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Correlation results found in international literature

Correlation results found in international literature

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Two types of Light Falling Weight Deflectometers (LFWD) are in use in Hungary: the German device (Zorn, HMP and Wemex) and the new B & C small-plate device, which was developed by Andreas Ltd. Both devices are able to measure the dynamic load bearing capacity of subgrades, subsoils, embankment layers and backfills. Extensive application of these ap...

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Context 1
... correlation results between E 2 and E vd are available in the international literature. The most relevant results are sum- marized in Fig. ...
Context 2
... conversion equations are not frequently used in prac- tice, generally limit values are given for both E 2 and E vd . Four different German standards give similar limit values, these are also presented in Fig. 1 (bold dash lines). Fig. 1 shows that the value of the static plate load test modulus clearly exceeds at least two times that of the E vd modulus. Some of the results show even higher ratios. Only two publications give a ratio less than two, but both of them are based on modulus values measured only at few points and within small ...
Context 3
... conversion equations are not frequently used in prac- tice, generally limit values are given for both E 2 and E vd . Four different German standards give similar limit values, these are also presented in Fig. 1 (bold dash lines). Fig. 1 shows that the value of the static plate load test modulus clearly exceeds at least two times that of the E vd modulus. Some of the results show even higher ratios. Only two publications give a ratio less than two, but both of them are based on modulus values measured only at few points and within small ...

Citations

... An area of 7.5 m in length and 1 m in width was selected in the field implementation for detailed studies. As shown in Fig (Tompai, 2008;Mikolainis et al., 2016;Fei et al., 2021). In this work, the GTJ-EVD apparatus ( ...
Article
A B S T R A C T A suitable bearing capacity of foundation is critical for the safety of civil structures. Sometimes foundation reinforcement is necessary and an effective and environmentally friendly method would be the preferred choice. In this study, the potential application of enzyme-induced carbonate precipitation (EICP) was investigated for reinforcing a 0.6 m bedding layer on top of clay to improve the bearing capacity of the foundation underneath an underground cable duct. Laboratory experiments were conducted to determine the optimal operational parameters for the extraction of crude urease liquid and optimal grain size range of sea sands to be used to construct the bedding layer. Field tests were planned based on orthogonal experimental design to study the factors that would significantly affect the bio-cementation effect on site. The dynamic deformation modulus, calcium carbonate content and long-term ground stress variations were used to evaluate the bio-cementation effect and the long-term performance of the EICP-treated bedding layer. The laboratory test results showed that the optimal duration for the extraction of crude urease liquid is 1 h and the optimal usage of soybean husk powder in urease extraction solution is 100 g/L. The calcium carbonate production rate decreases significantly when the concentration of cementation solution exceeds 0.5 mol/L. The results of site trial showed that the number of EICP treatments has the most significant impact on the effectiveness of EICP treatment and the highest dynamic deformation modulus (Evd) of EICP-treated bedding layer reached 50.55 MPa. The area with better bio-cementation effect was found to take higher ground stress which validates that the EICP treatment could improve the bearing capacity of foundation by reinforcing the bedding layer. The field trial described and the analysis introduced in this paper can provide a practical basis for applying EICP technology to the reinforcement of bedding layer in poor ground conditions.
... In Central Europe, quality adequacy is most often checked through static and dynamic elastic modules. The experimental measurements focused on static and dynamic plate load tests (PLT) of subsoil and road pavement subbase layers were presented by Zednik [14], Tompai [15], Elhakim et al. [16], Volovski et al. [17], Abulkareem [18], and Lehmann et al. [19]. ...
... According to [19] the correlation E v2 versus E vd is common in German engineering practice, Equation (22) shows the linear correlation proposed in FGSV:2009 (Forschungsgesellschaft für Straßen-Directive on earthworks in road construction) and for gravel in Equation (23) were performed at Technische Universität Darmstadt, Germany [53]. The next conversion between static and dynamic load-bearing capacity moduli is in [15]. The overview of linear and nonlinear (power and logarithmic) relationships between the measured static and dynamic modulus of elasticity was published in [54] (see Figure 13). ...
