The Impact of the Plate Diameter on the Determined Value of the Pre-Compaction Stress of Samples made of Silt Soil

2016 ◽  
Vol 20 (2) ◽  
pp. 5-14
Author(s):  
Dariusz Błażejczak ◽  
Jan B. Dawidowski
Keyword(s):  
Moisture Content ◽  
Humus Content ◽  
Testing Machine ◽  
Liquid Limit ◽  
Solid Particles ◽  
Degree Of Saturation ◽  
Stress Curve ◽  
Compaction Stress ◽  
Group Density ◽  
The Impact

AbstractThe objective of the paper was to investigate the impact of the plate diameter on the value of the measured pre-compaction stress of soil. The investigations were carried out on model samples with 100 mm diameter and 30 mm height made of the silt loam and the percentage moisture content of 13.7 and 21.9%. The following properties of the used material were measured: the granulation group, density of solid particles, humus content, reaction, plastic and liquid limit and the degree of saturation of samples. The samples were loaded with a testing machine using plates with varied diameters: 20, 30, 50, 70, 80, 90, 96, 98 and 99 mm. The pre-compaction stress value was measured with the method of searching for the crossing point of tangents with the secondary stress curve and original stress curve (a classic method). It was found out that for samples with saturation amounting to 13.7% of the moisture content the pre-compaction stress does not significantly depend on the plate diameter. For samples with saturation amounting to 21.9% of the moisture content the pre-compaction stress may significantly depend on the plate diameter. Based on the obtained results a conclusion was made that in the research on the pre-compaction stress with the method of uni-axial deformations, the relation of the plate diameter (d) to the diameter of the cylinder (D) should be within 0.3 ≤ d/D < 0.8.

scholarly journals Impact of the Plate Diameter on the Value of the Pre-Compaction Stress in Soils With Varied Textural Group

2016 ◽  
Vol 20 (3) ◽  
pp. 5-14 ◽  
Author(s):  
Dariusz Błażejczak ◽  
Jan B. Dawidowski
Keyword(s):  
Solid Phase ◽  
Classical Method ◽  
Testing Machine ◽  
Liquid Limit ◽  
Solid Particles ◽  
Degree Of Saturation ◽  
Dry Density ◽  
Stress Curve ◽  
Compaction Stress ◽  
The Impact

AbstractThe objective of the paper was to verify the previously obtained results of research concerning the impact of the plate diameter on the measured value of the pre-compaction stress of silt (NG), in conditions of a wider range of soil types and their initial stage. The research was carried out on samples with a diameter of 100 mm and height of 30 mm produced from the soil material (M) or collected from the subsoil of the selected soils (AWN) with the granulation type of: silt loam, loam, light loam, sandy-clay soil. The following soils properties were determined: the granulation type, density of the solid phase, content of humus and calcium carbonate, reaction, plastic and liquid limit. The properties of samples were described with moisture, dry density of solid particles, porosity of aeration, degree of plasticity and degree of saturation. The samples were loaded with a testing machine with plates with varied diameters. The value of the pre-compaction stress of soil was measured with the method of searching the crossing point of tangents with the secondary stress curve and the original stresses curve (a classical method). It was found out that for samples M with the degree of saturation of 0.40-0.50, the pre-compaction stress does not significantly depend on the plate diameter. For samples M or AWN, with the degree of saturation of 0.64-0.82, the pre-compaction stress significantly depends on the diameter of the plate. A conclusion was formulated that in the research of NG with the method of uniaxial defonnations, the relation of the diameter of the plate (d) to the diameter of the cylinder (D) should be within 0.5 ≤ d/D ≤ 0.8.

scholarly journals Impact of Plate Diameter and Sample Height on the Determined Pre-Compaction Value

2017 ◽  
Vol 21 (1) ◽  
pp. 19-28
Author(s):  
Dariusz Błażejczak ◽  
Jan B. Dawidowski
Keyword(s):  
Solid Phase ◽  
Sandy Loam ◽  
Liquid Limit ◽  
Solid Particles ◽  
Dry Density ◽  
Sample Height ◽  
Solid Phase Content ◽  
Stress Curve ◽  
Compaction Stress ◽  
The Impact

Abstract The objective of the paper was to verify previously obtained results of research on the impact of the plate diameter on the determined value of pre-compaction stress of soil (NG) with a wider selection of dimensions of samples. Tests were carried out on samples with a diameter (D) of 100 mm and heights (H) of 30, 50 or 100 mm produced from the soil material (M) or collected (NNS) from subsoil with the granulation group of: silt loam, loam, sandy loam, sandy clay loam. The following soil properties were determined: granulation type, density of the solid phase, content of humus and calcium carbonate, reaction, plastic and liquid limit. Properties of samples were described with moisture, dry density of solid particles, porosity of aeration, degree of plasticity and saturation. Samples were loaded with plates of varied diameters. The NG value was calculated with the method of searching for the crossing point of tangents with the secondary stress curve and the virgin stresses curve (a traditional method). It was stated that the plate diameter (d) and sample height (H) do not influence the measurement results when the relation d/D is within 0.5 ≤ d/D ≤ 0.8 and the ratio D/H equals 2. It is possible to omit the condition d/D in a situation when soil is low cohesive and its degree of moisture is ca. 0.41-0.44.

