scholarly journals The Dynamic Change and Effect of Rainfall Induced Groundwater Flow

Water ◽  
2021 ◽  
Vol 13 (19) ◽  
pp. 2625
Author(s):  
Yuqiong He ◽  
Rong Sun ◽  
Zemin Xu ◽  
Weijia Tang
Keyword(s):  
Groundwater Flow ◽  
Dynamic Change ◽  
Soil Layer ◽  
Flow Distribution ◽  
Friction Angle ◽  
Seepage Flow ◽  
Initial Water Content ◽  
Weak Zone ◽  
Softening Effect ◽  
Initial Water

This study aims to analyze the groundwater flow changes caused by rainfall and its influence on slope stability. Taking the slope in Dingjiafen, Chuxiong, Yunnan, China as the study area, the study monitored the data of rainfall and drew upon the calculation module of ArcGIS to predict the change of the groundwater flow and water level fluctuation in the soil. In this way, the visual simulation of groundwater flow distribution of the slope was realized; and the influence of groundwater flow distribution caused by rainfall seepage on the slope’s stability was also analyzed. The results indicate that: (1) the rainfall recharge rate is affected by the thickness of the soil layer, the slope, the rainfall intensity, and the initial water content of the soil; (2) the seepage flow of rainfall in per unit time is positively correlated with the soil layer thickness of the slope; (3) the groundwater is repeatedly raised, maintained, and dissipated by periodic rainfall which destroys the structure of the soil; and (4) the rainfall reduces the cohesion and internal friction angle of the soil resulting in the “muddy water softening effect” in the weak zone.

scholarly journals Treatment of Collapsible Soils with Granulated Blast Furnace Slag and Calcined Eggshell Waste

2021 ◽  
Vol 31 (2) ◽  
pp. 138-162
Author(s):  
Souhila Adjabi ◽  
Mohamed Salah Nouaouria ◽  
Wafa Djebabla
Keyword(s):  
Blast Furnace ◽  
Blast Furnace Slag ◽  
Friction Angle ◽  
Initial Water Content ◽  
Collapsible Soil ◽  
Initial Water ◽  
Collapse Potential ◽  
Granulated Blast Furnace Slag ◽  
Eggshell Waste ◽  
Furnace Slag

Abstract In order to meet environmental and socio-economic challenges, the recycling of waste to be used in the treatment of geotechnical problems is one of the main ways of preserving the environment with a lower economic value. The objective of this experimental work is to improve the characteristics and to study the mechanical behaviour of collapsible soil treated with a new hydraulic stabilizer composed of Crushed Granulated Blast Furnace Slag (CGBS) active by Eggshell Waste (CES). The specimens were mixed with stabilizer content, varying from 0 to 15% in mass, with an initial water content of 4, 6 and 8% respectively. in mass. Oedometer apparatus was used to study the addition of new hydraulic stabilizer effect on the Collapse Potential. Triaxial tests are also conducted to determine the shear strength parameters (cohesion and internal friction angle) of this treated soil. The results of this research study show that the mechanical properties of the treated collapsible soil were significantly improved. An appreciable reduction in the collapse potential is observed. The addition of 15% of this new stabilizer with initial water content of 4% under a compaction of 60 blows/layer is capable of increasing internal friction angle and cohesion. It can be concluded from this study that the mixture of granulated slag and calcined eggshell can be used as an effective treatment of collapsibility phenomenon at low cost while protecting the environment from industrial waste.

Research on the Shear Strength Properties of Expansive Soils

2012 ◽  
Vol 256-259 ◽  
pp. 287-292
Author(s):  
Yi Chen ◽  
Jing Zhao ◽  
Xiao Hong Hu
Keyword(s):  
Shear Strength ◽  
Water Content ◽  
Expansive Soils ◽  
Friction Angle ◽  
Strength Properties ◽  
Water Diversion ◽  
Dry Density ◽  
Initial Water Content ◽  
Initial Water ◽  
North Water

The shear strength of expansive soils is now a key geotechnical problem. The water content and dry density of expansive soils have deep effect on its shear strength. For analyzing the detail relationship of the water content, dry density and shear strength of this special soil, direct shear test was carried out with the samples from Xinxiang in middle line of South to North water diversion project. The results indicate that both of the cohesion and friction angle grow with dry density and decrease with initial water content. Applying the linear regression calculation, we obtained mathematical expressions which reveal the variation of shear strength with the dry density and initial water content of Xinxiang expansive soils.

