An Energy Criterion for Rheological Failure of Rock and Application in Stability Analysis of Natural High Slope
Zuan Chen,
Yu Zhou,
Jingbin Lu,
Shenwen Qi,
Songfeng Guo,
Shuaihua Song
Issue:
Volume 11, Issue 3, May 2023
Pages:
47-54
Received:
16 June 2023
Accepted:
3 July 2023
Published:
11 July 2023
Abstract: Rock fracture and its failure with time due to external forces and other factors such as fluids, temperature have always been a major concern in rock engineering and construction. Based on thermodynamics and theory of solid physics, authors propose an energy criterion for rheological failure of rock, which considers two effects: (1) energy dissipation of rock reduces strength of rock; (2) confining pressure increases strength of rock. Subsequently, we apply it to stability analysis of natural high slope, in order to indicate influence of long time rheology during geology process on material strength and stability of slope. After giving an equation of upper limit estimate for failure time of slide surface in slope, according to viscoelastic solution of stress about high slope under action of gravity, we calculate the relation between sliding time and dip angle (assuming slide line as straight line) and the relation between sliding time and corresponding slid radius (assuming slide line as arc. The minimum time is 105 years older. The distribution of contour lines for failure time at each point on the slope shows that points near the slope face have shorter failure times. The results explain topographic feature of high mountains in some extent and indicate that rheological failure of rock also is one of causes for topography forming of slope. It also indicates that the energy criterion for rheological failure of rock provides a base for rheological failure analysis relating to time.
Abstract: Rock fracture and its failure with time due to external forces and other factors such as fluids, temperature have always been a major concern in rock engineering and construction. Based on thermodynamics and theory of solid physics, authors propose an energy criterion for rheological failure of rock, which considers two effects: (1) energy dissipat...
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Synchrotron Radiation X-ray Fluorescence at Grazing Incident Angle (SR-GIXRF) and Total-Reflection (SR-TXRF) of Ormosil Films Containing TiO2 and Phosphotungstates
Issue:
Volume 11, Issue 3, May 2023
Pages:
55-79
Received:
11 April 2023
Accepted:
7 August 2023
Published:
27 September 2023
Abstract: In 2011-2013 during the experiments performed at LNLS (Brazilian Synchrotron Light Laboratory) based on Grazing Incident Angle X-ray Fluorescence analysis assisted by Synchrotron Radiation (SR-GIXRF) of Ormosil (Organic Modified Silicates) films containing Phosphotungstates ([PW12O40]3-) was obtained an image (Figure 8 in this article), which can be explained by different hypotheses based on physical and chemical phenomena. In 2021 the same author of this present investigation reported the possibility of to generate the conditions for the production of Maser-rays based on Total Reflection X-ray Fluorescence assisted by Synchrotron Radiation (SR-TXRF) measurements of ormosil films. Devices based on Maser-rays can extend their corresponding range of frequencies at microwave, radio, infrared, optical, ultraviolet, and X-ray regions possibly also (as was mentioned above). In this opportunity, the results of GIXRF measurements are presented. GIXRF is an XRF analysis mode in shallow incidence angles. Nonetheless, unlike of TXRF condition, GIXRF not only addresses Total Reflection phenomena, but also phenomena based on Partial Reflection (of secondary and primary X-rays), and X-ray Refraction. Thus, under these conditions, it was possible generate Molecular Fluorescence at visible region from Synchrotron Radiation X-ray Fluorescence (SR-XRF). We proposed models of Fluorescence at Molecular scale and Multiscale (from nanometer to millimeter size level) based on Luminescence phenomena, whose are result of the Interactions (physical and chemical) of Synchrotron Radiation with the matter. These Interactions can be based on the linear-polarization of relativistic electron beams generated from this X-ray source, which exhibits coherence of the rays produced. At molecular scale, the model of Fluorescence is based on the interaction of the molecular and ionic species of TiO2 with the atomic and molecular groups of Oxygen (—O=O—) present in PWA structure, which by the chemical resonance effects of the double bonds in diene structure conjugated (.......=O—W=O—W=O—) can enable luminescence phenomena, via electronic displacements. At Multiscale level of size (result of the summation of the fluorescence model mentioned above) play an important role the Van der Waals forces, taking in consideration the contact between the great surfaces of PWA clusters and the different TiO2 molecular and ionic species (TiO2, TiOH2+, and TiO−) in intramolecular and intermolecular configurations of PWA. SR-TXRF demonstrated be a suitable method for identification of Titanium and Tungsten in ormosil films.
Abstract: In 2011-2013 during the experiments performed at LNLS (Brazilian Synchrotron Light Laboratory) based on Grazing Incident Angle X-ray Fluorescence analysis assisted by Synchrotron Radiation (SR-GIXRF) of Ormosil (Organic Modified Silicates) films containing Phosphotungstates ([PW12O40]3-) was obtained an image (Figure 8 in this article), which can b...
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