Failure of an Embankment Founded on Varved Clay

1965 ◽  
Vol 2 (3) ◽  
pp. 234-253 ◽  
Author(s):  
K Y Lo ◽  
A G Stermac
Keyword(s):  
Stability Study ◽  
Northern Ontario ◽  
Continuous Sampling ◽  
Failure Region ◽  
Effective Stress Analysis ◽  
Order Of Magnitude ◽  
Tension Cracks ◽  
The Stability ◽  
Varved Clay

During the construction of a 19 ft. high roadway embankment at New Liskeard, Northern Ontario, on varved clay, a failure involving half the width of the embankment occurred, extending for a length of 350 ft. A comprehensive investigation was carried out, including continuous sampling and in situ vane tests at 2 ft. intervals to locate the failure zone.Stability analyses were carried out both for the failed and the stable side of the embankment, assuming different values of fill strength and depth of tension cracks.Prior to construction, 30 piezometers and 14 settlement gauges were installed at a section close to the failure region. Extrapolation of the pore-pressures measured at this location to the failure section enabled the stability study to be performed in terms of effective stresses. Analyses were also carried out for the instrumented section both in terms of total and effective stresses.The results of this study show that: (a) The discrepancy between in situ vane and laboratory tests carried out in the varved clay stratum is of the same order of magnitude as those experienced in homogeneous deposits. (b) The [Formula: see text] analysis gives approximately correct factors of safety in all the cases analysed when both fill strength and effect of tension cracks are taken into account. (c) The factors of safety given by effective stress analysis appear to be too high.The remedial measures subsequently carried out for the failure region are described.

scholarly journals Effect of H2O on the Pressure-Induced Amorphization of Hydrated AlPO4-17

Molecules ◽  
2019 ◽  
Vol 24 (16) ◽  
pp. 2864 ◽  
Author(s):  
Frederico G. Alabarse ◽  
Boby Joseph ◽  
Andrea Lausi ◽  
Julien Haines
Keyword(s):  
Pressure Range ◽  
Silicone Oil ◽  
Structural Response ◽  
Microporous Material ◽  
X Ray ◽  
Guest Species ◽  
Order Of Magnitude ◽  
Diamond Anvil ◽  
The Stability

The incorporation of guest species in zeolites has been found to strongly modify their mechanical behavior and their stability with respect to amorphization at high pressure (HP). Here we report the strong effect of H2O on the pressure-induced amorphization (PIA) in hydrated AlPO4-17. The material was investigated in-situ at HP by synchrotron X-ray powder diffraction in diamond anvil cells by using non- and penetrating pressure transmitting media (PTM), respectively, silicone oil and H2O. Surprisingly, in non-penetrating PTM, its structural response to pressure was similar to its anhydrous phase at lower pressures up to ~1.4 GPa, when the amorphization was observed to start. Compression of the structure of AlPO4-17 is reduced by an order of magnitude when the material is compressed in H2O, in which amorphization begins in a similar pressure range as in non-penetrating PTM. The complete and irreversible amorphization was observed at ~9.0 and ~18.7 GPa, respectively, in non- and penetrating PTM. The present results show that the insertion of guest species can be used to strongly modify the stability of microporous material with respect to PIA, by up to an order of magnitude.

Geotechnical problems related to the building of a tailings dam on sensitive varved clay

1982 ◽  
Vol 19 (4) ◽  
pp. 472-482 ◽  
Author(s):  
N. U. Capozio ◽  
J. M. Ouimet ◽  
M. M. Dupuis
Keyword(s):  
Mine Tailings ◽  
Tailings Dam ◽  
Tailings Pond ◽  
Geotechnical Investigations ◽  
The Stability ◽  
Longitudinal Cracks ◽  
Geotechnical Problems ◽  
Varved Clay ◽  
Thick Deposit

At Noranda Mines in Matagami, Quebec, the construction of a 7-m tailings dam was begun in 1974 by hydraulically depositing mine tailings across a lake. A tailings pond was thus created upstream together with a downstream sedimentation pond regulated by a weir. The presence of longitudinal cracks along the crest of the dam was observed in 1978. This generated some doubts as to the stability of the dam which rests on a 24-m thick deposit of soft sensitive varved clay.Following a first study in 1978, the fissured area was used as a berm for yet another embankment which was built upstream of the unstable zone. In order to reevaluate the stability of the structure and the consequences of an eventual dam rupture, second and third geotechnical investigations were undertaken in 1980 and 1981. This paper presents the main conclusions of these investigations. It also includes the results of borings, in-situ vane tests, and stability analyses that were used to study the problem and made the planning of remedial measures possible.

