scholarly journals Analysis and Evaluation Methods of Seismic Subsidence Characteristics of Loess and Field Seismic Subsidence

2021 ◽  
Vol 24 (4) ◽  
pp. 485-490
Author(s):  
Xiaotong Yan ◽  
Shun Wang ◽  
Ningwei Wang
Keyword(s):  
Evaluation Method ◽  
Soil Depth ◽  
Dynamic Properties ◽  
Soil Layer ◽  
Estimation Method ◽  
Dry Density ◽  
Cycle Times ◽  
Analysis And Evaluation ◽  
Stress Ratios ◽  
Triaxial Experiment

The objective of this research is to analyze the dynamic degeneration of loess and the evaluation method of field seismic subsidence. In this study, Q3 loess is taken as the research object, and the dynamic properties of loess with 10%, 20%, 30% and 35% moisture content are tested by triaxial experiment. In addition, seismic subsidence characteristics of loess with dry densities of 1.4g/cm3, 1.6g/cm3, and 1.8g/cm3 and consolidation stress ratios of 1.0, 1.2, 1.4, and 1.6 are analyzed. Then the simplified seismic subsidence estimation method is used to calculate the relationship between seismic subsidence coefficients at different soil depth in one dimensional field, cycle times, and subsidence depth. The results show that the higher the water content of loess is, the greater the change of seismic subsidence appears. The larger the dry density of loess is, the smaller the change degree of seismic subsidence appears. The larger the consolidation stress ratio is, the greater the change of seismic subsidence occurs in loess. When the depth of soil reaches 9.5m, the maximum seismic subsidence coefficient can reach 0.8%. When the depth of soil layer is 10m, the degree of seismic subsidence is the largest. When the depth of soil layer is 12~16m, the settlement depth caused by earthquake subsidence is small. While the depth of soil layer is 8~12m, the settlement degree is large.

Estimation of Failure Probability and its Applications in Reliability Data Analysis

2010 ◽  
Vol 118-120 ◽  
pp. 601-605
Author(s):  
Han Ming
Keyword(s):  
Parameter Estimation ◽  
Data Analysis ◽  
Bayesian Estimation ◽  
Failure Probability ◽  
Evaluation Method ◽  
Estimation Method ◽  
New Method ◽  
Reliability Parameter ◽  
Hierarchical Bayesian Estimation ◽  
Definition Of

Evaluation method of reliability parameter estimation needs to be improved effectively with the advance of science and technology. This paper develops a new method of parameter estimation, which is named E-Bayesian estimation method. In the case one hyper-parameter, the definition of E-Bayesian estimation of the failure probability is provided, moreover, the formulas of E-Bayesian estimation and hierarchical Bayesian estimation, and the property of E-Bayesian estimation of the failure probability are also provided. Finally, calculation on practical problems shows that the provided method is feasible and easy to perform.

Utility analysis and evaluation method study of side channel information

2013 ◽  
Vol 30 (5) ◽  
pp. 500-508
Author(s):  
Yingjian Yan ◽  
Jingchao Yu ◽  
Pengfei Guo ◽  
Jianfei Guo
Keyword(s):  
Evaluation Method ◽  
Side Channel ◽  
Utility Analysis ◽  
Analysis And Evaluation ◽  
Channel Information

A Study on Estimation of S-N Curves for Structural Steels Based on their Static Mechanical Properties

2014 ◽  
Vol 891-892 ◽  
pp. 1639-1644 ◽  
Author(s):  
Kazutaka Mukoyama ◽  
Koushu Hanaki ◽  
Kenji Okada ◽  
Akiyoshi Sakaida ◽  
Atsushi Sugeta ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Evaluation Method ◽  
Materials Science ◽  
Estimation Method ◽  
Structural Steels ◽  
Metallic Materials ◽  
Fatigue Reliability ◽  
Regression Parameters ◽  
Static Mechanical ◽  
Static Mechanical Properties

