scholarly journals Effect of Salt Content on the Evaporation and Cracking of Soil from Heritage Structures

2021 ◽  
Vol 2021 ◽  
pp. 1-9
Author(s):  
Kai Cui ◽  
Xiaozheng Zhao ◽  
Mingming Hu ◽  
Chen Yang ◽  
Guanchang Xie
Keyword(s):  
Fractal Dimension ◽  
Water Content ◽  
Salt Content ◽  
Residual Water ◽  
Fracture Development ◽  
Nacl Concentration ◽  
The Matrix ◽  
Matrix Suction ◽  
Rate Of Evaporation ◽  
Cracking Process

The degree of damage to heritage structures in arid areas can be particularly serious due to long-term exposure to a harsh arid climate. In this paper, the characteristics of evaporation and cracking of soil taken from heritage structures with different NaCl concentrations are experimentally investigated by subjecting saturated soil samples taken from the Wang-Jing tower in Weihui City, Henan Province. Making soil sample of water content of 110% is used to test the rate of evaporation at a constant temperature and humidity, through which the changes in the evaporation rate, water content, fracture development, and fracture fractal dimension are obtained. The results show that, (1) with higher water content, NaCl can affect the evaporation process by increasing the matrix suction of the soil of the Wang-Jing tower and then affect the cracking process of soil. When 0%, 1%, 2%, and 4% NaCl are added, the residual water content of the samples is 3.15%, 4.23%, 4.82%, and 5.89%, respectively, which show an obvious trend of increasing water content; (2) the period with a stable fracture fractal dimension of the samples is shortened with an increase in NaCl concentration, and its maximum fractal dimension is reduced in turn; and (3) at a lower water content, NaCl crystallizes and precipitates in the pores of the soil, which provide a cementitious effect among the soil particles, thus inhibiting crack development.

Influence of Matric Suction on Shear Strength Behavior of Unsaturated Silty Sand

2012 ◽  
Vol 446-449 ◽  
pp. 1627-1632
Author(s):  
Qian Dong ◽  
Liu Liu ◽  
Long Hou
Keyword(s):  
Shear Strength ◽  
Water Content ◽  
Peak Effect ◽  
Silty Sand ◽  
Direct Shear Tests ◽  
Suction Control ◽  
Two Factors ◽  
The Matrix ◽  
Matrix Suction ◽  
The Relationship

In order to research matrix suction how to influence the shear strengt of unsaturated silty sand. Based on the analysis of the Soil-water characteristic of unsaturated silty sand through pressure plate instrument test,the suction control direct shear tests under the different suction condition of unsaturated silty sand are studied. And then, the microscopic structure of two kinds soil sample with different water content are scanned to analyze the relationship between the matrix suction and the shear strengt of unsaturated silty sand. The results of the research show that unsaturated silty sand different from unsaturated clayey soil.When water content gradually reduce, the soil shear strength of unsaturated silty sand is not always increased with the increase of matrix suction, but there is a "peak effect".The appearance of "peak effect" is due to unsaturated silty sand has own microstructure characteristics.On the other hand, when the moisture content reduction constantly,the existence form of moisture change gradually.The two factors lead to the effect area of matrix suction change constantly,and then influence shear strengt of unsaturated silty sand to appear "peak effect". In addition,the stress environment also can influence contribution degree of matrix suction to the shear strengt of unsaturated silty sand.

scholarly journals The Effects of Rainfall, Soil Type and Slope on the Processes and Mechanisms of Rainfall-Induced Shallow Landslides

2021 ◽  
Vol 11 (24) ◽  
pp. 11652
Author(s):  
Yan Liu ◽  
Zhiyuan Deng ◽  
Xiekang Wang
Keyword(s):  
Water Content ◽  
Sediment Yield ◽  
Soil Type ◽  
Rainfall Intensity ◽  
Pore Water Pressure ◽  
Water Pressure ◽  
Shallow Landslides ◽  
Total Stress ◽  
The Matrix ◽  
Matrix Suction