Synthesis and Radiosynthesis of 17α-[p-(Iodophenylethynyl)]estra-3,17β-diols

2003 ◽  
Vol 58 (8) ◽  
pp. 799-804 ◽  
Author(s):  
Jian Wanga ◽  
Masataka Watanabe ◽  
Shuntaro Mataka ◽  
Thies Thiemann ◽  
Goreti Ribeiro Morais ◽  
...  
Keyword(s):  
Breast Cancer ◽  
Addition Reaction ◽  
Stability Study ◽  
The Stability ◽  
Positive Breast Cancer

Estrones have been subjected to an addition reaction with [(4-ethynylphenyl)azo]pyrrolidine to provide 17 α-{4-[(pyrrolidin-1-yl)-azo]phenylethynyl}estra-3,17 β -diols. A subsequent iodination with iodotrimethylsilane, produced in situ from chlorotrimethylsilane and NaI, leads to 17α-(piodophenylethynyl) estra-3,17 β -diols. This reaction can also be carried out with Na125 I to give radiolabelled estra-3,17 β -diols, which are potentially useful radiodiagnostic agents for the detection of estrogen positive breast cancer. The stability of the radiolabelled compounds is exemplified in a stability study of 3-O-methyl 17 α-(p-[125 I]iodophenylethynyl)estra-1,3,5(10),6-tetraene-17 β -ol in acetonitrile.

scholarly journals In Situ Local Oxidation of SnO Induced by Laser Irradiation: A Stability Study

Nanomaterials ◽  
2021 ◽  
Vol 11 (4) ◽  
pp. 976
Author(s):  
Antonio Vázquez-López ◽  
David Maestre ◽  
Julio Ramírez-Castellanos ◽  
Ana Cremades
Keyword(s):  
Raman Spectroscopy ◽  
Laser Irradiation ◽  
Stability Study ◽  
Thermal Treatments ◽  
X Ray Diffraction ◽  
Transmission Electron ◽  
Local Oxidation ◽  
Potential Applicability ◽  
The Stability

In this work, semiconductor tin oxide (II) (SnO) nanoparticles and plates were synthesized at room conditions via a hydrolysis procedure. X-ray diffraction (XRD) and transmission electron microscopy (TEM) confirmed the high crystallinity of the as-synthesized romarchite SnO nanoparticles with dimensions ranging from 5 to 16 nm. The stability of the initial SnO and the controlled oxidation to SnO2 was studied based on either thermal treatments or controlled laser irradiation using a UV and a red laser in a confocal microscope. Thermal treatments induced the oxidation from SnO to SnO2 without formation of intermediate SnOx, as confirmed by thermodiffraction measurements, while by using UV or red laser irradiation the transition from SnO to SnO2 was controlled, assisted by formation of intermediate Sn3O4, as confirmed by Raman spectroscopy. Photoluminescence and Raman spectroscopy as a function of the laser excitation source, the laser power density, and the irradiation duration were analyzed in order to gain insights in the formation of SnO2 from SnO. Finally, a tailored spatial SnO/SnO2 micropatterning was achieved by controlled laser irradiation with potential applicability in optoelectronics and sensing devices.