The aim of this study is to develop a statistical estimation method of S-N curve for iron and structural steels by using their static mechanical properties. In this study, firstly, the S-N data for pure iron and structural steels were extracted from "Database on fatigue strength of Metallic Materials" published by the Society of Materials Science, Japan (JSMS) and S-N curve regression model was applied based on the JSMS standard, "Standard Evaluation Method of Fatigue Reliability for Metallic Materials -Standard Regression Method of S-N Curve-". Secondly, correlations between regression parameters and static mechanical properties were investigated. As a result, the relationship between the regression parameters and static mechanical properties (e.g. fatigue limit E and static tensile strength σB) showed strong correlations, respectively. Using these correlations, it is revealed that S-N curve for iron and structural steels can be predicted easily from the static mechanical properties.

scholarly journals Depth-Dependent C-N-P Stocks and Stoichiometry in Ultisols Resulting from Conversion of Secondary Forests to Plantations and Driving Forces

Forests ◽  
2021 ◽  
Vol 12 (10) ◽  
pp. 1300
Author(s):  
Xiaogang Ding ◽  
Xiaochuan Li ◽  
Ye Qi ◽  
Zhengyong Zhao ◽  
Dongxiao Sun ◽  
...  
Keyword(s):  
Soil Depth ◽  
Soil Layer ◽  
Pinus Elliottii ◽  
Slash Pine ◽  
Pine Plantations ◽  
Secondary Forests ◽  
Masson Pine ◽  
Soil Layers ◽  
Soil C ◽  
Significant Difference

Stocks and stoichiometry of carbon (C), nitrogen (N), and phosphorus (P) in ultisols are not well documented for converted forests. In this study, Ultisols were sampled in 175 plots from one type of secondary forest and four plantations of Masson pine (Pinus massoniana Lamb.), Slash pine (Pinus elliottii Engelm.), Eucalypt (Eucalyptus obliqua L’Hér.), and Litchi (Litchi chinensis Sonn., 1782) in Yunfu, Guangdong province, South China. Five layers of soil were sampled with a distance of 20 cm between two adjacent layers up to a depth of 100 cm. We did not find interactive effects between forest type and soil layer depth on soil organic carbon (SOC), total nitrogen (TN), and total phosphorus (TP) concentrations and storages. Storage of SOC was not different between secondary forests and Eucalypt plantations, but SOC of these two forest types were lower than that in Litchi, Masson pine, and Slash pine plantations. Soil C:P was higher in Slash pine plantations than in secondary forests. Soil CNP showed a decreasing trend with the increase of soil depth. Soil TP did not show any significant difference among soil layers. Soil bulk density had a negative contribution to soil C and P stocks, and longitude and elevation were positive drivers for soil C, N, and P stocks. Overall, Litchi plantations are the only type of plantation that obtained enhanced C storage in 0–100 cm soils and diverse N concentrations among soil layers during the conversion from secondary forests to plantations over ultisols.

scholarly journals Effects of different biomass materials as a salt-isolation layer on water and salt migration in coastal saline soil

PeerJ ◽  
2021 ◽  
Vol 9 ◽  
pp. e11766
Author(s):  
Mao Yang ◽  
Runya Yang ◽  
Yanni Li ◽  
Yinghua Pan ◽  
Junna Sun ◽  
...  
Keyword(s):  
Water Content ◽  
Soil Water ◽  
Soil Water Content ◽  
Salt Concentration ◽  
Saline Soil ◽  
Soil Depth ◽  
Soil Layer ◽  
Thick Layer ◽  
Peat Layer ◽  
Salt Accumulation

