scholarly journals Modified Liu-Carter Compression Model for Natural Clays with Various Initial Water Contents

2016 ◽  
Vol 2016 ◽  
pp. 1-8 ◽  
Author(s):  
Sen Qian ◽  
Jian Shi ◽  
Jian-wen Ding
Keyword(s):  
Water Content ◽  
Soil Structure ◽  
Initial Water Content ◽  
Initial Water ◽  
Compression Behaviour ◽  
Compression Model ◽  
Proposed Model ◽  
Natural Clays ◽  
Water Contents ◽  
Carter Model

The initial water content has a significant effect on the compression behaviour of reconstituted clays. This effect has to be considered in the Liu-Carter model to ensure the addition voids ratio only related to soil structure. A modified Liu-Carter compression model is proposed by introducing the empirical equations for reconstituted clays at different initial water contents into the Liu-Carter model. The proposed model is verified against the experimental results from the literature. The simulations by the proposed method are also compared with that by old method where the influence of initial water content is not considered. The results show that the predicted virgin compression curves of natural clays are similar, but the values ofbandΔeymay be very different.

Determining the virgin compression lines of reconstituted clays at different initial water contents

2015 ◽  
Vol 52 (9) ◽  
pp. 1408-1415 ◽  
Author(s):  
Ling-Ling Zeng ◽  
Zhen-Shun Hong ◽  
Yu-Jun Cui
Keyword(s):  
Regression Analysis ◽  
Water Content ◽  
Liquid Limit ◽  
Initial Water Content ◽  
Initial Water ◽  
Kaolinite Clay ◽  
Soil Particles ◽  
Wide Range ◽  
Natural Clays ◽  
Water Contents

Forty-eight consolidometer tests were performed on various natural clays and a kaolinite clay reconstituted in the laboratory at different initial water contents using a modified consolidometer apparatus. These data together with those published previously allow a multi-regression analysis for the development of an approach for determining the intrinsic compression parameters that depend on initial water content and liquid limit. The approach proposed by Burland can be thereby extended to provide an expression describing the compression response of a wide range of clays. Based on the intrinsic concept, a simple way of determining the virgin compression lines of reconstituted clays is also proposed using the density of soil particles, initial water content, and liquid limit.

Kinetic Model with Effect of Water Content for Enzyme-Catalyzed Citronellyl Laurate Esterification Process

2013 ◽  
Vol 284-287 ◽  
pp. 423-428 ◽  
Author(s):  
Siti Asyura Zulkeflee ◽  
Suhairi Abd Sata ◽  
Norashid Aziz
Keyword(s):  
Experimental Data ◽  
Kinetic Model ◽  
Water Content ◽  
Model Development ◽  
Initial Water Content ◽  
Initial Water ◽  
Effect Of Water ◽  
Proposed Model ◽  
Optimal Value ◽  
Influence Of Water

A kinetic model with effect of water content for enzyme-catalyzed citronellyl laurate was developed. These models incorporate the combined influences of established kinetics model with the function model on the effect of initial water content with kinetic parameters. The model development was carried out by performing a linear and nonlinear regression based on the behavior of the kinetic parameter profiles and validated with experimental data. Using the developed models, the influence of water content towards the enzyme-catalyzed initial rate of reaction was theoretically explained. It has been shown that the proposed model have good agreement between experimental data and intends to capture the effect of water content towards the conversion of ester. With this model, the optimal value of initial water content for this process could be estimated.

Experimental Study on Dewatering Dredged Clay with Ventilating Vacuum Method

2011 ◽  
Vol 261-263 ◽  
pp. 1650-1654 ◽  
Author(s):  
Feng Ji ◽  
Jian Wen Ding ◽  
Zhen Shun Hong ◽  
Yue Gui
Keyword(s):  
Experimental Study ◽  
Spatial Distribution ◽  
Surface Water ◽  
Water Content ◽  
Liquid Limit ◽  
Initial Water Content ◽  
Distribution Law ◽  
Initial Water ◽  
Vacuum Method ◽  
Water Contents

A series of model tests were performed on dredged clay with high initial water contents for investigating the dewatering behavior by ventilating vacuum method (VVM). The results shows that the surface water separated from dredged clay can be quickly removed by VVM in which a new pattern PVD is used. In addition, the method also speeds up the deposition of dredged clay. The volume of dredged clay with an initial water content of 4.5 times liquid limit decreases by 50 percent within two months. This paper also investigated the spatial distribution law of water content by TDR method. It is found that the drainage distance of PVD is about 0.3-0.4m.

