Este trabalho apresenta resultados de ensaios de arrancamento de geogrelha, obtidos com a utilização de equipamento de dimensões reduzidas. A força de arrancamento foi aplicada por uma máquina universal com capacidade máxima de 30kN, dotada de instrumentação que permitiu registrar a força de arrancamento e o deslocamento da geogrelha em relação ao solo envolvente. Além disto, o ensaio foi instrumentado com uma célula de tensão total instalada no nível da inclusão. A grande vantagem deste equipamento é o pequeno volume de solo utilizado, resultando em um ensaio mais rápido e econômico, proporcionando um controle maior do teor de umidade e do grau de compactação do solo. Considerando que uma grande parte do estado de São Paulo é coberto por solos de granulometria fina, esse equipamento passa a ser uma excelente alternativa para obtenção dos parâmetros de ensaios de arrancamento necessários ao desenvolvimento de projetos em solo reforçado. Para averiguar a possibilidade de uso do ensaio de pequeno porte, nestas condições, para substituir uso das caixas de grandes dimensões foram inicialmente realizadas comparações, através do coeficiente de interação, entre os resultados obtidos através desses dois tipos de ensaios. Os resultados obtidos mostraram que, para as condições de ensaio empregadas utilizando solos com 100% passando na peneira de abertura 2mm e geogrelhas de abertura de malha aproximadamente de 20mm, a resposta do equipamento, se comparada à de ensaios de grandes dimensões, foi excelente. Isto permitiu que se procedesse a uma ampla análise paramétrica, de cunho experimental, em que se variou a velocidade de ensaio, a tensão confinante, as dimensões das amostras de geogrelha, o tipo de solo e a geogrelha, com o intuído de cobrir diferentes situações possíveis de se encontrar nos projetos de engenharia. O trabalho apresenta os principais resultados desta análise / This work presents results of geogrid pullout tests conducted using small scale equipment. The pullout load was applied using a universal load frame, with a maximum capacity of 30kN, capable of recording the pullout load and front displacement. In addition, the test was instrumented with an earth pressure cell installed at the level of the geogrid inclusion. The primary advantage of this equipment is the small volume of soil used in test preparation, resulting in reduced testing time, greater control of the water content and degree of compaction, and significant reduction in overall testing costs. Furthermore, a significant area of the state of Sao Paulo in Brazil is covered by fine grained soils which could be tested according to its pullout behavior using the proposed equipment. To investigate the feasibility of the small scale test facility, comparisons were made between the coefficient of interaction obtained from tests of small and large dimensions. The results show that for the tested materials there were no differences between pull out parameters from both equipment. Additionally it was investigated the effects of testing speed, confining pressure, sample dimensions, and soil and geogrid materials. Results of these tests are presented and discussed

<p>There are significant problems during construction to establish an adequate foundation for fills and/or subgrade for pavements when the natural ground has low-bearing soils. Geosynthetics such as geogrids, geotextiles and/or geocells could provide an alternative, less costly in time and money, to establish an adequate foundation for the fill and/or subgrade. There is extensive evidence in the literature and on DOTs practices about the suitability of using geotextiles in pavements as separators. Previous studies have also shown that the use of geogrids in flexible pavements as a reinforcing mechanism could decrease the thickness of the base layer and/or increase the life of the pavement. In this study, analyses of selected pavement designs using Pavement ME, while considering geogrid-enhanced base or subgrade resilient modulus values, showed that geogrid-reinforcement, when placed at the interface between subgrade and base, did not produce significant benefits, as only a modest increase in pavement life was predicted. In addition, parametric finite element analyses were carried out to investigate the potential benefits of placing a geogrid at the base of a fill over a localized weak foundation zone. The analyses showed that the use of geogrids is beneficial only when: (a) the stiffness of the weak foundation soil is about an order of magnitude smaller than the rest of the foundation soil; and (b) the horizontal extent of the weak foundation soil is at least 30% of the base of the embankment foundation. The largest decrease in differential settlements at the surface of the fill, resulting from geogrid-reinforcement, was less than 20% and, therefore, it is unlikely that the sole use of geogrids would be sufficient to mitigate differential settlements. Based on previous studies, a geocell mattress, which is a three-dimensional geosynthetic filled with different types of materials, could act as a stiff platform at the base of an embankment and bridge over weak zones in the foundation. However, given the limited experience on the use of geocells, further research is required to demonstrate that geocells can be effectively used instead of other reinforcement methods.</p>

In the reinforced backings, the pulling capacity is transmitted by built-in reinforcements for which design it is necessary to determinate accurately this capacity. In the diploma thesis, there is the effect of subsoil stiffness and selected constitutional relation on the capacity transmitted by individual reinforcements by the method of parametric study monitored.

