Gu Tianfeng

Abstract: Loess structures with large joints and fissures often undergo natural disintegration when subjected to contact with water. The slaking of loess results in the formation of loess gullies, caves, and landslides. To study the disintegration properties and the factors influencing them, we carried out field and laboratory tests. First, we carried out an in situ disintegration test using different sample shapes obtained from Heifangtai and analysed the effect of soil sample shape on loess disintegration. We then developed an improved disintegrator and tested the effect of different factors on the disintegration of loess. The effects of water content, salinity, and composition on disintegration are discussed. The results show that the loess disintegration process can be divided into three broad stages – wetting, softening, and subsidence – the disintegration is mainly concentrated in the third stage, while the first two stages are short and show very weak disintegration. The main factors influencing the disintegration of loess samples are shape, size, and clay mineral content. During the in situ disintegration test, the edge angles of soil samples are disintegrated, to soften all their edges. Disintegration duration increases with increasing sample size, but the extent of disintegration was found to decrease. Disintegration duration is inversely proportional to the loess disintegration rate. The loess disintegration rate is positively correlated with water temperature within a certain range; however, the reverse is observed with soil sample size and initial water content, and salinity was found to have little effect on the disintegration rate. Higher clay content of cohesive soil and weaker permeability leads to a slower disintegration rate. Additionally, lower cementation may easily cause loess disintegration. © 2019 John Wiley & Sons, Ltd.

TL;DR: In this article, the influence of train vibration on the tensile strength behavior of loess was investigated using a modified horizontal extensograph, and the results indicated that vibration reduces the tension-resistance and ductility of Loess soil structure.

TL;DR: Wang et al. as discussed by the authors investigated the triggering factors and movement process of the shallow loess landslide, based on the field investigation, collected the precipitation and temperature data more than 1 year before the landslide and comprehensively used UAV photogrammetry, numerical simulation, and laboratory test for comprehensive research.

TL;DR: Wang et al. as discussed by the authors used laboratory tests and numerical simulation to examine the mechanism of loess landslides owing to the irrigation hydrological cycle, and they selected the Heifangtai irrigation district in Yongjing County, Gansu Province, where frequent instabilities occur.