Статті в журналах: "Penetrometers Calibration"

1

MY, Kasali, Olla OO, D. James, MB Makanjuola, and IE Ahaneku. "CALIBRATION OF A MANUAL CONE PENETROMETER USING A DIGITAL PENETROLOGGER." American Journal of Agricultural Science, Engineering, and Technology 1, no. 3 (March 29, 2017): 10–17. http://dx.doi.org/10.54536/ajaset.v1i3.23.

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Cone penetrometers standardized by American Standards for Agricultural Engineering (ASAE) have been major instruments for investigating and quantifying soil compaction. However, the continuous use of penetrometers often introduces errors to the Cone Index (CI) readings obtained from the instruments over time. An ASAE calibrated digital cone penetrometer and a manual penetrometer were tested on a sandy clay loamy soil at the National Centre for Agricultural Mechanization (NCAM), Ilorin, Nigeria; using the ASAE small cone. The CI readings obtained for the two penetrometers were subjected to a statistical t-test. The results showed that the sensitivity of the manual cone penetrometer is comparable to that of the digital penetrologger at depths greater than 12cm as the mean difference showed no significant difference at this depth. However, at depths 0-11cm, there was significant difference in their mean difference; this shows the relative insensitivity of the manual cone penetrometer. The calibration results also showed that the continuous use of the manual cone penetrometer will require a multiplying facto r of 1.165 to get a CI reading close to ideal. Improvement on the manual cone penetrometer will also assist in obtaining CI readings after tillage operations.

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2

Parkin, A. A. "Calibration of cone penetrometers." International Journal of Rock Mechanics and Mining Sciences & Geomechanics Abstracts 27, no. 2 (April 1990): A91. http://dx.doi.org/10.1016/0148-9062(90)95076-d.

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3

Shrivastava, Abhay K. "Development and calibration of radio-isotope cone penetrometers." Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment 539, no. 1-2 (February 2005): 421–26. http://dx.doi.org/10.1016/j.nima.2004.09.044.

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4

Wesley, L. D. "Interpretation of calibration chamber tests involving cone penetrometers in sands." Géotechnique 52, no. 4 (May 2002): 289–93. http://dx.doi.org/10.1680/geot.2002.52.4.289.

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5

Salgado, Rodrigo, and Monica Prezzi. "Penetration Rate Effects on Cone Resistance: Insights From Calibration Chamber and Field Testing." Soils and Rocks 37, no. 3 (September 1, 2014): 233–42. http://dx.doi.org/10.28927/sr.373233.

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Cone penetration in mixed or intermediate soils (soils containing mixtures of sand, silt and clay) is neither fully drained nor fully undrained at the standard cone penetration rate of 20 mm/s. Considerable research, mainly relying on centrifuge tests, has been undertaken to quantify the effects of penetration rate (and thus partial drainage) on cone resistance. In this paper, the effects of penetration rate on cone resistance in saturated clayey soils were investigated by performing field tests and miniature cone penetration tests in a calibration chamber. The field tests were performed at sites especially selected to span the range of drainage conditions from fully drained to fully undrained. The calibration chamber tests, using both conical and flat-tip penetrometers, were performed at different penetration rates in two specimens prepared by mixing kaolin clay and sand with different mixing ratios and one-dimensionally consolidateding the mixtures. A correlation between cone resistance and drainage conditions is established based on the cone penetration test results. The transitions from no drainage to partial drainage and from partial drainage to full drainage are defined as a function of penetration rate normalized with respect to the penetrometer diameter and the coefficient of consolidation.

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6

Straż, Grzegorz. "Preliminary investigations of organics soil in a new calibration chamber with the use of the FVT and DPL probe." E3S Web of Conferences 49 (2018): 00109. http://dx.doi.org/10.1051/e3sconf/20184900109.

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The proposal of investigations of soft organic soils in a new calibration chamber performed at the Rzeszow University of Technology has been presented in this paper. The unique feature of this chamber is the possibility of simultaneous soil testing with the use of two penetrometers: FVT (Field Vane Test) and DPL (Dynamic Probing Light). It has been possible due to the large size of the cylindrical soil sample: 62.5 cm in diameter and max. 80 cm high. Additionally, a construction with a new calibration chamber has been described, concerning potential capabilities and restrictions when conducting researches. The presented calibration chamber ensures the stability of the parameters set during the tests, which allows one to compare the test results and search for the relationship between the analyzed parameters. Shear strength from the FVT test was adopted as reference. The results of preliminary research were presented and a detailed research plan was prepared, which will be implemented in the next stages of the investigations.

