Influence of freeze-thaw cycles in the presence of a supplementary water supply on mechanical properties of compacted soil

Lu, Zheng; Xian, Shaohua; Yao, Hailin; Fang, Ran; She, Jianbo

doi:10.1016/j.coldregions.2018.09.009

Cited by 50 publications

(20 citation statements)

References 27 publications

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“…Seasonal freezing and thawing are the main driving factors for the occurrence of soil salinization in arid areas. Freezing and thawing can change soil structure, as well as physical and chemical properties, and affect the spatial and temporal changes of soil moisture, temperature, and salt [24,25]. Temperature is the driving force of soil water and salt migration under freezing and thawing conditions [26].…”

Section: Discussionmentioning

confidence: 99%

Winter Irrigation Effects on Soil Moisture, Temperature and Salinity, and on Cotton Growth in Salinized Fields in Northern Xinjiang, China

Liu

et al. 2020

Sustainability

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Winter irrigation affected the movement of soil moisture, temperature, and salt, which was an effective improvement measure widely used in seasonal freeze–thaw areas. In this paper, we investigated the effects of different salinized cotton fields (mild salinization (S1), 5.15 g·kg−1; moderate salinization (S2), 8.17 g·kg−1; severe salinization (S3), 11.15 g·kg−1) and different winter irrigation rates (W0, 0 m3·hm-2; W1, 3000 m3·hm-2; W2, 3600 m3·hm-2; W3, 4200 m3·hm-2) on soil moisture, temperature, salinity, and cotton growth in seasonal freeze–thaw areas. The results showed that the winter irrigation affected the temporal and spatial dynamics of soil moisture, temperature, and salinity, and the winter irrigation rate and degree of soil salinization were significantly correlated with soil moisture, temperature, and salinity (p < 0.01). Winter irrigation stabilized the soil temperature and reduced the freeze–thaw index of the soil. The heat conservation effect of winter irrigation increased with increasing winter irrigation rate and salinization degree, with the greatest effect on the freezing index of S2 and on the thawing index of S3. The soil water content and total salt concentration before spring tillage were significantly correlated with winter irrigation rate and degree of soil salinization (p < 0.05), and when the winter irrigation quota of different salinized cotton fields was greater than 3600 m3·hm-2, the moisture content of soil layer 0–100cm increased by more than 20%, and the desalination reached over 40%, compared with the values before winter irrigation. Winter irrigation improved the emergence rate and yield of cotton, with the soil salinization degree being significantly negatively correlated and winter irrigation rate significantly positively correlated with the emergence rate and yield of cotton fields in the following year (p < 0.01). Compared with the control treatment without winter irrigation, the average increases in cotton yield were W3 (53.32%) > W2 (45.00%) > W1 (29.36%). There was no significant difference in seedling emergence rate or yield between slightly and moderately salinized cotton fields under high winter irrigation rates (W2 and W3) (p > 0.05), although the seedling emergence rate and yield of severely salinized cotton fields increased significantly with increasing winter irrigation rate. In conclusion, winter irrigation proved to be a valuable treatment for severely salinized cotton fields, and the results of this study allowed us to determine the optimal winter irrigation rate for saline alkali cotton fields.

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Section: Discussionmentioning

confidence: 99%

Winter Irrigation Effects on Soil Moisture, Temperature and Salinity, and on Cotton Growth in Salinized Fields in Northern Xinjiang, China

Liu

et al. 2020

Sustainability

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“…Then, the relationship between the shear strength loss rate and the freeze-thaw damage can be obtained from the Equations (14) and (15).…”

Section: =mentioning

confidence: 99%

“…Testing the strength of freeze-thaw cycle loess is of great importance for evaluating the stability of slopes and foundations in loess areas. In order to explore the changes of mechanical properties of loess under the action of freeze-thaw cycles, it is found that the change of water content and the rate of freezing have a great influence on the strength change [9,11,14]. Yan et al [15] studied the unconfined compressive strength and pore distribution characteristics of lime fly ash loess through a series of experiments under freeze-thaw cycles.…”

