Effect of Rainfall Infiltration on Loess Pitted Courtyard Cave Dwellings Stability

2012 ◽  
Vol 430-432 ◽  
pp. 1992-1995 ◽  
Author(s):  
Jia Ming Han ◽  
San Qing Su
Keyword(s):  
Water Content ◽  
Safety Factor ◽  
Triaxial Test ◽  
Field Measurements ◽  
Surrounding Rock ◽  
Rainfall Infiltration ◽  
Mechanical Parameter ◽  
Different Depths ◽  
Definition Of ◽  
The Relationship

Baishe villagers have inhabited loess pitted courtyard cave dwelling for hundreds of years in Sanyuan County of China.The sizes of local cave dwellings are mastered by field measurements, and variational regularity is summarized of average annual and monthly rainfall. By the soil routine and triaxial test, the physical and mechanical parameter is acquired with loess samples in different water content.At the same time, based on the literature datas, the relationship is established between rainfall and water content. Then, the definition of safety factor is given for loess cave dwellings in different depths, making use of the expressions of the surrounding rock loop stress and the Mohr - Coulomb intensity criterion. In the end,the variation of stability of loess cave dwelling could be analysed under different rainfall.

Study on Safety Factor of Loess Cave Dwellings with Pitted Courtyard in Different Rainfall Infiltration

2012 ◽  
Vol 446-449 ◽  
pp. 1555-1558
Author(s):  
Jia Ming Han
Keyword(s):  
Water Content ◽  
Safety Factor ◽  
Field Measurements ◽  
Surrounding Rock ◽  
Rainfall Infiltration ◽  
Monthly Rainfall ◽  
Soil Test ◽  
Mechanical Parameters ◽  
Different Depths ◽  
The Relationship

Baishe villagers have lived in loess cave dwelling with pitted courtyard for hundreds of years in Sanyuan County of China .Rainfall infiltration badly destroyed the habitation in recent years so that the study is very important on security and stability of the loess cave dwelling. By field measurements, the sizes of local cave dwellings were mastered and variation was grasped of average annual and monthly rainfall. The physical and mechanical parameters were acquired with loess samples in different water content by the conventional and triaxial soil test. At the same time, based on the literature data, the relationship was established between rainfall and water content. Safety factor was defined for loess cave dwellings in different depths utilizing the expressions of the surrounding rock loop stress and the Mohr-Coulomb theory. The variation of stability of loess cave dwelling could be ultimately analyzed under different rainfall.

scholarly journals Remotely Sensed Water Limitation in Vegetation: Insights from an Experiment with Unmanned Aerial Vehicles (UAVs)

2019 ◽  
Author(s):  
Kelly Easterday ◽  
Chippie Kislik ◽  
Tod E. Dawson ◽  
Sean Hogan ◽  
Maggi Kelly
Keyword(s):  
Unmanned Aerial Vehicles ◽  
Water Content ◽  
Water Deficit ◽  
Water Status ◽  
Field Measurements ◽  
Flying Height ◽  
Plant Water ◽  
Spectral Indices ◽  
Aerial Vehicles ◽  
The Relationship

Unmanned aerial vehicles (UAVs) equipped with multispectral sensors present an opportunity to monitor vegetation with on-demand high spatial and temporal resolution. In this study, we use multispectral imagery from quadcopter UAVs to monitor the progression of a water manipulation experiment on a common shrub, Baccharis pilularis (coyote brush), at the Blue Oak Ranch Reserve (BORR) near San Jose, California. We recorded multispectral data from the plants at several altitudes with nearly hourly intervals to explore the relationship between two common spectral indices, NDVI and NDRE, and plant water content and water potential, as physiological metrics of plant water status, across a gradient of water deficit. An examination of the spatial and temporal thresholds at which water limitations were most detectable revealed that the best separation between levels of water deficit were at higher resolution (lower flying height), and in the morning (NDVI) and early morning (NDRE). We found that both measures were able to identify moisture deficit in plants and distinguish them from control and watered plants; however, NDVI was better able to distinguish between treatments than NDRE and was more positively correlated with field measurements of plant water content than NDRE. Finally, we explored how relationships between spectral indices and water status changed when the imagery was scaled to courser resolutions provided by satellite-based imagery (PlanetScope) and found that PlanetScope data was able to capture the overall trend in treatments but was not able to capture subtle changes in water content. These kinds of experiments that evaluate the relationship between direct field measurements and UAV camera sensitivity are needed to enable translation of field-based physiology measurements to landscape or regional scales.