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7

Ross, Robert, Avinash Baji, and Dean Barnett. "Inner Profile Measurement for Pipes Using Penetration Testing." Sensors 19, no. 2 (January 10, 2019): 237. http://dx.doi.org/10.3390/s19020237.

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Penetration testing has been used to measure material properties for over fifty years. Currently, it is under-utilised as a contemporary scientific and engineering tool for investigating the condition of pipes whose inner surface has been exposed to chemical attack. We describe the design, development and calibration of a portable probe which uses a penetrative strain gauge load cell to measure where the semi-solid surface starts and stops within a pipe. We also describe the results of field tests of the probe in concrete sewers, affected by internal corrosion, where the probe proved to be a fast and reliable method for collecting pipe profile information. The results indicate significant benefit in the use of penetrometers to perform concrete sewer condition assessment.

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8

Been, K., B. E. Lingnau, J. H. A. Crooks, and B. Leach. "Cone penetration test calibration for Erksak (Beaufort Sea) sand." Canadian Geotechnical Journal 24, no. 4 (November 1, 1987): 601–10. http://dx.doi.org/10.1139/t87-074.

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Interpretation of the cone penetration test in sands is generally based on empirical calibrations from tests in large-diameter calibration chambers. Although interpretation of these calibration data for clean sands in terms of the state parameter is expected to be broadly applicable to other sands, material-specific correlations are desirable for many projects. This paper describes a series of calibration chamber tests carried out on a sand dredged from the Beaufort Sea for construction of artificial islands. This Erksak sand is a uniformly graded, subrounded medium-grained sand with a fines content of 3–6%. The testing chamber described is 1.4 m in diameter, and allows independent control of vertical, horizontal, and back pressures on the sand sample. Samples of the sand were prepared by moist compaction to preserve the fines content, and then back pressure saturated.The chamber test data are presented and confirm that the Erksak sand fits the general trends observed for other sands very well. A method is also described that allows the interpretation to be consistent, even in the event that nonuniform void ratios occur in the samples. Measurements of horizontal stress behind the cone tip, which is a new development in cone penetrometer testing, are also presented. Key words: cone penetrometer, sands, in situ tests, state, calibration chamber, horizontal stress measurement.

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9

Kurup, Pradeep U., and Mehmet T. Tumay. "Calibration of a Miniature Cone Penetrometer for Highway Applications." Transportation Research Record: Journal of the Transportation Research Board 1614, no. 1 (January 1998): 8–14. http://dx.doi.org/10.3141/1614-02.

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The electronic cone penetrometer is an important in situ investigation tool of choice for site characterization. Application of this proven concept of the cone penetration test (CPT) to highway design and construction control by miniaturization is described. A miniature cone penetrometer with a projected cone area of 2 cm2 has been developed and implemented in a continuous intrusion miniature cone penetration test system (CIMCPT). This device may be used for rapid, accurate, and economical characterization of sites and to determine engineering soil parameters needed in the design of pavements, embankments, and earth structures. The miniature cone penetration test (MCPT) gives finer details than the standard 10-cm2 cross-sectional area reference cone penetrometer. This makes the MCPT attractive for subgrade characterization, quality-control assessment, compaction control of embankments, and assessment of ground improvement effectiveness for transportation infrastructure. In situ calibration of the CIMCPT system was conducted at a highway embankment site in Baton Rouge, Louisiana. MCPT penetration profiles were compared with those obtained by using the standard cone penetrometer at the same site. The tip resistance of the MCPT was 10 percent higher than that of the reference CPT. The sleeve friction and friction ratio of the reference CPT were higher than that of the MCPT by 12 and 23 percent, respectively. Calibration was also performed to determine empirical cone factors required for estimating undrained shear strength from MCPT data.

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10

Konrad, J. M. "In situ tests in a sand dune." Canadian Geotechnical Journal 28, no. 2 (April 1, 1991): 304–9. http://dx.doi.org/10.1139/t91-036.

