scholarly journals Experimental study on fibre reinforced sandy soils behaviour under static loadings - drained and undrained conditions

2019 ◽  
Vol 92 ◽  
pp. 12002
Author(s):  
Jorge Hernán Flórez-Gálvez ◽  
Lucas Festugato ◽  
Nilo Cesar Consoli
Keyword(s):  
Experimental Study ◽  
Sandy Soils ◽  
Friction Angle ◽  
The Other ◽  
Triaxial Tests ◽  
Polypropylene Fibres ◽  
Undrained Conditions ◽  
Positive Effect ◽  
Drained And Undrained Conditions ◽  
Sustained Increase

The effect of the addition of 0.5% of randomly distributed polypropylene fibres in a round grained sand, composed mainly of silica, is presented on laboratory scale. The samples were compacted with two void ratios (0.75 and 0.63), corresponding to values of relative density of 50% and 90% respectively. 24 monotonic triaxial tests were performed, with initial effective mean pressures of 20, 100 and 200 kPa. Half of samples were tested in drained conditions, and the other half in undrained conditions. For the samples subjected to drained conditions, the effect of the fibres was identified at the post-failure stage, by showing sustained increase of strength. The positive effect of fibres could also be observed through the increase of material friction angle. In the samples subjected to undrained tests, the addition of fibres reduced the contractive behaviour, mainly for those more compacted.

Steady-state lines of sand–silt mixtures

2006 ◽  
Vol 43 (11) ◽  
pp. 1213-1219 ◽  
Author(s):  
S L Yang ◽  
R Sandven ◽  
L Grande
Keyword(s):  
Steady State ◽  
Key Words ◽  
Friction Angle ◽  
Triaxial Tests ◽  
Fines Content ◽  
Undrained Conditions ◽  
Drained And Undrained Conditions ◽  
Intergranular Void

The steady-state lines (SSLs) for sand–silt mixtures with various fines contents (0%, 5%, 10%, 15%, 20%, 30%, 50%, 70%, and 94%) were studied. It was indicated that the location of the SSL in the e–p′ space is different for each mixture, but the SSLs are parallel. In the e – ln p′ plot, the SSLs are similar for the mixtures with a fines content of less than the transitional fines content (TFC) when tested under drained and undrained conditions and the intergranular and interfine void ratios are used. The data diverge when the fines contents are equal to or greater than the TFC, even though the interfine void ratios are used. The results of the tests conducted under drained and undrained conditions produced a unique SSL in the p′–q space for each material. Different SSLs in the p′–q space were observed for the studied materials, and the friction angle at steady state varied in the range of 37.3°–42.2°. The study showed that the SSLs can be represented by one line in tests under drained conditions if the fines contents are less (0%–30%) than the TFC and the corrected intergranular void ratios are used. The lines can also be represented by one line for sand–silt mixtures with high fines contents (50%–94%) if the corrected interfine void ratios are used instead of void ratios. Key words: steady-state line, sand–silt mixtures, transitional fines content, drained and undrained triaxial tests.

The Strength and Stress-Strain Behavior of the Cemented Rockfill

2012 ◽  
Vol 598 ◽  
pp. 565-568 ◽  
Author(s):  
Qi Wen Zheng ◽  
Chen Wang ◽  
Jian Wei Zhang
Keyword(s):  
Friction Angle ◽  
The Other ◽  
Triaxial Tests ◽  
Elastoplastic Material ◽  
Test Results ◽  
Maximum Volume ◽  
Volume Strain ◽  
Stress Strain ◽  
Strain Behavior ◽  
Mixing Proportion

The cemented rockfill is mixed with cement, water and the siltstone rockfill with a certain mixing proportion. To study the strength and stress-strain behavior of the cemented rockfill, two groups of triaxial tests are carried out under the saturated and consolidated-drained conditions. One group specimens don’t include cement while the other group specimens include. The test results show that the cemented rockfill is a kind of elastoplastic material and the structure of the cemented rockfill is forced due to the effect of cementation. Compared with rockfill, the initial tangent elastic modulus, strength and cohesion of the cemented rockfill increase apparently, the residual strength and internal friction angle of the cemented rockfill increase a little, the maximum volume strain of the cemented rockfill decreases apparently.

scholarly journals How to show empathy as a coach: The effects of coaches’ imagine-self versus imagine-other empathy on the client’s self-change and coaching outcome