Landslides are a serious geohazard worldwide, causing many casualties and considerable economic losses every year. Rainfall-induced shallow landslides commonly occur in mountainous regions. Many factors affect an area’s susceptibility, such as rainfall, the soil, and the slope. In this paper, the effects of rainfall intensity, rainfall pattern, slope gradient, and soil type on landslide susceptibility are studied. Variables including soil volumetric water content, matrix suction, pore water pressure, and the total stress throughout the rainfall were measured. The results show that, under the experimental conditions of this paper, no landslides occurred on a 5° slope. On a 15° slope, when the rainfall intensity was equal to or less than 80 mm/h with a 1 h duration, landslides also did not happen. With a rainfall intensity of 120 mm/h, the rainfall pattern in which the intensity gradually diminishes could not induce landslides. Compared with fine soils, coarser soils with gravels were found to be prone to landslides. As the volumetric water content rose, the matrix suction declined from the time that the level of infiltration reached the position of the matrix. The pore water pressure and the total stress both changed drastically either immediately before or after the landslide. In addition, the sediment yield depended on the above factors. Steeper slopes, stronger rainfall, and coarser soils were all found to increase the amount of sediment yield.

Study on the Tests of Soil-Water Characteristic Curves of Unsaturated Soil

2013 ◽  
Vol 353-356 ◽  
pp. 16-19
Author(s):  
Xian Chun Zheng ◽  
Fang Zhao ◽  
Si Zhong Sun
Keyword(s):  
Water Content ◽  
Soil Water ◽  
Unsaturated Soil ◽  
Characteristic Curve ◽  
Initial Water Content ◽  
Initial Water ◽  
Soil Water Characteristic Curve ◽  
The Matrix ◽  
Practical Engineering ◽  
Matrix Suction

Soil-water characteristic curve is used to describe the matrix suction and water content of the curve of the relationship between volume, according to the soil-water characteristic curve can be deduced the unsaturated soil shear strength, permeability coefficient, etc., this paper gives the different initial water content and different types of soil, soil-water characteristic curve for practical engineering foundation reinforcement to provide reference.

Experimental Study on Gravel Soils of Matrix Suction

2013 ◽  
Vol 275-277 ◽  
pp. 310-315 ◽  
Author(s):  
Hong Mei Tang ◽  
Pei Wei Liao ◽  
Lin Feng Wang ◽  
Hong Kai Chen
Keyword(s):  
Moisture Content ◽  
Water Content ◽  
Soil Water ◽  
Characteristic Curve ◽  
Curved Surface ◽  
Soil Water Characteristic Curve ◽  
Content Change ◽  
Two Factors ◽  
The Matrix ◽  
Matrix Suction

Soil-water characteristic curve（SWCC）is closely relevant to two main factors which are structure and moisture content. According to the two factors the values of matrix suction of 45 groups experimental specimens within different moisture content and soil -stone ratio of unsaturated soil are get through filter paper method. Date analysis shows that relation between matrix suction and soil-stone ratio at different moisture states is of different characteristics. Relation between matrix suction and water content is notably nonlinear. Distribution of matrix suction is curved surface in the moisture and soil-stone ration state space which is the function of water content and soil-stone ratio, in which the axial plan is parallel to the axis of soil-stone ratio.At low water content,the matrix suction on the moisture content change is very sensitive, at high moisture content and closed to saturation stage matrix suction hardly changes along with water content and soil-stone ratio change. The curved surface which Located in the middle section ,the matrix suction on the change of water content are more sensitive, reduced with water content increasing; and in this phase the matrix suction is insensitive to the variation of soil-stone ratio. Finally, it is concluded that the saturation to describe the soil water characteristic curve is a bad choice, with moisture to depict the so. In contrast, directly using the water content to describe the soil water characteristic curve is better.

scholarly journals Effect of Tea Waste on Cracking of Foundation Soil

2021 ◽  
Vol 2021 ◽  
pp. 1-7
Author(s):  
Binbin Yang ◽  
Zepeng Zhang ◽  
Wenlong Ma ◽  
Mingming Hu ◽  
Yaning Zhang
Keyword(s):  
Fractal Dimension ◽  
Water Content ◽  
Soil Samples ◽  
Stage Iii ◽  
Residual Water ◽  
Foundation Soil ◽  
Desiccation Cracks ◽  
Residual Water Content ◽  
Tea Waste ◽  
Water Holding