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A field testing program using an electric piezocone penetrometer (CPTU) and a flat dilatometer (DMT) probe was carried out in a sand dune. The analysis of the field data in terms of relative density using current empirical correlations showed that significant differences were obtained at this site. It is suggested that any empirical correlation between relative density and CPT or DMT data obtained from calibration chambers should only be used for a sand that has the same slope of the steady-state line as the sand used in the calibration tests. Key words: sand, in situ density, field investigation, piezocone penetrometer, flat dilatometer, steady state.

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11

Houlsby, G. T., and R. Hitchman. "Calibration chamber tests of a cone penetrometer in sand." Géotechnique 38, no. 1 (March 1988): 39–44. http://dx.doi.org/10.1680/geot.1988.38.1.39.

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12

Houlsby, G. T., and R. Hitchman. "Discussion: Calibration chamber tests of a cone penetrometer in sand." Géotechnique 39, no. 4 (December 1989): 727–31. http://dx.doi.org/10.1680/geot.1989.39.4.727.

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13

Damavandi-Monfared, Sepideh, and Abouzar Sadrekarimi. "Development of a Miniature Cone Penetrometer for Calibration Chamber Testing." Geotechnical Testing Journal 38, no. 6 (May 29, 2015): 20150036. http://dx.doi.org/10.1520/gtj20150036.

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14

Zhang, Yu, Zhongtao Wang, and Huafu Pei. "Development of a novel lateral resistance measurement penetrometer for pipe–soil interaction centrifuge model test." International Journal of Distributed Sensor Networks 14, no. 11 (November 2018): 155014771881564. http://dx.doi.org/10.1177/1550147718815647.

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Offshore pipelines are exposed to potential submarine landslides. It is difficult to measure the impact forces exerted on a pipeline induced by submarine landslides because the upper seabed is very soft and an impact angle exists in practice. Current laboratory experiments are limited on measuring the normal force exerted on pipeline by the slides. This article describes the feasibility and performance of a novel penetrometer, which is designed to measure impact forces of submarine landslides on offshore pipeline including both the normal and frictional forces from variable impact angle in centrifuge test, termed as the lateral resistance measurement penetrometer. The calibration procedure for this particular version is illustrated in detail and the reliability and feasibility of the lateral resistance measurement penetrometer are preliminarily confirmed by an experimental study. Pipe–soil interaction centrifuge tests were subsequently performed on a normally consolidated kaolin sample with 40 g level conducted in Dalian University of Technology drum centrifuge to investigate the effect of incident angles on the impact forces exerted by submarine landslides on a pipeline. The impact forces deduced from the lateral resistance measurement penetrometer are analysed in comparison with published results. The lateral resistance measurement penetrometer is a potentially valuable device to measure the interaction force between submarine landslides and offshore pipeline, cables and other subsea facilities in small-scale centrifuge models.

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15

Roy, Marius, and Luc Tanguay. "Capacité portante de pieux isolés dans les argiles sensibles: étude de cas par la méthode pénétrométrique." Canadian Geotechnical Journal 26, no. 3 (August 1, 1989): 375–84. http://dx.doi.org/10.1139/t89-052.

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The penetrometer test has been used to determine the bearing capacity of driven and jacked-in single piles in sensitive clays. The cases presented in this paper were carried out on two sites with steel, concrete, and wooden piles. The bearing capacities calculated on the basis of the results of penetrometer tests show that this approach has a good potential and at the same time is simple and fast. It has been possible to obtain a calibration by a comparison with the loading tests carried out on each of the piles. Taking into account the low strength of some of our clays, experience has to be gained in order to adapt the lateral unit friction curves to our clays. This approach also has the advantage of allowing the determination of the bearing capacity of wooden piles and of taking into account the conical effect when determining the lateral friction component. Key words: penetrometer test, piles, bearing capacity, cohesive soils, point resistance, lateral friction, steel, concrete, wood. [Journal translation]

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16

Knodel, PC, YB Acar, AJ Puppala, and RK Seals. "Calibration of a Dynamic Penetrometer for Compaction Quality Control of Boiler Slag." Geotechnical Testing Journal 14, no. 1 (1991): 56. http://dx.doi.org/10.1520/gtj10191j.