2021 ◽  
Author(s):  
Sandra J. Diller ◽  
Christina Mühlberger ◽  
Nele Löhlau ◽  
Eva Jonas
Keyword(s):  
Experimental Study ◽  
Practical Implication ◽  
Cognitive Empathy ◽  
The Other ◽  
Survey Study ◽  
Future Research ◽  
Personnel Development ◽  
The Difference ◽  
Positive Effect

AbstractCognitive empathy, expressed as either imagine-self (imagining oneself in the other’s situation) or imagine-other (imagining the other person in his/her situation) empathy, is essential for self-change and satisfaction in coaching. In two studies, we investigated the difference between coaches’ imagine-self versus imagine-other empathy. In a survey study (N1 = 242), we found that the more important coaches perceived the client’s self-change, the more valuable they not only rated empathy in general but also imagine-other (but not imagine-self) empathy in particular. In an experimental study (N2 = 57), we manipulated the coaches’ imagine-self versus imagine-other empathy and examined the effect on the clients’ self-change and coaching satisfaction. The results revealed a positive effect of imagine-other (but not imagine-self) empathy on these coaching outcome factors. Thus, one main practical implication is the relevance of showing imagine-other instead of imagine-self empathy as a coach. However, future research should investigate other personnel development approaches like mentoring or training with regard to imagine-self versus imagine-other empathy. 

scholarly journals Stress-Dilatancy for Soils. Part II: Experimental Validation for Triaxial Tests

2016 ◽  
Vol 38 (4) ◽  
pp. 59-65 ◽  
Author(s):  
Zenon Szypcio
Keyword(s):  
Test Data ◽  
Experimental Validation ◽  
Triaxial Compression ◽  
Shear Resistance ◽  
State Theory ◽  
Triaxial Tests ◽  
Macro Scale ◽  
Undrained Conditions ◽  
Particle Rolling ◽  
Drained And Undrained Conditions

Abstract Different forms of the stress-dilatancy relations obtained based on the frictional theory for the triaxial condition are presented. The analysed test data show that the shear resistance of many soils is purely frictional. The angle Φ0 represents the resistance of the soil as a combined effect of sliding and particle rolling on the macro-scale during shear at the critical frictional state. The stress-plastic dilatancy relations differ not only for triaxial compression and extension but also for drained and undrained conditions. The experiment investigated shows the correctness of the frictional state theory in the triaxial condition.

Three-dimensional cyclic behavior of saturated clays: comparison between undrained and partly drained conditions

2021 ◽  
Author(s):  
Yanlin Zhang ◽  
Chuan Gu ◽  
Jun Wang ◽  
Yuanqiang Cai
Keyword(s):  
Resilient Modulus ◽  
Three Dimensional ◽  
Cyclic Stress ◽  
Cyclic Behavior ◽  
Triaxial Tests ◽  
Cyclic Stress Ratio ◽  
True Triaxial ◽  
Deformation Behaviors ◽  
Undrained Conditions ◽  
Drained And Undrained Conditions

The cyclic response of subgrade clays under traffic loadings is likely to be partly drained rather than undrained, and the traffic-induced dynamic stress field is three-dimensional rather than axisymmetric. To compare the three-dimensional deformation behaviors of saturated clays between partly drained and undrained conditions, a large number of cyclic true triaxial tests were conducted. Experimental results show that partly drained condition leads to a remarkable increase of permanent major principal strain ( ) compared to undrained condition, and the differences of between the two drainage conditions are affected greatly by the factors of cyclic stress ratio (CSR), overconsolidation ratio (OCR), and coefficient of cyclic intermediate principal stress (bcyc). The increase of bcyc induces a linear reduction of in undrained condition, while it causes a first increase and then a decrease of in partly drained condition. The clays undergo stiffness softening and hardening in partly drained and undrained conditions, respectively, and the effects of bcyc and CSR on the stiffness evolution are very different between the two drainage conditions. The mechanism of the complex and resilient modulus behaviors in three-dimensional state and partly drained condition is further discussed. In addition, two different empirical models are employed to predict in partly drained and undrained conditions, respectively.

