scholarly journals Analysis of the Sealing Mechanism of Cement-Sodium Silicate Grout in Rock Fractures with Flowing Water

Water ◽  
2020 ◽  
Vol 12 (7) ◽  
pp. 1935 ◽  
Author(s):  
Guangxuan Zhu ◽  
Qingsong Zhang ◽  
Xin Lin ◽  
Rentai Liu ◽  
Lianzhen Zhang ◽  
...  
Keyword(s):  
Sodium Silicate ◽  
Large Scale ◽  
Orthogonal Experiment ◽  
Three Dimensional ◽  
Fracture Plane ◽  
Fracture Aperture ◽  
Flowing Water ◽  
Water Drainage ◽  
Dimensional Simulation ◽  
Solidified Body

The diffusion and sealing mechanisms of cement-sodium silicate grout (C-S grout), which is widely used in flowing water sealing projects, are complicated. Based on a large-scale quasi-three-dimensional simulation test platform of fracture dynamic water grouting, an orthogonal experiment of flowing-water sealing of C-S grout was performed. The grout was shown to diffuse in the form of an asymmetric ellipse. The flowing-water sealing process consists of three stages: (1) the grout diffuses to the fracture boundary in an asymmetrical ellipse; (2) the solidified body of grout develops; (3) the stable solidified body forms. The sealing efficiency was evaluated and graded by the reduction of water drainage through the fracture after grouting. Based on the test data, the factors that affect sealing efficiency can be listed in the following order from strong to weak: grout gel time, flowing water velocity, grout take, fracture plane width, and fracture aperture. Finally, a fitting equation was acquired to provide a reference for practical engineering applications.

Three-dimensional simulation of large-scale structure in the Universe

Nature ◽  
1983 ◽  
Vol 305 (5931) ◽  
pp. 196-198 ◽  
Author(s):  
Joan Centrella ◽  
Adrian L. Melott
Keyword(s):  
Large Scale ◽  
Three Dimensional ◽  
Large Scale Structure ◽  
Scale Structure ◽  
Dimensional Simulation ◽  
The Universe

scholarly journals A THREE-DIMENSIONAL SIMULATION AND VISUALIZATION SYSTEM FOR UAV PHOTOGRAMMETRY

2017 ◽  
Vol XLII-2/W6 ◽  
pp. 217-222 ◽  
Author(s):  
Y. Liang ◽  
Y. Qu ◽  
T. Cui
Keyword(s):  
Large Scale ◽  
Three Dimensional ◽  
Cost Effective ◽  
Three Dimensions ◽  
Wind Condition ◽  
Plan Evaluation ◽  
Visualization System ◽  
Flight Plan ◽  
Aerial Photogrammetry ◽  
Dimensional Simulation

Nowadays UAVs has been widely used for large-scale surveying and mapping. Compared with manned aircraft, UAVs are more cost-effective and responsive. However, UAVs are usually more sensitive to wind condition, which greatly influences their positions and orientations. The flight height of a UAV is relative low, and the relief of the terrain may result in serious occlusions. Moreover, the observations acquired by the Position and Orientation System (POS) are usually less accurate than those acquired in manned aerial photogrammetry. All of these factors bring in uncertainties to UAV photogrammetry. To investigate these uncertainties, a three-dimensional simulation and visualization system has been developed. The system is demonstrated with flight plan evaluation, image matching, POS-supported direct georeferencing, and ortho-mosaicing. Experimental results show that the presented system is effective for flight plan evaluation. The generated image pairs are accurate and false matches can be effectively filtered. The presented system dynamically visualizes the results of direct georeferencing in three-dimensions, which is informative and effective for real-time target tracking and positioning. The dynamically generated orthomosaic can be used in emergency applications. The presented system has also been used for teaching theories and applications of UAV photogrammetry.

scholarly journals Flux correlations in supersonic isothermal turbulence

2012 ◽  
Vol 713 ◽  
pp. 482-490 ◽  
Author(s):  
R. Wagner ◽  
G. Falkovich ◽  
A. G. Kritsuk ◽  
M. L. Norman
Keyword(s):  
Large Scale ◽  
Three Dimensional ◽  
Compressible Turbulence ◽  
Navier Stokes ◽  
Navier Stokes Equation ◽  
Barotropic Fluids ◽  
Gravity Driven ◽  
Dimensional Simulation ◽  
Using Data ◽  
Astrophysical Flows

AbstractUsing data from a large-scale three-dimensional simulation of supersonic isothermal turbulence, we have tested the validity of an exact flux relation derived analytically from the Navier–Stokes equation by Falkovich, Fouxon & Oz (J. Fluid Mech., vol. 644, 2010, p. 465). That relation, for compressible barotropic fluids, was derived assuming turbulence generated by a large-scale force. However, compressible turbulence in simulations is usually initialized and maintained by a large-scale acceleration, as in gravity-driven astrophysical flows. We present a new approximate flux relation for isothermal turbulence driven by a large-scale acceleration, and find it in reasonable agreement with the simulation results.

