Difficult behavior of young continental “loess – like” clayey soil deposits of mud-volcanogenetic heritage in Azerbaijan

2016 ◽  
pp. 119-129
Author(s):  
E Vicente ◽  
A Krumb ◽  
F Ulbricht
1994 ◽  
Vol 31 (2) ◽  
pp. 204-214 ◽  
Author(s):  
Chang-Yu Ou ◽  
Ching-Her Lai

This paper presents an application of finite-element analysis to deep excavation in layered sandy and clayey soil deposits using a combination of the hyperbolic and the Modified Cam-clay models. In the analysis, the drained behavior of cohesionless soil and the undrained behavior of cohesive soil were simulated using the hyperbolic and Modified Cam-clay models, respectively. A rational procedure for determining soil parameters for each of the models was established. A simulation of the dewatering process during excavation was proposed. The analytical procedure was confirmed through an analysis of three actual excavation cases. Finally, analyses considering pore-water pressure dissipation during the actual elapsed time for each construction phase were carried out. The results indicate that the calculated displacement of a retaining wall during excavation is smaller than that given by undrained analysis. It was thought that some degree of pore-water pressure dissipation actually occurs during the intermediate excavation stages. This results in a decrease in the final deformation of the wall and ground.-surface settlement than would be predicted by undrained analysis. Key words : finite-element analysis, deep excavation, hyperbolic model, Cam-clay model.


2014 ◽  
Vol 21 (4) ◽  
pp. 1554-1564 ◽  
Author(s):  
Jian-lin Ma ◽  
Hussein Yousif Aziz ◽  
Chun-hui Su ◽  
Cong Shi

2014 ◽  
Vol 17 (10) ◽  
pp. 1387-1402 ◽  
Author(s):  
Behzad Fatahi ◽  
S. Hamid Reza Tabatabaiefar

In this study, the effects of Plasticity Index (PI) variation on the seismic response of mid-rise building frames resting on soft soil deposits are investigated. To achieve this goal, three structural models including 5, 10, and 15 storey buildings are simulated in conjunction with a clayey soil representing soil class Ee according to the classification of AS1170.4–2007 (Earthquake actions in Australia) and then varying the Plasticity Index. Structural sections of the selected frames were designed according to AS3600–2009 (Australian Standard for Concrete Structures) after undertaking dynamic analysis under the influence of four different earthquake ground motions. The frame sections are modelled and analysed, employing finite difference method adopting FLAC 2D software under two different boundary conditions: (i) fixed base (no Soil-Structure Interaction), and (ii) flexible base considering soil-structure interaction. Fully nonlinear dynamic analyses under the influence of different earthquake records are conducted and the results in terms of maximum lateral displacements and inter-storey drifts for the above mentioned boundary conditions are obtained, compared, and discussed. Base on the results of the numerical investigations, it becomes apparent that as the Plasticity Index of the subsoil increases, the base shears of mid-rise building frames resting on soft soil deposits increase, while the lateral deflections and corresponding inter-storey drifts decrease. It is concluded that reduction of the Plasticity Index could noticeably amplify the effects of soil-structure interaction on the seismic response of mid-rise building frames.


Author(s):  
Ahmed Elkhebu ◽  
◽  
Adnan Zainorabidin ◽  
Ismail Hj. Bakar ◽  
Bujang B. K. Huat ◽  
...  

2018 ◽  
Vol 28 (3) ◽  
pp. 1021-1026
Author(s):  
Rozalia Kuzmanova – Kartalova

An analysis of the social pedagogical work with difficult children is presented, outlining characteristics, specifics and approaches for prevention and social accompaniment. In order to highlight the specifics of this group of children, a comparison is made with two other groups of children in a situation of life difficulty - "socially disadvantaged children" and "children at risk". The analysis refers to the understanding that difficult children are children with impaired emotional development, difficulty in communicating with others and disrupted behavioral control, all of which can lead to consequences both on a personal and behavioral level. It is emphasized that difficult children turn into such in situations where adults cannot find an adequate approach to them, and most often these adults are members of the family, parents, or teachers. An overview of scientific positions on difficult children by English, American, Russian and Bulgarian researchers is offered. This is the basis for outlining the main spheres which affect children negatively and categorize them as "difficult children" - emotional-personal; learning-cognitive; behavioral; somatic. The reasons for children’s difficult behavior are examined, including: the family and the flaws in it; the lack of spiritual connection between parents and children; the asocial environment; participation in criminal groups; errors in the work of educational institutions; economic difficulties that have influenced all spheres of public life. The characteristics of problem children are presented that account for the formulation of the principles of social pedagogical work with them. It is emphasized that one of the important approaches in the work is the development of skills for social inclusion, social expression and self-assertion. The model for social pedagogical work with difficult children is developed in two aspects: preventive work and social accompaniment. Preventive work consists in constantly informing all stakeholders - teachers, educators, non-pedagogical staff in educational institutions and the family on the opportunities for preventing "difficult children" on the one hand, and ensuring interaction between the participants in the preventive activities as well as striving to attract more organizations and institutions, on the other. The social accompaniment as a social pedagogical work includes: identification of children with difficult behavior at the earliest stage of the disadaptation process, diagnosis of the factors of the difficult behavior and the reasons for the disadvantage, preparation of an individual road map for working with the child, implementation of the individual program for accompanying the child, measuring and analyzing the results of the child's work and his / her close circle.


2020 ◽  
Author(s):  
Harpinder Pal Singh ◽  
Jaspreet Singh Chana ◽  
Gurpreet Singh ◽  
Hardev Singh ◽  
Manvir Singh

1995 ◽  
Vol 32 (7) ◽  
pp. 215-219 ◽  
Author(s):  
Magdelinka Radenkova-Yaneva ◽  
Emilia Kostakeva ◽  
Dimiter Toshev

It is well known that the leachates from solid domestic waste sanitary landfills are heavily polluted with organic and inorganic substances. As they are of a potential danger for the environment, their uncontrolled seepage is avoided in the modern sanitary landfills by means of suitable insulation. This is mostly made of natural materials with a low filtration coefficient. The present paper considers the results of the filtration characteristics, studying natural clayey soil model liners. The leachate contaminants distribution from the sanitary landfill in Sofia (Suhodol) is traced out in different liner depths. The mechanism of pollutant attenuation in the liners is considered. It is found that a part of the leachate components (Fe, Mn, SO42−, PO43−) stays in clayey liners. Besides, as a result of pore colmatation the permeability of the liners is decreased. It is shown that soil monoliths with a proper thickness might serve as a sufficiently safe barrier against leachate filtration in adjacent aquifers. On the base of the results obtained the thickness of the clay liners in the solid domestic waste sanitary landfills could be optimized.


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