The aim of this study was to find a material suited for the prevention of evaporative water loss and salt accumulation in coastal saline soils. One-dimensional vertical water infiltration and phreatic evaporation experiments were conducted using a silty loam saline soil. A 3-cm-thick layer of corn straw, biochar, and peat was buried at the soil depth of 20 cm, and a 6-cm-thick layer of peat was also buried at the same soil depth for comparison. The presence of the biochar layer increased the upper soil water content, but its ability to inhibit salt accumulation was poor, leading to a high salt concentration in the surface soil. The 3-cm-thick straw and 6-cm-thick peat layers were most effective to inhibit salt accumulation, which reduced the upper soil salt concentration by 96% and 93%, respectively. However, the straw layer strongly inhibited phreatic evaporation and resulted in low water content in the upper soil layer. Compared with the straw layer, the peat layer increased the upper soil water content. Thus, burying a 6-cm-thick peat layer in the coastal saline soil is the optimal strategy to retain water in the upper soil layer and intercept salt in the deeper soil layer.

scholarly journals Kajian Potensi Produksi Hijauan Pakan pada Lahan Eksisting dan Potensial untuk Meningkatkan Populasi Ternak Ruminansia di Kabupaten Aceh Besar

2015 ◽  
Vol 15 (1) ◽  
pp. 33-40 ◽  
Author(s):  
Mira Delima ◽  
Abubakar Karim ◽  
M. Yunus
Keyword(s):  
Land Use ◽  
Evaluation Method ◽  
Soil Depth ◽  
Secondary Data ◽  
Primary Data ◽  
Forage Production ◽  
Land Capability ◽  
Livestock Population ◽  
Survey And Evaluation ◽  
Potential Land

(The study of prospective forage production on existing and potential land use to support increasing livestock population in Aceh Besar) ABSTRACT. The purpose of this research was to find out the width and scattered location of existing land use which its land capability class suitable for pastures; forage production prospective, and land carrying capacity. The combination of survey and evaluation method was used in this study. The primary data were obtained by field observation and compiling documents, while the secondary data were obtained from various sources, including Bappeda Aceh, and Dinas Peternakan Aceh Besar. Land capability classification was defined based on a modified USDA method and land capability class mapping was prepared based on overlay method by geoprocessing of Geographic Information Systems. The attributes delineating land capability classification included slope, erosion potential and soil depth. Spatial and attributes data were processed using ArcGIS 9.3. Interpretation of land use map derived from satellite imagery analysis results. Brachiaria humidicola green production (tons/year) was determined by assumption-based on obtaining data from various sources. Present livestock population and increasing of population target up to 2017 were obtained from Dinas Peternakan Aceh Besar. The results showed that the existing land use area was 28,632.23 ha (59.03 %), whereas the potential land use area was 19,875.73 ha (40.97%). Land use area for pastures in the district of Aceh Besar, both existing and potential, were sufficient to support the achievement of livestock population increasing program.

scholarly journals Depth distribution of belowground net primary production across global biomes

2021 ◽  
Author(s):  
Zhongkui Luo ◽  
Guocheng Wang ◽  
Liujun Xiao ◽  
Xiali Mao ◽  
Xiaowei Guo ◽  
...  
Keyword(s):  
Primary Production ◽  
Depth Distribution ◽  
Net Primary Production ◽  
Soil Depth ◽  
Soil Layer ◽  
Soil Nutrient ◽  
Data Sets ◽  
Large Variability ◽  
Belowground Carbon ◽  
Belowground Net Primary Production

Abstract The depth distribution of belowground net primary production (BNPP) has been unquantified globally, hindering our understanding of belowground carbon dynamics. We synthesize global observational data sets to infer the depth allocation of BNPP down to 2 m, and map depth-specific BNPP globally at 1 km resolution. We estimate that global average BNPP in the 0–20 soil layer is 1.1 Mg C ha–1 yr–1, accounting for >50% of total BNPP. Across the globe, the depth distribution of BNPP shows large variability, and more BNPP is allocated to deeper layers in hotter and drier regions. Edaphic, climatic and topographic properties (in the order of importance) can explain >80% of such variability in different soil depths; and the direction and magnitude of the influence of individual properties (e.g., precipitation and soil nutrient) are soil depth- and biome-dependent. Our results provide global benchmarks for predictions of whole-soil carbon profiles across global biomes.

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