... According to [19] the correlation Ev2 versus Evd is common in German engineering practice, Equation (22) shows the linear correlation proposed in FGSV:2009 (Forschungsgesellschaft für Straßen-Directive on earthworks in road construction) and for gravel in Equation (23) were performed at Technische Universität Darmstadt, Germany [53]. The next conversion between static and dynamic load-bearing capacity moduli is in [15]. The overview of linear and nonlinear (power and logarithmic) relationships between the measured static and dynamic modulus of elasticity was published in [54] (see Figure 13). ...
Article
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In the present study, credible analytical and numerical models are developed in order to explain the apparent discrepancies in the ratios of static and dynamic deformation models for assessing the quality of mechanical efficiency of transport structures in Central Europe. Through of experience, authors specifically deal with the comparison of two commonly used methods: the dynamic load plate test, known as the lightweight dynamic test and the static plate load test. This paper presents the relevant correlation dependency of the most commonly used quantification characteristics in earthworks quality control. Their correlation was obtained by applying the static theory of impact to earthworks quality control, which allows for the application of several quality control methods, in line with other member states of the European Union, specifically with regard to constructions under various boundary conditions (climate, soil moisture of the specified layer). According to an analysis of the results of comparisons of static and dynamic load tests, analytical and numerical models of the subsoil formed by soils and uncemented structural materials, respectively, the linear calculation usually used in the conditions of Central Europe does not have universal validity. Rather than relying on the analytical and FEM models for the soil, the authors have determined that the above dependence is a power dependence.
... The elastic modulus can be derived from some tests in the laboratory, including the triaxial compression test, 1-D consolidation test, oedometer test [9], and unconfined compressive strength test. In the case of on-site tests, the elastic modulus can be deducted from the standard penetration test (SPT) [10], dynamic penetration test (DPT) [11], and plate bearing test (PBT) [7,12]. The elastic modulus estimations via a triaxial compression test and an oedometer test in a laboratory are applicable for fine-grain or cohesive soil, where the largest grain is smaller than the mold diameter by 15 or 20 times as specified in ASTM D5321/D5321M-21. ...
Article
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In this paper, the moduli of elasticity of compacted loess and lateritic-loess soils on-site were estimated from the laboratory test. These were coarse grain soils used for the construction of base course and embankment of the railway line. The knowledge of the soil properties on-site such as the compacted elastic moduli is essential for the design and selection of materials. A total of 108 samples consisting of 36 samples of compacted soils on-site and 72 samples of compacted soils in laboratory were tested using plate bearing tests. The water contents of the compacted soil on-site were controlled to be within ±2% of optimum water content. The water content and density of compacted soil on-site were determined and used for the compaction of soils in the laboratory. For the testing in laboratory, two loading types viz., point load and uniform load were performed using the compacted 15-cm diameter mold (California Bearing Ratio). The results showed that the point load test gave a slightly better estimation of elastic modulus with R² of 0.977 than the uniform load test with R² of 0.970. The experiment showed that the on-site elastic moduli of loess and lateritic-loess soils could be accurately estimated from the laboratory load tests.
... Nazzal [26] and Tompai [46] found that the zone of influence of the LWD to vary between 1 and 2 times the plate diameter. Elhakim et al. [13] investigated the zone of influence of the LWD by performing the LWD test on calcareous and siliceous sands placed in layers with varying thicknesses resting on a rigid boundary (concrete floor). ...
... The influence of the rigid base boundary on the LWD modulus diminishes with increasing the thickness of the sand layer. For soil layer thickness to plate diameter ratios of 1.5-2, the effect of the rigid layer is considered negligible something which goes well with Nazzal [26] and Tompai [46] findings. ...
Article
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Resilient modulus is one of the important parameters used in the analysis and modelling of subgrade behaviour and it is directly related to the safety, economic and lifetime of roads structures. The determination of Resilient Modulus (MR) using repeated load triaxial (RLT) test is expensive, cumbersome and time consuming. Therefore, a new research approach has been adopted in this study based on performing cyclic light weight deflectometer (LWD). The objective of the cyclic loading is to bring the soil to its near elastic behaviour and then measure the dynamic deformations moduli (Evd). The cyclic LWD tests were performed in the field and in the laboratory and the measured Evds values were compared to the resilient moduli measured by RLT tests conducted under similar testing conditions. The number of LWD test cycles required to bring the soil to its elastic state can be decided directly during the test by using a new multifunctional LWD manufactured solely for the purpose of this study. It has been found that the required number of LWD repetitions (cycles) to conduct Evd moduli close to MR moduli depends on many influencing factors, namely, the moisture contents, lateral confinement and the maximum vertical axial stress levels during testing. Based on this study, it can be inferred that the cyclic LWD test can be used to predict simply and quickly the resilient behaviour of the tested soil with good precision and reliability.
