Reliability on the stability of long continuous earth-structures

2014 ◽  
pp. 239-246
Author(s):  
T Hara ◽  
M Nonoyama ◽  
Y Otake ◽  
Y Honjo
Keyword(s):  
Earth Structures ◽  
The Stability

scholarly journals Measurement of xylem water pressure using High-Capacity Tensiometer and benchmarking against Pressure Chamber and Thermocouple Psychrometer

2020 ◽  
Vol 195 ◽  
pp. 03014
Author(s):  
Roberta Dainese ◽  
Giuseppe Tedeschi ◽  
Thierry Fourcaud ◽  
Alessandro Tarantino
Keyword(s):  
Water Flow ◽  
Water Pressure ◽  
High Capacity ◽  
Ground Surface ◽  
Pressure Chamber ◽  
Rainwater Infiltration ◽  
Thermocouple Psychrometer ◽  
Earth Structures ◽  
Pressure Water ◽  
The Stability

The response of the shallow portion of the ground (vadose zone) and of earth structures is affected by the interaction with the atmosphere. Rainwater infiltration and evapotranspiration affect the stability of man-made and natural slopes and cause shallow foundations and embankments to settle and heave. Very frequently, the ground surface is covered by vegetation and, as a result, transpiration plays a major role in ground-atmosphere interaction. The soil, the plant, and the atmosphere form a continuous hydraulic system, which is referred to as Soil-Plant-Atmosphere Continuum (SPAC). The SPAC actually represents the ‘boundary condition’ of the geotechnical water flow problem. Water flow in soil and plant takes place because of gradients in hydraulic head triggered by the negative water pressure (water tension) generated in the leaf stomata. To study the response of the SPAC, (negative) water pressure needs to be measured not only in the soil but also in the plant. The paper presents a novel technique to measure the xylem water pressure based on the use of the High-Capacity Tensiometer (HCT), which is benchmarked against conventional techniques for xylem water pressure measurements, i.e. the Pressure Chamber (PC) and the Thermocouple Psychrometer (TP).

scholarly journals Stability of Road Earth Structures in the Complex And Complicated Ground Conditions

2018 ◽  
Vol 40 (4) ◽  
pp. 300-312
Author(s):  
Andrzej Batog ◽  
Elżbieta Stilger-Szydło
Keyword(s):  
High Variability ◽  
Stability Margins ◽  
The Road ◽  
Stability Of Slopes ◽  
Earth Structures ◽  
Ground Conditions ◽  
The Stability

AbstractSome important modern problems of the transport engineering, which occur in the newly built and modernised road objects, have been indicated in the work. A discussion was conducted regarding the methods of assessing the stability of slopes of the road embankments, the obtained stability margins and the interpretation of obtained results in the specific cases of foundations of the road earth structures. Presented observations result from analysing the stability assessments of slopes of the road embankments, which was conducted on many communication objects, characterised by high variability of foundation conditions.

Prediction of Soft Ground Settlement by BP Neural Network

2014 ◽  
Vol 608-609 ◽  
pp. 825-828
Author(s):  
Song Lin Li ◽  
Shun You He ◽  
Xiao Ting Wang ◽  
Shi Wan Chen ◽  
Xin Yuan Guo
Keyword(s):  
Neural Network ◽  
Prediction Method ◽  
Soft Ground ◽  
Ground Settlement ◽  
Matlab Simulation ◽  
Engineering Construction ◽  
Bp Artificial Neural Network ◽  
Earth Structures ◽  
The Stability ◽  
High Degree

There are many engineering characteristics for soft ground. It is an urgent problem for engineering construction to predict settlement according to the features of soft ground and existing settlement data. In this paper, we used the measured settlement data of soft ground, then come up with the prediction method of soft ground settlement based on the BP artificial neural network in the Matlab simulation environment. This method can modelling highly complex and nonlinear earth structures directly based on real samples. Practical test showed that this method has a high degree of accuracy, and it is very valuable to instruct construction and guarantee the stability of the ground.

scholarly journals Application of the terrestrial laser scanner in the monitoring of earth structures

2020 ◽  
Vol 12 (1) ◽  
pp. 503-517
Author(s):  
Janusz P. Kogut ◽  
Elżbieta Pilecka
Keyword(s):  
Laser Scanning ◽  
Numerical Models ◽  
Laser Scanner ◽  
The Finite Element Method ◽  
Earth Structures ◽  
Multiple Measurements ◽  
The Stability ◽  
Term Monitoring ◽  
Ground Material

AbstractTerrestrial laser scanning (TLS) assists in the detection of the unsafe behaviour of slopes and scarps. It also facilitates the assessment of the stability of earthworks. Earth structures are those that are usually made of qualified ground material. One may distinguish between point structures such as mounds, forts and dams, and linear structures such as roads, railways and flood embankments. This article concerns the problem of monitoring and analysing of the effects associated with the unstable behaviour of selected earth structures. TLS enables remote sensing of surface changes in a simple and automated manner. Regular, multiple measurements with the laser scanner are applied in long-term monitoring of the behaviour of the selected objects. The discrete numerical models using, for example, the finite element method (FEM) take into account geotechnical properties of substrate and allow for the risk assessment and stability testing of such structures. The numerical model of the structure along with the parameters of the substrate are introduced into the FEM package. This allows for the analysis of stresses, strains and displacements, along with different loading cases. The work here presents a few selected earth structures for which the aforementioned analyses have been undertaken.

