3D Simulation of Tunnel Collapse Consolidation and In Situ Monitoring Analysis

2011 ◽  
Vol 243-249 ◽  
pp. 3551-3555
Author(s):  
Zhi Min Chen ◽  
De An Zhao
Keyword(s):  
Numerical Models ◽  
Three Dimensional ◽  
In Situ Monitoring ◽  
3D Simulation ◽  
Actual Situation ◽  
Consolidation Effect ◽  
Tunnel Collapse ◽  
Simulation Results ◽  
Shallow Buried Tunnel

A shallow buried tunnel was collapsed during construction. According to the actual situation of the tunnel, different collapse consolidation schemes were put forward and corresponding three-dimensional finite difference numerical models were established and analyzed using FLAC3D software. Base on the 3D Simulation results, a collapse consolidation scheme was determined and constructed. The in-situ monitoring results of vault subsidence and convergence displacement were consistent approximately with the 3D Simulation results. The in-situ measured results were in line with the specification’s allowance and show that the consolidation effect of reinforced concrete casing arch and ahead grouting method is good. This could be referenced for similar engineering.

Ice-Phase Precipitation

2017 ◽  
Vol 58 ◽  
pp. 6.1-6.36 ◽  
Author(s):  
I. Gultepe ◽  
A. J. Heymsfield ◽  
P. R. Field ◽  
D. Axisa
Keyword(s):  
Collection Efficiency ◽  
Numerical Models ◽  
Mass Density ◽  
Three Dimensional ◽  
Phase Precipitation ◽  
Microphysical Parameters ◽  
Mass Size ◽  
Ice Water ◽  
Ice Phase

AbstractIce-phase precipitation occurs at Earth’s surface and may include various types of pristine crystals, rimed crystals, freezing droplets, secondary crystals, aggregates, graupel, hail, or combinations of any of these. Formation of ice-phase precipitation is directly related to environmental and cloud meteorological parameters that include available moisture, temperature, and three-dimensional wind speed and turbulence, as well as processes related to nucleation, cooling rate, and microphysics. Cloud microphysical parameters in the numerical models are resolved based on various processes such as nucleation, mixing, collision and coalescence, accretion, riming, secondary ice particle generation, turbulence, and cooling processes. These processes are usually parameterized based on assumed particle size distributions and ice crystal microphysical parameters such as mass, size, and number and mass density. Microphysical algorithms in the numerical models are developed based on their need for applications. Observations of ice-phase precipitation are performed using in situ and remote sensing platforms, including radars and satellite-based systems. Because of the low density of snow particles with small ice water content, their measurements and predictions at the surface can include large uncertainties. Wind and turbulence affecting collection efficiency of the sensors, calibration issues, and sensitivity of ground-based in situ observations of snow are important challenges to assessing the snow precipitation. This chapter’s goals are to provide an overview for accurately measuring and predicting ice-phase precipitation. The processes within and below cloud that affect falling snow, as well as the known sources of error that affect understanding and prediction of these processes, are discussed.

scholarly journals Fine-scale features on the sea surface in SAR satellite imagery – Part 1: Simultaneous in-situ measurements

2012 ◽  
Vol 9 (5) ◽  
pp. 2885-2914 ◽  
Author(s):  
A. Soloviev ◽  
C. Maingot ◽  
S. Matt ◽  
R. E. Dodge ◽  
S. Lehner ◽  
...  
Keyword(s):  
Numerical Models ◽  
Three Dimensional ◽  
Companion Paper ◽  
In Situ Measurements ◽  
Ocean Dynamics ◽  
Sea Surface ◽  
Upper Ocean ◽  
Fine Scale ◽  
Sar Imagery

Abstract. This work is aimed at identifying the origin of fine-scale features on the sea surface in synthetic aperture radar (SAR) imagery with the help of in-situ measurements as well as numerical models (presented in a companion paper). We are interested in natural and artificial features starting from the horizontal scale of the upper ocean mixed layer, around 30–50 m. These features are often associated with three-dimensional upper ocean dynamics. We have conducted a number of studies involving in-situ observations in the Straits of Florida during SAR satellite overpass. The data include examples of sharp frontal interfaces, wakes of surface ships, internal wave signatures, as well as slicks of artificial and natural origin. Atmospheric processes, such as squall lines and rain cells, produced prominent signatures on the sea surface. This data has allowed us to test an approach for distinguishing between natural and artificial features and atmospheric influences in SAR images that is based on a co-polarized phase difference filter.

