39 results
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2. Calibration of resistance factors for geotechnical seismic design.
- Author
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Naghibi, Farzaneh and Fenton, Gordon A.
- Subjects
EARTHQUAKE resistant design ,SEISMIC testing ,ROAD construction ,BRIDGE design & construction ,SHALLOW foundations ,CALIBRATION ,BRIDGES - Abstract
Copyright of Canadian Geotechnical Journal is the property of Canadian Science Publishing and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)
- Published
- 2019
- Full Text
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3. Calibration of the PM4Sand model for hard-rock mine tailings based on laboratory and field testing results.
- Author
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Contreras, Carlos Andrés, Yniesta, Samuel, Jahanbakhshzadeh, Abtin, and Aubertin, Michel
- Subjects
TAILINGS dams ,CALIBRATION ,TESTING laboratories ,DYNAMIC simulation - Abstract
A comprehensive campaign of laboratory and field tests has been conducted to characterize the behaviour of tailings from a hard-rock mine. Cyclic triaxial, direct simple shear, and triaxial simple shear tests have shown that the contractive tailings are susceptible to liquefaction and that their behaviour is similar to loose sand despite their higher fines' content. To model the behaviour of tailings' impoundments in dynamic simulations, the PM4Sand constitutive model is calibrated based on the dataset presented here. Some of the model parameters are defined based on consolidation and compression tests, while the critical state line (CSL) is defined based on the results of monotonic triaxial and direct simple shear tests. The CSL is lower for tailings than for most natural sands, which is consistent with previous studies. The calibrated model can reproduce reasonably well the monotonic behaviour and provides an excellent fit of the cyclic strength curves measured in the lab at different confining pressures and density index. The results presented in this paper indicate that the PM4Sand model can be used to simulate the cyclic behaviour of low-plasticity, hard-rock tailings. The proposed procedure also provides general guidelines regarding model calibration for other types of tailings. [ABSTRACT FROM AUTHOR]
- Published
- 2023
- Full Text
- View/download PDF
4. Discussion of 'Measurements of suction versus water content for bentonite-sand mixtures'.
- Author
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Haghighi, Ali, Medero, Gabriela M., Marinho, Fernando A.M., and Woodward, Peter K.
- Subjects
CALIBRATION ,BENTONITE ,SAND ,SOLUTION (Chemistry) ,SALT ,SOIL testing ,SOIL matric potential - Published
- 2011
- Full Text
- View/download PDF
5. Application of TDR in compacted clay soils: Issues of dry density, water content range, and calibration.
- Author
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Nachum, Shay, Talesnick, Mark, and Furman, Alex
- Subjects
CLAY soils ,SOIL drying ,CALIBRATION ,SOIL moisture ,DENSITY - Abstract
The paper deals with three issues relevant to the application of TDR methods for monitoring water content in compacted clay soils: (i) the dependence on dry density, (ii) the ability to monitor changes in water content in clay soil approaching saturation, and (iii) difficulties in performing efficient and reliable calibrations. A calibration scheme which inherently controls dry density of the specimen has been developed and applied. The methodology creates continuous calibration curves over a range of volumetric water content from a single test specimen. The new approach has been applied in monitoring the advance of a wetting front through a compacted swelling clay in a laboratory environment. [ABSTRACT FROM AUTHOR]
- Published
- 2023
- Full Text
- View/download PDF
6. Reply to discussion by Haghighi et al. on 'Measurements of suction versus water content for bentonite–sand mixtures'Appears in the Canadian Geotechnical Journal 48(2): 336–337 (2011)
- Author
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T. SchanzT. Schanz, S. S. AgusS.S. Agus, and D. G. FredlundD.G. Fredlund
- Subjects
Accuracy and precision ,Temperature gradient ,Materials science ,Suction ,Soil test ,Filter paper ,Calibration curve ,Calibration ,Geotechnical engineering ,Geotechnical Engineering and Engineering Geology ,Water content ,Civil and Structural Engineering - Abstract
The discussers presented filter paper calibration data measured using the vapour equilibrium technique using a salt solution for suctions greater than 300 kPa and through a pressure plate apparatus, in which the filter papers sandwiched between two soil samples were equilibrated to the induced suction values. The data presented agree well with those obtained by the authors for the matric suction (or the in-contact) filter paper calibration up to about 800 kPa and for the total suction greater than 8000 kPa. It should be noted that the accuracy of the total suction measurement using the noncontact technique reduces as total suction decreases. In contrast, the error of the matric suction measurement using the in-contact filter paper increases with increasing matric suction. The total suction (or the noncontact filter paper) calibration data presented by the authors were obtained for total suctions greater than 4000 kPa. It is thought that the errors associated with the measurement of total suction lower than this value are high and are not only caused by the possible temperature gradient during calibration, but also by the error in preparation of the salt solution involving a small amount of salt. No attempt was made by the authors to induce total suction less than 4000 kPa due to the above-mentioned reasons. However, the data presented in Agus (2005) suggest that an extrapolation to total suction values between 2000 and 4000 kPa is possible, but with a maximum possible error of 860 kPa. The use of this technique for measuring total suction of less than 2000 kPa is not recommended. The discussers have shown that in the suction range from 4000 to 8000 kPa the measured filter paper water contents are lower than those presented by the authors for the same total suction values. Filter papers equilibrated to total suctions within this range will normally undergo a wetting process due to the initially relatively dry filter paper used. The amount of water absorbed by the filter paper during the equilibration period is a function of the equilibration time allowed. Equilibrium is thought to be attained after a relatively long equilibration time and is affected by the temperature fluctuation in the calibration system, or more importantly by the temperature gradient between the salt solution, vapor space, and filter paper. The discussers used a 2 week equilibration time as opposed to a 5 week equilibration time adopted by the authors. It is thought that the discussers’ data would be closer to those obtained by the authors if the same equilibration time had been used. The resulting total suction calibration curve will consequently be different from that obtained for the matric suction measurement. Similarly, the equibration time at high matric suctions (i.e., close to 1500 kPa) is thought to be long as water may transfer in vapor form without good contact between the ceramic disk and the filter paper during the matric suction measurement. At high matric suctions, filter paper tends to absorb a smaller amount of absorbed water than it should had a sufficiently long equilibration time not been allowed. Hence, although theoretically the technique can be used to measure matric suction as high as 1500 kPa, the calibration data for matric suctions ranging from 1000 to 1500 kPa are difficult to obtain with sufficient accuracy. In conclusion, reasonable measurement accuracy will be obtained when the filter paper technique is used to measure matric suctions of less than 1000 kPa, or total suctions of greater than 4000 kPa.