scholarly journals Low-Strength Substrates and Anthropogenic Soils in Transportation Engineering

2018 ◽  
Vol 40 (4) ◽  
pp. 292-299 ◽  
Author(s):  
Andrzej Batog ◽  
Elżbieta Stilger-Szydło
Keyword(s):  
Power Plants ◽  
Transport Infrastructure ◽  
Transportation Engineering ◽  
Anthropogenic Soils ◽  
Soil Material ◽  
Earth Structures ◽  
Ground Conditions ◽  
Low Strength ◽  
The Stability ◽  
Construction Works

AbstractRoad embankments, especially their slopes’ surfaces, must fulfil all the requirements concerning the exploitation criteria after the completion of construction works. This is very important while constructing or modernizing the embankments, based on the substrate including low-strength soils as well as in simple ground conditions (most convenient). The last dozen or so years of intensive construction of transport infrastructure have shown how big is the problem of ensuring the required volumes of qualified soil material for the construction of road embankments or the modernization of railway embankments. The depleting deposits of natural and easily accessible soils for the construction of embankments result in the need to use anthropogenic soils, for example, in the form of aggregates from the recycling of construction waste and other locally available waste materials, usually in the form of slag and ashes from the combined heat and power plants. In such cases, there’s a need to treat transportation earth structures individually in the scope of designing and quality control, because there are no applicable standard provisions in this scope.This work indicates some of these important contemporary problems of transport engineering, occurring in newly built and modernized road objects, such as the stability of road embankments based on a low-strength substrate, use of anthropogenic soils and materials originating from the recycling of concrete surfaces for the construction of road embankments.

Open discussion

1982 ◽  
Vol 99 ◽  
pp. 605-613
Author(s):  
P. S. Conti
Keyword(s):  
Buenos Aires ◽  
Large Mass ◽  
List Type ◽  
Common Phenomenon ◽  
Open Discussion ◽  
The Stability ◽  
Ring Nebulae

Conti: One of the main conclusions of the Wolf-Rayet symposium in Buenos Aires was that Wolf-Rayet stars are evolutionary products of massive objects. Some questions:–Do hot helium-rich stars, that are not Wolf-Rayet stars, exist?–What about the stability of helium rich stars of large mass? We know a helium rich star of ∼40 MO. Has the stability something to do with the wind?–Ring nebulae and bubbles : this seems to be a much more common phenomenon than we thought of some years age.–What is the origin of the subtypes? This is important to find a possible matching of scenarios to subtypes.

Symmetric Multistep Methods Revisited: II. Numerical Experiments

1999 ◽  
Vol 173 ◽  
pp. 309-314 ◽  
Author(s):  
T. Fukushima
Keyword(s):  
Multistep Methods ◽  
Computational Time ◽  
Integration Time ◽  
Implicit Methods ◽  
Symmetric Methods ◽  
Celestial Bodies ◽  
The Stability ◽  
Predictor Corrector ◽  
Symmetric Multistep Methods ◽  
Integration Errors

AbstractBy using the stability condition and general formulas developed by Fukushima (1998 = Paper I) we discovered that, just as in the case of the explicit symmetric multistep methods (Quinlan and Tremaine, 1990), when integrating orbital motions of celestial bodies, the implicit symmetric multistep methods used in the predictor-corrector manner lead to integration errors in position which grow linearly with the integration time if the stepsizes adopted are sufficiently small and if the number of corrections is sufficiently large, say two or three. We confirmed also that the symmetric methods (explicit or implicit) would produce the stepsize-dependent instabilities/resonances, which was discovered by A. Toomre in 1991 and confirmed by G.D. Quinlan for some high order explicit methods. Although the implicit methods require twice or more computational time for the same stepsize than the explicit symmetric ones do, they seem to be preferable since they reduce these undesirable features significantly.

Uniformity of Magnification from Different Electron Microscopes

1967 ◽  
Vol 25 ◽  
pp. 32-33
Author(s):  
Godfrey C. Hoskins ◽  
V. Williams ◽  
V. Allison
Keyword(s):  
Diffraction Grating ◽  
The Other ◽  
Carbon Replica ◽  
Electron Microscopes ◽  
The Stability

The method demonstrated is an adaptation of a proven procedure for accurately determining the magnification of light photomicrographs. Because of the stability of modern electrical lenses, the method is shown to be directly applicable for providing precise reproducibility of magnification in various models of electron microscopes.A readily recognizable area of a carbon replica of a crossed-line diffraction grating is used as a standard. The same area of the standard was photographed in Phillips EM 200, Hitachi HU-11B2, and RCA EMU 3F electron microscopes at taps representative of the range of magnification of each. Negatives from one microscope were selected as guides and printed at convenient magnifications; then negatives from each of the other microscopes were projected to register with these prints. By deferring measurement to the print rather than comparing negatives, correspondence of magnification of the specimen in the three microscopes could be brought to within 2%.

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