scholarly journals Impact of the moisture content in medium sands on CPTU test results

2016 ◽  
Vol 48 (3) ◽  
pp. 221-231 ◽  
Author(s):  
Łukasz Zawadzki ◽  
Marek Bajda
Keyword(s):  
Moisture Content ◽  
Unsaturated Soils ◽  
Pore Water Pressure ◽  
Water Pressure ◽  
Degree Of Saturation ◽  
Test Results ◽  
Time Dynamic ◽  
Tip Resistance ◽  
The Impact ◽  
Resistance Value

Abstract Soils occurring in the soil “active zone” are in contact with the surface and are directly influenced by external factors (mainly climatic changes) that cause variation in their parameters over time. Dynamic and uncontrolled changes of soil properties e.g. due to rainfall and evapotranspiration processes may affect field test results leading to the misinterpretation of the obtained data. This paper presents investigations on the influence of moisture content changes in sandy soils on CPTU results. For this purpose, a field ground model has been constructed and five CPTU tests with a different moisture content of soil were carried out. During the investigations, the tip resistance (qc), friction on sleeve (fs), and pore water pressure (u2) were measured. Moreover, a TDR probe was applied to determine the distribution of the moisture content in the studied soil columns. Differences between CPT results obtained in saturated and unsaturated soils have been shown. Furthermore, a simple equation to correct the tip resistance value due to the impact of the degree of saturation has been proposed.

scholarly journals Predicting Unit Pressure Indispendable for Generation of Specific Compaction of a Soil Sample

2018 ◽  
Vol 22 (3) ◽  
pp. 85-92
Author(s):  
Kinga Śnieg ◽  
Dariusz Błażejczak ◽  
Małgorzata Słowik
Keyword(s):  
Bulk Density ◽  
Soil Sample ◽  
Uniaxial Compression ◽  
Compression Test ◽  
Humus Content ◽  
Soil Layer ◽  
Solid Particles ◽  
Uniaxial Compression Test ◽  
Group Density ◽  
Unit Pressure

AbstractThe objective of the research was to construct an empirical model for prediction of a unit pressure indispensable for generation of a specific compaction of soil samples. Soil material in the form of loose mass was collected from the soil layer deposited in the depth from 35 to 40 cm and then its typical properties were determined (textural group, density of solid particles, humus content, reaction, plastic and liquid limits) and in order to compact it in Proctor apparatus and in the uniaxial compression test. Results of both tests were used for construction of regression models reflecting the course of the unit strength (Pρd) necessary to generate compaction (ρdj) equal to the dry bulk density obtained in Proctor apparatus (ρdp), in relation to the sample moisture (ρdm). Searching for relations was restricted to the scope of moisure between an optimal one acc. to Proctor and the soil plastic limit. It was stated that the pressure value Pρdp made on the soil sample in the uniaxial compression test depends significantly on ws and ρdm, and for description of this relation the use of multiple regression is sufficient. It was found out that for model samples with a textural group of silt loam and loam, differences in dry bulk density obtained in Proctor apparatus are approximately up to 0.15 g⋅cm−3.

The Manufacturing of the Bamboo Buffer Packaging Material

2011 ◽  
Vol 328-330 ◽  
pp. 1369-1372 ◽  
Author(s):  
Ye Liu ◽  
Shi Hang Wang
Keyword(s):  
High Efficiency ◽  
Bubble Diameter ◽  
Testing Machine ◽  
Packaging Material ◽  
Impact Testing ◽  
Maximum Acceleration ◽  
Foaming Agents ◽  
Bamboo Pulp ◽  
Stress Curve ◽  
The Impact

At present work, to make cushioning packaging material from the bamboo fibers. Change the time of the surface treatment and the component contents of foaming agents, adhesives, plasticizers, cross-linking agents, etc. to analyze the effects on the foam density, foaming rate, elasticity, and bubble diameter. The best reagent and the optimal ratio of the various components have been identified. Determined the parameter of foaming techniques based on the high efficiency and no polluting foaming mechanism. Experiment with the impact testing machine to obtain the maximum acceleration - static stress curve, dynamic stress - strain curves, dynamic buffer factor - stress curve, Analyzed the dynamic buffer performance on the of changing the drop height and compared with other cushioning material. we know that: at height of 450mm, the product had lower peak acceleration value than EPE and EPS during the stress area of 2.8-5.4kpa, which means the cushioning property of the bamboo pulp product is better at that time.

scholarly journals A GNSS-IR Method for Retrieving Soil Moisture Content from Integrated Multi-Satellite Data That Accounts for the Impact of Vegetation Moisture Content

2021 ◽  
Vol 13 (13) ◽  
pp. 2442
Author(s):  
Jichao Lv ◽  
Rui Zhang ◽  
Jinsheng Tu ◽  
Mingjie Liao ◽  
Jiatai Pang ◽  
...  
Keyword(s):  
Soil Moisture ◽  
Moisture Content ◽  
Satellite Data ◽  
Vegetation Index ◽  
Soil Moisture Content ◽  
Support Vector ◽  
Observation Data ◽  
Multipath Effect ◽  
Mars Model ◽  
The Impact