Influence of initial water content and strain rate on remolded yield stress in marine clay

2021 ◽  
pp. 1-8
Author(s):  
Xiaobing Li ◽  
Jianpeng Chen ◽  
Xiuqing Hu ◽  
Hongtao Fu ◽  
Jun Wang ◽  
...  
Keyword(s):  
Strain Rate ◽  
Water Content ◽  
Yield Stress ◽  
Initial Water Content ◽  
Marine Clay ◽  
Initial Water

scholarly journals Application of the Calorimetric Methods to the Characteristics of Seeds from Olives

Proceedings ◽  
2020 ◽  
Vol 70 (1) ◽  
pp. 90
Author(s):  
Andrzej Bryś ◽  
Joanna Bryś ◽  
Marko Obranović ◽  
Dubravka Škevin ◽  
Szymon Głowacki ◽  
...  
Keyword(s):  
Olive Oil ◽  
Water Content ◽  
Cooling System ◽  
Waste Product ◽  
Normal Pressure ◽  
Ash Content ◽  
Initial Water Content ◽  
Scanning Calorimetry ◽  
Initial Water

The olive oil industry represents an important productive sector in the Mediterranean basin countries. Olive stone is an essential by-product generated in the olive oil extraction industries and it represents roughly 10% by weight of the olive fruit. The seeds of pickled olives are also a significant waste product. In the present study, we have investigated the possibility of the use of differential scanning calorimetry for the thermal characterization of seeds from green and black pickled olives from Croatia. The differential scanning calorimeter (DSC) with a normal pressure cell equipped with a cooling system was used to determine the thermal properties of seeds from olives. The following analyses were also performed: the determination of calorific values in a pressure bomb calorimeter, the determination of initial water content, the determination of changes of water content during drying at the temperatures of 30 °C, 50 °C and 80 °C, the determination of a percentage content of seeds mass to the mass of the whole olives, and the determination of ash content. Seeds from olives are characterized by very good parameters as a biomass. The analyzed olive seeds were characterized by low water content, low ash content, and a relatively high caloric value.

scholarly journals RESEARCH ON MODEL FITTING AND STRENGTH CHARACTERISTICS OF CRITICAL STATE FOR EXPANSIVE SOIL

2013 ◽  
Vol 19 (1) ◽  
pp. 9-15 ◽  
Author(s):  
Zhiqing Li ◽  
Chuan Tang ◽  
Ruilin Hu ◽  
Yingxin Zhou
Keyword(s):  
Critical State ◽  
Model Fitting ◽  
Expansive Soil ◽  
Dry Density ◽  
Initial Water Content ◽  
Test Results ◽  
Stress Strain ◽  
Initial Water ◽  
Curve Model ◽  
Shearing Strength

According to Mengzi expansive soil, consolidated drained tests and undrained tests are carried on under saturated and remoulded conditions. The stress-strain characteristics of saturated soil are researched systematically under different confining pressure, initial dry density, initial water content, shearing rate and drainage condition. The inherent unity of diversity of shearing strength for the same samples measured by different experimental methods is indicated according to the normalization of critical state test results. And the failure lines in p ‘- q - ν space of remoulded saturated expansive soil under consolidated drained and undrained conditions are attained. The hyperbolic curve model can fit well the weak hardening stress-strain curves and the exponential curve model can fit the weak softening stress-strain curves. The test results can provide technical parameters and theoretical help for shearing strength variation of slope during rainfall and strength state of soil structure in normal water level.

THREE-DIMENSIONAL SEEPAGE ANALYSIS OF A COAL REFUSE PILE RECLAMATION

2020 ◽  
Vol 9 (4) ◽  
pp. 44-66
Author(s):  
Iuri Lira Santos ◽  
Keyword(s):  
Mine Drainage ◽  
Characteristic Curve ◽  
Water Volume ◽  
Low Permeability ◽  
Initial Water Content ◽  
Initial Water ◽  
Seepage Analysis ◽  
Cover System ◽  
Coal Refuse ◽  
Refuse Pile

Abstract. A coal refuse pile located in Greenbrier County, West Virginia was studied to restrict generation of acid mine drainage through the use of a cap and cover system. This paper presents results of a finite element method seepage analysis on a proposed reclamation design. The proposed reclamation incorporates a cap and cover system with a 0.3-m thick surface vegetation cap layer over a 0.6-m thick low permeability layer. The low permeability layer is directly above the coal refuse. Unsaturated soil mechanics was utilized, adopting the Fredlund and Xing equation for soil-water characteristic curve (SWCC) estimation. SWCC fitting parameters were calculated using the Zapata and the Hernandez estimation techniques. Different precipitation events were used to evaluate seepage throughout the reclamation area and assess the effectiveness of the cap and cover system. A steep area (>4H:1V) and a flat area were considered. The water balance analysis showed a 50% to 88% reduction in water volume at the coal refuse layer and a reduction in the time for the refuse to return to initial water content due to the cap and cover system implementation. Moisture detainment was observed in the growth layer and is important for supporting vegetation persistence.

scholarly journals Effects of Initial Water Content on Microstructure and Mechanical Properties of Lean Clay Soil Stabilized by Compound Calcium-Based Stabilizer