Continued population growth is placing strain on the waste disposal facilities available in South Africa. However, limited air space suitable for landfilling drives the need for alternative solutions such as piggyback landfills to expand the waste disposal capacity. This method entails building a new, fully lined, landfill on top of existing waste. However, the old underlying waste is prone settlement that can result in the cracking of new landfill clay liner. Geogrid reinforcement have been successfully used in clay liners to mitigate cracking induced by waste settlement. This research focused on investigating of the optimal reinforcement strategy (ORS) of such a liner subject to settlement. The ORS entails the optimal position for geogrid reinforcement in a liner, and the stiffness to be used at that position, given a total reinforcement cost. Firstly, the fracture behaviour of unreinforced clay liners was investigated by means of four point bending tests on clay beams. It was found that the fracture of this clay occurred in three stages: linear behaviour, followed by non-linear behaviour when micro-cracks forms and finally macro-cracks that opened once the peak load was reached. Thereafter, the behaviour of geogrid-reinforced clay liners, subjected to differential settlement, was investigated with finite element analyses in ABAQUS. A number of key factors were varied and the resulting change in behaviour of the liners was observed. These were: the overburden stress applied, clay liner thickness, magnitude of central settlement and the width and shape of the settlement trough developing in the underlying waste body. Based on the numerical results, a series of plane-strain centrifuge tests of reinforced clay liners subject to differential settlement were designed. An unreinforced liner, a liner reinforced at the bottom quarter, a liner reinforced at the top quarter and a liner reinforced at both the bottom and top quarters were tested. Laser scanner scans of the surface and strains calculated from digital image velocimetry results were used to compare the behaviour of the liners. Based on these results it is recommended that for optimal performance the available reinforcement should be divided between the top and bottom quarters of the liner to mitigate the effect of settlement. / Volgehoude bevolkingsgroei in Suid-Afrika plaas bestaande rommelstortingsfasiliteite onder druk. ’n Tekort aan grond geskik vir die bou van stortingsterreine moedig die soektog na alternatiewe oplossings soos abba-stortingsterreine aan. Hierdie metode behels ’n splinternuwe stortingsterrein wat bo-op bestaande rommel gebou word. Versakking van die bestaande rommel kan egter veroorsaak dat krake vorm in die nuwe stortingsterrein se kleivoering wat daarop lê. Vorige navorsing het die vorming van krake in die kleivoerings al welgeslaagd verhoed deur van georoosters as versterking gebruik te maak. Die huidige studie het op daardie navorsing gebou deur die optimale versterkings strategie (OVS) te bepaal vir so ’n kleivoering wat vervorm onder versakking van die onderliggende rommel. Die OVS definieer beide die optimale versterkings posisie in ’n kleivoering, en die styfheid van die georooster wat in daardie posisie geplaas moet word, gegewe ’n sekere totale versterkingskoste. Eerstens was daar ondersoek ingestel na die kraakgedrag van onversterkte kleivoerings. Vierpuntbuigtoetse van kleibalkies was hiervoor gebruik. Die krake het oor drie fases gevorm: eerstens was daar lineêre gedrag tot en met mikro-krake gevorm het. Dit is gevolg deur nie-lineêre gedrag wat gelei het tot makro-krake. Sodra die makro-krake gevorm het, is die maksimum las bereik wat die klei kon ondersteun. Na afloop van die balkbuigtoetse was eindige element analises in ABAQUS uitgevoer om die gedrag van versterkte kleivoerings wat bo-op versakkende afval lê te ondersoek. Die spanning toegepas op die oppervlak van die kleivoerings, die dikte van die kleivoerings en die versakkingstrogwydte, -vorm en -diepte was gevarieer om die effek daarvan op die gedrag van die kleivoerings te ondersoek. Na aanleiding van die resultate van die numeriese analise is ’n reeks sentrifuge toetse van kleivoerings wat aan versakking onderwerp word uitgevoer. ’n Onversterkte kleivoering, kleivoerings versterk in die boonste en onderste kwarte, en een versterk in beide die boonste en onderste kwart was getoets. Die gedrag van die verskillende