Rapid magnetic susceptibility measurement for obtaining superficial soil layer thickness and its erosion monitoring implications

Geoderma ◽  
2019 ◽  
Vol 351 ◽  
pp. 163-173 ◽  
Author(s):  
Liang Liu ◽  
Keli Zhang ◽  
Suhua Fu ◽  
Baoyuan Liu ◽  
Mingbin Huang ◽  
...  
Keyword(s):  
Magnetic Susceptibility ◽  
Layer Thickness ◽  
Soil Layer ◽  
Magnetic Susceptibility Measurement

scholarly journals The Relationship between Soil Electrical Parameters and Compaction of Sandy Clay Loam Soil

Agriculture ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 114
Author(s):  
Katarzyna Pentoś ◽  
Krzysztof Pieczarka ◽  
Kamil Serwata
Keyword(s):  
Electrical Conductivity ◽  
Magnetic Susceptibility ◽  
Precision Agriculture ◽  
Soil Compaction ◽  
Soil Layer ◽  
Soil Parameters ◽  
Soil Electrical Conductivity ◽  
Electrical Parameters ◽  
Management Zones ◽  
Additional Information

Soil spatial variability mapping allows the delimitation of the number of soil samples investigated to describe agricultural areas; it is crucial in precision agriculture. Electrical soil parameters are promising factors for the delimitation of management zones. One of the soil parameters that affects yield is soil compaction. The objective of this work was to indicate electrical parameters useful for the delimitation of management zones connected with soil compaction. For this purpose, the measurement of apparent soil electrical conductivity and magnetic susceptibility was conducted at two depths: 0.5 and 1 m. Soil compaction was measured for a soil layer at 0–0.5 m. Relationships between electrical soil parameters and soil compaction were modelled with the use of two types of neural networks—multilayer perceptron (MLP) and radial basis function (RBF). Better prediction quality was observed for RBF models. It can be stated that in the mathematical model, the apparent soil electrical conductivity affects soil compaction significantly more than magnetic susceptibility. However, magnetic susceptibility gives additional information about soil properties, and therefore, both electrical parameters should be used simultaneously for the delimitation of management zones.

Effect of a Strong Middle Layer on Spudcan Penetration

2014 ◽  
Author(s):  
Wen Gao ◽  
Tom Harrup ◽  
Yuxia Hu ◽  
David White
Keyword(s):  
Bearing Capacity ◽  
Layer Thickness ◽  
Soft Clay ◽  
Soil Layer ◽  
Strength Ratio ◽  
Top Soil ◽  
Flow Mechanisms ◽  
Soil Flow ◽  
Jack Up ◽  
Peak Resistance

The rapid penetration of one or more of the foundations of a mobile jack-up rig into the seabed is an ongoing major problem in the offshore industry, with the potential to cause major damage to the structure and endangering any personnel on board. A recent example is the jack-up drilling rig Perro Negro 6 incident happened near the mouth of the Congo river in July 2013 with one of the rig’s crew of 103 reported missing and six others injured. This uncontrollable displacement is due to a form of failure known as punch through failure and commonly occurs on stratified seabed profiles. It has been reported that unexpected punch-through accidents have resulted in both rig damage and lost drilling time at a rate of 1 incident per annum with consequential costs estimated at between US$1 and US$10 million [1]. This paper presents the bearing capacity profiles and associated soil flow mechanisms of a common spudcan foundation penetrating into a three layer soft-stiff-soft clay soil through the use of large deformation finite element (LDFE) analysis. The Remeshing and Interpolation with Small Strain (RITSS) [2, 3] technique was implemented in the software package AFENA [4] to conduct the LDFE analysis. Both soil layer thickness and soil layer strength ratios were varied to study their effect on the spudcan penetration responses. The LDFE results of spudcan penetration into the soft-stiff-soft clay soils were calibrated by existing centrifuge test data. A parametric study was then conducted to study the bearing capacity responses and soil flow mechanisms during spudcan large penetrations by varying the soil layer strength ratio and relative layer thickness to the diameter of spudcan. It was found that there were three types of bearing responses during continuous penetration of spudcan: (a) when the top soft layer is relatively thin, the spudcan bearing response was similar to that of two layer soils with stiff over soft clays; (b) when the top soil layer thickness is medium, a peak resistance is observed when spudcan penetrates into the middle stiff layer followed by reduction; (c) when the soil layer is thick, the peak resistance occurs when spudcan gets into the bottom soft soil layer. The critical thickness of top soil layer is a function of soil strength ratio and middle stiff soil layer thickness. The bearing response types were also corresponding to the soil cavity formations during spudcan initial penetration.