scholarly journals Network of Palladium-Based Nanorings Synthesized by Liquid-Phase Reduction Using DMSO-H2O: In Situ Monitoring of Structure Formation and Drying Deformation by ASEM

2020 ◽  
Vol 21 (9) ◽  
pp. 3271 ◽  
Author(s):  
Takuki Komenami ◽  
Akihiro Yoshimura ◽  
Yasunari Matsuno ◽  
Mari Sato ◽  
Chikara Sato
Keyword(s):  
Surface Tension ◽  
Liquid Phase ◽  
Aqueous Solutions ◽  
Critical Point ◽  
Synthesis Method ◽  
Three Dimensional ◽  
In Situ Monitoring ◽  
Critical Point Drying ◽  
Micrometer Size

We developed a liquid-phase synthesis method for Pd-based nanostructure, in which Pd dissolved in dimethyl sulfoxide (DMSO) solutions was precipitated using acid aqueous solution. In the development of the method, in situ monitoring using atmospheric scanning electron microscopy (ASEM) revealed that three-dimensional (3D) Pd-based nanonetworks were deformed to micrometer-size particles possibly by the surface tension of the solutions during the drying process. To avoid surface tension, critical point drying was employed to dry the Pd-based precipitates. By combining ASEM monitoring with critical point drying, the synthesis parameters were optimized, resulting in the formation of lacelike delicate nanonetworks using citric acid aqueous solutions. Precipitation using HCl acid aqueous solutions allowed formation of 500-nm diameter nanorings connected by nanowires. The 3D nanostructure formation was controllable and modifiable into various shapes using different concentrations of the Pd and Cl ions as the parameters.

Simulation Research of Effect of Salinity Wastewater Discharging Ways on Range of Salt Content Rise Nearby the Outfall

2013 ◽  
Vol 777 ◽  
pp. 440-443
Author(s):  
Yao Chen ◽  
Li Li ◽  
Bai Lu Yang ◽  
Chun Long Li
Keyword(s):  
Salt Concentration ◽  
Single Port ◽  
Numerical Models ◽  
Salt Content ◽  
Three Dimensional ◽  
Simulation Research ◽  
Subcritical Flow ◽  
Simulation Results ◽  
Salinity Wastewater ◽  
Better Than

In order to study the effect of salinity wastewater discharging ways on the range of salt content rise nearby the outfall. Two three-dimensional numerical models of discharging ways which were single-port submerged-type and double-port submerged-type in the condition of subcritical flow were researched based on FLUENT. The range of salt content rise of the two discharging ways could be concluded according to the simulation results. The value of maximum salt concentration and average salt concentration of two discharging ways were compared and analyzed. The results showed that double-port submerged-type discharging way was better than single-port submerged-type discharging way.

Combining in situ monitoring using seabed instruments and numerical modelling to assess the transient stability of underwater slopes

2018 ◽  
Vol 477 (1) ◽  
pp. 511-521 ◽  
Author(s):  
Morelia Urlaub ◽  
Heinrich Villinger
Keyword(s):  
Slope Stability ◽  
Numerical Modelling ◽  
Transient Stability ◽  
Numerical Models ◽  
Failure Mechanisms ◽  
In Situ Monitoring ◽  
Physical Parameters ◽  
Submarine Landslides ◽  
Seafloor Deformation

AbstractThe stability of submarine slopes is often characterized using campaign-based geophysical and geotechnical measurements in combination with numerical modelling. However, such one-off measurements do not reflect transient changes in slope stability. In situ monitoring of physical parameters critical for slope stability over periods of months to years can provide crucial information on slope stability and can also be used in an early-warning system for submarine landslides and the possibly resulting tsunamis. We review existing techniques that are capable of monitoring seafloor deformation over long periods of time. Based on numerical models we can identify the magnitude of parameters related to landslide-induced seafloor deformation. Simulations of three different failure scenarios up to the point of failure show that the development of the stress state of a slope and hence stability over time can be captured by measurements of tilt, pressure and strain at the seafloor. We also find that different failure mechanisms induce different deformation signals at the seafloor, in particular tilt. Hence, with a site- and target-specific survey design (or a large pool of instruments), seafloor deformation measurements in combination with numerical modelling can be used to determine the temporal evolution of slope stability as well as to identify underlying failure mechanisms.

scholarly journals Vertical and Horizontal Profiles of Particulate Matter and Black Carbon Near Elevated Highways Based on Unmanned Aerial Vehicle Monitoring