There are two problems with using global navigation satellite system-interferometric reflectometry (GNSS-IR) to retrieve the soil moisture content (SMC) from single-satellite data: the difference between the reflection regions, and the difficulty in circumventing the impact of seasonal vegetation growth on reflected microwave signals. This study presents a multivariate adaptive regression spline (MARS) SMC retrieval model based on integrated multi-satellite data on the impact of the vegetation moisture content (VMC). The normalized microwave reflection index (NMRI) calculated with the multipath effect is mapped to the normalized difference vegetation index (NDVI) to estimate and eliminate the impact of VMC. A MARS model for retrieving the SMC from multi-satellite data is established based on the phase shift. To examine its reliability, the MARS model was compared with a multiple linear regression (MLR) model, a backpropagation neural network (BPNN) model, and a support vector regression (SVR) model in terms of the retrieval accuracy with time-series observation data collected at a typical station. The MARS model proposed in this study effectively retrieved the SMC, with a correlation coefficient (R2) of 0.916 and a root-mean-square error (RMSE) of 0.021 cm3/cm3. The elimination of the vegetation impact led to 3.7%, 13.9%, 11.7%, and 16.6% increases in R2 and 31.3%, 79.7%, 49.0%, and 90.5% decreases in the RMSE for the SMC retrieved by the MLR, BPNN, SVR, and MARS model, respectively. The results demonstrated the feasibility of correcting the vegetation changes based on the multipath effect and the reliability of the MARS model in retrieving the SMC.

scholarly journals Effects of temperature and impactor nose diameter on the impact behavior of PA6 and PP thermoplastic composites

2018 ◽  
Vol 51 (1) ◽  
pp. 64-74 ◽  
Author(s):  
Akar Dogan ◽  
Yusuf Arman
Keyword(s):  
Load Capacity ◽  
Testing Machine ◽  
Polyamide 6 ◽  
Impact Testing ◽  
Impact Behavior ◽  
Thermoplastic Composites ◽  
Test Machine ◽  
Effects Of Temperature ◽  
Impact Energies ◽  
The Impact

In this study, the effects of temperature and impactor nose diameter on the impact behavior of woven glass-reinforced polyamide 6 (PA6) and polypropylene (PP) thermoplastic composites were investigated experimentally. Impact energies are chosen as 10, 30, 50, 70, 90, 110, 130, and 170 J. The thickness of composite materials is 4 mm. Impact tests were performed using a drop weight impact testing machine, CEAST-Fractovis Plus, and the load capacity of test machine is 22 kN. Hemispherical impactor nose diameter of 12, 7, and 20 mm were used as an impactor. The tests are conducted at room temperature (20°C and 75°C). As a result, the PP composites of the same thickness absorbed more energy than PA6 composites. The amount of absorbed energy of PP and PA6 composites decreased with temperature.

Evaluation of Design Characteristics for Animal Mortality Composting Systems

2021 ◽  
Vol 65 (1) ◽  
pp. 23-30
Author(s):  
Tiago Costa ◽  
Neslihan Akdeniz
Keyword(s):  
Moisture Content ◽  
Linear Relationship ◽  
Compressive Stress ◽  
Flow Rate ◽  
Volumetric Flow Rate ◽  
Airflow Rate ◽  
List Type ◽  
Design Characteristics ◽  
The Impact ◽  
Composting Systems

HighlightsDesign characteristics for animal mortality compost cover materials were tested.Compressive stress was applied to simulate the effects of the mortalities on cover materials.The highest permeability was measured for sawdust at 25% moisture content.A linear relationship was found between the volumetric flow rate and the power required to aerate the piles.Abstract. Composting is an aerobic process that relies on natural aeration to maintain proper oxygen levels. Air-filled porosity, mechanical strength, and permeability are among the essential parameters used to optimize the process. This study’s objective was to measure the physical parameters and airflow characteristics of three commonly used cover materials at four moisture levels, which could be used in designing actively aerated swine mortality composting systems. A laboratory-scale experiment was conducted to measure pressure drops across the cover materials as a function of the airflow rate and the material’s moisture content. Compressive stress was applied for 48 h to simulate the impact of swine mortalities on the cover materials. The power required to aerate each material was determined as a function of volumetric flow rate and moisture content. As expected, air-filled porosity and permeability decreased with increasing bulk density and moisture content. The highest average permeability values were measured at 25% moisture content and ranged from 66 × 10-4 to 70 × 10-4 mm2, from 161 × 10-4 to 209 × 10-4 mm2, and from 481 × 10-4 to 586 × 10-4 mm2 for woodchips, ground cornstalks, and sawdust, respectively. For the range of airflow rates tested in this study (0.0025 to 0.0050 m3 s-1 m-2), a linear relationship (R2 = 0.975) was found between the volumetric flow rate (m3 s-1) and the power required to aerate the compost pile (W per 100 kg of swine mortality). Keywords: Airflow, Darcy’s law, Livestock, Modeling, Permeability, Pressure drop.

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