Influence of initial water content on unsaturated shear strength of compacted GaoMiaoZi (GMZ) bentonite

2021 ◽  
Vol 58 (1) ◽  
pp. 142-146
Author(s):  
N.F. Zhao ◽  
W.M. Ye ◽  
Q. Wang ◽  
B. Chen ◽  
Y.-J. Cui
Keyword(s):  
Shear Strength ◽  
Water Content ◽  
Critical State ◽  
Initial Water Content ◽  
Gmz Bentonite ◽  
Test Results ◽  
Loading Test ◽  
Initial Water ◽  
State Stress ◽  
Water Contents

This paper presents an experimental study on the influence of initial water content on unsaturated shear strength of compacted bentonite. Isotropic loading and triaxial shear tests were conducted on compacted GaoMiaoZi (GMZ) bentonite specimens with different initial water contents. Isotropic loading test and triaxial shear test results show that the compression index increases and yield stress decreases with increasing water content, while the swelling index stays constant. For normally consolidated and lightly overconsolidated bentonite, unsaturated shear strength can be described by the critical state line. For highly overconsolidated bentonite, unsaturated shear strength can be described by the Hvorslev surface. The critical state line and Hvorslev surface are found to be linear for the specimens with different water contents. The critical state stress ratio and the Hvorslev surface parameters are found to decrease with an increase in water content of the bentonite studied.

Soil curling process and its influencing factors

2020 ◽  
Vol 57 (3) ◽  
pp. 408-422 ◽  
Author(s):  
Khoa M. Tran ◽  
Ha H. Bui ◽  
Jayantha Kodikara ◽  
Marcelo Sánchez
Keyword(s):  
Water Content ◽  
Influencing Factors ◽  
Moisture Loss ◽  
Initial Water Content ◽  
Initial Water ◽  
Moisture Evaporation ◽  
Soil Desiccation ◽  
Desiccation Cracking ◽  
Natural Clays ◽  
Lift Off

Soil curling is a common phenomenon in nature due to the rearrangement of soil particles caused by moisture loss. The occurrence of curling in soils significantly affects soil performance in various disciplines. Despite its importance, most existing studies describe the soil curling process within the context of soil desiccation cracking, where boundary conditions facilitating soil curling are not well controlled, or often use the final stage of the desiccation process to infer the soil curling behaviour. Consequently, the underlying soil curling mechanism, the state of the curled soil, and the influencing factors (i.e., clay type, drying temperature, initial water content, and sand content) are not fully understood. In this study, soil curling tests were conducted to study the above-mentioned issues in different types of soils under well-controlled boundary and environmental conditions. It was found that natural clays consisting of higher portions of smectite underwent both upward curling (concave-up) and downward curling (convex-up), while artificial clay experienced only concave-up curling. Concave-up curling initiated when the samples were almost in the saturated condition, while convex-up curling started when the water content of samples was close to their plastic limits. The influencing factors had a profound effect on the moisture evaporation and thus on the soil curling state and its lift-off height. Finally, a conceptual model isproposed to explain the soil curling mechanism and factors influencing soil curling.

scholarly journals Fluid Characteristics of Biodiesel Produced from Palm Oil with Various Initial Water Contents

Processes ◽  
2021 ◽  
Vol 9 (2) ◽  
pp. 309
Author(s):  
Cherng-Yuan Lin ◽  
Lei Ma
Keyword(s):  
Water Content ◽  
Palm Oil ◽  
Iodine Value ◽  
Unsaturated Fatty Acids ◽  
Acid Value ◽  
Initial Water Content ◽  
Cold Filter Plugging Point ◽  
Initial Water ◽  
Water Contents ◽  
Fluid Characteristics

Biodiesel is regarded as a significant alternative fuel to petrodiesel due to its excellent combustion features and renewable character. The water content in the reactant mixtures needs to be considered so as to retard the conversion rate and it is suggested to be kept as low as possible. The fluid characteristics of biodiesel might be affected by initial water content; however, the optimum ratio of water content added to raw oil for achieving superior fluid characteristics of biodiesel has not yet been studied. Hence, this study empirically investigated the influences of the initial water content added to raw feedstock oil on the fluid characteristics of biodiesel. The experimental results show that an adequate amount of water content in the reactant mixture was found effective for improving the transesterification reaction and, in turn, the fluid characteristics. The biodiesel made from raw oil with 0.05 wt. % water content added was observed to bear the lowest water content, acid value, and cold filter plugging point (CFPP) and, therefore, superior fluidity at low temperatures. The lower CFPP of biodiesel is attributed to its more unsaturated fatty acids and lower iodine value. In addition, the biodiesel produced from feedstock oil with 0.02 wt. % water added was observed to have the lowest iodine value but the highest kinematic viscosity. The optimum content of initial water added to palm oil for superior fluid characteristics of the biodiesel product is thus suggested to be in the range between 0.02 wt. % and 0.05 wt. %.

scholarly journals Effect of rainfall infiltration on the hydraulic response and failure mechanisms of sandy slope models