Materials ◽  
2018 ◽  
Vol 11 (10) ◽  
pp. 1933 ◽  
Author(s):  
Chenglong Yin ◽  
Wei Zhang ◽  
Xunli Jiang ◽  
Zhiyi Huang
Keyword(s):  
Water Content ◽  
Soil Stabilization ◽  
Clay Soil ◽  
Soil Aggregates ◽  
Optical Microscope ◽  
Initial Water Content ◽  
Reaction Products ◽  
Unconfined Compression Test ◽  
Initial Water ◽  
X Ray

Initial water content significantly affects the efficiency of soil stabilization. In this study, the effects of initial water content on the compressibility, strength, microstructure, and composition of a lean clay soil stabilized by compound calcium-based stabilizer were investigated by static compaction test, unconfined compression test, optical microscope observations, environment scanning electron microscopy, energy dispersive X-ray spectroscopy, and X-ray diffraction. The results indicate that as the initial water content increases in the range studied, both the compaction energy and the maximum compaction force decrease linearly and there are less soil aggregates or agglomerations, and a smaller proportion of large pores in the compacted mixture structure. In addition, for specimens cured with or without external water supply and under different compaction degrees, the variation law of the unconfined compressive strength with initial water content is different and the highest strength value is obtained at various initial water contents. With the increase of initial water content, the percentage of the oxygen element tends to increase in the reaction products of the calcium-based stabilizer, whereas the primary mineral composition of the soil-stabilizer mixture did not change notably.

scholarly journals Solidification of High Organic Matter Content Sludge by Cement, Lime and Metakaolin

2018 ◽  
Author(s):  
Ke Rui ◽  
Wang Hongxing ◽  
Tan Yunzhi ◽  
Wang Lehua
Keyword(s):  
Organic Matter ◽  
Water Content ◽  
Organic Matter Content ◽  
Microscopic Analysis ◽  
Chemical Components ◽  
Orthogonal Experimental Design ◽  
Initial Water Content ◽  
Initial Water ◽  
Lime Content ◽  
Sheet Structure

Based on orthogonal experimental design, the key solidification controlling technology of Solidified/Stabilized (S/S) sludge with high total organic content (TOC) by cement, lime and metakaolin was explored by macroscopic tests, chemical components measurements and microscopic analysis. The macroscopic tests show that, the permeability coefficient is mainly affected by initial water content and lime content, and the unconfined compression strength is mainly affected by cement content and lime content. The chemical components measurements show that, the solidification effect of S/S sludge with high TOC is controlled by organic matter consumption, and organic matter consumption is determined by the alkaline environment from the cement and lime hydration reactions, which is mainly affect by the initial water content and lime-metakaolin content ratio. The microscopic analysis results show that, lime consumes parts of organic matter while excess lime produces weak Ca(OH)2 crystal fluffy sheet structure, matakaolin produces pozzolanic reactions with cement and lime instead of soil particles, and consumes the weak Ca(OH)2 crystal fluffy sheet structure produced by superfluous lime. The research has confirmed key controlling points of S/S sludge in case of high TOC, which will provide theoretical guidance and technical support for S/S sludge promotion with high TOC.

scholarly journals The effect of lyophilization on selected biologically active components (vitamin C, catalase, lysozyme), total antioxidant capacity and lipid oxidation in human milk

2017 ◽  
Vol 112 (3) ◽  
pp. 121-128
Author(s):  
Dorota Martysiak-Żurowska ◽  
Małgorzata Puta ◽  
Anna Rodzik ◽  
Edyta Malinowska-Pańczyk
Keyword(s):  
Vitamin C ◽  
Human Milk ◽  
Lipid Oxidation ◽  
Antioxidant Capacity ◽  
Total Antioxidant Capacity ◽  
Freeze Drying ◽  
Biologically Active ◽  
Initial Water Content ◽  
Initial Water ◽  
Total Antioxidant

Human milk is rich in polyunsaturated fatty acids, as well as lysozyme, vitamin C and other bioactive compounds. The effect of lyophilization on the content of antioxidants (vitamin C and catalase CAT), bactericidal compounds (lysozyme), total antioxidant capacity (TAC) and lipid peroxidation in human milk was investigated in this study. Samples of mature human milk were collected from five healthy women who gave birth on the scheduled date and without complications. Freeze drying resulted in the removal of 88.2 % of the initial water content from milk. The human milk lyophilizate was readily soluble in water. Lyophilization had no effect on the content of primary (lipid peroxides LP) and secondary (thiobarbituric acid reactive substances TBARS) products of lipid oxidation. Freeze-drying led to a significant decrease in the vitamin C content and TAC values of milk (by 31 % and 16.5 %, respectively). Catalase and lysozyme were resistant to freeze-drying. Lyophilization induced a decrease in lysozyme content (9 %) and catalase activity (11 %) but these changes were not statistically significant. Low-temperature dehydration and rehydration of human milk lyophilizates promote satisfactory retention of biologically active ingredients and prevent the oxidation of human milk lipids. The results of this study indicate that lyophilization can be considered as an effective method for prolonging the shelf life of human milk.

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