- Published
- 2011
7. Calibration concepts for load and resistance factor design (LRFD) of reinforced soil walls.
- Author
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Bathurst, Richard J., Allen, Tony M., and Nowak, Andrzej S.
- Subjects
CALIBRATION ,LOAD factor design ,FAULT tolerance (Engineering) ,ENGINEERING geology ,ENGINEERING design - Abstract
Copyright of Canadian Geotechnical Journal is the property of Canadian Science Publishing and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)
- Published
- 2008
- Full Text
- View/download PDF
8. Calibration of strain-softening constitutive model parameters from full-field deformation measurements.
- Author
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Singh, Vikram, Stanier, Sam, Bienen, Britta, and Randolph, Mark F.
- Subjects
DEFORMATIONS (Mechanics) ,DATA compression ,CALIBRATION ,PARTICLE image velocimetry - Abstract
Many offshore geotechnical problems—such as cyclic T-bar penetration and lateral buckling of pipelines—are affected by the tendency of fine-grained soils to strain-soften due to remoulding. Careful calibration of the constitutive model parameters that control strain softening is essential for accurate simulation of these processes. This is usually achieved by matching constitutive model response with standard element test data, which implicitly assumes that homogeneous stress/strain fields exist within the sample. However, popular element test protocols (e.g., triaxial, simple shear) cannot apply sufficient deformation—at least as measured at the boundaries—to achieve fully remoulded conditions. This work explores the potential to determine strain-softening parameters experimentally, directly from image-based full-field deformation measurements and external loading data. Artificial data generated from finite element simulations of biaxial compression and T-bar penetration tests, using a non-locally regularised strain-softening constitutive model based on Modified Cam Clay, are then used to demonstrate the potential of the proposed technique. The results demonstrate significant potential for the application of the technique to identify constitutive parameters from full-field measurements even when polluted with modest measurement noise. [ABSTRACT FROM AUTHOR]
- Published
- 2023
- Full Text
- View/download PDF
9. Reply to discussion by Haghighi et al. on 'Measurements of suction versus water content for bentonite-sand mixtures'.
- Author
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Agus, S. S., Schanz, T., and Fredlund, D. G.
- Subjects
CALIBRATION ,EXTRAPOLATION ,BENTONITE ,SAND ,SOLUTION (Chemistry) ,WETTING ,TEMPERATURE inversions - Published
- 2011
- Full Text
- View/download PDF
10. On the 'elastic stiffness' in a high-cycle accumulation model - continued investigations.
- Author
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Wichtmann, Torsten, Niemunis, Andrzej, and Triantafyllidis, Theodoros
- Subjects
STRAINS & stresses (Mechanics) ,RESIDUAL stresses ,MINERAL aggregates ,CALIBRATION ,PHYSICAL measurements ,STRENGTH of materials - Abstract
Copyright of Canadian Geotechnical Journal is the property of Canadian Science Publishing and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)
- Published
- 2013
- Full Text
- View/download PDF
11. Effect of flow rules and elastic strains on pressuremeter test results in dense sand.
- Author
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Silvestri, Vincenzo, Abou-Samra, Ghassan, and Bravo-Jonard, Christian
- Subjects
STRAINS & stresses (Mechanics) ,ELASTIC structures (Mechanics) ,DEFORMATIONS (Mechanics) ,ELASTIC analysis (Engineering) ,CALIBRATION ,SAND ,TESTING - Abstract
Simple numerical methods that allow to obtain stress and strain paths in sand during self-boring pressuremeter tests are presented in this paper. The material is considered to undergo deformation in drained and plane-strain conditions. The flow rules of Rowe, Cambridge-type (Cam clay and Nova) model, and the sawtooth model are used in the analysis. Elastic strains are also considered in relation with the flow rule of Rowe. The proposed approach has been evaluated using a reference pressuremeter test performed on Ticino sand in a calibration chamber. The results indicate that the stress–strain–volume change responses of the sand predicted by the various models are quite similar, with and without consideration of the elastic strain components. Des méthodes numériques simples, qui permettent d’obtenir les cheminements de contraintes et déformations pendant les essais pressiométriques autoforeurs dans le sable, sont présentées dans cet article. Le matériau est considéré être sollicité en conditions drainées et en déformation plane. Les règles d’écoulement plastique utilisées sont celles de Rowe, de type Cambridge (Cam clay et Nova), et le modèle « dents de scie ». L’approche proposée tient aussi compte des déformations élastiques dans le cadre du modèle de Rowe. La méthode a été évaluée à l’aide d’un essai pressiométrique de référence, effectué dans une chambre de calibration, sur le sable de Tessin. Les résultats indiquent que les réponses du sable en termes des relations contraintes – déformations – changements de volume, prédites par les différents modèles, sont assez similaires, avec ou sans la prise en compte des déformations élastiques. [ABSTRACT FROM AUTHOR]
- Published
- 2009
- Full Text
- View/download PDF
12. Evaluation of small-strain shear modulus of Fontainebleau sand based on innovative pressuremeter probe testing in a calibration chamber
- Author
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Jean Canou, Alexandre Lopes dos Santos, Alain Puech, Francis Cour, and Jean-Claude Dupla
- Subjects
Shear modulus ,Materials science ,Calibration ,Geotechnical engineering ,Geotechnical Engineering and Engineering Geology ,Small strain ,Civil and Structural Engineering - Abstract
This paper presents an experimental study aimed at evaluating the measuring capabilities of an innovative monocellular pressuremeter probe, the Monocell Francis Cour probe, based on calibration testing in the laboratory. The originality of the tested equipment is to allow evaluation of soil properties in both small- and large-strain domains, without the need of sophisticated point displacement measuring arms. This paper focuses on the evaluation of small-strain shear modulus G of Fontainebleau sand, NE34, based on tests carried out with this specific pressuremeter probe. Shear modulus values obtained with this probe are then compared with values resulting from more classical elementary tests, showing a fairly good consistency. It is shown, with satisfactory agreement, that it is possible to quantify the influence of the density index of the sand as well as the influence of the mean effective stress around the probe on the shear modulus, based on the analysis of specific unload−reload loops performed during the test. The experimental programme carried out under well-controlled laboratory conditions allows a validation to be proposed for a method of derivation of the shear modulus of sand at small strain levels using this prototype pressuremeter.
