Influence of Moisture Content and Dry Density on the Compressibility of Disturbed Loess: A Case Study in Yan’an City, China

Self Cite

Loess disintegration is a significant physicochemical and mechanical dissolution process that occurs when loess comes into contact with water. This phenomenon contributes to geological disasters such as loess cave erosion, landslides, and debris flows. The disintegration of loess can be influenced by both internal and external factors. Research on internal factors of loess disintegration has been widely recorded, but the research progress on external environmental factors that affect loess disintegration is not well summarized. This review summarizes the impacts of external water environmental factors on loess disintegration and reveals that six external water environmental factors, namely the temperature of the aqueous solution, hydrodynamic conditions, solution pH, salt concentration and type in the solution, freeze–thaw cycles, and dry–wet cycles, can significantly impact loess disintegration. Furthermore, this review delves into three key research areas in loess disintegration under the influence of these water environmental factors: experimental research on loess disintegration, the disintegration parameters used in such research and their variations, and the water–soil chemical reactions and microstructural changes during loess disintegration. It concludes that current experimental research on loess disintegration suffers from inadequate studies, with existing research associated with poor comparability and weak representativeness, and a lack of comprehensive, systematic analysis of its regularities of influence and response mechanisms from both microscopic and macroscopic perspectives. This paper can provide valuable insights for the prevention of loess geological disasters and engineering safety construction.

Section: Introductionmentioning

confidence: 99%

Unraveling the Mystery of Water-Induced Loess Disintegration: A Comprehensive Review of Experimental Research

Chen,

Li,

Wang

et al. 2024

Self Cite

“…The collapsibility of loess in the Loess Plateau poses unique challenges for the sustainable operation of infrastructure. These challenges make resource development and the continuous progress of various projects in the Loess region more difficult [6]. As the western development progresses, engineering endeavors in loess regions are bound to encounter collapsibility issues, posing significant challenges to site selection and the safe operation of constructed facilities [7].…”

Section: Introductionmentioning

confidence: 99%

Effects of Paleosol on the Collapsibility of Loess Sites under Immersion Test Conditions

Li,

Wang,

et al. 2024

The existence of multiple layers of red paleosol within loess strata presents a unique challenge due to its high hardness, which resists settlement deformation upon exposure to water. This attribute significantly influences the subsidence measurements of the loess strata. Despite this, the current literature lacks reports on the control effect of paleosol on collapsibility, leading to a deficiency in the theoretical basis for scientifically selecting collapsibility in these strata. This paper seeks to bridge this gap by examining the differences in self-weight collapsibility under various conditions, both indoor and outdoor, across different paleosol layers and strata. The analysis is grounded on statistical results derived from immersion tests conducted in the Loess Plateau. Moreover, the research zeroes in on two test sites in Xi’an, conducting extensive immersion tests and considering measurements such as water diffusion, changes in water content, soil pressure, and cumulative collapsibility under different test conditions. The study probes into the influence of paleosol layers on water infiltration and their role in controlling total weight collapse. The final results suggest that the presence of a paleosol layer inhibits collapsibility transfer to the lower layer and restricts water infiltration, thereby reducing total collapsibility. Discrepancies between measured and calculated collapsibility values showed a positive correlation with the number of paleosol layers. This research offers valuable insights into the collapsibility mechanism of paleosol-loess strata.

“…Loess is a kind of silty clay with large pores, incomplete consolidation, and collapsibility. Based on a large number of studies [56][57][58][59][60], undisturbed loess is observed to have the following remarkable properties:…”

Section: Introductionmentioning

confidence: 99%

Influence of Dry-Wet Cycles on the Structure and Shear Strength of Loess

Wang,

Li,

Zhong

et al. 2023

The dry-wet cycle is an important factor that causes slope instability and foundation settlement in loess regions. In order to study the effects of the dry-wet cycle on the structure and shear strength of loess, isotropic compression tests and triaxial shear tests were carried out on loess with different numbers of dry-wet cycles. The results show that the dry-wet cycles mainly reduce the cohesion of loess, and the most obvious decline is after the first cycle; however, they have no effect on the angle of internal friction of loess. The structural yield strength and structural parameters of loess can represent the structure of loess well, which gradually decrease with the increase in the number dry-wet cycles and water content. The initial yield surface is approximately an ellipse, which gradually shrinks with the increase in water content and dry-wet cycles. The structure and cohesion of loess have similar changes, and there is an obvious exponential function relationship between them.