Modelling the rate-sensitive characteristics of the Gloucester foundation soil

1998 ◽  
Vol 35 (5) ◽  
pp. 769-789 ◽  
Author(s):  
Sean D Hinchberger ◽  
R Kerry Rowe
Keyword(s):  
Yield Surface ◽  
Field Performance ◽  
Element Model ◽  
Triaxial Tests ◽  
Surface Model ◽  
Test Results ◽  
Foundation Soil ◽  
Sensitive Characteristics ◽  
Test Embankment

Stages 1 (1967) and 2 (1982) of the Gloucester test embankment are studied using a fully coupled finite-element model. The rate-sensitive characteristics of the foundation soil are modelled using an elastoviscoplastic constitutive equation based on the elliptical cap yield surface and Perzyna's overstress theory of viscoplasticity. The aspect ratio of the yield surface for the Gloucester foundation soil is estimated using conventional laboratory shear and consolidation test results. Calculated and measured behaviour during consolidated isotropically undrained triaxial tests and long-term Rowe cell consolidation tests are compared and the ability of the model to describe the measured behaviour of stages 1 and 2 of the Gloucester test embankment is studied. This paper explores the implications of modelling the residual or restructured properties of the Gloucester foundation soil and demonstrates the ability of a single elastoviscoplastic yield-surface model to describe the undrained and drained response of the Gloucester foundation soil during laboratory and field loading conditions.Key words: elliptical cap, rate sensitive, elastoviscoplasticity, embankment settlements, pore pressures, field performance.

The significance of rate effects in modelling the Sackville test embankment

1998 ◽  
Vol 35 (3) ◽  
pp. 500-516 ◽  
Author(s):  
R Kerry Rowe ◽  
Sean D Hinchberger
Keyword(s):  
Yield Surface ◽  
Soft Soil ◽  
Surface Model ◽  
Foundation Soil ◽  
Clayey Silt ◽  
Rate Effects ◽  
Measured Time ◽  
Sensitive Characteristics ◽  
Fully Coupled ◽  
Test Embankment

It has been reported that conventional methods of analysis could not adequately describe all aspects of the behaviour of a geotextile-reinforced test embankment constructed to failure on a soft clayey silt with some organics at Sackville, New Brunswick (Canada). This paper presents the results of an analysis of the Sackville embankment using a fully coupled elasto-viscoplastic constitutive model with an elliptical cap yield surface. The importance of modelling the rate sensitive characteristics of the Sackville foundation soil is demonstrated. A comparison of calculated and measured behaviour of the Sackville test embankment demonstrates that the single elasto-viscoplastic yield surface model adequately described much of the measured time-dependent behaviour of the Sackville test embankment including post construction increases in pore pressure, deformation and reinforcement strain.Key words: Embankment; soft soil; geosynthetic; reinforcement; analysis; field case, viscoplasticity

An Elastoplastic Model for Coarse Grained Soils Obeying Lade's Dilatancy Rule

2013 ◽  
Vol 850-851 ◽  
pp. 381-386
Author(s):  
Jin Wang ◽  
Jiao Na Li ◽  
Sheng Zhu
Keyword(s):  
Potential Function ◽  
Yield Surface ◽  
Large Scale ◽  
Coarse Grained ◽  
Triaxial Tests ◽  
Surface Model ◽  
Test Results ◽  
Elastoplastic Model ◽  
Plastic Potential ◽  
Plastic Potential Function

This paper discussed the mechanism of dilatancy in coarse grained soils. Large-scale triaxial tests were also conducted to study the dilatancy law of coarse grained soils. Based on the results of the previous studies, it is found that plastic potential function proposed by Lade can fit the test results well. Lades dilatancy rule was then applied to a practical two-yield-surface model. Elastoplastic formula of the two-yield-surface model was also deduced in detail. The new model was verified with several groups of different materials. Results showed that this model could predict the behaviors of coarse grained soils well.