kleivoerings was vergelyk deur die oppervlaktekrake op te meet met ’n laserskandeerder. Verder is die vervorming van die kleivoerings bepaal vanaf die verplasing van die grondpartikels tussen opeenvolgende digitale foto’s. Na aanleiding van hierdie resultate word dit aanbeveel dat die beskikbare georooster versterking opgedeel moet word tussen die boonste en onderste kwart van die kleivoerings ten einde optimale gedrag te verseker indien versakking sou plaasvind. / Dissertation (MEng)--University of Pretoria, 2017. / Deutscher Akademischer Austausch Dienst (DAAD) / Geosynthetics Interest Group of South Africa (GIGSA) / National Research Foundation of South Africa (NRF) / Civil Engineering / MEng / Unrestricted

The purpose of a geotextile separator beneath a granular base, or subbase in a flexible pavement system is to prevent the road aggregate and the underlying subgrade from intermixing. It has been hypothesized that in the absence of a geotextile, intermixing between base course aggregate and soft subgrade occurs. Nine heavily instrumented flexible pavement test sections were built in Bedford County Virginia to investigate the benefits of geosynthetic stabilization in flexible pavements. Three groups of different base course thicknesses (100, 150 and 200mm) test sections were constructed with either geotextile or geogrid stabilization or no stabilization. Woven geotextile was used in sections 2, 5 and 8. Geogrids were used in sections 3, 6 and 9, and sections 1, 4 and 7 were controls. Six Falling weight deflectometer (FWD) tests were performed on all the nine sections over 30 months. The nine sections were subjected to at least 5 load drops with wide loading range each time. The measured deflections were analyzed using the MODULUS back-calculation program to determine layer moduli. The measured deflections were used together with elastic, viscoelastic and the MODULUS program to determine the extent of intermixing at base-subgrade interface. The study concluded that a transition layer would develop when a separator is absent, especially in the weak sections (designed to fail in three years). Other measurements such as in-situ stresses, rut depth, and subsurface profiling (using ground penetrating radar) support the conclusion of the development of a transition layer. / Master of Science

For the past three decades, geosynthetics have been recognized as materials that can significantly improve the performance of pavements on weak subgrade. Pavements exhibit non-linear elasto-plastic behavior. The addition of geosynthetics is undoubtedly beneficial. This being said, researchers have concentrated more on lower life cycle cost and high benefit-cost ratio whereas much less attention has been given to the complex behavior of the reinforced pavement system. Comprehension of the short-term and long-term field performance of reinforced pavements under continued traffic and cyclic environmental loading has remained unexplored. There is empirical evidence indicating quantitative benefits of reinforced versus unreinforced pavement structure. However, quantification of the relative benefits of different types of reinforcement like geogrids and geotextiles lacks information. Further, evaluation of the benefits and comparison of chemical stabilization in the form of lime treatment with mechanical stabilization in the form of reinforcement for pavements on soft soils has received lack of attention. In view of this, full-scale instrumented reinforced and lime treated pavement sections with different schemes were studied. Regular Falling Weight Deflectometer (FWD) testing was conducted in a Farm-to-Market Road, in Grimes County, Texas. Three different geosynthetic products were used for base reinforcement and lime treatment was used for subbase stabilization. Deflection measurements for 9 field trips in 3.5 years were evaluated. Modified deflection basin parameters (DBPs) were defined to typically identify layer properties and were used to measure the relative damage to the base, subbase and subgrade for different sections. A modified Base Damage Index (BDI) and a modified Base Curvature Index (BCI) were defined as a part of this study to capture the benefit of reinforced base and lime stabilized subbase respectively. The variation in the DBPs over three periods of wetting and drying along with explanation of the observed trends forms a part of this research. In addition, a number