DEVELOPMENT OF NOVEL IN-SITU LIQUID BANDAGES OF DICLOFENAC SODIUM

INDIAN DRUGS ◽  
2013 ◽  
Vol 50 (09) ◽  
pp. 25-29
Author(s):  
T. Harish ◽  
◽  
R. Deveswaran ◽  
S Bharath ◽  
B.V Basavaraj ◽  
...  
Keyword(s):  
Diclofenac Sodium ◽  
Stability Study ◽  
High Drug ◽  
Drug Content ◽  
Inflammatory Agent ◽  
Film Forming ◽  
Anti Inflammatory ◽  
The Stability

The present work was aimed at developing dermatologically acceptable film forming composition containing an anti-inflammatory agent. The prepared liquid bandages were found to be opaque, compatible, possessing high drug content with sufficient viscosity and thickness. Pores were observed on the surface and texture was found to be rough. The prepared formulations were found to be stable in terms of sedimentation and viscosity during the stability study. The release of drug was prolonged up to 4 hours from the liquid bandages. Thus its application can be explored in various formulations by using the described methodology.

Influence of ion-milling on the T2 phase in Al-2.5%Li-2.5%Cu alloy

1989 ◽  
Vol 47 ◽  
pp. 288-289
Author(s):  
J. R. Reed ◽  
D. J. Michel ◽  
P. R. Howell
Keyword(s):  
Thin Foil ◽  
Icosahedral Symmetry ◽  
Ion Milling ◽  
Cu Alloy ◽  
Thin Foils ◽  
Heat Treated ◽  
Aluminum Solid Solution ◽  
In Situ Heating ◽  
The Stability

The Al6Li3Cu (T2) phase, which exhibits five-fold or icosahedral symmetry, forms through solid state precipitation in dilute Al-Li-Cu alloys. Recent studies have reported that the T2 phase transforms either during TEM examination of thin foils or following ion-milling of thin foil specimens. Related studies have shown that T2 phase transforms to a microcrystalline array of the TB phase and a dilute aluminum solid solution during in-situ heating in the TEM. The purpose of this paper is to report results from an investigation of the influence of ion-milling on the stability of the T2 phase in dilute Al-Li-Cu alloy.The 3-mm diameter TEM disc specimens were prepared from a specially melted Al-2.5%Li-2.5%Cu alloy produced by conventional procedures. The TEM specimens were solution heat treated 1 h at 550°C and aged 1000 h at 190°C in air to develop the microstructure. The disc specimens were electropolished to achieve electron transparency using a 20:80 (vol. percent) nitric acid: methanol solution at -60°C.

scholarly journals Underground Microseismic Event Monitoring and Localization within Sensor Networks

Sensors ◽  
2021 ◽  
Vol 21 (8) ◽  
pp. 2830
Author(s):  
Sili Wang ◽  
Mark P. Panning ◽  
Steven D. Vance ◽  
Wenzhan Song
Keyword(s):  
Sensor Networks ◽  
Real Time ◽  
Information Needs ◽  
Localization Algorithm ◽  
Distributed Sensors ◽  
Distributed Sensor ◽  
Microseismic Events ◽  
The Stability ◽  
Stability And Accuracy

Locating underground microseismic events is important for monitoring subsurface activity and understanding the planetary subsurface evolution. Due to bandwidth limitations, especially in applications involving planetarily-distributed sensor networks, networks should be designed to perform the localization algorithm in-situ, so that only the source location information needs to be sent out, not the raw data. In this paper, we propose a decentralized Gaussian beam time-reverse imaging (GB-TRI) algorithm that can be incorporated to the distributed sensors to detect and locate underground microseismic events with reduced usage of computational resources and communication bandwidth of the network. After the in-situ distributed computation, the final real-time location result is generated and delivered. We used a real-time simulation platform to test the performance of the system. We also evaluated the stability and accuracy of our proposed GB-TRI localization algorithm using extensive experiments and tests.

scholarly journals A Superhydrophobic, Antibacterial, and Durable Surface of Poplar Wood

Nanomaterials ◽  
2021 ◽  
Vol 11 (8) ◽  
pp. 1885
Author(s):  
Xinyu Wu ◽  
Feng Yang ◽  
Jian Gan ◽  
Zhangqian Kong ◽  
Yan Wu
Keyword(s):  
Stearic Acid ◽  
Antibacterial Properties ◽  
Alkali Resistance ◽  
Poplar Wood ◽  
X Ray Diffraction ◽  
X Ray ◽  
Different Temperatures ◽  
Acid And Alkali Resistance ◽  
The Stability

