Shear strength and mesoscopic character of undisturbed loess with sodium sulfate after dry-wet cycling

Xu, Jian; Li, Yanfeng; Wang, Songhe; Wang, Qinze; Ding, Jiulong

doi:10.1007/s10064-019-01646-4

Cited by 59 publications

(27 citation statements)

References 34 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Cylindrical soil specimens for triaxial tests and CT scans were cut from soil blocks, with diameter of 3.91 cm and height of 8.0 cm. Following the procedure for preparing saline intact loess specimens [4], i.e., the self-designed saline infiltration method, the gravimetric water content w was controlled to be 20% and four Na 2 SO 4 contents η were considered, i.e., 0.0%, 0.5%, 1.0%, and 1.5%. e method uses a sponge filled with a certain proportion of saline water to wrap a soil sample with a perforated film.…”

Section: Soil Specimen Preparationmentioning

confidence: 99%

“…e second is the crystallization of migrated soluble salts under the surface evaporation, with soil structure loosened, and consequently the permeability coefficient significantly increases. e third is the repeated process of crystallization-dissolution of solutes, mainly the sodium sulfate (Na 2 SO 4 ) as revealed by field surveys, that causes the structural change of the eroded soil to expand and thus the internal cracks gradually develop [4]. Salt weathering is a frequently encountered phenomenon in the loess region, developed in the loess in different stratigraphic ages, paleosol and compacted loess.…”

Section: Introductionmentioning

confidence: 99%

“…Salt weathering is a frequently encountered phenomenon in the loess region, developed in the loess in different stratigraphic ages, paleosol and compacted loess. Induced by both dry-wet cycles and salt weathering, the natural environment of the loess region, which is already very fragile, is easy to form a gradual stripping of surface soils of the slope and even leads to landslides [4,5].…”

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Permeability and Microstructure of a Saline Intact Loess after Dry‐Wet Cycles

Ren

Wang

et al. 2021

Advances in Civil Engineering

Self Cite

View full text Add to dashboard Cite

Influenced by both dry-wet cycles and salt weathering, the loess will exhibit significant changes in microstructure and permeability, which threatens the stability of loess slopes. Triaxial permeability tests and industrial computed tomography (CT) scans were carried out on saline intact loess with sodium sulfate. The relationship between permeability and pore structure of the loess after dry-wet cycles was discussed. Results show that the permeability coefficient of loess increases after dry-wet cycles, with the increment declining. After specified dry-wet cycles, the permeability coefficient increases approximately linearly with sodium sulfate content. However, the permeability coefficient significantly declines at higher confining pressures, while its attenuation rate decreases. An empirical relationship based on log 10 1 + e − log 10 k was proposed to estimate the permeability coefficient of saline intact loess considering dry-wet cycles and salt content. Comparisons of measured and calculated results proved its rationality. CT scan images imply the damage to soil microstructure induced by dry-wet cycles and salt weathering, corresponding to the decline of the mean CT value (ME) and the increase of both crack ratio and fractal dimension of crack network.

show abstract

Section: Soil Specimen Preparationmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Permeability and Microstructure of a Saline Intact Loess after Dry‐Wet Cycles

Ren

Wang

et al. 2021

Advances in Civil Engineering

Self Cite

View full text Add to dashboard Cite

show abstract

“…Permeability parameters vary with the change in soil types [7][8][9]. Unsaturated loess, one of the most widely distributed soil types, is a special soil with water sensitivity and macropore structure [10][11][12]. Zhang et al [13] reported that the permeability coefficient of unsaturated loess is affected by pore characteristics, and the pore characteristics of loess with different densities and water contents under different pressures were studied.…”

Section: Introductionmentioning

confidence: 99%

Permeability Coefficient of Unsaturated Loess and Its Gaseous and Liquid Water Migration Modeling

Nan¹,

Zhao

Jin

et al. 2021

Advances in Civil Engineering

View full text Add to dashboard Cite

Water migration changes the water distribution of loess and significantly affects the engineering properties of loess. However, because of the characteristics of loess such as water sensitivity and special structure, it is still difficult to understand the water migration trend of loess. The objectives of this study are to investigate the water diffusion coefficient and soil-water characteristic curve (SWCC) of loess, focusing on the effect of temperature and density, and establish a mixed migration equation for gaseous and liquid water to develop a new calculation method of loess water migration. The results show that the density of loess with larger liquid water content has a more significant effect on the diffusion coefficient than that of less liquid water content. Furthermore, the density significantly affects the matric suction of unsaturated loess, while the temperature change at normal temperature has slight effect. Based on the data obtained in this study, the soil water permeability coefficient was obtained. Moreover, considering the characteristics of mixed migration of gas and liquid water in unsaturated loess, an equation was derived for the gas-liquid water transfer in unsaturated loess. The calculation results are consistent with the experimental results of water migration experiment. Based on the calculation results of water migration, the trend of water migration and proportion of gaseous water during migration were analyzed.

show abstract

“…Dijkstra et al [22] found that the shear strength of loess decreased with soluble salt's lixiviation. In a shear test of loess, it was found that the salt content and water content of the soil had a certain influence on its shear strength and other parameters [23][24][25][26]. The salt solution concentration in the pores has also been found to significantly improve soil's shear strength [27,28].…”

Section: Introductionmentioning

confidence: 99%

Effect of Soluble Salt Loss via Spring Water on Irrigation-Induced Landslide Deformation

Zong-lin

Zeng

Meng

et al. 2020

Water

View full text Add to dashboard Cite

Landslide exposes the previously blocked groundwater discharge. High concentrations of soluble salt form salt sinters that can be observed near discharge passages. Based on existing laboratory investigation results of soil leaching and shearing reported in the literature, the effect of the soluble salt loss via spring water on irrigation-induced landslide deformation was studied under large-scale conditions. During our field investigation of landslides in the Heitai terrace of the Yellow River’s upper reaches in Gansu Province, China, 35 spring outlets were found, and the Heitai terrace was divided into five subareas, based on the difference in spring flow. Deformation data for the terrace were obtained by small baseline subset technology (SBAS-InSAR). These data were analyzed in combination with the amount of soluble salt loss, to explore the correlation between the deformation of the landslide and the soluble salt loss in the loess irrigation area. The results showed that the cumulative deformation and the loss of soluble salt were increasing continuously in the terrace. Although the increasing intensity of each subarea was different, the changing intensity of the two during the corresponding monitoring period was highly consistent. The statistical analysis revealed a strong positive correlation between the accumulated loss of soluble salt via spring water and the accumulated displacement of the terrace edge (p < 0.01). After the slope k between the two was tested by the Grubbs test and t-test, the k was no abnormality (α = 0.05) and difference (Sig > 0.05), further providing the basis for confirming the existence of this positive correlation. When the loss of soluble salt in rock and soil increased gradually, the accumulated deformation of the terrace edge also increased continuously. The findings of this study are of great significance for understanding the formation mechanism of landslides and the identifying landslide revival in irrigation areas of the Loess Plateau.

show abstract

Shear strength and mesoscopic character of undisturbed loess with sodium sulfate after dry-wet cycling

Cited by 59 publications

References 34 publications

Permeability and Microstructure of a Saline Intact Loess after Dry‐Wet Cycles

Permeability and Microstructure of a Saline Intact Loess after Dry‐Wet Cycles

Permeability Coefficient of Unsaturated Loess and Its Gaseous and Liquid Water Migration Modeling

Effect of Soluble Salt Loss via Spring Water on Irrigation-Induced Landslide Deformation

Contact Info

Product

Resources

About