scholarly journals The equilibrium time and deformation characteristic of sulfate saline soil in 1D saline expansion test

2021 ◽  
Vol 135 (2) ◽  
pp. 58-63
Author(s):  
Y.J. Ji ◽  
◽  
X. Li ◽  
Keyword(s):  
Saline Soil ◽  
Standard Procedure ◽  
Deformation Characteristic ◽  
Test Method ◽  
Equilibrium Time ◽  
One Dimensional ◽  
Expansion Test ◽  
Temperature Equilibrium ◽  
Cooling Media ◽  
Stability Time

The salt expansion disease is serious for the soil containing sodium sulfate in cold regions. This paper carried out one-dimensional swelling tests of saline soil, and numerical cooling tests of soil to explore the stability time of salt swelling deformation and determine the standard procedure of the salt swelling test method. The test results demonstrate that: (A) the temperature equilibrium and crystallization process are almost completed simultaneously in the one-dimensional (1D) salt expansion test; (B) Referring to the standard of consolidation test, a standard that the expansion rate is less than 0.02mm/h can be used in the salt expansion test; (C) The required time for temperature equilibrium of soil is quadratic to sample size and is much faster with liquid bath condition comparing to gas bath condition. Because the deformation and temperature are synchronized, the deformation stabilization time of different size samples in different cooling media is recommended.This can provide a reference for the deformation equilibrium time of the salt swelling test.

scholarly journals The Equilibrium Time and Salt Expansion Characteristic of Sulfate Saline Soil upon Cooling

2021 ◽  
Vol 2021 ◽  
pp. 1-17
Author(s):  
Yanjie Ji ◽  
Xu Li ◽  
Wei Wang ◽  
Li Liu
Keyword(s):  
Sodium Sulfate ◽  
Saline Soil ◽  
Standard Procedure ◽  
Sulfate Solution ◽  
Soil Consolidation ◽  
Stabilization Time ◽  
Equilibrium Time ◽  
One Dimensional ◽  
Expansion Test ◽  
Stability Time

The salt expansion disease is severe for the soil containing sodium sulfate in cold regions. This paper carried out one-dimensional salt expansion tests of saline soil, the crystallization test of saturated sodium sulfate solution, and the numerical cooling tests to explore the stability time of the salt expansion test and determine the standard procedure of salt expansion tests. The test results demonstrate that (i) the temperature equilibrium and the crystallization process are almost simultaneously completed in both sulfate saline soil and sulfate solution upon cooling; (ii) referring to the deformation equilibrium standard used in soil consolidation test, an expansion rate of less than 0.02 mm/h is suggested in the saline expansion test; and (iii) the equilibrium time is found to have a quadratic polynomial relationship to sample size and is much shorter under liquid bath conditions than under gas bath conditions. Based on these findings, a standard procedure of the one-dimensional salt expansion test is proposed, in which the test equipment, the test process, the deformation stabilization time of salt expansion, and the data processing method are provided. As the deformation and the temperature are synchronized, the deformation stabilization time of samples with different sizes in different cooling media is recommended.

Determination of soil water hydraulic parameters from infiltration data

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Yan Gao ◽  
Kai Chang ◽  
Xuguang Xing ◽  
Jiaping Liang ◽  
Nian He ◽  
...  
Keyword(s):  
Soil Water ◽  
Water Retention ◽  
Test Method ◽  
Water Retention Curve ◽  
Absorption Method ◽  
Retention Curve ◽  
Content Type ◽  
One Dimensional ◽  
Water Diffusivity

PurposeTraditional laboratory measurements of soil water diffusivity (D) and soil water retention curve (SWRC) are always time-consuming and labor-intensive. Therefore, this paper aims to present a simple and robust test method for determining D and SWRC without reducing accuracy.Design/methodology/approachIn this study, a D model of unsaturated soil was established based on Gardner–Russo model and then a combination of Gardner–Russo model with one-dimensional horizontal absorption method to obtain n and a parameters of Gardner–Russo model. One-dimensional horizontal absorption experiments on loam, silt loam and sandy clay loam were conducted to obtain the relationships between measured infiltration rate and cumulative infiltration with wetting front distance. Based on the obtained relationships, the measured infiltration data from the one-dimensional horizontal absorption tests were used to calculate n and a parameters and further constructing D and SWRC.FindingsBoth the calculated D and SWRC inversed from the infiltration data were in good agreement with the measured ones that obtained from the traditional horizontal absorption method and the centrifuge method, respectively. Error analysis indicated that only the infiltration data are enough to reliably synchronously determine D and SWRC.Originality/valueA simple and robust method is proposed for synchronous determination of soil water diffusivity and water retention curve.