Density-dependent calibration of multisensor capacitance probes in coarse soil

2015 ◽  
Vol 95 (4) ◽  
pp. 331-336 ◽  
Author(s):  
Julie D. Zettl ◽  
Mingbin Huang ◽  
S. Lee Barbour ◽  
Bing C. Si
Keyword(s):  
Water Content ◽  
Soil Water ◽  
Field Measurements ◽  
Water Dynamics ◽  
Laboratory Measurements ◽  
Calibration Equation ◽  
Density Dependent ◽  
Capacitance Probe ◽  
The Relationship ◽  
Coarse Soil

Zettl, J. D., Huang, M., Barbour, S. L. and Si, B. C. 2015. Density-dependent calibration of multisensor capacitance probes in coarse soil. Can. J. Soil Sci. 95: 331–336. Coarse-textured reconstructed soils are utilized extensively in the reclamation of mining waste. Accurate and continuous sensing of soil water content is required to understand soil water dynamics and evaluate the hydraulic characteristics of these soils. The EnviroSCAN (Sentek Pty. Ltd, Australia) is a semi-permanent multisensor capacitance probe (MCP) capable of continuous measurement of volumetric water content (θv) and has been used to monitor reclamation soil cover performance. Calibration of these probes is required to improve the accuracy of field measurements. In this study, field and laboratory measurements were undertaken over a range of water contents and bulk densities to refine the relationship between θvand scaled frequency (SF) measured by the MCP. The manufacturer's calibration equation tended to underestimate θvunder wet conditions (θv>0.35 cm3cm–3). Our experimental data showed that bulk density (ρb) did affect the MCP calibration and consequently a new calibration equation that includes the effect of ρbis developed using laboratory measurements and validated using field measurements. This equation provided the highest degree of correlation and the smallest standard deviation of prediction to measured values of θvfor laboratory and field measurements, respectively. This calibration improves the application of the EnviroSCAN for coarse-textured soils such as those utilized in this study.

scholarly journals Remotely Sensed Water Limitation in Vegetation: Insights from an Experiment with Unmanned Aerial Vehicles (UAVs)

2019 ◽  
Vol 11 (16) ◽  
pp. 1853 ◽  
Author(s):  
Kelly Easterday ◽  
Chippie Kislik ◽  
Todd Dawson ◽  
Sean Hogan ◽  
Maggi Kelly
Keyword(s):  
Unmanned Aerial Vehicles ◽  
Water Content ◽  
Water Deficit ◽  
Water Status ◽  
Field Measurements ◽  
Leaf Water Content ◽  
Multispectral Imagery ◽  
Spectral Indices ◽  
Aerial Vehicles ◽  
The Relationship

Unmanned aerial vehicles (UAVs) equipped with multispectral sensors present an opportunity to monitor vegetation with on-demand high spatial and temporal resolution. In this study we use multispectral imagery from quadcopter UAVs to monitor the progression of a water manipulation experiment on a common shrub, Baccharis pilularis (coyote brush) at the Blue Oak Ranch Reserve (BORR) ~20 km east of San Jose, California. We recorded multispectral imagery at several altitudes with nearly hourly intervals to explore the relationship between two common spectral indices, NDVI (normalized difference vegetation index) and NDRE (normalized difference red edge index), leaf water content and water potential as physiological metrics of plant water status, across a gradient of water deficit. An examination of the spatial and temporal thresholds at which water limitations were most detectable revealed that the best separation between levels of water deficit were at higher resolution (lower flying height), and in the morning (NDVI) and early morning (NDRE). We found that both measures were able to identify moisture deficit across treatments; however, NDVI was better able to distinguish between treatments than NDRE and was more positively correlated with field measurements of leaf water content. Finally, we explored how relationships between spectral indices and water status changed when the imagery was scaled to courser resolutions provided by satellite-based imagery (PlanetScope).We found that PlanetScope data was able to capture the overall trend in treatments but unable to capture subtle changes in water content. These kinds of experiments that evaluate the relationship between direct field measurements and UAV camera sensitivity are needed to enable translation of field-based physiology measurements to landscape or regional scales.