2016 ◽  
Vol 25 (43) ◽  
pp. 97-109
Author(s):  
Juan David Montoya-Domínguez ◽  
Edwin Fabián García-Aristizábal ◽  
Carlos Alberto Vega-Posada
Keyword(s):  
Water Content ◽  
Failure Mechanisms ◽  
Rainfall Infiltration ◽  
Silty Sand ◽  
Initial Water Content ◽  
Initial Water ◽  
Rainfall Events ◽  
Artificial Rainfall ◽  
Sandy Slope ◽  
Water Contents

This paper presents experimental results obtained from silty sand slope models subjected to an artificial rainfall. Four models were constructed to evaluate the effect of initial water content and rainfall intensity on the hydraulic behavior and failure mechanisms of the slopes. The models were instrumented with volumetric water content sensors to monitor the advance of the water front, and inclinometers to measure lateral movements of the slope. The models were subjected to rainfall intensities ranging from 25 to 50 mm/h, and durations from 19 to 152 minutes. The influence of low intensity rainfall events before a high intensity rainfall is discussed herein. The results showed that the time the slope models required to reach failure was influenced by the soil initial water content, being shorter at high initial water contents. These results are useful to understand the behavior of unsaturated natural slopes and embankments exposed to rainfall infiltration, and to complement the existing laboratory database existing in this subject.

Effects of initial water content and soil mechanical strength on the runoff erosion resistance of clay soils

Soil Research ◽  
1993 ◽  
Vol 31 (5) ◽  
pp. 549 ◽  
Author(s):  
G Govers ◽  
RJ Loch
Keyword(s):  
Water Content ◽  
Water Uptake ◽  
Soil Strength ◽  
Clay Soils ◽  
Initial Water Content ◽  
Simple Relationship ◽  
Initial Water ◽  
Indirect Measure ◽  
Water Contents ◽  
Rill Flow

Effects of antecedent water content and soil strength on the resistance to erosion by overland (rill) flow were tested for two clay soils of the eastern Darling Downs, Queensland. Both shear and unconfined compressive strength of wet soil (for soil wet to saturation immediately prior to application of rill flow) mere higher for soil with initially high water contents than for soil initially air-dry. Rates of runoff erosion did not show a simple relationship with soil strength across the two soils, though for each soil, higher strength was associated with much lower rates of erosion. The results show that variations in initial water content can be associated with large chang;es in soil erodibility. Particularly for the initially wet soils of higher strength, rates of runoff erosion were controlled by rates of detachment of sediment. From size distributions of wet aggregates and of sediment, and from measured water contents of wet soil, it can be suggested that the extent of incipient failure of aggregates on wet;ting was a major factor controlling ease of detachment by rill flow, as it can be inferred that detachment of sediment involved breakdown of aggregates. Consistent with this, rates of runoff erosion across the two soils showed a direct relationship with the amount of water uptake on wetting, which appears to be a useful measure of susceptibility to detachment by rill flow. Water uptake on wetting would be an indirect measure of incipient failure and, hence, of aggregate strength.

scholarly journals Soluble sugars and germination of Annona emarginata (Schltdl.) H. Rainer seeds submitted to immersion in GA3 up to different water contents

2014 ◽  
Vol 36 (spe1) ◽  
pp. 281-287 ◽  
Author(s):  
Juliana Iassia Gimenez ◽  
Gisela Ferreira ◽  
Jaqueline Malagutti Corsato
Keyword(s):  
Seed Germination ◽  
Plant Growth ◽  
Water Content ◽  
Plant Growth Regulator ◽  
Soluble Sugars ◽  
Germination Percentage ◽  
Initial Water Content ◽  
Germination Test ◽  
Initial Water ◽  
Water Contents

The objective of this study was to evaluate the effect of different water contents achieved by Annona emarginata (Schltdl.) H. Rainer seeds during immersion in GA3 solutions, in variation of soluble sugars levels and germination. Seeds with 10% of initial water content were submitted to imbibition in GA3 solutions with concentrations of 0; 250; 500; 750 and 1000 mg L-1 and when they reached the water content of 15%, 20%, 25%, 30% and 35%, the quantification of soluble sugars levels and germination test were performed. Seeds immersed up to they reach 15% of water with GA3 and immersed up to the water acquisition of 20% without GA3, presented higher soluble sugars levels and germination percentage, which were decreased when the seeds reached 30% and 35% of water, independently of the presence of the plant growth regulator. It was conclude that different water contents reached by the seeds in immersion treatments with GA3 affect the soluble sugars levels and germination percentage of Annona emarginata seeds. Thus, in treatments with Annona emarginata, the seeds must remain immersed in water without GA3 up to they reach 20% of water, as higher water contents (35%) reduce the soluble sugars levels and the seed germination percentage.

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