- Published
- 2022
13. Calibration of constitutive parameters by inverse analysis for a geotechnical boundary problem.
- Author
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Knabe, Tina, Schweiger, Helmut F., and Schanz, Tom
- Subjects
CALIBRATION ,FINITE element method ,NUMERICAL analysis ,SOIL creep ,BOUNDARY value problems ,ALGORITHMS - Abstract
Copyright of Canadian Geotechnical Journal is the property of Canadian Science Publishing and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)
- Published
- 2012
- Full Text
- View/download PDF
14. An empirical model for the evaluation of the degree of saturation of shallow soils in relation to rainfalls.
- Author
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Valentino, Roberto, Montrasio, Lorella, Losi, Gian Luca, and Bittelli, Marco
- Subjects
SOIL moisture ,RAINFALL ,EMPIRICAL research ,HYDROLOGIC models ,REFLECTOMETER ,CALIBRATION ,WEATHER ,TEMPERATURE effect - Abstract
Copyright of Canadian Geotechnical Journal is the property of Canadian Science Publishing and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)
- Published
- 2011
- Full Text
- View/download PDF
15. Evaluation of dielectric-based probes for expansive soils: application to Regina clay.
- Author
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Yafei Hu, Vu, Hung Q., and Hubble, David W.
- Subjects
DIELECTRIC devices ,SWELLING soils ,MATERIAL plasticity ,SOIL testing ,ELECTRIC properties of soils ,ELECTRONIC probes - Abstract
Copyright of Canadian Geotechnical Journal is the property of Canadian Science Publishing and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)
- Published
- 2010
- Full Text
- View/download PDF
16. Time domain reflectometry for water content and density of soils: study of soil-dependent calibration constants.
- Author
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Drnevich, V. P., Ashmawy, A. K., Yu, X., and Sallam, A. M.
- Subjects
SOILS ,DIELECTRICS ,WATER ,CALIBRATION ,SOIL compaction ,SOIL stabilization - Abstract
Copyright of Canadian Geotechnical Journal is the property of Canadian Science Publishing and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)
- Published
- 2005
- Full Text
- View/download PDF
17. A new simple system for measuring volume changes in unsaturated soils.
- Author
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Ng, C W.W, Zhan, L T, and Cui, Y J
- Subjects
SOILS ,PRESSURE transducers ,CALIBRATION ,VOLUMETRIC analysis ,TUBES - Abstract
A new simple system for accurately measuring overall total volume changes in unsaturated soil specimens with a triaxial apparatus is introduced in this paper. The basic principle of the measuring system is to record changes in the differential pressure due to changes in the water level inside an open-ended, bottle-shaped inner cell caused by volume change in the specimen and inside a reference tube using an accurate differential pressure transducer. Several important steps were taken to improve the accuracy and sensitivity of the measuring system. Detailed calibrations were carried out to account for apparent volume changes as a result of changes in cell pressure, fluctuation in the ambient temperatures, creep in the inner cell wall, and relative movement between the loading ram and the inner cell. The calibration results demonstrate that the measuring system is reasonably linear, reversible, and repeatable. The estimated accuracy of the measuring system is in the order of 32 mm[sup 3] (or 0.04% volumetric strain for a triaxial specimen 38 mm in diameter and 76 mm in height) once the system is properly calibrated.Key words: unsaturated soils, volume-change measurement, open-ended, bottle-shaped, inner cell, differential pressure, calibration.On introduit dans cet article un nouveau système simple pour mesurer précisément les changements de volume totaux globaux dans les spécimens de sol non saturé avec un appareil triaxial. Le principe de base du système de mesure consiste à enregistrer les changements dans la pression différentielle dus aux changements des niveaux d'eau dans une cellule intérieure à bout ouvert et en forme de bouteille causés par le changement de volume du spécimen et à l'intérieur d'un tube de référence utilisant un capteur de pression différentielle (DPT). Plusieurs étapes importantes ont été suivies pour améliorer la précision et la sensibilité du système de mesure. Des calibrages détaillés ont été réalisés pour tenir compte des changements de volume apparents dus aux changements de la pression cellulaire, à la fluctuation des températures ambiantes, au fluage dans la paroi de la cellule intérieure et au mouvement relatif entre le piston de chargement et la cellule intérieure. Les résultats du calibrage démontrent que le système de mesure est raisonnablement linéaire, réversible et répétitif. La précision estimée du système de mesure est de l'ordre de 32 mm[sup 3] (ou 0,04 % de la déformation volumétrique pour un spécimen triaxial de 38 mm de diamètre et de 76 mm de hauteur) lorsque le système est convenablement calibré.Mots clés : sols non saturés, mesure de changement de volume, bout ouvert, forme de bouteille, cellule intérieure, pression différentielle, calibrage.[Traduit par la Rédaction] [ABSTRACT FROM AUTHOR]
- Published
- 2002
- Full Text
- View/download PDF
18. Synthèse géoélectrique appliquée à la caractérisation des contacts entre nappes de charriage et son apport hydrogéologique dans la Plaine de Tamlouka « Région de Guelma, Est Algérien ».
