Groundwater modelling of a weathered gneissic cover

2006 ◽  
Vol 43 (11) ◽  
pp. 1153-1166 ◽  
Author(s):  
Leonardo Cascini ◽  
Giovanni Gullà ◽  
Giuseppe Sorbino
Keyword(s):  
Flow Model ◽  
Unsaturated Flow ◽  
Rainfall Events ◽  
Stability Of Slopes ◽  
Pore Pressures ◽  
Weathered Rocks ◽  
Quiescence Period ◽  
The Stability

Knowledge of the groundwater regime, which is generally necessary in studying the stability of slopes, is of fundamental importance in the analysis of landslides involving intensely weathered rocks, as in the case of a landslide in the western Sila Massif (southern Italy) reactivated by heavy and prolonged rainfall. For this landslide, the total absence of displacements during the actual quiescence period and the long return period of the critical rainfall events did not allow measurement of the critical pore pressures capable of reactivating the landslide. To solve such a problem, a saturated–unsaturated flow model was calibrated taking into account in situ pore pressure measurements acquired over a long period of time. The analyses permitted determination of the role played by the hydraulic heterogeneity of the involved soils and the hydraulic boundary conditions for simulation of the response of in situ pore pressures to rainfall. Such conditions were therefore used to predict the critical unknown values attained during landslide reactivations and were indirectly tested using different models.Key words: landslide, weathered rocks, groundwater monitoring, unsaturated–saturated flow model, rainfall, critical pore pressures.

scholarly journals Non-Invasive Approaches for the Evaluation of the Functionalization of Melamine Foams with In-Situ Synthesized Silver Nanoparticles

Polymers ◽  
2020 ◽  
Vol 12 (5) ◽  
pp. 996 ◽  
Author(s):  
Suset Barroso-Solares ◽  
Paula Cimavilla-Roman ◽  
Miguel Angel Rodriguez-Perez ◽  
Javier Pinto
Keyword(s):  
Polymeric Nanocomposites ◽  
Free Standing ◽  
X Ray ◽  
Color Changes ◽  
Non Invasive ◽  
Silver Nps ◽  
Promising Solution ◽  
The Stability

The use of polymeric nanocomposites has arisen as a promising solution to take advantage of the properties of nanoparticles (NPs) in diverse applications (e.g., water treatment, catalysis), while overcoming the drawbacks of free-standing nanoparticles (e.g., aggregation or accidental release). In most of the cases, the amount and size of the NPs will affect the stability of the composite as well as their performance. Therefore, a detailed characterization of the NPs present on the nanocomposites, including their quantification, is of vital importance for the optimization of these systems. However, the determination of the NPs load is often carried out by destructive techniques such as TGA or ICP-OES, the development of non-invasive approaches to that aim being necessary. In this work, the amount of silver NPs synthesized directly on the surface of melamine (ME) foams is studied using two non-invasive approaches: colorimetry and X-ray radiography. The obtained results show that the amount of silver NPs can be successfully determined from the luminosity and global color changes of the surface of the foams, as well as from the X-ray attenuance.

Stability analysis of mobile cranes and determination of outriggers loading

2018 ◽  
Vol 16 (6) ◽  
pp. 938-958 ◽  
Author(s):  
Giuseppe Romanello
Keyword(s):  
Stability Margin ◽  
Content Type ◽  
Stability Behavior ◽  
Mobile Crane ◽  
Computer Codes ◽  
The Stability ◽  
Practical Implications

Purpose The purpose of this paper is to develop mathematical tools that are reliable and easily implementable in computer codes, which address the determination of the outriggers reaction of mobile cranes and the monitoring of the actual stability margin available during lift operations. Design/methodology/approach An algorithm that determines the load transmitted to the ground by a mobile crane with four outriggers has been developed. Static theory of rigid body is adopted for the development of the algorithm and the static indeterminancy, due to the presence of more than three outriggers, is eluded through the adoption of specific hypotheses. An analysis of crane stability is also performed, and a method to monitor the actual stability behavior during lift operations is suggested. Findings A case study is proposed to test the algorithm and outcomes show a good matching with the actual outriggers reaction measured during a test conduct in situ. Two indices are introduced as a measure of the stability margin. Research limitations/implications The method developed accounts only for gravitational forces statically applied. Future works should be addressed to extend the model to the effect of wind and inertial forces. Practical implications This paper supplies a reliable tool to assess, in the design phase of a lifting operation, the compliance between bearing capacity of the ground and loads transmitted by outriggers. The method proposed for the analysis of the stability behavior is suitable for the development of an anti-upset device. Originality/value This study contributes to efforts to increase safety during lifting operations with mobile cranes. The method proposed is applicable to cranes with any geometry of the outriggers pattern and is extensible to a number of outriggers greater than four. Furthermore, the evaluation of the measure in real time of the stability margin, is not affected by the data entered by the crane’s operator with the consequence that human factor does not affect this measure.

Investigation of the Influence of the Physical Properties of Landfill Soils on the Stability of Slopes in the Context of Solving Civil Security Problems

2021 ◽  
Vol 1038 ◽  
pp. 407-416
Author(s):  
Nina Rashkevich ◽  
Roman Shevchenko ◽  
Ihor Khmyrov ◽  
Alexandr Soshinskiy
Keyword(s):  
Physical Properties ◽  
Gradual Increase ◽  
Laboratory Studies ◽  
Domestic Waste ◽  
Solid Domestic Waste ◽  
Angle Of Internal Friction ◽  
Stability Of Slopes ◽  
The Stability ◽  
The Mathematical Model

The paper presents the results of laboratory studies of the influence of the physical properties of landfill soils on the stability of slopes, namely, the determination of mechanical properties – the angle of internal friction, specific adhesion, and the shear angle of experimental landslide blocks under conditions of different humidity, density and temperature; determination of physical properties – humidity, temperature and density on the fact of shear of the experimental blocks, taking into account the gradual increase in humidity. The results of laboratory tests are processed using the classical statistical method. This made it possible to confirm the reliability of the mathematical model, which includes the solution of individual tasks for assessing the physical properties of landfill soils, and the corresponding methodology developed on its basis for preventing emergencies associated with shear of landfill soils at potentially hazardous burial sites for solid domestic waste.