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17

Gamez, Joseph A., and Scott M. Olson. "Compressibility-Based Interpretation of Cone Penetrometer Calibration Chamber Tests and Corresponding Boundary Effects." Geotechnical Testing Journal 45, no. 4 (June 6, 2022): 20210129. http://dx.doi.org/10.1520/gtj20210129.

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18

Butlanska, Joanna, Marcos Arroyo, and Antonio Gens. "Steady state of solid-grain interfaces during simulated CPT." Studia Geotechnica et Mechanica 35, no. 4 (December 1, 2013): 13–22. http://dx.doi.org/10.2478/sgem-2013-0034.

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Abstract It has recently been shown (Arroyo et al. [1]) that 3D DEM models are able to reproduce with reasonable accuracy the macroscopic response of CPT performed in calibration chambers filled with sand. However, the cost of each simulation is an important factor. Hence, to achieve manageable simulation times the discrete material representing the sand was scaled up to sizes that were more typical of gravel than sand. A side effect of the scaled-up discrete material size employed in the model was an increased fluctuation of the macro-response that can be filtered away to observe a macroscopic steady-state cone resistance. That observation is the starting point of this communication, where a series of simulations in which the size ratio between penetrometer and particles is varied are systematically analyzed. A micromechanical analysis of the penetrometer-particle interaction is performed. These curves reveal that a steady state is arrived also at the particle-cone contact level. The properties of this dynamic interface are independent of the initial density of the granular material.

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19

White, David J., Pavana Vennapusa, Erol Tutumluer, William (Bill) Vavrik, Maziar Moaveni, and Steven Gillen. "Spatial Verification of Modulus for Pavement Foundation System." Transportation Research Record: Journal of the Transportation Research Board 2672, no. 52 (June 30, 2018): 333–46. http://dx.doi.org/10.1177/0361198118782266.

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This paper presents the results of a field study recently completed on an Illinois Tollway construction project, in which intelligent compaction (IC) measurements were calibrated on site with in situ elastic modulus (E), resilient modulus (Mr), modulus of subgrade reaction ( k), and California bearing ratio (CBR) testing. The purpose of the field calibration was to generate geo-referenced spatial modulus maps that can be used for field verification of design input parameters. E values were obtained using light weight deflectometer (LWD), stress-dependent Mr values and static k values were obtained using automated plate load testing (APLT), and CBR values were obtained using a dynamic cone penetrometer (DCP). The IC measurements were obtained using a vibratory smooth drum roller outfitted with an index measurement value system, and a roller outfitted with a retrofit kit programmed to produce validated integrated compaction (VIC) measurements through a process of field calibration. Results showed that VIC based calibration can produce correlations with R2 > 0.9 with Mr and k values, and the VIC maps can be reliably used for quality assurance/verification testing. Although the index based IC measurement values showed statistically significant relationships, the R2 values were lower (<0.6). An implementation framework that emphasizes an independent certification approach for field calibration is being developed based on these test results for the Illinois Tollway, to aid in the effective implementation of the modulus-based mapping approach for pavement design field verification.

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20

Finn, P. S., R. M. Nisbet, and P. G. Hawkins. "Guidance on Pressuremeter, Flat Dilatometer and Cone Penetration Testing." Geological Society, London, Engineering Geology Special Publications 2, no. 1 (1986): 223–33. http://dx.doi.org/10.1144/gsl.1986.002.01.42.

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AbstractBS 5930 provides little guidance on the specification, practice and interpretation of pressuremeter, flat dilatometer and cone penetration tests. This paper describes certain key elements in the successful use of such tests which are frequently overlooked in practice. The different types of pressuremeter available in the United Kingdom are reviewed and the importance of care in the installation of pressuremeters of all types is highlighted. The principles of operation of the flat dilatometer are presented and comments made on the interpretation and application of results. Cone penetrometer testing and the types of equipment available are also discussed. The necessity for frequent and thorough calibration of all testing devices is emphasised and requirements for data presentation and reporting of these in situ tests are indicated.

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21

Topp, G. C., D. R. Lapen, M. J. Edwards, and G. D. Young. "Laboratory Calibration, In-Field Validation and Use of a Soil Penetrometer Measuring Cone Resistance and Water Content." Vadose Zone Journal 2, no. 4 (November 1, 2003): 633–41. http://dx.doi.org/10.2113/2.4.633.

