtained results were compared to parameters of the brand-new geogrid samples. The tests indicated only insignificant changes in geosynthetics, physical, or mechanical performance properties, and the slope has not been compromised in its stability or performance.
21 December 2017 in IOP Conference Series: Earth and Environmental Science
The paper aims at the research of pioneering applications of geosynthetic materials used for improvement of anthropogenic material for road contraction challenges in Poland. The presented case study concerns a road embankment construction process within an area of underground mining coal extraction for which significant deformations have been frequently recorded. To improve the bearing capacity of the structure base, the geosynthetic materials were used. The question; however, was how the anthropogenic materials, filling the embankment, will interact with each other over time. The assessment of the structural condition of the motorway surface was performed using the falling weight deflectometer and the calculated modules based on the back-analysis method. They confirmed the effectiveness of the geosynthetics used in the study. They also revealed that the mining exploitation, with simultaneous use of aggregate stabilization with geogrids, did not cause significant changes in the stiffness of the pavement layers. All observations, based on both field and laboratory tests, did not show any negative impact of anthropogenic soils on the structural behavior of geogrids.
Dykes, or levees, are structures designed and constructed to keep the water in a river within certain bounds in the event of a flood. In relation with climate change, more frequent floods, of higher intensity, can be expected due to anthropogenic emissions of greenhouse gases into the atmosphere. The objective of this review paper is to address the many ways in which geosynthetics contribute to sustainable construction of dykes and thus to water systems management. This review paper, prepared by the four Technical Committees and the Sustainability Committee of the International Geosynthetics Society, briefly describes geosynthetics and their function, dykes and dyke failure modes, before presenting the main focus of the use of geosynthetics for the design and construction of durable dykes to ensure the protection of life and infrastructure. The optimization of dyke construction with geosynthetics to increase their resilience not only results in performance advantages, but also in economic advantages. The way geosynthetics can contribute to mitigating greenhouse gas emissions for a sustainable river management is discussed. This is done not only by allowing more economic construction methods to be implemented, but also solutions with increased resilience to face the extreme stresses related to climate change, while at the same time bringing about a positive contribution to the reduction of greenhouse gas emissions during the construction process itself. Finally, it is shown that by following state of the art standards and design practice any possible risk associated with the use of geosynthetics in dykes can be mitigated.
Landfills are elements of the waste management system, without possibility of further reclaiming, according to the requirements of a closed-loop economy, but with the possibility of transforming the area into other functions. The research combined monitoring of plant species, suggesting the composition of vegetation cover for pro-ecological management, analysis of functional and infrastructural incorporation of the landfill in the surrounding landscape, and proposals for reclamation and social application. An assessment of geotechnical safety was also made. Modernization of the landfill suggests that the pressure placed on other untouched locations should decrease. The designed space allows reintroducing socio-ecological life into this degraded area. Taking advantage of the character of the area, including variable development and significant landscape potential on the outskirts of a large city in the vicinity of protected areas, there is the possibility of creating new spatial quality following the standards of modern architecture-urban planning. One of the innovative elements of the project is the implementation of energy from renewable sources, including landfill biogas, photovoltaic panels and heat pumps. The development design includes social expectations and adaptation of new techniques to functioning in times of increased sanitary threats. The proposed design direction may be considered as a recommended trend for the sustainable development of urban areas.