Design and Construction Aspects of the Largest ''Pile Curtain'' Retaining Structure Built in the Tropical Soil of the Brazilian Central Area

2006 ◽  
Author(s):  
R. P. Cunha ◽  
A. G. B. Medeiros ◽  
C. M. Silva
Keyword(s):  
Central Area ◽  
Tropical Soil ◽  
Retaining Structure ◽  
Design And Construction

Analysis on Reinforcement and Design of a Historic Building Retrofitting Project

2013 ◽  
Vol 671-674 ◽  
pp. 622-625
Author(s):  
Ming Liu ◽  
Xin Hai Fan ◽  
Lin Liu
Keyword(s):  
Seismic Performance ◽  
Frame Structure ◽  
Original Structure ◽  
Construction Process ◽  
Exterior Wall ◽  
Historic Building ◽  
Retaining Structure ◽  
Concrete Frame ◽  
Reinforcement Design ◽  
Design And Construction

Retrofitting and reinforcement project of a historic hotel building are introduced in article. The method of increasing new concrete frame structure in original structure interior and the original exterior wall considered as a retaining structure was adopted in the retrofitting and reinforcement project. The structure subjecting to the force was clear and the reinforcement construction process was relatively simple after the retrofitting and reinforcement. Design and construction of the structure strengthened are according to the existing code completely and can ensure the safety and the seismic performance of the structure.

scholarly journals Class A prediction of a retaining structure made by a pile curtain wall executed on a tropical soil

DYNA ◽  
2017 ◽  
Vol 84 (202) ◽  
pp. 278-288 ◽  
Author(s):  
Juan Carlos Ruge-Cárdenas ◽  
Renato Da Cunha ◽  
Julio Esteban Colmenares ◽  
Cristhian Camilo Mendoza
Keyword(s):  
Tropical Soil ◽  
Curtain Wall ◽  
Retaining Structure ◽  
Class A

Algunas estructuras de contención de acuerdo con su diseño geotécnico y plan de construcción predefinido.  Por supuesto, esto no extrapolable a todos los sitios de análisis, sin embargo, en Brasilia, donde predominan los suelos residuales y lateralizados, se obtienen las mejores resistencias mecánicas en los estratos porosos durante la estación seca. Esto significa que es controlada por la succión del suelo, es decir, el comportamiento del material presenta una dependencia de la respuesta no saturada del medio. En términos numéricos, para predecir el comportamiento suelo-estructura fue necesario incluir la interacción atmósfera-suelo en una herramienta computacional, utilizando un modelo hipoplástico. El trabajo detalla de esta manera las simulaciones numéricas de una estructura de retención fundada en el suelo tropical de Brasilia. La estructura fue monitoreada en términos de desplazamiento, a lo largo de las estaciones locales secas y húmedas, y fue simulada por una ley constitutiva calibrada mediante pruebas de laboratorio no saturadas.

scholarly journals Design and Execution of Turdas Tunnel

2019 ◽  
Vol 8 (2) ◽  
pp. 44-57
Author(s):  
Flaviu Ioan Nică ◽  
Teodor Iftimie
Keyword(s):  
Three Dimensional ◽  
Central Area ◽  
Optimal Solution ◽  
Middle Part ◽  
Component Part ◽  
Maximum Speed ◽  
Silty Clay ◽  
Alluvial Deposits ◽  
Retaining Structure ◽  
Internal Lining

Abstract The paper presents aspects of the design and execution of the Turdas tunnel located on the local variant (route), on the Coşlariu - Simeria section, from the rehabilitation project of Brasov – Simeria railway line, component part of Pan European Railway Corridor IV, for train circulation with maximum speed of 160km/h. The tunnel crosses through alluvial deposits with silt and clay with locally sand layers at the upper part, sand and gravel with water in the middle part and marly silty clay and neogenic marl, with swelling phenomena, at the lower part. The overburden is between 2.00m and 13.00m. The initial project provided execution in underground, on 510.00m in the central area and from surface at both ends, 225.00m at the entrance and 45.00m at the exit. The new optimized project, based on new geological and geotechnical studies, proposed an execution from surface for the entire length of the tunnel. To establish the optimal solution two methods of surface execution and structural solutions were analyzed comparatively: “Cut and Cover” and “Cover and Cut”. The adopted method was “Cut and Cover”, with a structural solution composed of a temporary retaining structure – diaphragm walls with a special internal lining. This has been divided in six sections with different behavioral types, taking into account the ground configuration in longitudinal profile and the geological and geotechnical data. The technological execution phases are presented in detail. To investigate the behavior of this type of structure under soil and swelling actions, three-dimensional finite element analyses were carried out, taking into account the execution phases for each cross section. A monitoring system was provided to verify the stresses in the temporary retaining structure and the internal lining and also to calibrate future calculations.