Desiccation cracks form on the surface of foundation soils due to matric suction and surface shrinkage with water loss. This paper investigates the effect of tea waste on the change of water content and cracking characteristics of foundation soil during drying. Digital image processing was carried out based on laboratory experiments. The characteristics are monitored with a variation in water content. The effects of different amounts of tea waste on soil drying and cracking were obtained, in order to provide an efficient and new green sustainable material for improving soil evaporation cracking under drought conditions. The results show that the development of cracks of soil samples with tea waste can be categorized into three stages in accordance with the fractal dimension of the desiccation cracks: Stages I, II, and III. The desiccation cracks in Stage III are wider and longer than those in Stages I and II, however, the maximum fractal dimension and stability are also obtained in Stage III. The residual water content of the sample without tea waste is 1.5%. The residual water content of the samples containing 4% and 8% tea waste is 4.6% and 5.4%, respectively, which shows that the tea waste can effectively improve the residual water content of the foundation soil and the water holding capacity of the soil. The fractal dimension of cracks on the soil samples increases gradually with drying. The total length of cracks increases and the development of cracks is more complex. The cracking time of soil samples with different tea waste contents is different. The soil samples with 8% tea waste content crack first. Combined with the variation characteristics of water content, tea waste has water absorption and improves the water holding capacity and stability of foundation soil.

scholarly journals Application of microbial risk assessment on a residentially-operated Bio-toilet

2006 ◽  
Vol 4 (4) ◽  
pp. 479-486 ◽  
Author(s):  
Naoko Nakagawa ◽  
Hana Oe ◽  
Masahiro Otaki ◽  
Katsuyoshi Ishizaki
Keyword(s):  
Risk Assessment ◽  
Water Content ◽  
Risk Level ◽  
Microbial Risk Assessment ◽  
Microbial Risk ◽  
Infectious Risk ◽  
The Matrix ◽  
Pathogenic Viruses ◽  
Scale Experiment ◽  
Time Required

The Sustainable Sanitation System is a new wastewater treatment system that incorporates a non-flushing toilet (Bio-toilet) that converts excreta into a reusable resource (as fertilizer or humus for organic agriculture) and reduces the pollution load to environments of the rivers, the lakes, and the sea. However, the risk of exposure to pathogens should be considered, because excrement is stored in the Bio-toilet. The aim of the present work is to analyze the health risk of dealing with the matrix (excreta and urine mixed with sawdust) of the Bio-toilet. Therefore, the fate of pathogenic viruses was investigated using coliphages as a virus index, and the modeling of the die-off rate in matrix was introduced. Then the microbial risk assessment was applied to a Bio-toilet that was actually used in a residential house; the infection risks of rotavirus and enterovirus as reference pathogens were calculated. According to the lab-scale experiment using coliphages for investing the die-off rate of viruses in the Bio-toilet, Qβ had a higher die-off, which was greatly influenced by the water content and temperature. On the other hand, T4 showed a lower rate and was independent of water content. Therefore, these two phages' data were used as critical examples, such as viruses having high or low possibilities of remaining in the Bio-toilet during the risk assessment analysis. As the result of the risk assessment, the storage time required for an acceptable infectious risk level has wide variations in both rotavirus and enterovirus cases depending on the phage that was used. These were 0–260 days' and 0–160 days' difference, respectively.

scholarly journals PENGOLAHAN WADI IKAN PATIN (Pangasius hypophthalmus) PROSES CEPAT DAN TIDAK ASIN

2021 ◽  
Vol 46 (3) ◽  
pp. 336
Author(s):  
Restu Yuda Bakrie
Keyword(s):  
Lactic Acid ◽  
Lactic Acid Bacteria ◽  
Protein Content ◽  
Water Content ◽  
Salt Content ◽  
Fat Content ◽  
Traditional Food ◽  
Fish Meat ◽  
Fermented Product

