A novel analytical approach for predicting the noncylindrical pile penetration-induced soil displacement in undrained soil by combining use of cavity expansion and strain path methods

2018 ◽  
Vol 42 (11) ◽  
pp. 1270-1305 ◽  
Author(s):  
Hang Zhou ◽  
Hanlong Liu ◽  
Jingrong Yuan
1998 ◽  
Vol 35 (4) ◽  
pp. 541-559 ◽  
Author(s):  
Branko Ladanyi ◽  
Adolfo Foriero

A numerical solution of a spherical and cylindrical cavity expansion problem in sand is presented herein. The underlying theory is unbiased in that it is based directly on experimentally determined stress-strain curves. The solution makes it possible to follow the continuous variation of strains, stresses, and volume changes produced by cavity expansion. It essentially uses the "strain path" approach to determine the state of stress around the cavity, taking into account large strains and the effect of spherical stress variation on the mobilized shear resistance and the associated volume strains. A limited comparison with experimental data shows a reasonable agreement between theory and measurements.Key words: cavities, expansion, sand, stress-strain curves, numerical solution.


2020 ◽  
Vol 17 (2) ◽  
pp. 2-15
Author(s):  
Ye Lu ◽  
Yun Jiang ◽  
Xiaoyong Wang

In recent years, installing piles using the press-in method has gained popularity in urban areas. However, pushing piles into the ground squeezes the surrounding soils and consequently causes a disturbance or even damage to the underground structures and facilities close by. In order to investigate the squeezing effect incurred by press-in piling, a series of model tests were performed. The soil displacement field was captured using a non-contact technique called digital image correlation (DIC), and the horizontal soil stresses were measured by mini pressure cells. Analyses of the soil displacement fields showed that the pile press-in process caused different soil displacement paths at different depths and locations. The development of horizontal soil stresses correlated well with the horizontal and vertical displacements. A thin disturbance layer could be observed along the pile-soil interface and it was about 7.4-11.1 D50 in thickness (D50, median particle size). At the end, the soil displacements caused by pushing the model pile with different pile shoes were analyzed and compared, and the analyses showed that a greater shoe angle resulted in greater disturbance to the surrounding soils. However, the influence of the pile shoe angle became less substantial with the increase of the pile penetration depth.


1998 ◽  
Vol 35 (1) ◽  
pp. 27-42 ◽  
Author(s):  
Dayakar Penumadu ◽  
Arumugam Skandarajah ◽  
Jean-Lou Chameau

The objective of the present research was to study the effect of rate of probe expansion in pressuremeter testing for cohesive soil. Emphasis in this paper was given to quantifying and modeling the effect of strain rate on the undrained shear strength. The strain path followed by an element of clay adjacent to the expanding probe was simulated using an automated flexible boundary cuboidal shear device (CSD) typically up to a magnitude of strain level of 10%. Two types of soil (kaolin, kaolin-silica mix) were used consistently for all the testing. Repeatable cubical cohesive specimens were obtained from a high water content slurry consolidation technique. K0 consolidation was performed by using a constant vertical stress - zero lateral strain boundary condition using a closed-loop pneumatic system. A series of strain-controlled tests with increasing strain rates from 0.01 to 5%/min was performed under undrained conditions. The effects of increase of strain rate on shear stress - strain behavior and undrained shear strength were quantified. A numerical model based on cylindrical cavity expansion theory which accounts for higher strain rate and its variation with radial distance from an expanding probe membrane was calibrated using the single-element CSD test data.Key words: strain rate, pressuremeter, stress-strain, shear strength, strain path, cavity expansion.


Author(s):  
Benoît Verdon ◽  
Catherine Chabert ◽  
Catherine Azoulay ◽  
Michèle Emmanuelli ◽  
Françoise Neau ◽  
...  