- Author
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Hemila, Mohammed Laid and Kowalski, Waclaw Marian
- Subjects
STRUCTURAL geology ,THRUST faults (Geology) ,ALLUVIUM ,CALIBRATION - Abstract
The geological work undertaken in the north oriental regions of Algeria have considered the plain of Tamlouka, region of Guelma, as a meeting crossroad of the three structural domains of Sellaoua, Néritic Constantine, and Tellian. The tectonic contact between the overthrust sheets is hidden by a thick alluvium cover and has remained undetermined in spite of recent exploration attempts by a geoelectric method. In this paper, we present the results of our work on the reinterpretation of the basic geoelectric data, which were founded on the calibration principle, considering all the geological information available from outcrops and cuttings of recent drill holes. Twenty-nine geoelectric profiles and three maps are drawn in which (i) the facies and geometry of the Mio-Plio-Quaternary fill are much better identified; (ii) an underground synthesis of the relation between the tectonic units is proposed after an inventory of the subsurface formations; and (iii) the ground-water potential in the plain is much better assessed.Key words: geoelectric method, geometry, overthrust sheets, ground-water potential, Tamlouka, Algeria.Les travaux géologiques entrepris dans les régions Nord orientales de l'Algérie ont considéré la plaine de Tamlouka « région de Guelma » comme le carrefour de rencontre de trois domaines structuraux : du Sellaoua, du Néritique constantinois et du Tellien. Le contact tectonique entre les nappes qui sont masquées par une puissante couverture alluvionnaire est resté indéterminé malgré les tentatives récentes de son exploration par méthodes géoélectriques. Dans cet article, nous exposons les résultats du travail de ré-interprétation des données géoélectriques de base, fondé sur le principe d'étalonnage et prenant en compte la totalité des informations géologiques des affleurements ainsi que des débris de forages implantés récemment. Vingt-neuf profils géoélectriques et trois cartes sont dressés et avec lesquels : (i) le faciès et la géométrie du remplissage Mio-Plio-Quaternaire sont mieux identifiés; (ii) une synthèse des relations souterraines entre les unités tectoniques est avancée après une reconnaissance des formations substratums; (iii) une identification de la possibilité aquifère dans la plaine est mieux précisée.Mots clés : méthode géoélectrique, géométrie, nappe de charriage, potentiel aquifère, Tamlouka, Algérie. [ABSTRACT FROM AUTHOR]
- Published
- 2002
- Full Text
- View/download PDF
19. Influence of placement method on the cone penetration resistance of hydraulically placed sand fills.
- Author
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Lee, K M
- Subjects
SAND ,CONES ,PENETRATION mechanics ,HYDRAULICS ,CALIBRATION ,AIRPORTS - Abstract
The reclamation for the new airport at Chek Lap Kok in Hong Kong included the placement of a substantial volume of sand fill by various hydraulic placement techniques, which resulted in a wide range of as-placed densities of the sand fill. This paper described the use of cone penetration tests (CPT) on the evaluation of the possible ranges of density achievable by various hydraulic placement methods adopted in the construction of the new airport. The results of the CPT indicated that the placement technique is one of the most important factors in controlling the as-placed density of hydraulically placed sand fill. There is a marked contrast in cone tip resistance (and the associated relative density) profiles for the sand fills formed by subaerial and subaqueous placement methods, in which the cone tip resistance of the sand fill formed by subaerial placement is substantially higher than that of the sand fill formed by subaequeous placement. The results confirm that dense sand fill cannot be formed by subaqueous placement methods. The weakest zone is generally located just beneath the water level where fill is placed by subaqueous discharge.Key words: sand, hydraulic fill, cone penetration test, calibration chamber test, in situ density.Le remblayage pour le nouvel aéroport à Chek Lap Kok de Hong Kong comprend la mise en place d'un volume substantiel de remblai de sable par différentes techniques de mise en place hydraulique, qui ont résulté en une large plage de densités en place du remblai de sable. Cet article décrit l'utilisation de l'essai de pénétration au cône (CPT) pour l'évaluation des plages possibles de densité qui peuvent être obtenues par différentes méthodes de mises an place hydrauliques adoptées pour la construction du nouvel aéroport. Les résultat de CPT indiquent que la technique de mise en place est un des facteurs les plus importants pour le contrôle de la densité en place de sable remblayé par méthode hydraulique. Il y a un contraste marqué entre les profils de résistance à la pointe (et la densité relative correspondante) pour les remblais de sable mis en place par des méthodes subaériennes ou sous l'eau, le premier étant appréciablement plus élevé. Les résultats confirment qu'un remblai de sable dense ne peut pas être obtenu par des méthode de mise en place sous l'eau. La zone la plus faible est en général localisée juste sous le niveau d'eau, là où la déposition du matériau de remblayage se fait par décharge sous-l'eau.Mots clés : sable, remblai hydraulique, essai de pénétration au cône, essai en chambre de calibrage, densité in situ.[Traduit par la Rédaction] [ABSTRACT FROM AUTHOR]