of condition surveys were performed, during 3 years, to visually identify distresses in various sections. A unique distress quantification technique was developed for measuring deterioration of the pavement sections in terms of the observed distresses and FWD measurements. With this, an index of pavement performance was developed. Thus, the FWD deflection data analyses complemented by visual observation, reveals important information on performance of different geosynthetics with the same base course. Analysis of the field performance of the multiple experimental sections throws light on the relative merits of base reinforcement against lime stabilization. / text

[pt] A aplicação de geossintéticos em obras geotécnicas vem crescendo intensamente nos últimos tempos, tornando cada vez mais importantes e necessários os estudos da resistência de interface para aplicação em projetos e obras. Em particular, tais estudos devem tratar das técnicas de ensaios de campo e de laboratório para a obtenção dos parâmetros de resistência (adesão e ângulo de atrito). Os ensaios de laboratório são utilizados com maior freqüência por serem mais acessíveis e de fácil execução. Os ensaios de campo reproduzem mais diretamente as condições das obras, mas apresentam como desvantagem o custo elevado e a dificuldade de execução. Este trabalho tem como finalidades apresentar o equipamento de ensaio utilizado e analisar os resultados de um programa em interfaces solo- geossintético. O programa experimental envolveu ensaios de rampa, cisalhamento direto convencional e cisalhamento direto inclinado em solo com granulação grosseira (brita), em contacto com as geomembranas e as geogrelhas. Os resultados foram analisados avaliando-se as influências da tensão confinante e da inserção dos geossintéticos, e comparandose os diferentes tipos de materiais e de técnicas de ensaio. A influência da tensão confinante foi estudada com base em três tensões confinantes distintas, de baixa magnitude (1,0; 1,7 e 2,4kPa). O aumento da tensão confinante implicou em um aumento, tanto do deslocamento até a ruptura quanto da resistência da interface. Este comportamento deve-se à possibilidade de rearranjo e imbricamento entre os grãos da brita. Em relação ao tipo de geossintético, a interface brita-geogrelha apresentou maior resistência do que a interface brita-geomembrana. Isto pode ser explicado em função da estrutura do geossintético, pois a geomembrana perde possui uma superfície lisa, o que favorece o deslizamento, ao contrário da geogrelha, que conta com o efeito do imbricamento do solo nas aberturas da malha. / [en] The use of geosynthetics in geotechnical construction is growing up intensively on the last years, which make the study on interface strength more important and necessary to its application on projects and construction. Particularly, these studies should watch out field and laboratory tests in order to obtain strength parameters (adhesion and friction angle). Laboratory tests are more frequently used, due to their accessibility and easy execution. Field tests reproduce construction condition in a directly way, but have as disadvantages high cost and hard execution condition. The current research have as objectives present the test equipment used and analyze software results obtained for soil and geosynthetic interfaces. The experimental program involved ramp tests, conventional direct shear test and inclined direct shear test. This program was carried out on gravel soil in contact with two different types of geosynthetics (geomembrane and geogrids). Results were analyzed based on the influence of confining pressure and the introduction of geosynthetics, and comparing the different materials and test techniques. The confining pressure influence/importance was studied based on three different low magnitude confining pressures (1,0; 1,7 e 2,4kPa). The confining pressure increases resulted in an increase of both displacements until the failure and interface strength. This behavior could be explained due to the possibility of interlocking e between the gravel grains. Considering the geosynthetic type, gravel-geogrid interface presented higher strength than gravel- geomembrane interface. This could be explained by the structure of the geosynthetic; geomembrane has low strength due to its smooth surface, which benefits the slide. Geogrid instead, counts with the soil interlocking; effects in the mesh holes.