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22

Topp, G. C., D. R. Lapen, M. J. Edwards, and G. D. Young. "Laboratory Calibration, In-Field Validation and Use of a Soil Penetrometer Measuring Cone Resistance and Water Content." Vadose Zone Journal 2, no. 4 (2003): 633. http://dx.doi.org/10.2136/vzj2003.0633.

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23

Topp, G. C., D. R. Lapen, M. J. Edwards, and G. D. Young. "Laboratory Calibration, In-Field Validation and Use of a Soil Penetrometer Measuring Cone Resistance and Water Content." Vadose Zone Journal 2, no. 4 (November 2003): 633–41. http://dx.doi.org/10.2136/vzj2003.6330.

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24

Mitchell, M. R., R. E. Link, and Xinzhuang Cui. "Development and Calibration of an Electronic Miniature Cone Penetrometer for Design of Small Piles in Silty Clays." Journal of Testing and Evaluation 39, no. 5 (2011): 103432. http://dx.doi.org/10.1520/jte103432.

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25

Allman, Michal, Martin Jankovský, Zuzana Allmanová, and Valéria Messingerová. "Comparison of the gravimetric sampling and impedance methods for measuring soil moisture content." Forestry Studies 62, no. 1 (June 1, 2015): 14–25. http://dx.doi.org/10.1515/fsmu-2015-0002.

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Abstract This paper was focused on determining whether gravimetric sampling and impedance method of measuring soil moisture content provided different results and if they did, what was the size of the differences between particular methods on rendzinas and cambisols. The means of moisture content should be equal when using both methods on similar spots. During the research, an Eijkelkamp Penetrologger penetrometer equipped with impedance probes and gravimetric sampling cylinders from Eijkelkamp were used. The samples were taken from the undisturbed stand, ruts, and the centre of the skid trail. The impedance probes were inserted six centimetres deep into the soil. Soil samples were taken from similar depth in order to calculate the moisture content through the gravimetric method. 138 measurements were carried out for each method. The minimal difference of moisture contents measured by individual methods was 0.01%, maximal difference was 22.06%, and on average it was 7.42%. Oneway ANOVA was used for first stage analysis of the statistical sample. It proved that the differences between measurements were statistically significant in two out of three considered stands. Tukey’s HSD test was used to identify which data groups contributed to refuting the aforementioned hypothesis. The test showed that in one stand all relevant pairs of data were significantly different, while in the other stand only data pairs from the ruts were significantly different. The calibration method provided by the producers did not refine the accuracy of the impedance probes sufficiently and different calibration procedures have to be used.

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26

Foray, P., L. Balachowski, and J. L. Colliat. "Bearing capacity of model piles driven into dense overconsolidated sands." Canadian Geotechnical Journal 35, no. 2 (April 1, 1998): 374–85. http://dx.doi.org/10.1139/t97-082.

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Model piles were driven into dense siliceous sand samples and tested in a large calibration chamber. Axial tension and compression tests were performed on open-ended pipe piles. The objective of this research was to study the effect of overconsolidation on the bearing capacity of piles driven into dense sands representative of North Sea soil conditions. Emphasis was put on points of interest for the offshore petroleum industry in particular: dense to very dense normally consolidated (NC) and overconsolidated (OC) sands, unit end bearing and unit skin friction capacities, and comparison with tip resistances from cone penetration tests. Design parameters are proposed for computing the axial bearing capacity of piles driven into dense to very dense siliceous sands. They are compared with those given in the current American Petroleum Industry's Recommended Practice 2A document. A relationship between CPT cone resistance and ultimate unit end bearing and skin friction capacities of piles is also proposed.Key words: model test, dense sand, offshore pile driving, axial capacity, end bearing, skin friction, design parameters, cone penetrometer.

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27

Pei, Xiaoshuai, Kenneth Sudduth, Kristen Veum, and Minzan Li. "Improving In-Situ Estimation of Soil Profile Properties Using a Multi-Sensor Probe." Sensors 19, no. 5 (February 27, 2019): 1011. http://dx.doi.org/10.3390/s19051011.