Construction and performance of a full-scale geotextile reinforced test embankment, Sackville, New Brunswick

1995 ◽  
Vol 32 (3) ◽  
pp. 512-534 ◽  
Author(s):  
R. Kerry Rowe ◽  
C.T. Gnanendran ◽  
A.O. Landva ◽  
A.J. Valsangkar
Keyword(s):  
Field Performance ◽  
High Strength ◽  
Full Scale ◽  
Foundation Soil ◽  
Construction Sequence ◽  
And Performance ◽  
Pore Pressure Response ◽  
Compressible Soil ◽  
Field Behaviour ◽  
Test Embankment

The instrumentation, construction, and field performance of a full-scale geotextile reinforced test embankment constructed on a soft compressible soil is presented. A relatively high-strength polyester woven geotextile was used as reinforcement. The construction sequence, the observed pore pressure response, and the vertical and horizontal displacements are reported. The development and propagation of cracks in relation to the construction sequence and the manner in which the embankment failed are described. The field data suggest that the shear strength of the foundation soil was mobilized at a fill thickness between 5 and 5.7 m. However, due to the stabilizing effect of the geotextile reinforcement, the embankment did not fail until the geotextile reached its ultimate tensile strength and tore when the fill thickness reached 8.2 m. The failure of the embankment was of a viscoplastic nature and although additional fill could be placed after failure of the geotextile and embankment at 8.2 m, no additional gain in the net height (i.e., relative to the surrounding area) could be maintained above the maximum of 6.6 m recorded when the fill thickness reached 8.2 m. Key words : embankment, geotextile reinforcement, field behaviour, stability, deformations, pore pressures.

scholarly journals An extended super/subloading surface model for soft rock considering structure degradation

PLoS ONE ◽  
2021 ◽  
Vol 16 (10) ◽  
pp. e0258813
Author(s):  
Kai Cui ◽  
Bin Hu ◽  
Aneng Cui ◽  
Jing Li ◽  
Erjian Wei ◽  
...  
Keyword(s):  
Yield Surface ◽  
Soft Rock ◽  
Yield Function ◽  
Surface Shape ◽  
Surface Model ◽  
Test Results ◽  
Structure Degradation ◽  
Proposed Model ◽  
Comparison Results ◽  
Cam Clay

The strain-softening and dilatancy behavior of soft rock is affected by the loading history and the development of structure. This study regards soft rock as a structured and overconsolidated soil and develops a new elastoplastic model based on the classical super yield surface Cam-clay model. The proposed model is capable of capturing the effect of yield surface shape on the mechanical behavior of soft rock by introducing a new yield function. The proposed model is validated against the triaxial test results on different types of soft rocks under drained condition. The comparison results indicate that the proposed model is suitable for describing the constitutive behavior of soft rock.

Parents' long-term adjustment to the genetic test results of minors at risk for Long QT Syndrome

2004 ◽  
Author(s):  
K. S. W. H. Hendriks ◽  
F. J. M. Grosfeld ◽  
A. A. M. Wilde ◽  
J. van den Bout ◽  
I. M. van Langen ◽  
...  
Keyword(s):  
At Risk ◽  
Long Qt Syndrome ◽  
Genetic Test ◽  
Test Results ◽  
Long Qt ◽  
Genetic Test Results ◽  
Qt Syndrome

The Implementation Of Make A-Match Model In Social Science Learning To Improve Student Learning Outcomes In Class IV SDN 115 Manado

2019 ◽  
Vol Volume 2 Nomor 2 ◽  
Keyword(s):  
Social Science ◽  
Learning Outcomes ◽  
Teaching And Learning ◽  
Science Learning ◽  
Design Activity ◽  
Test Results ◽  
Match Model ◽  
Fourth Grade Students ◽  
Improve Student Learning

There is a tendency in the education field today to return to the idea that children will learn better if the environment is created naturally. Learning will be more meaningful if children "experience" themselves what they are learning, not 'knowing' it. Target-oriented learning of material mastery proves to be successful in short-term 'remembering' competitions, but fails to equip children to solve problems in long-term life. The problems that would to be studied in this study are: (a) how is the improvement of Social Science learning outcomes by applying the Make A-Match Model to it? (b) how does the Make A-Match Model apply towards the learning motivation? The objectives of this study are: (a) want to know the improvement in Social Science learning achievement after the implemetation of the Make A-Match Model. (b) want to know the effect of Make A-Match Model towards students’ motivation of the subject after it is applied. This research is used two rounds of action research. In each round consists of four stages, namely: design, activity and observation, reflection and revision. The target of this research is the fourth grade students of Mongodow. The data obtained in the form of formative test results, observation sheets of teaching and learning activities. From the results of analysts obtained student achievement has increased from cycle I to cycle II namely, cycle I (65%), cycle II (83%). The conclusion of this research is the Make A-Match Model of Social Science learning could positively influence the motivation of learning of central students, and this learning model could be used as an alternative to Social Science learning.