Numerical Model of Road Tunnel with Void between the Liner and Surrounding Rock and its Application

2011 ◽  
Vol 261-263 ◽  
pp. 1257-1260
Author(s):  
Jia Yan Zheng ◽  
Hai Jing Liu
Keyword(s):  
Numerical Model ◽  
Safety Factor ◽  
Surrounding Rock ◽  
Contact Method ◽  
Tunnel Engineering ◽  
Road Tunnel ◽  
Decrease Rate ◽  
Status Assessment ◽  
Operation Status ◽  
The Relationship

Void between road tunnel liner and surrounding rock is one of the most frequent defects in tunnel engineering. In this paper, contact method is introduced into the numerical model to simulate the interaction between tunnel liner and surrounding rock. The relationship between the key parameters of void and safety factor of the structure is systematically studied with the numerical model. Results show that position and width of void are the key parameters, while depth and shape of void are unimportant and negligible. It can also be concluded that the decrease rate of safety factor to the increase of circular width is almost the same while void is in different position. Conclusions gained are helpful for inspection, operation status assessment and rehabilitation of road tunnel in future.

scholarly journals Measurements of Daily Variations in the Subsurface Wetness Gradient

1985 ◽  
Vol 6 ◽  
pp. 254-255
Author(s):  
A. Denoth ◽  
A. Foglar
Keyword(s):  
Dielectric Constant ◽  
Water Content ◽  
Liquid Water ◽  
Field Measurements ◽  
Liquid Water Content ◽  
Strip Line ◽  
Snow Surface ◽  
Dielectric Sensor ◽  
Different Depths ◽  
Destructive Measurement

A flat condenser in strip-line technique has been developed to measure the gradient in liquid water content near the snow surface. This dielectric sensor is connected to a twin-T-bridge with an operating frequency of 27 MHz. The special design of the sensor allows the non-destructive measurement of the mean dielectric constant of underlying material at two different depths of 0 to 2 cm, and of 2 to 4 cm below the snow surface. Based on the model of Polder and van Santen, changes in the gradient of liquid water content can be calculated from measured changes in the dielectric constant in different depths; the density has to be measured separately. Results of measurements of wetness gradient with this flat capacitative sensor are given. Field measurements have been carried out in the Stubai Alps (3100 m a.s.1.) and at the Hafelekar (2256 m a.s.l.) near Innsbruck.

Analysis of Pitted Courtyard Cave Dwellings Stability in Baishe Village when Rainfall Infiltration

2011 ◽  
Vol 250-253 ◽  
pp. 2468-2472 ◽  
Author(s):  
Jia Ming Han ◽  
San Qing Su
Keyword(s):  
Water Content ◽  
Field Measurements ◽  
Strength Criterion ◽  
Annual Rainfall ◽  
Rock Stress ◽  
Average Annual Rainfall ◽  
The Stability ◽  
The Relationship ◽  
Water Contents

Pitted courtyard cave dwellings were used as a long-term living form in Baishe village. After field measurements, the size of local pitted courtyards and cave dwellings had been mastered, and the variation of average annual rainfall and monthly rainfall had been analyzed. By the experiment, the changes of physical and mechanical indexes could be showed with different water contents. At the same time, based on the literature, the relationship could be established between rainfall and water content. Basis in the expression of room rock stress and the Mohr-Coulomb strength criterion, the stability of the cave dwellings could be analyzed under different water contents, and the definition could be found of safety factor of loess cave. Then, the stability variation of loess cave dwelling could be obtained in different rainfall, and the evaluation results are given.

scholarly journals Measurements of Daily Variations in the Subsurface Wetness Gradient

1985 ◽  
Vol 6 ◽  
pp. 254-255 ◽  
Author(s):  
A. Denoth ◽  
A. Foglar
Keyword(s):  
Dielectric Constant ◽  
Water Content ◽  
Liquid Water ◽  
Field Measurements ◽  
Liquid Water Content ◽  
Strip Line ◽  
Snow Surface ◽  
Dielectric Sensor ◽  
Different Depths ◽  
Destructive Measurement