The silver particles were grown in situ on the surface of wood by the silver mirror method and modified with stearic acid to acquire a surface with superhydrophobic and antibacterial properties. Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), and X-ray energy spectroscopy (XPS) were used to analyze the reaction mechanism of the modification process. Scanning electron microscopy (SEM) and contact angle tests were used to characterize the wettability and surface morphology. A coating with a micro rough structure was successfully constructed by the modification of stearic acid, which imparted superhydrophobicity and antibacterial activity to poplar wood. The stability tests were performed to discuss the stability of its hydrophobic performance. The results showed that it has good mechanical properties, acid and alkali resistance, and UV stability. The durability tests demonstrated that the coating has the function of water resistance and fouling resistance and can maintain the stability of its hydrophobic properties under different temperatures of heat treatment.

scholarly journals High temperature structural study of decagonal Al-Cu-Rh quasicrystal.

2014 ◽  
Vol 70 (a1) ◽  
pp. C94-C94
Author(s):  
Pawel Kuczera ◽  
Walter Steurer
Keyword(s):  
Structural Changes ◽  
Configurational Entropy ◽  
Lattice Vibrations ◽  
X Ray Diffraction ◽  
Stabilization Mechanism ◽  
X Ray ◽  
Comparative Structure ◽  
The Stability

The structure of d(ecagonal)-Al-Cu-Rh has been studied as a function of temperature by in-situ single-crystal X-ray diffraction in order to contribute to the discussion on energy or entropy stabilization of quasicrystals (QC) [1]. The experiments were performed at 293 K, 1223 K, 1153 K, 1083 K, and 1013 K. A common subset of 1460 unique reflections was used for the comparative structure refinements at each temperature. The results obtained for the HT structure refinements of d-Al-Cu-Rh QC seem to contradict a pure phasonic-entropy-based stabilization mechanism [2] for this QC. The trends observed for the ln func(I(T1 )/I(T2 )) vs.|k⊥ |^2 plots indicate that the best on-average quasiperiodic order exists between 1083 K and 1153 K, however, what that actually means is unclear. It could indicate towards a small phasonic contribution to entropy, but such contribution is not seen in the structure refinements. A rough estimation of the hypothetic phason instability temperature shows that it would be kinetically inaccessible and thus the phase transition to a 12 Å low T structure (at ~800 K) is most likely not phason-driven. Except for the obvious increase in the amplitude of the thermal motion, no other significant structural changes, in particular no sources of additional phason-related configurational entropy, were found. All structures are refined to very similar R-values, which proves that the quality of the refinement at each temperature is the same. This suggests, that concerning the stability factors, some QCs could be similar to other HT complex intermetallic phases. The experimental results clearly show that at least the ~4 Å structure of d-Al-Cu-Rh is a HT phase therefore entropy plays an important role in its stabilisation mechanism lowering the free energy. However, the main source of this entropy is probably not related to phason flips, but rather to lattice vibrations, occupational disorder unrelated to phason flips like split positions along the periodic axis.

Research on 2D Limit Equilibrium Method of Slopes Considering the Effect of Horizontal In Situ Stress

2013 ◽  
Vol 671-674 ◽  
pp. 245-250
Author(s):  
Wen Hui Tan ◽  
Ya Liang Li ◽  
Cong Cong Li
Keyword(s):  
Limit Equilibrium ◽  
Limit Equilibrium Method ◽  
In Situ Stress ◽  
Open Pit ◽  
Open Pit Mines ◽  
Equilibrium Method ◽  
Iron Mine ◽  
The Stability ◽  
Slice Method

At present, in-situ stress was not considered in Limit Equilibrium Method (LEM) of slopes, the influence of in-situ stress is very small on the stability of conventional slopes, but in deep-depressed open-pit mines, the influence should not be neglected. Formula for calculating the Factor of Safety (FOS) under the effect of horizontal in-situ stress was deduced using General Slice Method (GSM) of two-dimensional (2D) limit equilibrium method in this paper，a corresponding program SSLOPE was built, and the software was used in a deep- depressed open-pit iron mine. The results show that the FOS of the slope decreased by 20% when horizontal in-situ stress is considered, some reinforcements must be taken. Therefore, the influence of in-situ stress on slope stability should be taken into account in deep open –pit mines.

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