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Optical diffuse reflectance spectroscopy (DRS) has been used for estimating soil physical and chemical properties in the laboratory. In-situ DRS measurements offer the potential for rapid, reliable, non-destructive, and low cost measurement of soil properties in the field. In this study, conducted on two central Missouri fields in 2016, a commercial soil profile instrument, the Veris P4000, acquired visible and near-infrared (VNIR) spectra (343–2222 nm), apparent electrical conductivity (ECa), cone index (CI) penetrometer readings, and depth data, simultaneously to a 1 m depth using a vertical probe. Simultaneously, soil core samples were obtained and soil properties were measured in the laboratory. Soil properties were estimated using VNIR spectra alone and in combination with depth, ECa, and CI (DECS). Estimated soil properties included soil organic carbon (SOC), total nitrogen (TN), moisture, soil texture (clay, silt, and sand), cation exchange capacity (CEC), calcium (Ca), magnesium (Mg), potassium (K), and pH. Multiple preprocessing techniques and calibration methods were applied to the spectral data and evaluated. Calibration methods included partial least squares regression (PLSR), neural networks, regression trees, and random forests. For most soil properties, the best model performance was obtained with the combination of preprocessing with a Gaussian smoothing filter and analysis by PLSR. In addition, DECS improved estimation of silt, sand, CEC, Ca, and Mg over VNIR spectra alone; however, the improvement was more than 5% only for Ca. Finally, differences in estimation accuracy were observed between the two fields despite them having similar soils, with one field demonstrating better results for all soil properties except silt. Overall, this study demonstrates the potential for in-situ estimation of profile soil properties using a multi-sensor approach, and provides suggestions regarding the best combination of sensors, preprocessing, and modeling techniques for in-situ estimation of profile soil properties.

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Polom, U., I. Arsyad, and H. J. Kümpel. "Shallow shear-wave reflection seismics in the tsunami struck Krueng Aceh River Basin, Sumatra." Advances in Geosciences 14 (January 2, 2008): 135–40. http://dx.doi.org/10.5194/adgeo-14-135-2008.

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Abstract. As part of the project "Management of Georisk" (MANGEONAD) of the Federal Institute for Geosciences and Natural Resources (BGR), Hanover, high resolution shallow shear-wave reflection seismics was applied in the Indonesian province Nanggroe Aceh Darussalam, North Sumatra in cooperation with the Government of Indonesia, local counterparts, and the Leibniz Institute for Applied Geosciences, Hanover. The investigations were expected to support classification of earthquake site effects for the reconstruction of buildings and infrastructure as well as for groundwater exploration. The study focussed on the city of Banda Aceh and the surroundings of Aceh Besar. The shear-wave seismic surveys were done parallel to standard geoengineering investigations like cone penetrometer tests to support subsequent site specific statistical calibration. They were also partly supplemented by shallow p-wave seismics for the identification of (a) elastic subsurface parameters and (b) zones with abundance of groundwater. Evaluation of seismic site effects based on shallow reflection seismics has in fact been found to be a highly useful method in Aceh province. In particular, use of a vibratory seismic source was essential for successful application of shear-wave seismics in the city of Banda Aceh and in areas with compacted ground like on farm tracks in the surroundings, presenting mostly agricultural land use areas. We thus were able to explore the mechanical stiffness of the subsurface down to 100 m depth, occasionally even deeper, with remarkably high resolution. The results were transferred into geotechnical site classification in terms of the International Building Code (IBC, 2003). The seismic images give also insights into the history of the basin sedimentation processes of the Krueng Aceh River delta, which is relevant for the exploration of new areas for construction of safe foundations of buildings and for identification of fresh water aquifers in the tsunami flooded region.

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29

Jayawardane, NS, and J. Blackwell. "Use of the neutron method in assessing the changes in soil strength of undisturbed and ameliorated transitional red-brown earths during soil drying cycles." Soil Research 28, no. 2 (1990): 167. http://dx.doi.org/10.1071/sr9900167.

