Local Displacement Transducer with Miniature Position Encoder

Witowski, Marcin

doi:10.1520/gtj20170016

Cited by 9 publications

(9 citation statements)

References 31 publications

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“…Figure 2 shows the general division of internal deformation measurement systems, based on [ 3 ], and referred to the inventors of the presented methods and the researchers who made a significant contribution to the next development of the technology [ 4 , 5 , 6 , 7 , 8 , 9 , 10 , 11 , 12 , 13 , 14 , 15 , 16 , 17 , 18 , 19 , 20 , 21 , 22 , 23 , 24 , 25 , 26 , 27 , 28 , 29 , 30 , 31 , 32 , 33 , 34 , 35 , 36 , 37 , 38 , 39 , 40 ].…”

Section: Modern Measuring Systemsmentioning

confidence: 99%

Modern Displacement Measuring Systems Used in Geotechnical Laboratories: Advantages and Disadvantages

Jastrzębska

2021

Sensors

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The paper presents the contemporary displacement measurement systems used in geotechnical laboratories during the determination of soil precise mechanical parameters, e.g., the shear modules G: initial and in the range of small and very small strains. In the laboratory, researchers use standard sensors for measuring deformation, pressure, and force as well as modern measuring systems such as linear variable differential transformers (LVDT), proximity transducers (PT), magnetic encoder sensors with fiber Bragg grating (FBG), or methods based on laser or X-ray measurement. None of the measurements are universal and their use depends on the type of soil (cohesive, non-cohesive), its condition (loose or dense, stiff or very soft), and its characteristic properties (e.g., organic soil, swelling soil). This study points out the interesting equipment solutions and presents the guidelines for selecting appropriate methods of deformation measurement.

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Section: Modern Measuring Systemsmentioning

confidence: 99%

Modern Displacement Measuring Systems Used in Geotechnical Laboratories: Advantages and Disadvantages

Jastrzębska

2021

Sensors

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“…The test was carried out on a sample of quartz sand from the Biała Góra site, more information about basic parameters of used soil are presented in Table 1 and article [10]. The sample was formed by dry pluviation technique, with relative density Dr, of 85 %.…”

Section: Soilmentioning

confidence: 99%

“…However, these methods require specialized and expensive measuring devices and have low resolution and accuracy. A new type of system of sensors for measuring local displacements based on an encoder has been developed [10]. This system made it possible to measure only axial deformations of soil samples.…”

Section: Introductionmentioning

confidence: 99%

Local measurements of axial and radial strains using magnetic encoders in triaxial apparatus

Witowski

2019

E3S Web Conf.

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The requirement for implementing local measurements at small strains is well known. Without this type of measurement, it is not possible to accurately identify the soil stiffness characteristics over the entire stiffness degradation curve. The paper presents the results of the use of new sensor based on miniature magnetic encoders for axial and radial deformation measurements in triaxial soil test. Presented results include two types of measurement techniques for radial direction and one for axial deformation.

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“…Generated and received S-and P-waves allow for estimating the Poisson's coefficient and the initial deformation modulus E0 of the tested soil. More details about this equipment and technical information were presented in [7], [12], [62].…”

Section: Reference Laboratory Testmentioning

confidence: 99%

“…Additionally, lowpass filter was used with the frequency of 10 kHz, which helped with the removal of the noise. More details about the procedure and some aspects of measurement were described by Witowski [62]. The basic statistical information concerning selected parameters of the tested soils are presented in table…”

Section: Reference Laboratory Testmentioning

confidence: 99%

Evaluation of Stiffness Degradation Curves from in Situ Tests in Various Soil Types

Godlewski

2018

Archives of Civil Engineering

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Increasingly complex design systems require an individual approach when determining the necessary design parameters. As soils are characterized by strong strain-dependent nonlinearity, test methods used to characterize the subsoil should be carefully selected, in terms of their “sensitivity” as well as suitability for the analyzed type of problem. When direct measurements are not available, while design calculation models require specific parameters, indirect parameter estimation may be used. This approach requires calibration and validation of empirical correlations, based on well documented database of tests and case studies. One of the parameters often used, when analyzing soil-structure interaction problems, is the shear stiffness of the soil and its strain-dependent degradation. The aim of the article is to present the procedure for description and evaluation of soil stiffness based on field tests (CPTU, DMT and SDMT) and a large number of reference curves obtained from laboratory tests (TRX) for selected soil types. On the basis of the given algorithm, it is possible to obtain a stiffness module G0 value at any level of deformation, based on in-situ tests.

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Local Displacement Transducer with Miniature Position Encoder

Cited by 9 publications

References 31 publications

Modern Displacement Measuring Systems Used in Geotechnical Laboratories: Advantages and Disadvantages

Modern Displacement Measuring Systems Used in Geotechnical Laboratories: Advantages and Disadvantages

Local measurements of axial and radial strains using magnetic encoders in triaxial apparatus

Evaluation of Stiffness Degradation Curves from in Situ Tests in Various Soil Types

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