A presente pesquisa tem por objetivo desenvolver, montar e testar um equipamento de grandes dimensões (largura de 1,5 x 1,5 m e altura de 1,2 m) para o ensaio em laboratório de estruturas de pavimentos com materiais, espessuras de camadas e condições de carregamento similares às de campo. Ainda nesta pesquisa analisou-se o emprego de geossintético como reforço da camada de base de novos pavimentos sobre o efeito da variação da umidade do subleito. O carregamento cíclico é gerado a partir de um cilindro pneumático. A instrumentação é constituída de LVDTs, células de carga e de tensão total que permitem o monitoramento das cargas aplicadas, das tensões no interior das camadas, e deformações elásticas e permanentes na superfície do pavimento. O carregamento cíclico, com frequência de 1 Hz, foi aplicado sobre placas rígidas com diâmetros de 300 mm e 216 mm e magnitudes de 40 kN e 20 kN, respectivamente. A partir das bacias de deflexões obtidas, foi possível, por meio de retro-análise, a determinação dos módulos de resiliência dos materiais e a partir das curvas de recalque obter uma equação da deformação plástica em função do número de ciclos de carga. O equipamento apresentou bom funcionamento, atendeu às expectativas e os transdutores forneceram medidas com a precisão exigida. E a utilização de geogrelha como reforço de camada de base mostrou eficaz tanto na redução das deformações permanentes como elásticas. / This research aims at develop, assembly and test of application of large-scale equipment (width of 1.5 x 1.5 m and height of 1.2 m) for the testing in pavement structures laboratory, with materials, thicknesses of layers and loading conditions similar to the field ones. The research still studied the application of geosynthetics as base layer reinforcement to news pavements by effect of variation in subgrade layer moisture. The loading is cyclic and generated from a pneumatic actuator. The instrumentation is constituted of LVDTs, load-cells and soil pressure transducers that permit monitoring the applied loads and the stress distribution in the interior of the layers, as well as plastic and elastic deformations. The cyclic-loading (frequency of 1 Hz) was applied on a 30-mm-diameter and a 26-mm-diameter rigid plate with force of 40 kN and 20 kN, respectively. From the deflection basin obtained, it is possible, by means of back calculation, the determination of the resilient modulus of the materials and from the deformation basin obtained the equation of permanent deformation in function of the cycle number. The equipment showed a good operation, attended to the expectations and the transducers supplied measures with the precision required.

Este trabalho apresenta um estudo comparativo da eficiência de diferentes geossintéticos no reforço de base de pavimentos de obras viárias com ensaios de arrancamento de pequeno porte. Utilizou-se geogrelhas de polipropileno, poliéster e de fibra de vidro e geotêxtil tecido de polipropileno. Um solo com 58% de argila (subleito) e um pedregulho areno-siltoso (camada de base) foram empregados. Os ensaios de arrancamento foram executados com diferentes combinações entre solos e geossintéticos. Nestes foi utilizado um novo sistema de medida direta de deslocamentos ao longo da inclusão com sensores óticos a laser. Além de analisar os resultados com curvas força de arrancamento x deslocamentos, foi possível utilizar gráficos rigidez x deformação para determinar o melhor geossintético no reforço de base de pavimentos. Como o corpo-de-prova de geossintético é de tamanho reduzido, garante-se a mobilização completa do reforço durante o ensaio de arrancamento e assim, é possível obter a deformação do mesmo. A abertura frontal da caixa de arrancamento tem influência no valor da força máxima ao arrancamento registrada no ensaio. Os resultados mostram que a interação solo-reforço é mais importante que a rigidez não-confinada do geossintético no comportamento do material em situação de confinamento no interior do maciço de solo. Observou-se que a resistência de junta, a geometria e o agulhamento da geogrelha, além da granulometria do solo, afetam a rigidez inicial do sistema. A melhor opção para os solos e geossintéticos estudados segue a seguinte ordem: (1) geogrelha de polipropileno, (2) geogrelha de poliéster, (3) geotêxtil tecido de polipropileno e (4) geogrelha de fibra de vidro. / This work presents an evaluation of various geosynthetics efficiency in reinforced base course of road pavements using small scale pullout tests. It was used polypropylene, polyester and glass fiber geogrids and polypropylene woven geotextile. A soil with 58% of clay (subgrade), and a sandy-silty gravel (base course) were used. The pullout tests were conducted with different combinations among soils and geosynthetics. In these tests, a new system of direct measurement of inclusion displacements with laser optical sensors was used. Beyond analyzing the results with curves pullout force x displacements, it was possible to use graphics rigidity x deformation in order to determinate the best geosynthetic in base course reinforcement. As the geosynthetic specimen is of small size, the complete mobilization of the reinforcement is guaranteed and, therefore, it is possible to obtain its deformation. The frontal aperture of the pullout box influences the maximum pullout resistance. The results show that the soil-reinforcement interaction is more important than the unconfined rigidity of the geosynthetic on the material behavior in confinement situation inside the soil block. The joint resistance, the geogrid geometry and its nailing, besides the soil particles size, affect the initial system rigidity. Therefore, they are important for base course reinforcement of road pavements. The results showed that the best option for the soils and geosynthetics studied are in the following order: (1) polypropylene geogrid, (2) polyester geogrid, (3) polypropylene woven geotextile and (4) glass fiber geogrid.