Long Term Field Test Results of Experimental EPDM and PUF Roofing

1990 ◽  
Author(s):  
David M. Bailey ◽  
Stuart D. Foltz ◽  
Myer J. Rosenfield
Keyword(s):  
Field Test ◽  
Test Results ◽  
Term Field

Development of a Performance-Related Framework for Asphalt Mixture Design for the Illinois Tollway

2021 ◽  
pp. 036119812110148
Author(s):  
Behnam Jahangiri ◽  
Punyaslok Rath ◽  
Hamed Majidifard ◽  
William G. Buttlar
Keyword(s):  
Asphalt Mixture ◽  
Field Performance ◽  
Compact Tension ◽  
T Test ◽  
Novel Approach ◽  
Final Adjustment ◽  
Development And Validation ◽  
High Degree ◽  
Selection Of

Various agencies have begun to research and introduce performance-related specifications (PRS) for the design of modern asphalt paving mixtures. The focus of most recent studies has been directed toward simplified cracking test development and evaluation. In some cases, development and validation of PRS has been performed, building on these new tests, often by comparison of test values to accelerated pavement test studies and/or to limited field data. This study describes the findings of a comprehensive research project conducted at Illinois Tollway, leading to a PRS for the design of mainline and shoulder asphalt mixtures. A novel approach was developed, involving the systematic establishment of specification requirements based on: 1) selection of baseline values based on minimally acceptable field performance thresholds; 2) elevation of thresholds to account for differences between short-term lab aging and expected long-term field aging; 3) further elevation of thresholds to account for variability in lab testing, plus variability in the testing of field cores; and 4) final adjustment and rounding of thresholds based on a consensus process. After a thorough evaluation of different candidate cracking tests in the course of the project, the Disk-shaped Compact Tension—DC(T)—test was chosen to be retained in the Illinois Tollway PRS and to be presented in this study for the design of crack-resistant mixtures. The DC(T) test was selected because of its high degree of correlation with field results and its excellent repeatability. Tailored Hamburg rut depth and stripping inflection point thresholds were also established for mainline and shoulder mixes.

scholarly journals Laboratory Study of the Ultraviolet Radiation Effect on an HDPE Geomembrane

Membranes ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 390
Author(s):  
Fernando Luiz Lavoie ◽  
Marcelo Kobelnik ◽  
Clever Aparecido Valentin ◽  
Érica Fernanda da Silva Tirelli ◽  
Maria de Lurdes Lopes ◽  
...  
Keyword(s):  
Ultraviolet Radiation ◽  
Morphological Changes ◽  
Field Performance ◽  
Melt Flow Index ◽  
Flow Index ◽  
Test Results ◽  
Upward Trend ◽  
Scanning Calorimetry ◽  
Ultraviolet Exposure ◽  
Brittle Behavior

High-density polyethylene (HDPE) geomembranes are polymeric geosynthetic materials usually applied as a liner in environmental facilities due to their good mechanical properties, good welding conditions, and excellent chemical resistance. A geomembrane’s field performance is affected by different conditions and exposures, including ultraviolet radiation, thermal and oxidative exposure, and chemical contact. This article presents an experimental study with a 1.0 mm-thick HDPE virgin geomembrane exposed by the Xenon arc weatherometer for 2160 h and the ultraviolet fluorescent weatherometer for 8760 h to understand the geomembrane’s behavior under ultraviolet exposure. The evaluation was performed using the melt flow index (MFI) test, oxidative-induction time (OIT) tests, tensile test, differential scanning calorimetry (DSC) analysis, and Fourier transform infrared spectroscopy (FTIR) analysis. The sample exposed in the Xenon arc equipment showed a tendency to increase the MFI values during the exposure time. This upward trend may indicate morphological changes in the polymer. The tensile behavior analysis showed a tendency of the sample to lose ductility, without showing brittle behavior. The samples’ OIT test results under both device exposures showed faster antioxidant depletion for the standard OIT test than the high-pressure OIT test. The DSC and FTIR analyses did not demonstrate the polymer’s changes.

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