Strength of tree roots and landslides on Prince of Wales Island, Alaska

1979 ◽  
Vol 16 (1) ◽  
pp. 19-33 ◽  
Author(s):  
Tien H. Wu ◽  
William P. McKinnell III ◽  
Douglas N. Swanston
Keyword(s):  
Shear Strength ◽  
Root System ◽  
Forest Cover ◽  
Safety Factors ◽  
In Situ Tests ◽  
Tree Roots ◽  
Stability Of Slopes ◽  
Before And After ◽  
The Stability

The stability of slopes before and after removal of forest cover was investigated. Porewater pressures and shear strengths were measured and the soil properties were determined by laboratory and in situ tests. A model of the soil–root system was developed to evaluate the contribution of tree roots to shear strength. The computed safety factors are in general agreement with observed behaviors of the slopes. Decay of tree roots subsequent to logging was found to cause a reduction in the shear strength of the soil–root system.

In situ phase equilibria determination of a manganese ferrite by electrical means

1988 ◽  
Vol 3 (3) ◽  
pp. 552-556 ◽  
Author(s):  
Han-Ill Yoo ◽  
Harry L. Tuller
Keyword(s):  
Spinel Ferrite ◽  
X Ray Diffraction ◽  
Equilibrium Conditions ◽  
X Ray ◽  
Temperature Equilibrium ◽  
The Stability ◽  
Mnzn Ferrites ◽  
Iron And Manganese

Electrical conductivity and thermoelectric power have been measured for a series of MnZn ferrites as functions of the oxygen partial pressure under high-temperature equilibrium conditions. The isothermal variation of both properties was successfully correlated to the onset of phase transitions at characteristic Po2's. The ferrite 0.482MnO-0.518Fe2O3 was examined in some detail to locate the stability fields of the metallic alloy of iron and manganese, manganowustite, the spinel ferrite, and the hematitelike phase, and to extract the appropriate free-energy data. The results confirmed by x-ray diffraction are in satisfactory agreement with literature data.

scholarly journals METHODS FOR THE DETERMINATION OF THE STABILITY OF THE EARTH CONSTRUCTION DEVICE

2017 ◽  
pp. 81-87
Author(s):  
О. L. TIUTKIN ◽  
О. І. DUBINCHIK ◽  
V. R. KILDEEV
Keyword(s):  
Geological Structure ◽  
Calculation Model ◽  
Theoretical Research ◽  
Advantages And Disadvantages ◽  
Earth Construction ◽  
Stability Of Slopes ◽  
Research Findings ◽  
The Stability ◽  
Selection Of

Purpose. Conduct a generalized analysis of methods for assessing the stability of slopes and slopes, which are currently used. An assessment of the stability of slopes and slopes can be carried out only on the basis of a comprehensive study using different methods. Methodology. Theoretical research. Findings. The analysis carried out in the framework of this study to determine the stability characteristics of landslide slopes suggests that the coefficient of stability depends directly on the nature, steepness and geological structure of the slope. Originality. The calculation scheme for determining the coefficient of stability directly depends on the methods chosen. The calculation will be reliable in the event that the corresponding scheme is more accurately and more detailed. Practical value. The use of each of the methods considered provides for the use of a number of special geotechnical surveys and the selection of a calculation model by comparing advantages and disadvantages.

scholarly journals Hydrofracturing in Situ Stress Measurements in Itabirite Brazilian Ferriferous Quadrilater, and their Limitations

2021 ◽  
Author(s):  
Henrique de Andrade Penido ◽  
Rodrigo Peluci de Figueiredo ◽  
André Pacheco de Assis ◽  
Vidal Félix Navarro Torres ◽  
Juan Manuel Girao Sotomayor ◽  
...  
Keyword(s):  
Rock Mass ◽  
In Situ Stress ◽  
Open Pit ◽  
Stress Tests ◽  
K Index ◽  
Fracture Tests ◽  
The Stability ◽  
In Situ Stress Measurements

Abstract This article presents a first attempt to carry out measurements (magnitudes and orientations) of the in situ stress in itabirite rocks in the region of the Brazilian Ferriferous Quadrilater obtained by hydraulic fracture tests at a depth of 399 m. Previous studies available in this rock mass consider estimated values of k index (Sh / Sv), and it is not a practice adopted to carry out in situ stress tests in this region and rockmass to support geotechnical analysis. The area of study is located at a depth of 500 m in a pit; therefore, the determination of the in situ stress distribution is very important to assess the stability of the mining open pit. The activities, from the planning to the execution of the tests, and the results are presented. The rock mass under study shows the presence of different geological structures, such as banding and foliation, which resulted in difficulties with performing the tests, and only 12.5% of the tests were successful. The results contribute to understanding the strains and stresses induced by mining activities in slopes in the Brazilian Ferriferous Quadrilater and their impacts on surrounding structures. For a better determination of the regional in situ stresses in the rock mass of the Brazilian Ferriferous Quadrilater, it is recommended to perform hydraulic tests on pre-existing fractures.

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