Characterization of yield stress surface and strain-rate potential for tubular materials using multiaxial tube expansion test method

2020 ◽  
Vol 133 ◽  
pp. 102838
Author(s):  
Sobhan Alah Nazari Tiji ◽  
Taejoon Park ◽  
Amir Asgharzadeh ◽  
Hyunki Kim ◽  
Madhura Athale ◽  
...  
Keyword(s):  
Strain Rate ◽  
Yield Stress ◽  
Test Method ◽  
Expansion Test ◽  
Stress Surface ◽  
Tube Expansion

Analysis of Six Organophosphorus Pesticide Residues in Apples and Pears Using Cloud-point Extraction Coupled with HPLC-UV

2014 ◽  
Vol 97 (4) ◽  
pp. 1202-1205 ◽  
Author(s):  
Lijin Zhang ◽  
Fang Chen ◽  
Wenhuan Zhang ◽  
Canping Pan
Keyword(s):  
Cloud Point ◽  
Extraction Method ◽  
Cloud Point Extraction ◽  
Organophosphorus Pesticides ◽  
Extraction Procedure ◽  
Organophosphorus Pesticide ◽  
Equilibrium Temperature ◽  
Equilibrium Time ◽  
Temperature Equilibrium ◽  
Triton X

Abstract A cloud-point extraction (CPE) method with Triton X-114 has been developed for analysis of six organophosphorus pesticides (OPPs) in apples and pears. In this CPE procedure, the effects of the surfactant volume, mass of sodium chloride, equilibrium temperature, equilibrium time, and pH on the extraction procedure were investigated. Under the optimal CPE conditions, the analytes were enriched 20-fold and the LODs dropped to 0.44–5.20 μg/kg. Furthermore, the proposed extraction method was validated by the correlation coefficient (R2) of the calibration curve, repeatability (RSD, n = 6), and fortified recoveries, which were 0.9967–0.9993, 2.7–6.5, and 74.7–104.5%, respectively. Based on these results, it could be concluded that the proposed CPE method with Triton X-114 was suitable for the effective extraction and enrichment of OPP residues in the apple and pear samples.

The Discussion about Concrete on the Relationship between Corrosion Resistance and Time under Bending Loads

2014 ◽  
Vol 599-601 ◽  
pp. 148-152
Author(s):  
Zhao Feng Xue ◽  
Jian Li
Keyword(s):  
Corrosion Resistance ◽  
Saline Soil ◽  
Concrete Structures ◽  
Concrete Specimen ◽  
Test Method ◽  
Mineral Admixture ◽  
Prevention Measures ◽  
Fly Ash Concrete ◽  
Bending Loads ◽  
The Relationship

Through the corrosion test method of different active mineral admixture concrete under bending loads,we studied the C50 concrete specimen under bending loads on corrosion resistance and with the relation to corrosion time about the condition of specimen in saline soil. The results showed that the maximum corrosion effect on concrete with the saline soil in the short-term (1 year) appeared from the sixth to the ninth month (under maximum corrosion loss coefficient), but in other time is smaller. Concrete with gas forming admixture exhibit best corrosion resistance, fly ash concrete come second and normal concrete show worst performance in corrosion resistance, we propose corrosion prevention measures for concrete structures under loads in saline soil region to improve the durability of concrete structures according to the result.

Study on the Bearing Capacity Test for the Saline Soil Soft Ground

2014 ◽  
Vol 587-589 ◽  
pp. 947-951
Author(s):  
Jun Yong Liu ◽  
Liu Jun Zhang
Keyword(s):  
Bearing Capacity ◽  
Saline Soil ◽  
Test Methods ◽  
Test Method ◽  
Soft Ground ◽  
Characteristic Value ◽  
Soft Foundation

The test methods provided by current related "specifications" do not apply to saline soil soft foundation bearing capacity test. Through discussing the limitations of the related specifications and based on the experience on saline soil soft ground capacity test, the paper made some improvements of test on such aspects: conditions of loading and stopping load, determination of the characteristic value of the ground bearing capacity and evaluation, the paper also put forward the saline soil soft ground capacity test method.

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