scholarly journals Effect of Moisture Content on the Shear Behaviour of a Completely Decomposed Granite: An Experimental Study

2021 ◽  
Vol 2021 ◽  
pp. 1-10
Author(s):  
Pan Liu ◽  
Jinhong Lin ◽  
Yang Wang ◽  
Xueqiang Yang
Keyword(s):  
Moisture Content ◽  
Linear Equations ◽  
Safety Evaluation ◽  
Shear Behaviour ◽  
Strength Parameters ◽  
Direct Shear Tests ◽  
Decomposed Granite ◽  
Effect Of Moisture ◽  
Completely Decomposed Granite

To figure out the effect of moisture content on the shear behaviour of undisturbed completely decomposed granite (CDG) soil, a series of in situ and laboratory direct shear tests were carried out, under different normal stress and moisture contents. The test results showed that the increasing moisture content could obviously weaken the shear strength, cohesion, and frictional angle. Two linear equations were proposed for estimating the cohesion and the frictional angle at any moisture content in the field. The estimated strength parameters could be used for safety evaluation and/or engineering design of CDG cutting slope. The rate of reduction of the cohesion was much higher than that of the tangent value of frictional angle. Due to the disturbance of laboratory sample and size effect, the strength parameters obtained from the in situ test were a little bit higher than those from the laboratory test.

scholarly journals RISK ANALYSIS OF THE PILLAR STRENGTH IN THE ESTONIA MINE

2015 ◽  
Vol 1 ◽  
pp. 19
Author(s):  
Juri-Rivaldo Pastarus ◽  
Sergei Sabanov ◽  
Jekaterina Shestakova ◽  
Oleg Nikitin
Keyword(s):  
Experimental Data ◽  
Risk Analysis ◽  
Moisture Content ◽  
Bearing Capacity ◽  
Oil Shale ◽  
Volume Density ◽  
Analysis Method ◽  
Strength Parameters ◽  
In Situ Conditions

This paper deals with the risk analysis and assessment of the pillars strength problems in the Estonia oil shale mine. Aim of this investigation was to determine the strength parameters and predict the bearing capacity of the pillars in Estonia mine, mining block No. 3107 Methods were based on theoretical investigation and experimental data of in-situ conditions. It is given the geological description of the mining block and determined the strength parameters, moisture content and volume density of the oil shale and limestone layers. Analysis showed that the used risk analysis method is applicable for Estonian oil shale mines. The results of the risk analysis are of particular interest for practical purposes.

scholarly journals Influence of principal stress direction on the stress-strain-strength behaviour of completely decomposed granite

2010 ◽  
Vol 8 (1) ◽  
pp. 79-97 ◽  
Author(s):  
Md. Kumruzzaman ◽  
Jian-Hua Yin
Keyword(s):  
Principal Stress ◽  
Hollow Cylinder ◽  
Principal Stress Rotation ◽  
Strength Parameters ◽  
Principal Stress Direction ◽  
Stress Rotation ◽  
Strength Behavior ◽  
Major Principal Stress ◽  
Decomposed Granite ◽  
Completely Decomposed Granite

The measurement and study of the stress-strain-strength behavior of soils in general stress states involving principal stress rotation are necessary and valuable. To investigate the strength behavior under principal stress rotation, a series of undrained tests on compacted hollow cylinder specimens of completely decomposed granite (CDG) was carried in hollow cylinder apparatus. Tests were conducted using constant inside and outside pressures and maintained a fixed angle of rotation of principal stress with the vertical (?). Seven different angles of major principal stress orientations were used to cover the entire range of major principal stress directions from vertical to the horizontal. Two different confining stresses were used to find out the variations of the experimental results. It is observed that the deviator stresses as well as excess pore pressures decrease with the angle ?. It is also observed that specimens were getting softer with the increase of ?. The results also show a significant influence of principal stress direction angle on the strength parameters. It is found that the angle ? is related to the occurrence of cross-anisotropy and the localization which resulted in a pronounced influence on the strength parameters of the CDG specimens.

scholarly journals Development of a rapid field testing method for metals in horizontal directional drilling residuals with XRF sensor

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Hailin Zhang ◽  
João Antonangelo ◽  
Chad Penn
Keyword(s):  
Moisture Content ◽  
Standard Method ◽  
Field Testing ◽  
Field Method ◽  
Filter Press ◽  
Directional Drilling ◽  
Horizontal Directional Drilling ◽  
Excess Water ◽  
Spiked Soil

AbstractPortable X-ray fluorescence (pXRF) spectrometer allows fast in-situ elemental determination without wet digestion for soils or geological materials, but the use of XRF on wet materials is not well documented. Our objective was to develop a rapid field method using pXRF to measure metals in the residues from horizontal directional drilling (HDD) operations so that proper disposal decisions can be made in-situ. To establish the procedure, we spiked soil samples with 4 concentrations of Cr, Ni, Cu, Zn, As, Cd, and Pb up to 1000 mg kg−1, and then the metal concentrations were determined by wet chemical method after drying and acid digestion (standard method), and by pXRF, also at laboratory conditions, after drying and at two different moisture conditions. The measurements by pXRF and standard method after drying and after removal of excess water (AREW) were highly correlated with slopes ranging from 0.83 ± 0.01 to 1.08 ± 0.01 (P < 0.001) for all metals. The relationship was better AREW than the saturated paste without removal of excess water and the moisture content affected only the accuracy of As, Cd, and Pb. The procedure established was successfully used for HDD residues collected from 26 states of US with moisture content ranging from 14 to 83% AREW. The pXRF was proven to be a reliable tool for fast detection of common metals in dried soils and HDD residues, and samples containing < 30% moisture content without needing to correct for moisture. If the moisture is > 30%, excess water in samples need to be removed with a commercially available filter press to achieve high accuracy. The developed procedures reduce time of metal detection from days to about an hour which allows drilling operators to make quick decisions on soil or HDD disposal.

scholarly journals Effect of Moisture Content on the Processing and Mechanical Properties of a Biodegradable Polyester

Polymers ◽  
2021 ◽  
Vol 13 (10) ◽  
pp. 1616
Author(s):  
Vincenzo Titone ◽  
Antonio Correnti ◽  
Francesco Paolo La Mantia
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Moisture Content ◽  
Mechanical Testing ◽  
Hydrolytic Degradation ◽  
Slight Reduction ◽  
Biodegradable Polyester ◽  
Molding Process ◽  
Elongation At Break ◽  
Effect Of Moisture

This work is focused on the influence of moisture content on the processing and mechanical properties of a biodegradable polyester used for applications in injection molding. The pellets of the biodegradable polyester were exposed under different relative humidity conditions at a constant temperature before being compression molded. The compression-molded specimens were again placed under the above conditions before the mechanical testing. With all these samples, it is possible to determine the effect of moisture content on the processing and mechanical properties separately, as well as the combined effect of moisture content on the mechanical properties. The results obtained showed that the amount of absorbed water—both before processing and before mechanical testing—causes an increase in elongation at break and a slight reduction of the elastic modulus and tensile strength. These changes have been associated with possible hydrolytic degradation during the compression molding process and, in particular, with the plasticizing action of the moisture absorbed by the specimens.

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