Section: Introductionmentioning

confidence: 99%

The Influence of Regional Freeze–Thaw Cycles on Loess Landslides: Analysis of Strength Deterioration of Loess with Changes in Pore Structure

Yang

Liu

2020

Water

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The loess landslide in Gaoling District of Xi’an, Shaanxi in China is closely related to the seasonal freeze–thaw cycle, which is manifested by the destruction of pore structure and strength deterioration of the loess body under freeze–thaw conditions. In order to study the relationship between macro-strength damage and pore structure deterioration of saturated loess under freeze–thaw conditions and its influence on the stability of landslides, this paper explores the effect of freeze–thaw cycles on the strength of saturated undisturbed loess through triaxial compression test, and explores the micro-microstructure changes of saturated undisturbed loess through scanning electron microscopy (SEM) and nuclear magnetic resonance (NMR). This is to analyze the evolution of the pore structure and strength loss evolution of saturated loess during the freeze–thaw process, and to describe the freeze–thaw damage of saturated undisturbed loess through the change of porosity and strength deterioration. Then, the internal correlation expression between the porosity change and the strength degradation is established to realize the verification analysis of the test data based on the correlation model. The research results show that: (1) As the number of freeze–thaw cycles increases, the peak strength loss rate gradually increases, and the strength deterioration of saturated loess becomes more and more obvious. (2) The freeze–thaw cycle will lead to the development of pores and cracks in the sample, accompanied by the generation of new cracks, which will cause the deterioration of the pore structure of the sample as a whole. (3) The response of strength damage and porosity deterioration of saturated undisturbed loess is roughly similar under the freeze–thaw cycle. The change in porosity can be measured to better reflect the strength deterioration of saturated loess. Therefore, the change of pore structure of undisturbed loess under freeze–thaw cycle conditions is tested by field sampling and indoor tests to reflect the phenomenon of strength deterioration, thereby analyzing the stability of loess slopes.

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“…Преодолеть просадочность лёссовых грунтов можно только прорезкой всей просадочной толщи сваями фундаментов [1,2]. Сооружение фундаментов на цементогрунтовых сваях по сравнению с ленточными обеспечивает существенную экономию цемента, снижение объема земляных работ, исключает необходимость изготовления опалубки и, как следствие, ускоряет выполнение нулевого цикла в 1,5-2 раза [3][4][5][6][7]. При этом монтаж цементогрунтовых свай буросмесительным способом с механоактивацией позволяет сооружать свайные фундаменты рядом с существующими зданиями или сооружениями без опасения их разрушения.…”

Section: материалы и методыunclassified

Research of properties of cement-soil piles of foundations of buildings and structures

Seregin¹,

Запруднов²

2020

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The review of soil types prevailing in Western Siberia of the Russian Federation is presented. The compositions and physical and mechanical properties of soils are analyzed. Special attention is paid to loess subsidence soils. The problem of obtaining a homogeneous cement-ground mixture is formulated and set. The technological scheme of production of cement-ground piles of foundations of buildings and structures by drilling-mixing method with mechanical activation is considered. Considers methods of strengthening the loess subsidence of soils. Methods for studying the properties of cement-based piles of foundations of buildings and structures are formulated. A multi-factor experiment was conducted to evaluate the parameters that affect the properties of cement-based piles. Based on the research results, conclusions and recommendations are formulated.

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Influence of freeze-thaw cycles in the presence of a supplementary water supply on mechanical properties of compacted soil

Cited by 50 publications

References 27 publications

Winter Irrigation Effects on Soil Moisture, Temperature and Salinity, and on Cotton Growth in Salinized Fields in Northern Xinjiang, China

Winter Irrigation Effects on Soil Moisture, Temperature and Salinity, and on Cotton Growth in Salinized Fields in Northern Xinjiang, China

The Influence of Regional Freeze–Thaw Cycles on Loess Landslides: Analysis of Strength Deterioration of Loess with Changes in Pore Structure

Research of properties of cement-soil piles of foundations of buildings and structures

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