scholarly journals Design, construction and analysis for super-wide, deep and large foundation pit

2021 ◽  
Vol 72 (1) ◽  
pp. 117-126
Author(s):  
Shi Shenjie ◽  
Tian Angran ◽  
Zheng Yongsheng ◽  
Yin Peng ◽  
Qi Weilin ◽  
...  
Keyword(s):  
Mechanical Performance ◽  
Side Wall ◽  
Developed Countries ◽  
Underground Space ◽  
Deep Foundation ◽  
Foundation Pit ◽  
Maximum Deformation ◽  
Retaining Structure ◽  
Finite Element Software ◽  
Design And Construction

Both developing and developed countries are facing a series of difficulties and challenges in the process of urbanization. In recent years, in order to alleviate the problem of urban congestion, underground space has developed rapidly, and the excavation of foundation pit is the most important step in the development of underground space. This paper takes the foundation pit of the tunnel under construction in Suzhou as a research object. The design width of the foundation pit reaches 61.5 m and the depth reaches 18 m, so it belongs to the super wide and deep foundation pit. Numerical analysis is performed by finite element software to calculate the deformation of the foundation pit. The research shows that the main problem to be solved is the deformation of the foundation pit, and the deformation of side wall of foundation pit tunnel is the most obvious. The maximum deformation of the side wall of the main tunnel and the auxiliary tunnel reached the maximum at 15 m. The maximum deformation of the main tunnel is about 1.3 cm, and that of the auxiliary tunnel is about 0.9 cm. Through targeted design and construction, the mechanical performance of the foundation pit retaining structure is optimized, and the stability of the foundation pit is strengthened. The reasonable retaining structure can ensure the good construction quality. The design and construction of the project can provide reference for related engineering construction.

The crystallography characteristic of (Mn,Fe)S single crystal

1990 ◽  
Vol 48 (4) ◽  
pp. 898-899
Author(s):  
Jiang Xishan
Keyword(s):  
Single Crystal ◽  
Cast Steel ◽  
Point Group ◽  
Central Area ◽  
Hexagonal Crystal ◽  
Growth Step ◽  
Left And Right ◽  
Relationship Of ◽  
Fcc Structure ◽  
New Discovery

This paper reports the growth step pattern and morphology at equilibrium and growth states of (Mn,Fe)S single crystal on the wall of micro-voids in ZG25 cast steel by using scanning electron microscope. Seldom report was presented on the growth morphology and steppattern of (Mn,Fe)S single crystal.Fig.1 shows the front half of the polyhedron of(Mn,Fe)S single crystal,its central area being the square crystal plane,the two pairs of hexagons symmetrically located in the high and low, the left and right with a certain, angle to the square crystal plane.According to the symmetrical relationship of crystal, it was defined that the (Mn,Fe)S single crystal at equilibrium state is tetrakaidecahedron consisted of eight hexagonal crystal planes and six square crystal planes. The macroscopic symmetry elements of the tetrakaidecahedron correpond to Oh—n3m symmetry class of fcc structure,in which the hexagonal crystal planes are the { 111 } crystal planes group,square crystal plaits are the { 100 } crystal planes group. This new discovery of the (Mn,Fe)S single crystal provides a typical example of the point group of Oh—n3m.