- Published
- 2001
- Full Text
- View/download PDF
20. Laboratory-scale seismic CPT calibration chamber tests on Fraser River sand.
- Author
-
Sadrekarimi, Abouzar and Jones, Stephen
- Subjects
CONE penetration tests ,PORE water pressure ,SOIL consolidation ,CALIBRATION ,SANDY soils ,SEISMIC testing ,SAND waves ,SAND - Abstract
Copyright of Canadian Geotechnical Journal is the property of Canadian Science Publishing and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)
- Published
- 2022
- Full Text
- View/download PDF
21. Calibration concepts for load and resistance factor design (LRFD) of reinforced soil walls
- Author
-
Tony M. Allen, Richard J. Bathurst, and Andrzej S. Nowak
- Subjects
Engineering ,business.industry ,Calibration ,Geotechnical engineering ,Structural engineering ,Geotechnical Engineering and Engineering Geology ,business ,Reliability (statistics) ,Civil and Structural Engineering - Abstract
Reliability-based design concepts and their application to load and resistance factor design (LRFD or limit states design (LSD) in Canada) are well known, and their adoption in geotechnical engineering design is now recommended for many soil–structure interaction problems. Two important challenges for acceptance of LRFD for the design of reinforced soil walls are (i) a proper understanding of the calibration methods used to arrive at load and resistance factors, and (ii) the proper interpretation of the data required to carry out this process. This paper presents LRFD calibration principles and traces the steps required to arrive at load and resistance factors using closed-form solutions for one typical limit state, namely pullout of steel reinforcement elements in the anchorage zone of a reinforced soil wall. A unique feature of this paper is that measured load and resistance values from a database of case histories are used to develop the statistical parameters in the examples. The paper also addresses issues related to the influence of outliers in the datasets and possible dependencies between variables that can have an important influence on the results of calibration.
- Published
- 2008
22. Reply to the discussion by Wang and Dallo on 'Hydraulic conductivity of saturated granular soils determined using a constriction-based technique' 1Appears in the Canadian Geotechnical Journal, 49(10): 1221–1222 [doi:10.1139/t2012-078]
- Author
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NguyenVo Trong, RujikiatkamjornCholachat, and IndraratnaBuddhima
- Subjects
Distribution (mathematics) ,Hydraulic conductivity ,Analyser ,Isotropy ,Range (statistics) ,Calibration ,Geotechnical engineering ,Geotechnical Engineering and Engineering Geology ,Shape factor ,Anisotropy ,Civil and Structural Engineering ,Mathematics - Abstract
1. Equation [6] has been typed incorrectly and the correct equation is indeed the one given by the Discussers. The correct equation and its derivation have been given in the Ph.D. thesis of co-Author Nguyen (2012), and the computer program uses the correct equation. A corrigendum has already been submitted to the Canadian Geotechnical Journal giving the correct equation, which has subsequently been published (Indraratna et al. 2012). 2. The papers by Silveira (1965), Silveira et al. (1975), and Locke et al. (2001) discuss various aspects of the constriction-size distribution (CSD) corresponding to a given particle-size distribution (PSD). Locke’s (2001) Ph.D. thesis at the University of Wollongong extended the classical work of Silveira (1965) and Silveira et al. (1975) considerably. However, papers published later by Indraratna and Raut (2006), Indraratna et al. (2007), and Raut and Indraratna (2008) further extended the work of Locke et al. (2001) by introducing the novel concept of critical constriction size, Dc35. The Discussers have clearly overlooked the most important aspect that these recent papers have proposed in terms of critical constriction size for the accurate assessment of filtration effectiveness. 3. The Authors agree with the Discussers that the Kozeny– Carmen (KC) equation cannot be applied unless the void ratio is known or assumed. As the void ratios were not provided in past studies, the Authors employed the approach proposed by Aberg (1992) for the determination of the void ratios based on the PSD and associated relative densities. Given that this technique takes into account the compacted density in addition to PSD, indirectly, it can be considered equivalent to the CSD approach. 4. In this study, the Authors used the KC equation (eq. [2] in the paper) that is mathematically arranged to obtain another form (Carrier 2003) in which the shape factor, SF, captures the angularity ranging from 6.0 to 8.4. As the materials used for testing were mainly sand of high angularity, and having calibrated the experimental data for a range of SF values, the Authors determined SF 8.4 to be the most appropriate value for the KC equation for these angular sand particles. Any value of SF less than 8.4 within the range presented above will induce significant discrepancies (overprediction) when using the KC equation. Therefore, the data presented in Table 3 are related to SF 8.4. SF 1.36 cited by the Discussers is not appropriate for any realistic sandy material that contains predominantly angular grains. 5. The Authors agree that if the specific surface area is determined accurately, the predictions using the KC equation are proper. However, in this manner, using the KC equation requires more dependence and calibration using laboratory data, and this in itself shows the disadvantage of the KC equation. Empirically, SF needs to be estimated, presenting the inaccuracies of this approach. Therefore, the Discussers are correct in pointing out that poor predictions can be encountered if the surface areas of silty sands and similar particle gradations are not properly evaluated. Besides, for highly anisotropic materials, the KC equation hardly gives an accurate estimation of the hydraulic conductivity, and for materials such as uniform fine sand that are closer to being isotropic in pore distribution, Chapuis and Aubertin’s (2003) statement “. . . the KC equation provides good predictions for vertical hydraulic conductivity . . .” makes little sense. For very small particles, the Melvern particle-size analyser and other electronic and laser techniques are now being used for better estimation of the surface areas of particles.
- Published
- 2012
23. Statistical evaluation of model factors in reliability calibration of high-displacement helical piles under axial loading
- Author
-
Chong Tang and Kok-Kwang Phoon
- Subjects
Helix ,Calibration ,Displacement (orthopedic surgery) ,Geotechnical engineering ,Geotechnical Engineering and Engineering Geology ,Reliability (statistics) ,Geology ,Civil and Structural Engineering - Abstract
An industry survey suggests an increasing application of high-displacement helical piles with greater shaft and helix diameters to support various structures. In this paper, a database of 84 static load tests is compiled and analyzed to evaluate the disturbance effect and characterize the model factors that can be used for reliability-based limit state design. The measured capacity is defined as the load at a pile head settlement equal to 5% of helix diameter. For similar helix configurations tested at the same site, the ratio of uplift to compression capacity indicates a low degree of disturbance for very stiff clay (0.8–1) and a medium degree of disturbance for dense sand (0.6–0.8). At the ultimate limit state, the model factor is defined as the ratio between measured and calculated capacity, where three design guidelines are considered. A hyperbolic model with two parameters is used to fit the load–displacement curves. At the serviceability limit state, the model factor can be defined with the hyperbolic parameters. Based on the database, probabilistic distributions of the capacity model factor and hyperbolic parameters are established. Finally, the capacity model statistics are applied to calculate the resistance factor in the load and resistance factor design.