Os ensaios de arrancamento cíclicos são utilizados para avaliar o comportamento de sistemas de solo reforçado quando submetidos a carregamentos cíclicos, podendo ser aplicados na área de pavimentos reforçados com geossintéticos ou em comportamento sísmico de solos reforçados com geossintéticos. O comportamento de sistemas de solo reforçado submetidos a carregamentos cíclicos ainda não é bem compreendido. Em vista disso, equipamentos de arrancamento cíclicos de geossintéticos são desejáveis para o estudo deste comportamento. O equipamento de arrancamento de geossintéticos existente no laboratório de geossintéticos da Escola de Engenharia de São Carlos da Universidade de São Paulo foi modificado para a realização de ensaios de arrancamento cíclico de geossintéticos. Dois tipos de ensaios foram implementados para avaliar o comportamento cíclico de sistemas de solo reforçado com geogrelhas: o ensaio de módulo de cisalhamento de resiliência de interface solo-geogrelha, Gi, e o ensaio de resistência pós-ciclagem. Foram realizados 20 ensaios, entre ensaios de arrancamento monotônico, cíclicos e de testes, de geogrelhas. Foram avaliados dois sistemas, um deles de inclusão longa, de 510 mm de comprimento e 310 mm de largura; e o outro de inclusão curta, de 240 mm de comprimento e 310 mm de largura. Os ensaios para a obtenção de Gi mostraram que para o sistema de inclusão longa, foi possível ajustar os valores obtidos através de vários modelos de calibração e no caso do sistema de inclusão curta, foi impossível realizar medidas de deslocamento devido à precisão dos LVDT. Os ensaios de resistência pósciclagem foram realizados em um sistema análogo ao sistema de inclusão curta do ensaio para obtenção de Gi. Os resultados dos ensaios de resistência pós-ciclagem mostraram-se consistentes com os valores esperados em termos de resistência e deslocamentos cíclicos. Os ensaios de resistência pós-ciclagem mostram que o sistema de solo reforçado avaliado é susceptível a atingir a condição de ruína quando submetidos a carregamentos cíclicos de amplitude alta, mesmo sendo estáveis para carregamentos monotônicos de serviço. No entanto, sob uma amplitude de ciclagem baixa o sistema se comporta de maneira estável em termos de evolução de deslocamentos mesmo em condições cíclicas. As incertezas de medição, as vibrações transmitidas, a ausência de representatividade do comprimento da inclusão, presença de ruídos elétricos, bem como as limitações do equipamento evidenciam a necessidade de melhoria dos procedimentos de ensaio recomendados para a obtenção de Gi, e melhorar a qualidade da avaliação do comportamento da resistência pós-ciclagem. / Cyclic pull out tests have been used to evaluate the behavior of reinforced soil systems when subjected to cyclic loading. These tests are applied in areas such as geosynthetic reinforced pavements or geosynthetics reinforced soil systems when subjected to seismic loadings. Cyclic behavior of reinforced systems is not yet well understood. In this sense, cyclic test apparatus are desirable to study this behavior. Pull out test apparatus of the School of Engineering of São Carlos of the University of São Paulo was modified to perform cyclic pull out tests of geosynthetics. Two types of tests were conducted to evaluate cyclic behavior of geogrid reinforced systems: soil-geogrid interface resilient shear modulus test, Gi, and postcycling resistance test. Twenty tests were carried out such as monotonic, cyclic and calibration tests of geogrids. Two systems were evaluated: the first called long inclusion, with 510 mm length and 310 mm width, and the second system called short inclusion, with 240 mm length and 310 mm width. Concerning the long inclusion system, Gi tests showed that it was possible to adjust the values obtained through various calibration models; the short inclusion system presented deficiency to measure displacements due to LVDTs accuracy. Post-cycling resistance tests were performed on a system similar to the short inclusion test. Post-cycling resistance tests showed good performance when compared to the literature values regarding to resistance and cyclic displacements. These tests showed that the reinforced system evaluated could suffer rupture when subjected to high amplitude cyclic loading, even when this system is stable for the same monotonic load levels. Besides that, the system behaved stably under a low amplitude cyclic loading in terms of cyclic displacements evolution, even under cyclic condition. Uncertainty in measures, transmitted vibrations, lack of inclusion length representativeness, electric noises, and equipment limitations need improvements in test procedures to evaluate Gi as well to enhance the evaluation quality of the post-cycling resistance.