scholarly journals Técnica constructiva de terraplenes húmedos y su aplicación en la geotecnia moderna

2016 ◽  
Vol 17 (3) ◽  
pp. 311
Author(s):  
Gonzalo Carnero ◽  
Erasmo Carnero Carnero
Keyword(s):  
Three Dimensional ◽  
High Capacity ◽  
Sao Paulo ◽  
Triaxial Tests ◽  
Residual Soil ◽  
São Paulo ◽  
Three Dimensional Representation ◽  
Optimum Water Content ◽  
Unsaturated Condition ◽  
Optimum Water

<p align="center"><strong>RESUMEN</strong></p><p>La compactación de suelos en lugares con elevada precipitación pluvial presenta dificultades que afectan los cronogramas físicos y financieros de las obras. Comúnmente, el suelo requiere ser secado cerca a la humedad óptima (+/- 3%), sin embargo, existe la posibilidad de emplear la técnica constructiva de “terraplenes húmedos” que consiste en compactar el suelo con humedades altas, en las cuales, el suelo se encuentra en el “estado quasi-saturado”. Para poder emplear esta técnica, es importante conocer la succión que el suelo tendrá durante la construcción que puede ser obtenida en laboratorio mediante el tensiómetro de alta capacidad (HCT), equipo moderno que monitora la succión en tiempo real. El presente trabajo realiza una revisión de las investigaciones ejecutadas por Marinho y Massad (2011) y Carnero (2014) ambas realizadas con un suelo residual de la Universidade de Sao Paulo, Brasil que fue estudiado ampliamente para conocer su comportamiento en condición no saturada. Los investigadores realizaron ensayos de confinamiento constante (PH), ensayos triaxiales en condición saturada (CU) y no saturada (CW). Los valores de succión de los ensayos PH y CW fueron obtenidos con el HCT y demostraron la eficiencia del equipo. La investigación concluye definiendo el valor de presión de positivación, los parámetros de resistencia efectivos, las ecuaciones de resistencia no saturada según Bishop (1959) y Fredlund et al. (1978) y la representación tridimensional de resistencia en condición no saturada.</p><p> </p> <p> </p><p align="center"><strong>ABSTRACT</strong></p><p>The compaction of soils in places with high rainfall has problems that affects the physical and financial schedule of works. Commonly, the soils requires to be dry in the vicinity of the optimum water content (+/-3 %), however, there is the possibility to use the constructive technique of “wet fills” consisting in compact the soils with high moisture values, in which, the soils is the “quasi-saturated state”. To employ this technique, it is important to know the soil suction during the construction, which it may be obtained in laboratory using the high capacity tensiometer (HCT), modern equipment that monitors the suction in real time. The present work makes a revision of the investigations conducted by Marinho y Massad (2011) and Carnero (2014), both performed with a residual soil from the Universidade de Sao Paulo, Brasil which was broadly studied in order to know its behaviour in unsaturated condition. The researchers conducted constant confined test (PH), saturated (CU) and unsaturated (CW) triaxial tests. The values of suction of the PH and CW tests were obtained by the HCT and validated the equipment efficiency. The research concluded defining the positivation pressure value, the effective strength parameters, the equations of unsaturated resistance according to Bishop (1959) and Fredlund et al. (1978) and the resistance three-dimensional representation in unsaturated condition.</p>

Experimental Study on Mechanical Characteristics of CSG Materials

2011 ◽  
Vol 243-249 ◽  
pp. 2059-2064
Author(s):  
De Gao Zou ◽  
Dong Qing Li ◽  
Bin Xu ◽  
Xian Jing Kong
Keyword(s):  
Mechanical Characteristics ◽  
Shear Failure ◽  
Triaxial Tests ◽  
Cemented Sand ◽  
Optimum Water Content ◽  
Strain Relationship ◽  
Mode Stress ◽  
New Type ◽  
Sand And Gravel ◽  
Optimum Water

Cemented sand and gravel (CSG) is a new type of dam materials. It not only can reduce the waste of resources and environmental pollution, but has the merits of both gravel and concrete. In this study, Cemented sand and gravel specimens with three cement ratios were compacted at optimum water content and cured for 14 days. Based on the consolidated drained shear triaxial tests, the mechanical properties of different proportion of CSG are studied on shear failure mode, stress-strain relationship, shear strength. Research results showed that, with the increasing of the content of cement, the peak and residual strength of CSG were improved, but the failure strains were decreased. In addition, CSG material behaves distinctly softening.

scholarly journals Morphometric analysis of an Areal Watershed in Taubaté, SP, Brazil

2019 ◽  
Vol 14 (7) ◽  
pp. 1
Author(s):  
Vicente Rodolfo Santos Cezar ◽  
Marcelo Dos Santos Targa ◽  
Celso De Souza Catelani
Keyword(s):  
Land Use ◽  
River Basin ◽  
Morphometric Analysis ◽  
High Surface ◽  
High Capacity ◽  
Sediment Concentration ◽  
Sao Paulo ◽  
São Paulo ◽  
Circularity Index