After many years of clinical practice, research and the teaching of projective tests, Shentoub and her colleagues (Debray, Brelet, Chabert & al.) put forward an original and rigorous method of analysis and interpretation of the TAT protocols in terms of psychoanalysis and clinical psychopathology. They developed the TAT process theory in order to understand how the subject builds a narrative. Our article will emphasize the source of the analytical approach developed by V. Shentoub in the 1950s to current research; the necessity of marking the boundary between the manifest and latent content in the cards; the procedure for analyzing the narrative, supported by an analysis sheet for understanding the stories' structure and identifying the defense mechanisms; and how developing hypotheses about how the mental functions are organized, as well as their potential psychopathological characteristics; and the formulation of a diagnosis in psychodynamic terms. In conjunction with the analysis and interpretation of the Rorschach test, this approach allows us to develop an overview of the subject's mental functioning, taking into account both the psychopathological elements that may threaten the subject and the potential for a therapeutic process. We will illustrate this by comparing neurotic, borderline, and psychotic personalities.


Author(s):  
Olha Shumilina

Relevance of the study. The article studies recently found symphony of the prominent Ukrainian composer of the second half of the eighteenth century Maxim Berezovsky. He is widely known now as the author of cyclic spiritual concerts written for the Orthodox worship, and is practically unknown as a musician instrumentalist associated with the imperial theater and the court musical life. The work of M. Berezovsky as a secular musician determined the creative interest in composing instrumental music intended for secular chamber and orchestral music. Main objective of the article is a clarification of M.Berezovsky symphony as one of secular field artworks in the light of new summaries about artist’s life-creativity. Methodology. Taking into account peculiarities of the material and the analytical approach to its study, the methods of theoretical research have been chosen(abstraction, analysis and synthesis, induction and deduction, mental modeling, ascension from abstract to concrete, etc.). Conclusions. As a result of a study the symphony analysis in a context of new authentic statements about M.Berezovsky’s life-creativity. It was stated that this artwork was written not accidentally and detects absolute awareness of the artist in all composer’s niceties – how to build a topic and build a homophonic construction based on it, in a technique of orchestral construction, form creations of that time and etc. From the beginning of his creative career, M. Berezovsky was well aware of the possibilities of the orchestra as a performer, attached to the Italian opera and instrumental music. Symphony enriches our imagination about the works of M. Berezovsky in the field of secular instrumental and operatic music and extends the range of works of the artist beyond the spiritual direction. Some signs indicate that the Symphony was not an independent work, but an overture to the opera Demofont.


Author(s):  
Olha Shumilina

Relevance of the study. The article studies recently found symphony of the prominent Ukrainian composer of the second half of the eighteenth century Maxim Berezovsky. He is widely known now as the author of cyclic spiritual concerts written for the Orthodox worship, and is practically unknown as a musician instrumentalist associated with the imperial theater and the court musical life. The work of M. Berezovsky as a secular musician determined the creative interest in composing instrumental music intended for secular chamber and orchestral music. Main objective of the article is a clarification of M.Berezovsky symphony as one of secular field artworks in the light of new summaries about artist’s life-creativity. Methodology. Taking into account peculiarities of the material and the analytical approach to its study, the methods of theoretical research have been chosen(abstraction, analysis and synthesis, induction and deduction, mental modeling, ascension from abstract to concrete, etc.). Conclusions. As a result of a study the symphony analysis in a context of new authentic statements about M.Berezovsky’s life-creativity. It was stated that this artwork was written not accidentally and detects absolute awareness of the artist in all composer’s niceties – how to build a topic and build a homophonic construction based on it, in a technique of orchestral construction, form creations of that time and etc. From the beginning of his creative career, M. Berezovsky was well aware of the possibilities of the orchestra as a performer, attached to the Italian opera and instrumental music. Symphony enriches our imagination about the works of M. Berezovsky in the field of secular instrumental and operatic music and extends the range of works of the artist beyond the spiritual direction. Some signs indicate that the Symphony was not an independent work, but an overture to the opera Demofont.


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