Chronic immobilization stress induces anxiety-related behaviors and affects brain essential minerals in male rats

2020 ◽  
pp. 1-8
Author(s):  
Zafer Sahin ◽  
Alpaslan Ozkurkculer ◽  
Omer Faruk Kalkan ◽  
Ahmet Ozkaya ◽  
Aynur Koc ◽  
...  
Keyword(s):  
Immobilization Stress ◽  
Central Area ◽  
Essential Elements ◽  
Male Rats ◽  
Control Group ◽  
Male Wistar Rats ◽  
Swimming Test ◽  
The Brain ◽  
Center Area ◽  
Chronic Immobilization Stress

Abstract. Alterations of essential elements in the brain are associated with the pathophysiology of many neuropsychiatric disorders. It is known that chronic/overwhelming stress may cause some anxiety and/or depression. We aimed to investigate the effects of two different chronic immobilization stress protocols on anxiety-related behaviors and brain minerals. Adult male Wistar rats were divided into 3 groups as follows ( n = 10/group): control, immobilization stress-1 (45 minutes daily for 7-day) and immobilization stress-2 (45 minutes twice a day for 7-day). Stress-related behaviors were evaluated by open field test and forced swimming test. In the immobilization stress-1 and immobilization stress-2 groups, percentage of time spent in the central area (6.38 ± 0.41% and 6.28 ± 1.03% respectively, p < 0.05) and rearing frequency (2.75 ± 0.41 and 3.85 ± 0.46, p < 0.01 and p < 0.05, respectively) were lower, latency to center area (49.11 ± 5.87 s and 44.92 ± 8.04 s, p < 0.01 and p < 0.01, respectively), were higher than the control group (8.65 ± 0.49%, 5.37 ± 0.44 and 15.3 ± 3.32 s, respectively). In the immobilization stress-1 group, zinc (12.65 ± 0.1 ppm, p < 0.001), magnesium (170.4 ± 1.7 ppm, p < 0.005) and phosphate (2.76 ± 0.1 ppm, p < 0.05) levels were lower than the control group (13.87 ± 0.16 ppm, 179.31 ± 1.87 ppm and 3.11 ± 0.06 ppm, respectively). In the immobilization stress-2 group, magnesium (171.56 ± 1.87 ppm, p < 0.05), phosphate (2.44 ± 0.07 ppm, p < 0.001) levels were lower, and manganese (373.68 ± 5.76 ppb, p < 0.001) and copper (2.79 ± 0.15 ppm, p < 0.05) levels were higher than the control group (179.31 ± 1.87 ppm, 3.11 ± 0.06 ppm, 327.25 ± 8.35 ppb and 2.45 ± 0.05 ppm, respectively). Our results indicated that 7-day chronic immobilization stress increased anxiety-related behaviors in both stress groups. Zinc, magnesium, phosphate, copper and manganese levels were affected in the brain.

Shall I Move My Right or My Left Hand?

2003 ◽  
Vol 17 (2) ◽  
pp. 69-86 ◽  
Author(s):  
Claudio Babiloni ◽  
Fabio Babiloni ◽  
Filippo Carducci ◽  
Febo Cincotti ◽  
Claudio Del Percio ◽  
...  
Keyword(s):  
Bimanual Coordination ◽  
Central Area ◽  
Eeg Analysis ◽  
Complementary Information ◽  
Left Hand ◽  
Mirror Movements ◽  
Related Potentials ◽  
Motor Acts ◽  
Abstract Event

Abstract Event-related desynchronization/synchronization (ERD/ERS) at alpha (10Hz), beta (20Hz), and gamma (40Hz) bands and movement-related potentials (MRPs) were investigated in right-handed subjects who were “free” to decide the side of unilateral finger movements (“fixed” side as a control). As a novelty, this “multi-modal” EEG analysis was combined with the evaluation of involuntary mirror movements, taken as an index of “bimanual competition.” A main issue was whether the decision regarding the hand to be moved (“free” movements) could modulate ERD/ERS or MRPs overlying sensorimotor cortical areas typically involved in bimanual tasks. Compared to “fixed” movements, “free” movements induced the following effects: (1) more involuntary mirror movements discarded from EEG analysis; (2) stronger vertex MRPs (right motor acts); (3) a positive correlation between these potentials and the number of involuntary mirror movements; (4) gamma ERS over central areas; and (5) preponderance of postmovement beta ERS over left central area (dominant hemisphere). These results suggest that ERD/ERS and MRPs provide complementary information on the cortical processes belonging to a lateralized motor act. In this context, the results on vertex MRPs would indicate a key role of supplementary/cingulate motor areas not only for bimanual coordination but also for the control of “bimanual competition” and involuntary mirror movements.

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