... The dynamic devices that are most often used for checking the quality of loose soil compaction were invented in the late 1970-ies (Tompai 2008). The thickness of the tested soil layer depends on the diameter of the plate of the device, i.e. the bigger the diameter, the thicker the tested layer is (Tirado et al. 2015;Koukoulidou et al. 2017). ...
Article
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The surface of earth on the territory of Lithuania is covered by sediments of the Quaternary system, which are the object of human economic activities. Reliable assessment of sediment deformations is an important task of modern engineering geology and geotechnical engineering. The deformation of sediments is most often described using the modulus of deformation. The current article overviews different methods employed in deformation moduli determination and their application possibilities. The deformation moduli, which are used in various calculations, are usually calculated using correlation formulas and empirical coefficients. Thus, the obtained results may be inaccurate or completely unsuitable for further interpretation of the numerical situation. This article presents recommendations with regard to the use of various calculated deformation moduli in interpreting Lithuanian Quaternary system sediments.
... One of the main requirements towards road structures is design stiffness, expressed via the modulus of deformation on the top of the road. The extra requirements for the modulus of deformation and the minimum height for the pavement structural layers are introduced as well (see, e.g. in Lithuanian Road Administration (2007), Tompai (2008)). Another aim in designing road structures is using local soils (Bheemasetti, Pedarla, Puppala & Acharya 2015;Čygas, Laurinavičius, Pauliukaitė, Motiejūnas, Žiliūtė & Vaitkus, 2015;Köhler, Herald, Hering, 1998;Lithuanian Road Administration, 2007;Mair 2005;Mateos & Soares, 2014). ...
... Such correlations for several soil types were reported in, e.g. Meanwhile, several significant investigations aimed at deriving analogous correlations of the dynamic modulus of deformation versus the static modulus of deformation have been carried out (Adam & Kopf, 2003;Bertuliene, 2011;Kopf & Erdmann, 2005;Kopf, Adam, & Paulmichl, 2005a, 2005bSchmidt & Rumpelt, 2009;Tompai, 2008;Weingart, 2003). ...
Article
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Soil, or soil structure modulus of deformation, is one of the main design parameters for road engineering and traffic infrastructure design of, for example, highways, railways, runways and embankments. It is also the main soil improvement criterion. When creating any road structure with codified design resistance, one employs structural layers of certain thicknesses and modulus of deformation. Both values need to satisfy the minimum values in accordance with codified requirements. This paper analyzes correlations for the widely applied in engineering practice methods to determine the soil stiffness. The static test methods acknowledged to be exact enough for determining the modulus of deformation for the primary and secondary loadings. As dynamic test methods require significantly less time and financial resources, they are widely accepted in engineering practice. The dynamic methods determine only the dynamic modulus of deformation. Design practice aims to relate it with the static modulus of deformation of the secondary loading. Many countries propose codified correlations, with differing levels of conservatism, to convert the dynamic modulus of deformation into the static one. Developed correlations between the results of the static plate load test and the dynamic plate load tests processed from own test results of different soils are presented and a comparative analysis with other proposed correlations is given.
... Entre as técnicas de ensaios geotécnicos em ferrovias, uma das mais utilizadas atualmente, é o ensaio de Deflectômetro de Impacto Leve (Light Weight Deflectometer -LWD) (RUBIN et al., 2018;LAMAS-LOPEZ et al., 2016 ;ELHAKIM et al., 2014 ;STAATSMINISTERIUM, 2016;SHAFIEE et al., 2011 ;TOMPAI, 2008 ;WOODWARD et al., 2014). Este ensaio permite a avaliação do subleito e demais camadas do pavimento, estimando o módulo dinâmico do solo em cada etapa da construção deste, e também usado para controle de qualidade. ...