AC Magnetic Susceptibility Measurement and Irreversibility Line in (Bi,Pb)2Sr2Ca2Cu3Oy

1992 ◽  
pp. 377-380
Author(s):  
Masaya Watahiki ◽  
Ryozo Yoshizaki ◽  
Hiroshi Ikeda ◽  
Kozo Yoshikawa ◽  
Nobuyoshi Tomita
Keyword(s):  
Magnetic Susceptibility ◽  
Irreversibility Line ◽  
Magnetic Susceptibility Measurement ◽  
Ac Magnetic Susceptibility

scholarly journals Analysis of Factors Influencing Stability of Overlying Soil Layer on Thin Bedrock Based on Crack Development-Closure Test

2019 ◽  
Vol 2019 ◽  
pp. 1-20 ◽  
Author(s):  
Guangming Wu ◽  
Haibo Bai ◽  
Luyuan Wu ◽  
Shixin He ◽  
Bin Du
Keyword(s):  
Water Content ◽  
Layer Thickness ◽  
Crack Width ◽  
Soil Layer ◽  
Crack Development ◽  
Sand Content ◽  
Particle Composition ◽  
Thin Bedrock ◽  
The Stability ◽  
Seam Mining

The water-blocking properties of the clay layer at the bottom of the Cenozoic overburden in China are an important factor influencing the safety of thin bedrock coal seam mining. Clay has remolding properties that are unlike the nonreversible characteristics of cracks in brittle rock, and failure cracks in clay can reclose or continue to expand under the influence of different external factors. In this work, the soil layer on top of thin bedrock is the research object, and the influences of the particle composition, water content, soil layer thickness, and crack width on the crack development-closure state of soil layer are analyzed by the orthogonal test method. Visual analysis shows that the order of influence of each factor on the stability of soil layer is the crack width, particle composition, soil layer thickness, and water content. The stability of soil layer decreases with increasing crack width and sand content and decreasing soil layer thickness; in addition, soil layer stability decreases first and then increases with increasing water content. Further variance analysis shows that the crack width and particle composition are key factors that impact the stability of soil layer and that the soil layer thickness has some influence, while the water content has little effect on the stability of soil layer. In addition, the crack will reclose when the sand content in soil is less than 50% and the crack width is less than or equal to 1.0 mm, and the soil layer is prone to further failure when the sand content in soil is more than 50% and the crack width is greater than or equal to 3.0 mm; when the soil layer thickness is 15.0 cm, its stability is better than when the soil layer thickness is 10.0 cm or 5.0 cm.

SOLID REACTION, OXYGEN ABSORPTION AND AMORPHOUS STATE IN Bi-Ca-Sr-Cu-O SYSTEM

1989 ◽  
Vol 03 (12) ◽  
pp. 949-953
Author(s):  
N.P. ZHU ◽  
L.J. ZHOU ◽  
T.F. LI ◽  
Y.Z. Wang ◽  
Y.S. ZHANG ◽  
...  
Keyword(s):  
Magnetic Susceptibility ◽  
Oxygen Content ◽  
Amorphous State ◽  
Magnetic Susceptibility Measurement ◽  
Oxygen Absorption ◽  
Solid Reaction ◽  
Content Determination

Solid reaction, oxygen relief and absorption in Bi-Sr-Ca-Cu-O system have been investigated by TGA technique. Oxygen contents (x=5.5 and 5.64) for BiSrCaCu 2Ox samples quenched and furnace-cooled were determined, respectively. No oxygen absorption and relief happens below 800°C. Amorphous state can be obtained by heating the sample up to 1000°C and then cooling it quickly. Magnetic susceptibility measurement and oxygen content determination suggest that Cu+ and Cu3+ exist in the quenched and furnace-cooled samples.

Magnetic susceptibility measurement applied to the minerals industry

2006 ◽  
Vol 19 (15) ◽  
pp. 1588-1595 ◽  
Author(s):  
G.L. Cavanough ◽  
P.N. Holtham ◽  
T.M. Powell
Keyword(s):  
Magnetic Susceptibility ◽  
Magnetic Susceptibility Measurement
Sign in / Sign up

Export Citation Format

Share Document