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The relationships between penetrometer resistance (qp) and volumetric moisture content (�v) measured using the neutron method in an undisturbed transitional red-brown earth and after an~elioration by application of surface gypsum and slotted gypsum were examined. A very highly significant (P < 0.001) negative correlation was obtained between qp and �v in all treatments. The low r2 values of the regressions were attributed to heterogeneity in strength characteristics of the soil matrix, due to presence of cracks and macropores and the associated wetting patterns. The qp at any given e, was significantly reduced in the slots with lower bulk density compared to the undisturbed soil. The differences in qp- �v relationship of the undisturbed part of the soil under different ameliorative practices were attributed to changes in the swelling characteristic, and hence in the bulk density at any given �v of the undisturbed soil, caused by the presence of gypsum and the slots. Regression equations between qp and neutron count rate (n) for the undisturbed soil and for the slots were developed by combining the qp on �v relationships with the neutron meter calibration for �v measurements. The use of these regression equations and measured n values to predict changes in soil strength profiles during a wheat crop drying cycle in an undisturbed and ameliorated transitional red-brown earth was evaluated on another experimental site. There were no significant differences between the predicted and measured qp values in the non-ameliorated soil and the gypsum-slotted soil. Significant differences were observed between the predicted and measured qp values in the surface gypsum applied soil. The study shows the potential for using the neutron method as a convenient in-situ field technique to predict qp profile changes, preferably using qp on n relationships developed at the experimental site.

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30

Yan, Qina, Haruko Wainwright, Baptiste Dafflon, Sebastian Uhlemann, Carl I. Steefel, Nicola Falco, Jeffrey Kwang, and Susan S. Hubbard. "A hybrid data–model approach to map soil thickness in mountain hillslopes." Earth Surface Dynamics 9, no. 5 (October 11, 2021): 1347–61. http://dx.doi.org/10.5194/esurf-9-1347-2021.

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Abstract. Soil thickness plays a central role in the interactions between vegetation, soils, and topography, where it controls the retention and release of water, carbon, nitrogen, and metals. However, mapping soil thickness, here defined as the mobile regolith layer, at high spatial resolution remains challenging. Here, we develop a hybrid model that combines a process-based model and empirical relationships to estimate the spatial heterogeneity of soil thickness with fine spatial resolution (0.5 m). We apply this model to two aspects of hillslopes (southwest- and northeast-facing, respectively) in the East River watershed in Colorado. Two independent measurement methods – auger and cone penetrometer – are used to sample soil thickness at 78 locations to calibrate the local value of unconstrained parameters within the hybrid model. Sensitivity analysis using the hybrid model reveals that the diffusion coefficient used in hillslope diffusion modeling has the largest sensitivity among all input parameters. In addition, our results from both sampling and modeling show that, in general, the northeast-facing hillslope has a deeper soil layer than the southwest-facing hillslope. By comparing the soil thickness estimated between a machine-learning approach and this hybrid model, the hybrid model provides higher accuracy and requires less sampling data. Modeling results further reveal that the southwest-facing hillslope has a slightly faster surface soil erosion rate and soil production rate than the northeast-facing hillslope, which suggests that the relatively less dense vegetation cover and drier surface soils on the southwest-facing slopes influence soil properties. With seven parameters in total for calibration, this hybrid model can provide a realistic soil thickness map with a relatively small amount of sampling dataset comparing to machine-learning approach. Integrating process-based modeling and statistical analysis not only provides a thorough understanding of the fundamental mechanisms for soil thickness prediction but also integrates the strengths of both statistical approaches and process-based modeling approaches.

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31

"Calibration of a dynamic penetrometer for compaction quality control of boiler slag." International Journal of Rock Mechanics and Mining Sciences & Geomechanics Abstracts 28, no. 5 (September 1991): 294. http://dx.doi.org/10.1016/0148-9062(91)90314-c.

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32

Moghaddam, Rozbeh. "Resistance Factors at Serviceability Limit State Using the Texas Cone Penetrometer as the Predictive Model." DFI Journal The Journal of the Deep Foundations Institute 15, no. 1 (April 30, 2021). http://dx.doi.org/10.37308/dfijnl.20200409.216.