      In 1991, the Integrated Water Resources Management System (SIGRHI) in the State of São Paulo adopted the watershed as a territorial unit for studies, integrated planning and sustainable development. The morphometric analysis of small watersheds, which involves the characterization of geometric parameters, relief, drainage network, combined with land use and occupation, may constitute an important model for environmental analysis of larger watersheds. This study aimed at characterization of the morphometry in the Areal river basin, in the city of Taubaté, São Paulo. The study found 1.89 km² of area, 7.44 km of perimeter and 3.11 km in length of the basin axis, which allowed the calculation of the compactness coefficient (Kc = 1.51), form factor, (F = 0.195) and circularity index (CI = 0.43), indicating that under normal precipitation conditions, this basin is unlikely to be flooded, due to the distance from the unit, leading to smaller concentrate outflow. The results obtained for the Maintenance Coefficient (Cm) indicate that 260 m² is required to maintain each meter of perennial channel. The high values of drainage density (Dd = 3.35 km.km-2) and sinuosity index (Is = 0.95) indicate that drainage channels in the area are rectilinear, thus suggesting the occurrence of a high surface runoff associated with high dissection. The analysis of land use and occupation revealed that, from the seven types of vegetation cover, the dominant cover in the Areal basin is 0.756 km2 (40%) constituted of pasture, while forest represents 0.580 km2 (31%), 0.321 km2 (17%) of the land cover is constituted of degraded forest. In terms of conservation, the Areal basin is conserved because, besides being located in the environmental preservation area of the Una River Basin, it is located at the meeting of two ecological corridors and is occupied by only 8 families of rural producers. On the other hand, the creation of approximately 120 head of cattle in the upper part of the basin and the existence of gully erosion of the order of 0.018 km2 (1%) of the basin area, which led to increased runoff and sediment concentration in the flat areas marginal to the creek of Areal. Based on morphometric analysis, it was concluded that: Areal watershed presents high capacity to form new watercourses and their relief characteristics, with low sinuosity channels and high values of altimetric amplitude, channel gradient, and density. Drainage, allied to the existence of erosive processes, favors sediment flow and transport. Conservation actions are required to control erosion.

Improving Population Mapping and Exposure Assessment: Three-Dimensional Dasymetric Disaggregation in New York City and São Paulo, Brazil

2019 ◽  
Vol 5 (1-2) ◽  
pp. 45-57 ◽  
Author(s):  
Andrew Maroko ◽  
Juliana Maantay ◽  
Reinaldo Paul Pérez Machado ◽  
Ligia Vizeu Barrozo
Keyword(s):  
New York ◽  
New York City ◽  
Exposure Assessment ◽  
York City ◽  
Three Dimensional ◽  
Sao Paulo ◽  
São Paulo ◽  
Population Mapping

Three-Dimensional Nonlinear Analyses of a Metro Tunnel in São Paulo Porous Clay, Brazil

2011 ◽  
Vol 137 (4) ◽  
pp. 376-384 ◽  
Author(s):  
J. Almeida e Sousa ◽  
A. Negro ◽  
M. Matos Fernandes ◽  
A. S. Cardoso
Keyword(s):  
Three Dimensional ◽  
Sao Paulo ◽  
São Paulo ◽  
Nonlinear Analyses ◽  
Metro Tunnel

Revealing gross three-dimensional structure in the SEM

1987 ◽  
Vol 45 ◽  
pp. 656-657
Author(s):  
Sterling P. Newberry
Keyword(s):  
Freeze Drying ◽  
Three Dimensional ◽  
Dimensional Structure ◽  
Small Object ◽  
Final Solution ◽  
Dimensional Representation ◽  
X Ray ◽  
Three Dimensional Representation ◽  
Freeze Dried ◽  
Critical Point Drying

The beautiful three dimensional representation of small object surfaces by the SEM leads one to search for ways to open up the sample and look inside. Could this be the answer to a better microscopy for gross biological 3-D structure? We know from X-Ray microscope images that Freeze Drying and Critical Point Drying give promise of adequately preserving gross structure. Can we slice such preparations open for SEM inspection? In general these preparations crush more readily than they slice. Russell and Dagihlian got around the problem by “deembedding” a section before imaging. This some what defeats the advantages of direct dry preparation, thus we are reluctant to accept it as the final solution to our problem. Alternatively, consider fig 1 wherein a freeze dried onion root has a window cut in its surface by a micromanipulator during observation in the SEM.

Seasonal Variation of Suicide in the City of São Paulo, Brazil, 1996–2010

Crisis ◽  
2014 ◽  
Vol 35 (1) ◽  
pp. 5-9 ◽  
Author(s):  
Daniel Hideki Bando ◽  
Fernando Madalena Volpe
Keyword(s):  
Seasonal Pattern ◽  
Total Sample ◽  
Sao Paulo ◽  
Seasonal Patterns ◽  
São Paulo ◽  
Health Statistics ◽  
Males And Females ◽  
June July ◽  
The City ◽  
Over Time

Background: In light of the few reports from intertropical latitudes and their conflicting results, we aimed to replicate and update the investigation of seasonal patterns of suicide occurrences in the city of São Paulo, Brazil. Methods: Data relating to male and female suicides were extracted from the Mortality Information Enhancement Program (PRO-AIM), the official health statistics of the municipality of São Paulo. Seasonality was assessed by studying distribution of suicides over time using cosinor analyses. Results: There were 6,916 registered suicides (76.7% men), with an average of 39.0 ± 7.0 observed suicides per month. For the total sample and for both sexes, cosinor analysis estimated a significant seasonal pattern. For the total sample and for males suicide peaked in November (late spring) with a trough in May–June (late autumn). For females, the estimated peak occurred in January, and the trough in June–July. Conclusions: A seasonal pattern of suicides was found for both males and females, peaking in spring/summer and dipping in fall/winter. The scarcity of reports from intertropical latitudes warrants promoting more studies in this area.

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