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Projeto de investigação
Risks and Sustainability in Construction
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3D numerical modeling of geosynthetics for soil reinforcement: a bibliometric analysis and literature review
Publication . Paiva, Lucas; Pinho-Lopes, Margarida; Paula, António Miguel; Valente, Robertt
Soil reinforcement using geosynthetics is an efficient and cost-effective solution for a variety of geotechnical structures. Along with the increasing use of geosynthetics, there is a need to expand and enhance the design methodologies for these elements, which are still frequently based on conservative limit equilibrium approaches. In this paper, a bibliometric analysis was conducted on geosynthetic-reinforced soil structures (GRS), identifying the state of the art, research trends, and other indicators. The data were obtained from the Scopus platform and processed by VOSViewer v1.6 software. The initial search comprised 552 papers and the screening process selected 516 relevant papers from 1992 to October 2023. The study analyzed the occurrence of publications by year, keyword trends, authors, citations/co-citations, and bibliographic coupling. Then, a focus was given to 3D modeling research on geosynthetics, highlighting the dominant modeling techniques, material properties, and design challenges in GRS. The bibliometric analysis provided a crucial guideline in the identification of relevant papers and research trends, and a series of conclusions were presented regarding the 3D modeling techniques, choice of material properties, and boundary conditions.
A simple 3D orthotropic model for the tensile response of geogrids: in-isolation and soil–geogrid interaction applications
Publication . Paiva, Lucas; Pinho-Lopes, Margarida; Valente, Robertt; Paula, António Miguel
The short-term tensile response is one of the key aspects in designing geogrid-reinforced soil structures. In this paper a simple data-driven 3D orthotropic model for the short-term tensile response is proposed. The Hill48 yield model is chosen to represent the orthotropic behaviour of the geogrid, and a procedure to obtain the necessary parameters, from simple tensile test data, is presented. The model is then implemented in ABAQUS, and validated against a realistic problem where the geogrid is embedded in soil. The influence of the orthotropy (against isotropy) on both the reinforcement and the overall soil-geogrid structure is evaluated. The results show that the orthotropic model can accurately predict the tensile response of the geogrid in different directions, with the orthotropy having a significant influence on the reinforcement and the overall structural response, especially in highly orthotropic materials. The study further examined stress redistribution capabilities in geogrids with notches, revealing enhanced stabilization performance using the orthotropic model. Parametric tests indicated that traditional isotropic assumptions might underpredict or overpredict reinforcement performance, emphasizing the advantages for accurate orthotropic characterization. The proposed 3D framework provides a robust, straightforward method for evaluating and optimizing geogrid designs, enabling better prediction of reinforced soil behaviour in geotechnical applications.
A simple 3D orthotropic model for the tensile response of geogrids: in-isolation and soil-geogrid interaction applications
Publication . Paiva, Lucas; Pinho-Lopes, Margarida; Valente, Robertt; Paula, António Miguel
The short-term tensile response is one of the key aspects in designing geogrid-reinforced soil structures. In this paper a simple data-driven 3D orthotropic model for the short-term tensile response is proposed. The Hill48 yield model is chosen to represent the orthotropic behaviour of the geogrid, and a procedure to obtain the necessary parameters, from simple tensile test data, is presented. The model is then implemented in ABAQUS, and validated against a realistic problem where the geogrid is embedded in soil. The influence of the orthotropy (against isotropy) on both the reinforcement and the overall soil-geogrid structure is evaluated. The results show that the orthotropic model can accurately predict the tensile response of the geogrid in different directions, with the orthotropy having a significant influence on the reinforcement and the overall structural response, especially in highly orthotropic materials. The study further examined stress redistribution capabilities in geogrids with notches, revealing enhanced stabilization performance using the orthotropic model. Parametric tests indicated that traditional isotropic assumptions might underpredict or overpredict reinforcement performance, emphasizing the advantages for accurate orthotropic characterization. The proposed 3D framework provides a robust, straightforward method for evaluating and optimizing geogrid designs, enabling better prediction of reinforced soil behaviour in geotechnical applications.
A constitutive model for describing the tensile response of woven polyethylene terephthalate geogrids after damage
Publication . Lombardi, Giovani; Pinho-Lopes, Margarida; Paula, António Miguel; Pereira, António
A constitutive model was used to describe the tensile response of two woven Polyethylene Terephthalate (PET) geogrids, before and after mechanical damage. The model parameters of undamaged and damaged specimens were estimated via numerical regressions of test results. For each sample, the experimental and fitted tensile strengths were statistically compared using hypothesis tests. For each geogrid, tensile load-strain curves of damaged samples were drawn by applying scaling factors to the plot of the undamaged sample. The curve fittings resulted in high R-2 values for undamaged and damaged specimens of the geogrids. For most samples, there was no significant mean difference between the experimental and fitted tensile strength. The model allowed us to describe the load-strain curve of a geogrid from its tensile properties: & epsilon;(max), T-max and J(i). Regardless of the type of damage (in laboratory or in situ), the model was able to describe the load-strain curves of damaged samples using data from undamaged samples and scaling factors.
Tensile behavior of weathered thermally bonded polypropylene geotextiles: analysis using constitutive models
Publication . Carneiro, Jose Ricardo; Paula, António Miguel; Pinho-Lopes, Margarida
Weathering agents can significantly affect the mechanical response of geotextiles, particularly when long exposure periods are involved. Usually, in design, changes in the mechanical behavior of geotextiles are represented by reduction factors for their tensile strength. However, their full tensile force versus elongation response can be affected. The main aim of this work was to contribute to defining simple procedures to estimate tensile force versus elongation curves for weathered samples of geotextiles. The tensile response of two thermally bonded polypropylene geotextiles, before and after natural and artificial weathering, was assessed experimentally and analyzed using different constitutive models: polynomial (Orders 4 and 6) and hyperbolic. The influence of weathering on the mechanical response of the geotextiles was analyzed, polynomial and hyperbolic models for representing the tensile force versus elongation response were adopted and their parameters derived, and simple relations were implemented to estimate model parameters for weathered samples. Results revealed the occurrence of changes in the tensile behavior of the geotextiles, both under natural and artificial weathering conditions. Both groups of models fitted the experimental data properly. The Order 4 and 6 polynomial models are shown to have limited application, as the model parameters had no link to the tensile properties of the geotextiles. By contrast, the parameters of the hyperbolic model were linked to the tensile properties, particularly if affected by correction factors. The hyperbolic model parameters of the weathered samples were estimated using the model parameters of the reference samples and the reduction factors to allow for weathering (initial stiffness and tensile strength). These estimates proved to be adequate for representing the tensile response of weathered samples, particularly for low ranges of elongation. Finally, a simple procedure to represent the tensile response of weathered geotextiles was proposed. This procedure has shown promise in generating realistic tensile versus elongation curves.
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Entidade financiadora
Fundação para a Ciência e a Tecnologia
Programa de financiamento
6817 - DCRRNI ID
Número da atribuição
UIDP/04450/2020