- Published
- 2020
24. Laboratory thermal calibration of contact pressure cells installed on integral bridge abutments.
- Author
-
Huntley, Shelley A. and Valsangkar, Arun J.
- Subjects
CONTACT angle ,HYDRAULICS ,TEMPERATURE ,CALIBRATION ,SCIENTIFIC apparatus & instruments - Abstract
Copyright of Canadian Geotechnical Journal is the property of Canadian Science Publishing and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)
- Published
- 2016
- Full Text
- View/download PDF
25. Pierre3D: a 3D stochastic rockfall simulator based on random ground roughness and hyperbolic restitution factors.
- Author
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Gischig, Valentin S., Hungr, Oldrich, Mitchell, Andrew, and Bourrier, Franck
- Subjects
ROCKFALL ,COMPUTER simulation of earth movements ,HYPERBOLIC processes ,SURFACE roughness ,STOCHASTIC processes ,DEFORMATIONS (Mechanics) ,TALUS (Geology) ,CALIBRATION - Abstract
Copyright of Canadian Geotechnical Journal is the property of Canadian Science Publishing and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)
- Published
- 2015
- Full Text
- View/download PDF
26. Stress measurement in partially saturated soils and its application to physical modeling of tunnel excavation.
- Author
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Berthoz, Nicolas, Branque, Denis, Wong, Henry, and Subrin, Didier
- Subjects
WATERLOGGING (Soils) ,SOIL mechanics ,EARTH pressure ,EXCAVATION ,CALIBRATION - Abstract
Copyright of Canadian Geotechnical Journal is the property of Canadian Science Publishing and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)
- Published
- 2013
- Full Text
- View/download PDF
27. A new interparticle friction apparatus for granular materials.
- Author
-
Cavarretta, I., Rocchi, I., and Coop, M.R.
- Subjects
PARTICLE analysis ,FRICTION ,STIFFNESS (Engineering) ,CALIBRATION ,MATHEMATICAL models ,STICK-slip response - Abstract
Copyright of Canadian Geotechnical Journal is the property of Canadian Science Publishing and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)
- Published
- 2011
- Full Text
- View/download PDF
28. Development of a new calibration chamber for conducting cone penetration tests in unsaturated soils.
- Author
-
Pournaghiazar, Mohammad, Russell, Adrian R., and Khalili, Nasser
- Subjects
CALIBRATION ,SOIL penetration test ,SOIL testing ,HYDRAULICS ,SOIL matric potential ,SOIL classification ,SOIL composition - Abstract
A calibration chamber has been developed to conduct laboratory-controlled cone penetration tests in unsaturated soils. The chamber allows independent application of lateral and vertical pressures to an unsaturated soil specimen. Horizontal pressure is applied by cell water pressure pushing on a rubber membrane enclosing the specimen, while vertical pressure is maintained by a hydraulic loading ram at the base of the specimen. Suction is controlled using the axis-translation technique. Air pressure is applied to the top of the chamber where it spreads uniformly across the top of the specimen. Pore-water pressure is applied through eight high air-entry value porous disks embedded in the bottom plate. A particularly original aspect of the chamber design is the specimen formation system comprising four moveable cylinder quarters, which enables the creation of specimens of repeatable properties from a variety of soil types. The results of typical cone penetration tests conducted on dry, saturated, and unsaturated sand specimens are presented and highlight the contribution of suction to cone penetration resistance. Une chambre de calibrage a été développée pour effectuer des essais de pénétration au cône contrôlés en laboratoire pour des sols non saturés. La chambre permet d'appliquer des pressions latérales et verticales de façon indépendantes sur un échantillon de sol non saturé. La pression horizontale est appliquée par la pression de l'eau sur la cellule qui pousse sur une membrane en caoutchouc qui entoure l'échantillon, tandis que la pression verticale est maintenue par un bélier de chargement hydraulique à la base de l'échantillon. La succion est contrôlée à l'aide de la technique de translation de l'axe. La pression d'air est appliquée à la partie supérieure de la chambre et est distribuée uniformément sur le dessus de l'échantillon. La pression interstitielle est appliquée par huit disques poreux ayant une pression à l'entrée d'air élevée placés dans la plaque du bas de la chambre. Un aspect original du design de la chambre est le système de formation des échantillons, qui comprend quatre quarts de cylindre mobiles, ce qui assure la création d'échantillons avec des propriétés reproductibles pour une variété de types de sols. Les résultats d'essais de pénétration au cône typiques réalisés sur des échantillons de sable sec, saturé et non saturé sont présentés et mettent en évidence la contribution de la succion à la résistance à la pénétration du cône. [ABSTRACT FROM AUTHOR]