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This study presents the development and calibration of resistance factors for the serviceability limit state (SLS) condition (φSLS) used in the load and resistance factor design (LRFD) of deep foundations. The performance function was established based on load corresponding to tolerable displacement (Qδtol) and design load (Qd). A dataset of published full-scale load tests including projects from Texas, Missouri, Arkansas, Louisiana, and New Mexico was compiled and consisted of 60 load test cases comprising 33 driven piles and 27 drilled shafts. Resistance factors for SLS conditions were calibrated for tolerable displacements using both the Monte Carlo simulation (MCS) and the First Order Second Moment (FOSM) approaches. From the calibration study, resistance factors at SLS conditions were obtained ranging from 0.33 to 0.62 using FOSM method and 0.37 to 0.67 using the MCS for driven piles. In the case of drilled shafts, SLS resistance factors ranged from 0.37 to 0.77 following the FOSM method and 0.41 to 0.86 based on MCS.

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33

Lehane, Barry M., Varvara Zania, Shiao Huey Chow, and Mathias Jensen. "Interpretation of centrifuge CPT data in normally consolidated silica and carbonate sands." Géotechnique, April 19, 2022, 1–10. http://dx.doi.org/10.1680/jgeot.21.00177.

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This paper presents the results from a systematic investigation into the effects of stress level, penetrometer diameter, penetration depth and relative density on the end resistance (qc) measured in centrifuge-scale cone penetration tests (CPTs) in a variety of normally consolidated siliceous and carbonate sands. Simple empirical formulations are developed that provide a good description of all measurements and that are consistent with expressions developed in calibration chambers and at field scale. The formulations address the significant discrepancies seen between centrifuge and field scale qc profiles and enable development of qc-based correlations for centrifuge tests that are applicable at full scale, as well as providing a means to interpret very shallow CPTs in the field.

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Yasmine Shafiq, Stuart Haigh, Rochelle Holm, and Alison Parker. "Re-evaluating the strength of pit-latrine faecal sludge from dynamic cone penetrometer test data." Water SA 46, no. 4 October (October 27, 2020). http://dx.doi.org/10.17159/wsa/2020.v46.i4.9077.

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In 2017, 55% of the global population were without safely managed sanitation services. On-site sanitation solutions, such as pit latrines, provide the majority of sanitation coverage across developing countries. Appropriate technologies are required in order to safely empty these latrines without damage to people or the environment. The design of appropriate emptying technologies can be hampered by a lack of knowledge of the mechanical properties of the waste, such as its strength. This paper will develop a calibration for a dynamic cone penetrometer to give accurate measurements of faecal sludge strength against a standard scale, rendering existing data comparable. It will be shown that the maximum shear strengths of faecal sludge found in practice are substantially greater than those previously reported; some pit latrines contain faecal sludge with strength values of 5–20 kPa at the surface, and exceeding 80 kPa at depth.

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Kang, Mingu, Issam I. A. Qamhia, Erol Tutumluer, Won-Taek Hong, and Jeb S. Tingle. "Bender Element Field Sensor for the Measurement of Pavement Base and Subbase Stiffness Characteristics." Transportation Research Record: Journal of the Transportation Research Board, March 5, 2021, 036119812199835. http://dx.doi.org/10.1177/0361198121998350.

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Layer modulus values are important input parameters in mechanistic pavement design and evaluation methods. Direct measurement of the stiffness characteristics of pavement base/subbase has been a challenging task. Nondestructive testing methods that are commonly used based on surface deflection measurements not only require a backcalculation process, but also have limitations on measuring local stiffness within the layer. This paper presents the result of a recent research effort at the University of Illinois aimed to develop a new sensor for the direct measurement of the in-situ moduli of constructed unbound pavement layers. The new sensor employs bender element (BE) shear wave transducers embedded in a granular base/subbase to evaluate the layer modulus from shear wave velocity measured at any depth and any orientation. To provide appropriate protection for the BE sensor and its cable connections, a stainless-steel cable guide, a sensor protection module, and a protection cover for the sensor were designed and optimized. A laboratory calibration box containing sand-sized crushed aggregates was used in the development stage of the BE sensor design. The BE sensor results were also studied for a typical dense-graded base course aggregate commonly used in Illinois. Finally, the BE sensor was installed in a field trial in newly constructed airport pavement test sections, and its layer modulus measurements were compared with results estimated from Dynamic Cone Penetrometer testing. The new BE field sensor has proven to be a viable direct measurement technique in transportation geotechnics applications to monitor stiffness characteristics of pavement granular base/subbase layers.

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