2020 ◽  
Vol 12 (3) ◽  
pp. 1204 ◽  
Author(s):  
Rong Cao ◽  
Bai Li ◽  
Hong-Wei Wang ◽  
Shikang Tao ◽  
Zhong-Ren Peng ◽  
...  
Keyword(s):  
Black Carbon ◽  
Dispersion Model ◽  
Three Dimensional ◽  
Ground Level ◽  
In Situ Monitoring ◽  
Pollution Dispersion ◽  
Vehicle Monitoring ◽  
Aerial Vehicle ◽  
Monitoring Technologies

Highways passing through cities cause additional pollution inside the city. However, most of the current studies are using ground-based monitoring technologies, which make it difficult to capture the dispersion patterns of pollutants near elevated highways or transportation interchanges. The purpose of this study is to discover short-term three-dimensional variations in traffic-related pollutants based on unmanned aerial vehicles. The monitoring locations are at suburban elevated highway and transportation interchanges. The monitoring parameters include the particle number concentration (PN), particle mass concentration (PM), and black carbon (BC). The vertical profiles showed that most air pollutants increased significantly with the height of the elevated highways. Compared with the ground level, PNs increased by 54%–248% and BC increased by 201%. The decline rate of particle concentrations decreased with the increase of height and remained stable after 120 m. Furthermore, the R2 heatmap for regressions between each altitude showed that the linear relationship between 0–120 m was higher than that of other altitudes. In horizontal profiles, PNs spread to 100 m and then began to decline, BC began to decay rapidly after 50 m, but PMs varied less. After crossing another highway, PNs increased by 69–289%, PMs by 7–28%, and BC by 101%. Furthermore, the formation of new particles was observed at both locations as PN3 increased with distance within 100 m from the highway. This paper fills in the void of three-dimensional in situ monitoring near elevated highways, and can help develop and refine a three-dimensional traffic-related air pollution dispersion model and assess the impacts of transportation facilities on the urban environment.

Advances in In Situ SiC Growth Analysis Using Cone Beam Computed Tomography

2019 ◽  
Vol 963 ◽  
pp. 5-9 ◽  
Author(s):  
Michael Salamon ◽  
Matthias Arzig ◽  
Norman Uhlmann ◽  
Peter J. Wellmann
Keyword(s):  
Computed Tomography ◽  
Three Dimensional ◽  
In Situ Monitoring ◽  
Material Structure ◽  
Two Dimensional ◽  
Accurate Analysis ◽  
X Ray ◽  
Characteristic Features ◽  
Third Dimension

Computed Tomography is becoming a valuable method for the in-situ monitoring of vapor grown silicon carbide single crystals [1]. Already the two-dimensional X-ray radiography has shown the potential of surveilling the growth process [2] and its characteristic features like the evolution of the facet, the crystal volume or the source material structure from one imaging plane. Even though the demands on imaging capability of the applied X-ray components used for a tomographic analysis are higher than for two-dimensional imaging, the extension of this method to the third dimension is highly beneficial. It allows investigating the full geometry and three-dimensional location of the features and by this provides a more accurate analysis. In this contribution we present the physical characteristics and the latest advances of our technique for the visualization of facets.

scholarly journals Non-Invasive Measurement, Mathematical Simulation and In Situ Detection of Biofilm Evolution in Porous Media: A Review

2021 ◽  
Vol 11 (4) ◽  
pp. 1391
Author(s):  
Yajun Zhang ◽  
Aoshu Xu ◽  
Xin Lv ◽  
Qian Wang ◽  
Caihui Feng ◽  
...  
Keyword(s):  
Porous Media ◽  
Mathematical Simulation ◽  
Pore Space ◽  
Three Dimensional ◽  
Structural Complexity ◽  
In Situ Monitoring ◽  
Spatiotemporal Resolution ◽  
Non Invasive ◽  
Invasive Measurement

The development of biofilms and the related changes in porous media in the subsurface cannot be directly observed and evaluated. The primary reason that the mechanism of biofilm clogging in porous media cannot be clearly demonstrated is due to the opacity and structural complexity of three-dimensional pore space. Interest in exploring methods to overcome this limitation has been increasing. In the first part of this review, we introduce the underlying characteristics of biofilm in porous media. Then, we summarize two approaches, non-invasive measurement methods and mathematical simulation strategies, for studying fluid–biofilm–porous medium interaction with spatiotemporal resolution. We also discuss the advantages and limitations of these approaches. Lastly, we provide a perspective on opportunities for in situ monitoring at the field site.

Sign in / Sign up

Export Citation Format

Share Document