- Published
- 2011
- Full Text
- View/download PDF
29. Reliability-based calibration of resistance factors for static bearing capacity of driven steel pipe piles.
- Author
-
Kiseok Kwak, Kyung Jun Kim, Jungwon Huh, Ju Hyung Lee, and Jae Hyun Park
- Subjects
CALIBRATION ,LOAD factor design ,STEEL pipe ,MONTE Carlo method ,PHYSICAL measurements - Abstract
As part of a study to develop load and resistance factor design (LRFD) codes for foundation structures in South Korea, resistance factors for the static bearing capacity of driven steel pipe piles were calibrated in the framework of the reliability theory. A database of 52 static load test results was compiled, and the data from these load test piles were sorted into two cases: a standard penetration test (SPT) N-value at pile tip (i) less than 50 and (ii) equal to or more than 50. Reliability analyses and resistance factor calibration for the two static bearing capacity analysis methods adopted in the Korean Design standards for foundation structures were performed using the first-order reliability method (FORM) and the Monte Carlo simulation (MCS). Reliability indices and resistance factors computed by the MCS are statistically identical to those computed by FORM. Target reliability indices were selected as 2.0 and 2.33 for the group pile case and 2.5 for the single pile case. The resistance factors recommended from this study are specific for the pile foundation design and construction practice and the subsurface conditions in South Korea. Des facteurs de résistance pour la capacité portante de pieux faits de tuyaux d’acier ont été calibrés dans le cadre de la théorie de fiabilité, ceci en tant que partie d’une étude sur le développement de codes de facteurs de chargement et de résistance pour des fondations de structures en Corée du Sud. Une base de donnée de 52 essais de chargement statique a été compilée, et les données de ces pieux d’essais ont été classés en deux catégories : essai de pénétration standard (SPT) N à la pointe du pieu (i) de moins de 50 et (ii) égal ou supérieur à 50. Les analyses de fiabilité et le calibrage des facteurs de résistance pour les deux méthodes d’analyse de la capacité portante adoptées par les normes Design standards for foundation structures de la Corée ont été effectuées à l’aide de la méthode de fiabilité de premier ordre (FORM) et la simulation Monte Carlo (MCS). Les indices de fiabilité et les facteurs de résistance obtenus avec la MCS sont statistiquement identiques à ceux obtenus par FORM. Les indices de fiabilité visés ont été choisis comme 2,0 et 2,33 pour le cas de groupement de pieux, et de 2,5 pour le cas de pieux uniques. Les facteurs de résistance recommandés suite à cette étude sont spécifiques à la conception et à la construction de pieux dans les conditions de la Corée du Sud. [ABSTRACT FROM AUTHOR]
- Published
- 2010
- Full Text
- View/download PDF
30. Calibration of models for pile settlement analysis using 64 field load tests.
- Author
-
Zhang, L. M., Xu, Y., and Tang, W. H.
- Subjects
CALIBRATION ,PHYSICAL measurements ,STANDARDIZATION ,MULTIVARIATE analysis ,STATISTICAL correlation ,DEAD loads (Mechanics) ,HYDRAULIC structures ,HYDRAULIC engineering ,STRUCTURAL engineering - Abstract
Copyright of Canadian Geotechnical Journal is the property of Canadian Science Publishing and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)
- Published
- 2008
- Full Text
- View/download PDF
31. Calibration of thermal conductivity sensors with consideration of hysteresis.
- Author
-
Feng, Man and Fredlund, Delwyn G
- Subjects
DETECTORS ,HYSTERESIS ,ELECTROMAGNETIC induction ,THERMAL analysis ,CALIBRATION - Abstract
Copyright of Canadian Geotechnical Journal is the property of Canadian Science Publishing and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)
- Published
- 2003
- Full Text
- View/download PDF
32. Long-term measurement of matric suction using thermal conductivity sensors.
- Author
-
Nichol, Craig, Smith, Leslie, and Beckie, Roger
- Subjects
HYSTERESIS ,ELECTROMAGNETIC induction ,ELASTICITY ,TEMPERATURE ,CALIBRATION - Abstract
Thermal conductivity (TC) sensors, which provide estimates of matric suction, were used in a field experiment designed to characterize unsaturated water movement through coarse mine waste rock at a mine site in northern Saskatchewan. Two years oF monitoring data were used to evaluate long-term TC sensor performance and accuracy. Thermal conductivity sensor output requires corrections of sensor hysteresis and changes in ambient temperature. A correction method for ambient temperature is derived. A comparison oF the uncorrected field measurements with the values corrected for both hysteresis and ambient temperature indicates that the magnitude of these corrections can be similar. Corrected TC sensor measurements are compared to measurements of matric suction made using tensiometers. Thermal conductivity sensor response to the initial arrival of a wetting front lagged 1 3 days behind the tensiometer measurements. The TC sensor data tended to overestimate matric suction in the waste rock, when compared to the tensiometer data. Long-term drift in the TC sensors located at depths oF 50 cm and below (where the sensors have been continuously exposed to matric suctions less than 20 kPa) has lead to data that are not interpretable using the calibration curves derived prior to sensor emplacement in the waste rock pile. [ABSTRACT FROM AUTHOR]
- Published
- 2003
- Full Text
- View/download PDF
33. Cone penetration test calibration for Erksak (Beaufort Sea) sand: Discussion
- Author
-
J A Sladen
- Subjects
Volume (thermodynamics) ,Cone penetration test ,Calibration ,Geotechnical engineering ,Beaufort sea ,Geotechnical Engineering and Engineering Geology ,Geology ,Civil and Structural Engineering - Abstract
This is a discussion of a paper by the same title which appeared in Volume 24, Canadian Geotechnical Journal, pp 601-610. The authors of the original paper are K. Been, B.E. Lingnau, J.H.A. Crooks, and B. Leach.
- Published
- 1989
34. An alternative method for in situ determination of rock strength
- Author
-
NaderiMahmood
- Subjects
In situ ,Core (optical fiber) ,Alternative methods ,Compressive strength ,Materials science ,Calibration ,Torque ,Geotechnical engineering ,Geotechnical Engineering and Engineering Geology ,Reduction (mathematics) ,Maximum torque ,Civil and Structural Engineering - Abstract
The friction-transfer method, which is described in this paper, can be used for in situ determination of intact rock strength. With this method it is possible to estimate the equivalent uniaxial compressive strengths (UCS), using appropriate calibration graphs. In this method a specially devised apparatus fits over the top the partial core and is clamped to it. To measure the rock strength, torque is applied using an ordinary torque meter and the maximum torque at failure is recorded. Comparative studies of UCS values and friction-transfer test results showed that a strong correlation exists between UCS and the friction-transfer readings. The measured values for uniaxial compressive tests ranged from 26 to 207 MPa. The average coefficients of variation of laboratory and site tests were found to be less than 14% for uniaxial compressive tests and less than 12.5% for the friction-transfer method. Fully saturated rock samples showed between about 18%–56% reduction in their torsional and core compressive strengths compared with their respective values obtained under dry laboratory conditions.