Effective friction angle of clays and silts from piezocone penetration tests

2018 ◽  
Vol 55 (9) ◽  
pp. 1230-1247 ◽  
Author(s):  
Zhongkun Ouyang ◽  
Paul W. Mayne
Keyword(s):  
South Carolina ◽  
Effective Stress ◽  
Friction Angle ◽  
Triaxial Tests ◽  
Fine Grained ◽  
Undisturbed Samples ◽  
Undrained Conditions ◽  
Plastic Clays ◽  
Penetration Tests ◽  
Effective Friction

An existing effective stress limit plasticity solution for piezocone penetration tests (CPTu) is calibrated to evaluate the effective stress friction angle ([Formula: see text]) for undrained conditions for a variety of fine-grained soils ranging from natural lean to plastic clays and clayey silts from marine, alluvial, lacustrine, deltaic, and glaciofluvial origins. Data from 105 clay sites are compiled to examine the CPTu-interpreted [Formula: see text] values in comparison with laboratory benchmark values obtained from undrained consolidated anisotropic (CAUC) and undrained compression (CIUC) triaxial tests made on undisturbed samples. An approximate inversion of the theoretical solution is developed to allow profiles of [Formula: see text] to be evaluated with depth. Five well-documented case studies in Illinois, Louisiana, South Carolina, Ireland, and Massachusetts are presented to illustrate the application of the solution. Lastly, results from 1g chamber tests involving kaolin and kaolinitic–silica mixtures tested by miniature piezocone probes are shown for additional verification.

The Determinants of Capital Adequacy Ratio: The Case of the Vietnamese Banking System in the Period 2011-2015

2017 ◽  
Vol 33 (2) ◽  
Author(s):  
Ngoc Anh Nguyen
Keyword(s):  
Banking System ◽  
Precious Metals ◽  
Capital Adequacy ◽  
The Other ◽  
Total Asset ◽  
Data Set ◽  
Hand Size ◽  
Net Interest Margin ◽  
Capital Adequacy Ratio ◽  
Positive Effect

The analysis of a data set of observation for Vietnamese banks in period from 2011 - 2015 shows how Capital Adequacy Ratio (CAR) is influenced by selected factors: asset of the bank SIZE, loans in total asset LOA, leverage LEV, net interest margin NIM, loans lost reserve LLR, Cash and Precious Metals in total asset LIQ. Results indicate based on data that NIM, LIQ have significant effect on CAR. On the other hand, SIZE and LEV do not appear to have significant effect on CAR. Variables NIM, LIQ have positive effect on CAR, while variables LLR and LOA are negatively related with CAR.

Effectiveness of Virtual Resilience Training on Assertiveness in Student Girls Aged 9–10 Years: A 1-Month Follow-Up

2021 ◽  
pp. 105984052110135
Author(s):  
Shima Gadari ◽  
Jamile Farokhzadian ◽  
Parvin Mangolian Shahrbabaki
Keyword(s):  
Experimental Study ◽  
Internal Stress ◽  
Intervention Group ◽  
The Other ◽  
Hormonal Changes ◽  
Emotional Instability ◽  
Other Hand ◽  
Significant Difference ◽  
Resilience Training

Girls between the ages of 9 and 10 begin to experience physical, physiological, and hormonal changes that may lead to internal stress. At this age, children are struggling for autonomy; on the other hand, they may experience emotional instability, and for these reasons, they may be vulnerable in many ways. This experimental study aimed to investigate the effect of resilience training on assertiveness in student girls aged 9–10. Data were collected before, immediately after, and 1 month after the intervention in the control ( n = 40) and intervention ( n = 37) groups. There was a significant difference between the assertiveness of the intervention immediately (26.80 ± 3.73) and 1 month after the intervention (27.05 ± 3.73), and assertiveness significantly increased in the intervention group ( p = .0001). Resilience training leads to improvements in assertiveness in student girls aged 9–10.

The Effects of Online Assignments and Weekly Deadlines on Student Outcomes in a Macroeconomics Course

2020 ◽  
pp. 056943452096825
Author(s):  
Laurie A. Miller ◽  
James R. Schmidt
Keyword(s):  
Student Retention ◽  
Adaptive Learning ◽  
Student Outcomes ◽  
Knowledge Retention ◽  
The Other ◽  
Student Knowledge ◽  
Final Exam ◽  
Online Assignments ◽  
Positive Effect ◽  
Jel Classifications

This study examined how weekly, externally set deadlines affected the completion of adaptive learning assignments and student outcomes in an introductory macroeconomics course. We imposed different deadline schemes for the same adaptive learning assignments in two sections of the course. One section was given flexible deadlines and the other section was given rigid weekly deadlines. We found that weekly deadlines did not affect assignment completions or total points earned on unit exams. We investigated how the adaptive learning assignments affected student retention of material. A measure of staying on pace in the course provided a positive effect on the comprehensive final exam for students with weekly deadlines. The weekly deadlines may not have influenced assignment completions but consistent engagement with the flow of topics through the course increased student knowledge retention. Regardless of deadline type, completions of adaptive learning assignments positively affected outcomes on the unit exams and final exam. JEL Classifications: A20, A22

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