Thesis
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Os pavimentos ferroviários apresentam trechos com pontos de grande deformabilidade e acúmulo de tensões, necessitando de manutenções na infraestrutura e não somente na superestrutura, o que representa gastos para as operadoras ferroviárias. Neste trabalho foi elaborado uma análise mecanística de um trecho do pavimento ferroviário da Ferrovia Centro-Atlântica, verificando o comportamento mecânico e deformabilidade das camadas de lastro e lastro degradado, e principalmente, da camada de subleito, a qual é mais suscetível a efeitos da variação da umidade. Por meio de uma metodologia baseada na mecânica dos pavimentos, foi realizada uma investigação geotécnica das camadas de um pavimento ferroviário com a abertura de trincheiras de inspeção, coleta de material do subleito para caracterização e ensaios triaxiais de cargas repetidas com variação de teores de umidade, para simular situações reais presenciadas no campo. Foram realizados ensaios in situ de DCP (Dynamic Cone Penetrometer) e LWD (Light Weight Deflectometer). Em um pavimento ferroviário experimental monitorado em tanque-teste foram realizados ensaios de LWD para verificar a profundidade de influência e correlação dos resultados deste ensaio com o MR. De posse de todas informações geométricas e geotécnicas foram realizadas análises de tensões e deformações em 15 pontos no pavimento do trecho analisado, por modelagem computacional no software SysTrain. Através da análise mecanística do pavimento, pôde-se identificar trechos críticos. Os pontos 26 e 38 alcançaram os maiores valores de deflexão do pavimento, e os pontos 2, 38, 39 e 40, os quais apresentaram menores valores de MR, foram os pontos que expuseram valores de tensão vertical acima dos valores admissíveis para a camada de subleito. Portanto, notou-se necessidade de adoção de diferentes estratégias de manutenção nestes trechos, priorizando a infraestrutura e obras de drenagem. Palavras-chave: pavimento ferroviário, análise mecanística de pavimentos, LWD, DCP.
... As shown in Table 2, we list these indicators in some countries, by collecting and analysing compaction requirements in related specifications in China, Japan, Germany and France, i.e. Chinese (ÁKMI Kht, 1995;Lietuvos automobilių kelių direkcija, 1995;Zorn instruments, 2004;Tompai, 2008;Ustinovičius, 2015;Mikolainis et al., 2016;Niu Linxin and Li Yijie, 2017 ...
... Rezultati eksperimentalnih ispitivanja pokazuju da postoji dobra korelacija između rezultata ispitivanja prenosivim deflektometrom s padajućim teretom (PFWD) i standardnim deflektometrom s padajućim teretom (FWD). Tompai[25]je proveo usporednu analizu statičke i dinamičke metode. Ukratko je prikazana i opravdana mogućnost pouzdane konverzije između vrijednosti dvaju dinamičkih modula (E vd , E d ) dobivene uporabom deflektometra s padajućim teretom i statičkog modula E 2 . ...
Article
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U ovom radu prikazan je odnos između statičkog i dinamičkog deformacijskog modula, te je uspostavljena korelacija između fizičkih svojstava i pokazatelja nosivosti sloja kolničke konstrukcije za zaštitu od smrzavanja. Prikazani su korekcijski koeficijenti dinamičkih mjerenja u odnosu na statička očitanja. Rezultati pokazuju da u odsutnosti statičkog mjernog uređaja mogu se statička očitanja zamijeniti očitanjima bilo kojih od tri predstavljene vrste dinamičkih uređaja, te na taj način odrediti nosivost sloja kolničke konstrukcije za zaštitu od smrzavanja.
... Tompai [25] conducted a comparative analysis of the static method (B & C Small -Plate Device) and dynamic method (light falling weight deflectometer, LFWD). The possibility of reliable conversion between the values of two dynamic moduli (E vd , E d ) obtained by using the LFWD and the static modulus E 2 is briefly presented and justified. ...
Article
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The relationship between the static and dynamic deflection modulus is presented in the paper, and a correlation between the FBL physical and strength indicators is determined. The correction coefficients of dynamic measurements, as related to static beam readings, are presented. The results show that, in the absence of a static beam, static beam readings can be replaced by the readings of any of the three analysed dynamic devices, and the FBL strength can thus be measured. 2019 © Union of Croatian Civil Engineers and Technicians. All Rights Reserved.