scholarly journals Remote thermal detection of exfoliation sheet deformation

Landslides ◽  
2020 ◽  
Author(s):  
Antoine Guerin ◽  
Michel Jaboyedoff ◽  
Brian D. Collins ◽  
Greg M. Stock ◽  
Marc-Henri Derron ◽  
...  
Keyword(s):  
Laser Scanning ◽  
Large Scale ◽  
Three Dimensional ◽  
Fracture Aperture ◽  
Thermally Induced ◽  
Temperature Changes ◽  
Frequency Monitoring ◽  
Maximum Temperatures ◽  
Deformation Patterns ◽  
Rock Deformations

Abstract A growing body of research indicates that rock slope failures, particularly from exfoliating cliffs, are promoted by rock deformations induced by daily temperature cycles. Although previous research has described how these deformations occur, full three-dimensional monitoring of both the deformations and the associated temperature changes has not yet been performed. Here we use integrated terrestrial laser scanning (TLS) and infrared thermography (IRT) techniques to monitor daily deformations of two granitic exfoliating cliffs in Yosemite National Park (CA, USA). At one cliff, we employed TLS and IRT in conjunction with in situ instrumentation to confirm previously documented behavior of an exfoliated rock sheet, which experiences daily closing and opening of the exfoliation fracture during rock cooling and heating, respectively, with a few hours delay from the minimum and maximum temperatures. The most deformed portion of the sheet coincides with the area where both the fracture aperture and the temperature variations are greatest. With the general deformation and temperature relations established, we then employed IRT at a second cliff, where we remotely detected and identified 11 exfoliation sheets that displayed those general thermal relations. TLS measurements then subsequently confirmed the deformation patterns of these sheets showing that sheets with larger apertures are more likely to display larger thermal-related deformations. Our high-frequency monitoring shows how coupled TLS and IRT allows for remote detection of thermally induced deformations and, importantly, how IRT could potentially be used on its own to identify partially detached exfoliation sheets capable of large-scale deformation. These results offer a new and efficient approach for investigating potential rockfall sources on exfoliating cliffs.

scholarly journals Three-dimensional simulation of non-uniform sediment transport based on multi-phase Eulerian approach: Application to debris flow

2018 ◽  
Vol 40 ◽  
pp. 05051
Author(s):  
Kazuyuki Ota ◽  
Hitoshi Suto ◽  
Takahiro Sato
Keyword(s):  
Numerical Model ◽  
Debris Flow ◽  
Large Scale ◽  
Three Dimensional ◽  
Flow Property ◽  
Size Segregation ◽  
Particle Collisions ◽  
Sediment Size ◽  
Dimensional Simulation ◽  
Multi Phase

To simulate 3D flow of a non-uniform and highly concentrated sediment, a numerical model using a multi-phase Eulerian method for air, water, and particles of various class size is developed. This model accounts for turbulence in pore water, particle-particle collisions, and enduring friction. To test its performance, simulations were performed for large scale debris-flow experiments. The numerical model reproduces successfully the flow property and sediment size segregation of the debris flow.

Direct Numerical Simulation of Turbulent Separated Flow and Heat Transfer Over a Blunt Flat Plate

2003 ◽  
Vol 125 (5) ◽  
pp. 779-787 ◽  
Author(s):  
Hideki Yanaoka ◽  
Hiroyuki Yoshikawa ◽  
Terukazu Ota
Keyword(s):  
Heat Transfer ◽  
Reynolds Number ◽  
Flat Plate ◽  
Large Scale ◽  
Three Dimensional ◽  
Separated Flow ◽  
Flow Region ◽  
Essential Difference ◽  
Flow And Heat Transfer ◽  
Dimensional Simulation

Three-dimensional simulation of turbulent separated and reattached flow and heat transfer over a blunt flat plate is presented. The Reynolds number analyzed is 5000. The vortices shed from the reattachment flow region exhibit a hairpin-like structure. These large-scale vortex structures greatly influence the heat transfer in the reattachment region. Present results are compared with the previous three-dimensional calculations at low Reynolds number and it is found that there is no essential difference between two results with respect to the flow structure. The reattachment length is about five plate thicknesses, which is nearly equal to the previous experimental ones. The velocity distributions and turbulence intensities are in good agreement with the experimental data. Further, it is clarified that Nusselt number and temperature distributions greatly depend upon the Reynolds number, though their characteristic behaviors are qualitatively well simulated.

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