- Published
- 2011
35. An empirical model for the evaluation of the degree of saturation of shallow soils in relation to rainfalls
- Author
-
BittelliMarco, ValentinoRoberto, LosiGian Luca, MontrasioLorella, Valentino R., Montrasio L., Losi G.L., and Bittelli M.
- Subjects
Hydrology ,Relation (database) ,Water flow ,TENEUR EN EAU ,Degree of saturation ,MODÈLE EMPIRIQUE ,Geotechnical Engineering and Engineering Geology ,SOLS PEU PROFONDS ,PLUIE ,Air temperature ,Soil water ,Calibration ,Environmental science ,Geotechnical engineering ,Sensitivity (control systems) ,Water content ,DEGRÉ DE SATURATION ,Civil and Structural Engineering - Abstract
The evaluation of shallow soils water content is very important in many fields, and different hydrological models are widely applied to simulate field-scale water flow and soil water content. The degree of saturation of a shallow soil is a time-varying variable, depending on different weather conditions. In many applications, it is useful to directly correlate the soil degree of saturation to time series of rainfall amount. This paper presents a simplified empirical model, which allows for computation of the soil degree of saturation using readily available climate data on air temperature and rainfall depths. The model is tested with in situ measurements of soil water content collected at three sites in the Emilia Romagna region in northern Italy. The experimental data are compared with the results obtained from the simplified model over an observation period of almost 5 years. The model has been used to generate soil water content time series at different depths and requires a separate calibration for each depth where the degree of saturation is computed. A discussion on the model’s calibration is also carried out to clarify the model sensitivity to the different parameters and the choice of input data.
- Published
- 2011
36. A new simple system for measuring volume changes in unsaturated soils
- Author
-
Charles Wang Wai Ng, Yu-Jun Cui, and Liangtong Zhan
- Subjects
Correlation coefficient ,Volume (thermodynamics) ,Simple (abstract algebra) ,Chemistry ,Soil water ,Vadose zone ,Calibration ,Geotechnical engineering ,sense organs ,skin and connective tissue diseases ,Geotechnical Engineering and Engineering Geology ,Civil and Structural Engineering - Abstract
A new simple system for accurately measuring overall total volume changes in unsaturated soil specimens with a triaxial apparatus is introduced in this paper. The basic principle of the measuring system is to record changes in the differential pressure due to changes in the water level inside an open-ended, bottle-shaped inner cell caused by volume change in the specimen and inside a reference tube using an accurate differential pressure transducer. Several important steps were taken to improve the accuracy and sensitivity of the measuring system. Detailed calibrations were carried out to account for apparent volume changes as a result of changes in cell pressure, fluctuation in the ambient temperatures, creep in the inner cell wall, and relative movement between the loading ram and the inner cell. The calibration results demonstrate that the measuring system is reasonably linear, reversible, and repeatable. The estimated accuracy of the measuring system is in the order of 32 mm3 (or 0.04% volumetric strain for a triaxial specimen 38 mm in diameter and 76 mm in height) once the system is properly calibrated.Key words: unsaturated soils, volume-change measurement, open-ended, bottle-shaped, inner cell, differential pressure, calibration.
- Published
- 2002
37. Analysis of calibration chamber plate load tests
- Author
-
Junhwan Lee and Rodrigo Salgado
- Subjects
Materials science ,Base (geometry) ,Calibration ,Geotechnical engineering ,Geotechnical Engineering and Engineering Geology ,Civil and Structural Engineering - Abstract
The estimation of base resistance is a key step in the design of piles embedded in moderately dense to dense sand. Calibration chamber plate load tests are sometimes used to investigate the base load - settlement relationship of nondisplacement piles in sand. In such tests, the sand specimens are carefully prepared to simulate the installation of nondisplacement piles. In this paper, calibration chamber tests are analyzed using the finite element method; experimental and numerical results are compared. The finite element models are axisymmetric and use a nonlinear, elastic-plastic constitutive model. Plate resistance values predicted using the finite element analysis are shown to be in good agreement with measured values, which validates the proposed numerical model. Questions regarding the existence of calibration chamber size effects have not, to this date, been adequately addressed. Finite element analyses of both pile base resistance and plate resistance for sands with various relative densities and stress states show that size effects are usually small for settlement levels of interest in practice. This suggests that the use of calibration chambers in pile base capacity studies is justified.Key words: calibration chambers, plate load tests, constitutive modeling, size effects, piles, sands.
- Published
- 2000
38. Eighteenth Canadian Geotechnical Colloquium: Limit States Design For Foundations. Part II. Development for the National Building Code of Canada: Discussion
- Author
-
L D Baikie
- Subjects
Reliability theory ,Engineering ,Development (topology) ,business.industry ,National Building Code of Canada ,Calibration ,Geotechnical engineering ,Bearing capacity ,Limit (mathematics) ,Geotechnical Engineering and Engineering Geology ,Design methods ,business ,Civil and Structural Engineering - Abstract
The following comments and observations deal only with the direct calibration of the limit states design (LSD) method by fitting with the traditional working stress design (WSD) method. However, it is observed by the author that the results of direct fitting calibration are quite similar to those obtained by calibrating the LSD method with reliability theory as discussed in the paper. In the WSD method a design is considered acceptable if Rn $ FSΣ Sni, while in the LSD method a design is acceptable if ΦRn $ ΣαiSni. In these expressions Rn is the nominal resistance and Sn is the nominal load. If it is assumed that the nominal loads are the same in both design methods then we have the following relationship which applies to all limit states, e.g., bearing capacity, sliding
- Published
- 1997
39. Cone penetration test calibration for Erksak (Beaufort Sea) sand
- Author
-
J. H. A. Crooks, B. E. Lingnau, B. Leach, and K. Been
- Subjects
Cone penetration test ,Calibration ,Geotechnical engineering ,Beaufort sea ,Geotechnical Engineering and Engineering Geology ,Geology ,Civil and Structural Engineering ,Interpretation (model theory) - Abstract
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.
- Published
- 1987
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