A flat condenser in strip-line technique has been developed to measure the gradient in liquid water content near the snow surface. This dielectric sensor is connected to a twin-T-bridge with an operating frequency of 27 MHz. The special design of the sensor allows the non-destructive measurement of the mean dielectric constant of underlying material at two different depths of 0 to 2 cm, and of 2 to 4 cm below the snow surface. Based on the model of Polder and van Santen, changes in the gradient of liquid water content can be calculated from measured changes in the dielectric constant in different depths; the density has to be measured separately. Results of measurements of wetness gradient with this flat capacitative sensor are given. Field measurements have been carried out in the Stubai Alps (3100 m a.s.1.) and at the Hafelekar (2256 m a.s.l.) near Innsbruck.

scholarly journals Sensitivity and regression analysis of acoustic parameters for determining physical properties of frozen fine sand with ultrasonic test

2020 ◽  
Vol 54 (1) ◽  
pp. qjegh2020-021
Author(s):  
Ji-wei Zhang ◽  
Julian Murton ◽  
Shu-jie Liu ◽  
Li-li Sui ◽  
Song Zhang ◽  
...  
Keyword(s):  
Physical Properties ◽  
Water Content ◽  
Wave Velocity ◽  
Field Measurements ◽  
Fine Sand ◽  
Dominant Frequency ◽  
Acoustic Parameters ◽  
Supplementary Material ◽  
The Difference ◽  
The Relationship

Determining the development of artificial frozen walls by present methods is challenging where substantial seepage occurs because fixed monitoring points only indicate physical properties in small areas. Here we use ultrasonic acoustic methods to determine the physical properties between two freezing pipes during freezing. Sensitivity analysis indicates that wave velocity is sensitive to physical properties, and the sensitivity rank is water content > temperature > density. The attenuation coefficient has a low sensitivity to physical parameters, whereas dominant frequency is sensitive to temperature and water content but insensitive to density. Wave velocity increases with temperature and density in a quadratic relationship, and with water content in a linear relationship. Dominant frequency increases with temperature and water content in a quadratic relationship. A multiple regression model of wave velocity and dominant frequency established by stepwise regression can be used to predict the relationship between wave velocity and temperature of frozen fine sand in different areas where the soil properties are similar to those reported here. Wave velocity and dominant frequency measured in the laboratory can be used to predict the relationship between acoustic parameters and temperature in field conditions after curve move based on the first data point from field measurements. The procedure of curve moving involves calculating the difference in value of the first data point between laboratory and field measurements at the same temperature level, and then moving the predicted curve of the laboratory test upward or downward according to the difference.Supplementary material: Experimental datasets are available at https://doi.org/10.6084/m9.figshare.12268970

ADMINISTRATIVE AND LEGAL STATUS OF THE CAPITAL OF UKRAINE - THE HERO CITY OF KYIV AS A GUARANTEE OF THE RIGHTS OF CITIZENS OF UKRAINE AND THE TERRITORIAL COMMUNITY OF THE CITY

2017 ◽  
Author(s):  
Oleksii Chepov ◽  
Keyword(s):  
Legal Status ◽  
Modern World ◽  
Legal Regime ◽  
Legal Doctrine ◽  
City Councils ◽  
The Social ◽  
District Management ◽  
Definition Of ◽  
The Relationship ◽  
The City

The qualitative and clear definition of the legal regime of the capital of Ukraine, the hero city of Kyiv, is influenced by its legislative enshrinement, however, it should be noted that discussions are ongoing and one of the reasons for the unclear legal status of the capital is the ambiguity of current legislation in this area. Separation of the functions of the city of Kyiv, which are carried out to ensure the rights of citizens of Ukraine and the functions that guarantee the rights of the territorial community of the city of Kyiv. In the modern world, in legal doctrine and practice, the capital is understood as the capital of the country, which at the legislative level received this status and, accordingly, is the administrative and political center of the state, which houses the main state bodies and diplomatic missions of other states. It is the identification of the boundaries of the relationship between the competencies of state administrations and local self-government, in practice, often raises questions about their delimitation and ways of regulatory solution. Peculiarities of local self-government in Kyiv city districts are defined in the provisions of the Law on the Capital, which reveal the norms of the Constitution in these legal relations, according to which the issue of organizing district management in cities belongs to city councils. Likewise, it is unregulated by law to lose the particularity of the legal status of the territory of the city. It should be emphasized that the subject of administrative-legal relations is not a certain administrative-territorial entity, but the social group is designated - the territorial community of the city of Kiev, kiyani. Thus, the provisions on the city of Kyiv partially ignore the potential of the territorial community.

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