This study aims to determine processing of wadi patin fish (Pangasiu hypophthalmus) quick process and not salty, It is a fermented product from fish, in the form of a wet material through a salting process, the addition of spices then followed by fermentation for several days until it produces an aroma and taste. This traditional food is the result of fermentation assisted by synergistic microorganisms, namely lactic acid bacteria. The results of the study by washing fish after the salting process were able to accelerate fermentation from 7 days to 3 days. The best treatment is to wash the fish meat twice after the salting process. the specifications of the resulting wadi are as follows: protein content = 18.64%; salt content = 0.79%; Water content = 58.65%; Fat content = 3.29%; total microbes (LAB) 6.5x104; organoleptic value (taste) = 7.55.

scholarly journals Effects of Saline Solutions on the Desiccation Cracking and Shrinkage Behavior of Gaomiaozi Bentonite

2020 ◽  
Vol 2020 ◽  
pp. 1-13
Author(s):  
Long Tan ◽  
Penglin Zheng ◽  
Qingbing Liu
Keyword(s):  
Water Content ◽  
Saline Solution ◽  
Shrinkage Strain ◽  
Sample Surface ◽  
Water Evaporation ◽  
Gmz Bentonite ◽  
Residual Water ◽  
High Concentration ◽  
Desiccation Cracking ◽  
Saline Solutions

Bentonite, when used as buffer/backfill material in the deep disposal of high-level radioactive waste (HLW), could undergo desiccation shrinkage or even cracking due to the heat released from HLW, impairing the efficiency of the barrier system. Furthermore, in-service buffer materials are inevitably in contact with the groundwater, which sometimes contain high salt concentrations. The groundwater salinity may modify the properties of bentonite and hence affect the process of desiccation and its performance. To investigate this effect, in this study, a series of temperature-controlled desiccation tests was conducted on compacted specimens of Gaomiaozi (GMZ) bentonite preliminarily saturated with two different saline solutions (NaCl and CaCl2) at the concentration varying from 0.5 to 2.0 mol/L. The experimental results indicated that, as the concentration of saline solution increases, the initial saturated water content of bentonite decreases, whereas the residual water content at the completion of the desiccation test increases. The water evaporation rate is reduced for the specimens saturated with a high-concentration saline solution, and CaCl2 has a more significant influence on water evaporation than NaCl. The evolution of cracks on the sample surface during the desiccation process can be divided into four stages: crack growth, maintenance, closure, and stabilization; an increase in the salt concentration effectively inhibits crack development. It was shown that the infiltration of saline solutions alters the microstructure of bentonite by changing the arrangement of clay particles from a dispersed pattern to more aggregate state, which results in a decrease in shrinkage strain and shrinkage anisotropy.

scholarly journals Design of Monitoring System for Salt Concentration in Milkfish Ponds using Android

2019 ◽  
Vol 9 (2) ◽  
pp. 42-46
Author(s):  
Nuzlya Ramadhana
Keyword(s):  
Water Quality ◽  
Water Content ◽  
Monitoring System ◽  
Salt Concentration ◽  
Sea Water ◽  
Salt Content ◽  
Temperature Sensors ◽  
Fish Mortality ◽  
Measuring Instruments ◽  
Ph Sensors

In the cultivation of milkfish, water quality is very concerned about in order to minimize fish mortality when cultivated. Several important factors in the cultivation of milkfish are the level of salt content in the water, temperature and pH. Currently, farmers monitor water quality manually by coming directly to see water quality. If there are dead fish, the cultivator will replace the new water. This will have an impact on fish production which will decrease. The milkfish pond uses brackish water for pond waters. The salt content is between the sea water content and the fresh water content. The grade level may change from season to season. This change is due to biological processes that occur in these waters as well as the interaction between pond waters and the surrounding environment. The results showed that the results of the design of the salt concentration monitoring system in the milkfish ponds that have been carried out using Arduino Uno, conductivity sensors, pH sensors, temperature sensors, wifi modules, Mi-Fi and Smartphones to access android applications. The results of testing the microcontroller functionality that have been made are in accordance with the design and are running well. The system designed to transmit information in the form of salinity values, pH sensors, temperature sensors and TDS values ??with sensor accuracy that is linear with measurement results using conventional measuring instruments with the highest error values ??of 1.3%, 2.06%, 0.702% and 1.5 respectively. %.

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