Preface to the special issue on “Loess engineering properties and loess geohazards”

Peng, Jianbing; Qi, Shengwen; Williams, Ann; Dijkstra, Tom

doi:10.1016/j.enggeo.2017.11.017

Cited by 30 publications

(7 citation statements)

References 18 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Loess is a silty yellow sediment formed in the Quaternary Period that was gradually transported and accumulated during a long geological age [1,2]. It is widely distributed in China and is mainly concentrated in the Loess Plateau and other arid or semi-arid areas, covering an area of 640,000 km 2 and accounting for about 6% of China's total land area [3][4][5][6]. At present, with the implementation and advancement of China's "Western Development" strategy, more and more infrastructure projects are being constructed in the Loess Plateau [4].…”

Section: Introductionmentioning

confidence: 99%

The Influence of Drying-Wetting Cycles on the Suction Stress of Compacted Loess and the Associated Microscopic Mechanism

Nie

et al. 2021

Water

View full text Add to dashboard Cite

To better understand and analyze the unsaturated stability of loess filling body, it is necessary to study the changes in suction stress before and after the drying-wetting cycles. In this study, the SWCC of compacted loess before and after drying-wetting cycles was tested using the filter paper method. Then, the suction stress was calculated and the microstructure of the loess sample was determined by the SEM and NMR. The results showed that the drying-wetting cycles had an important influence on the SSCC and microstructure of compacted loess. The change in suction stress before and after the drying-wetting cycles can be well explained by the loess microstructure. The drying-wetting cycles did not significantly change the basic trend of the compacted loess’s SSCC, but it increased the porosity and the dominant pore diameter of loess, and reduced the suction stress under the same matric suction. The main significant change in suction stress with matric suction occurred within the range of the dominant soil pores. The larger the dominant pore diameter, the smaller the suction stress under the same matric suction. In addition, this study proposes a new method for calculating suction stress based on the PSD parameters.

show abstract

Section: Introductionmentioning

confidence: 99%

The Influence of Drying-Wetting Cycles on the Suction Stress of Compacted Loess and the Associated Microscopic Mechanism

Nie

et al. 2021

Water

View full text Add to dashboard Cite

show abstract

“…Loess is a predominantly silt-sized Quaternary sediment which has a wide distribution in arid and semi-arid regions (Peng et al, 2018). It covers approximately 10% of the Earth's land surface, and can be found over large areas of Eurasia, South and North America, and smaller areas of New Zealand, Australia, Africa, and the Middle East (Muhs et al, 2014).…”

Section: Introductionmentioning

confidence: 99%

A comparative study on the physical properties of natural sedimentary loess and manual filling compacted loess

Zhang

Yang³

et al. 2021

Environ Earth Sci

Self Cite

View full text Add to dashboard Cite

With the development of human society, mega engineering projects of removing the tops of hills to in ll valleys began to appear in the loess region. The thickness of the manual lling compacted loess can reach tens of meters. For such large-scale construction projects, studying the properties of compacted loess is essential to ensure the safety and reliability of land creation and arti cial infrastructure. In this paper, the specimens from two exploration well pro les were carried out to study the physical properties of natural loess and compacted loess from the Loess Plateau. Here the natural loess selected was deposited in old ages (Q 2 and Q 1 ) and had strong stability. The natural water content, dry density, speci c gravity, liquid limit, plastic limit, plasticity index, clay fraction, silt fraction, sand fraction, compression modulus, and permeability coe cient have been determined. Statistical theories such as t-test and correlation coe cient checks were used to describe the difference between the two kinds of loess, and the degree of correlation among various indicators. Besides, 14 groups of exploration well data in 8 studies were collected. The variation of natural water content and dry density with well depth was analyzed to supplement the existing data. Results have shown that the manual lling compacted loess is signi cantly different from the natural loess. On the whole, the liquid limit, plastic limit, plasticity index, clay fraction, silt fraction, sand fraction and compression modulus of the compacted loess are smaller. And compared with the natural sedimentary loess with strong stability, it deforms more easily. The difference of compression modulus between the compacted loess and natural loess is mainly controlled by the dry density and the particle composition. Moreover, the heterogeneous level of the manual lling compacted loess is greater than that of the natural loess in the horizontal direction and smaller than that of the natural loess in the vertical direction. Under a combination of external hydrologic conditions and dead weight, the compacted loess will become more stable.

show abstract

“…Loess is a silty yellow sediment formed in the Quaternary period that was gradually transported and accumulated during a long geological age (Peng et al 2018;Peng et al 2017). It is widely distributed in China and is mainly concentrated in the Yellow River, the upper reaches of Shanxi, Shaanxi, southeastern Gansu, and western Henan, as well as other arid and semi-arid areas, covering an area of 640,000 km 2 and accounting for about 6% of China's total land area (Derbyshire 2000;Feng et al 2015;Luo et al 2017;Ni et al 2020).…”

Section: Introductionmentioning

confidence: 99%

The Influence of Drying-Wetting Cycles on the Suction Stress of Compacted Loess and the associated Microscopic Mechanism

Nie¹,

Ni²,

Li³

et al. 2021

Preprint

View full text Add to dashboard Cite

In order to better understand and analyze the unsaturated stability of loess fillings, it is necessary to study the changes in suction stress before and after the drying-wetting cycles. In this study, the soil-water characteristic curve (SWCC) of compacted loess before and after drying-wetting cycles was tested using the filter paper method. Then, the suction stress was calculated and the microstructure of the loess sample was determined by the scanning electron microscope（SEM）and nuclear magnetic resonance (NMR). The results showed that the drying-wetting cycles had an important influence on the suction stress characteristic curve (SSCC) and microstructure of compacted loess. The change in suction stress before and after the drying-wetting cycles can be explained by the loess microstructure. The drying-wetting cycles did not significantly change the basic trend of the compacted loess's suction stress, but it increased the porosity and the diameter of the dominant pore (i.e., the inter-aggregate pore) of the sample, and reduced the suction stress when the same matrix suction was applied. The main significant change in suction stress with matrix suction occurred within the range of the dominant soil pores. The larger the diameter of the dominant pore, the smaller the suction stress under the same matrix suction. In addition, this study also proposes a new method for calculating suction stress based on the pore size distribution（PSD） parameters, which is more convenient than traditional calculation methods based on SWCC parameters.

show abstract

Preface to the special issue on “Loess engineering properties and loess geohazards”

Cited by 30 publications

References 18 publications

The Influence of Drying-Wetting Cycles on the Suction Stress of Compacted Loess and the Associated Microscopic Mechanism

The Influence of Drying-Wetting Cycles on the Suction Stress of Compacted Loess and the Associated Microscopic Mechanism

A comparative study on the physical properties of natural sedimentary loess and manual filling compacted loess

The Influence of Drying-Wetting Cycles on the Suction Stress of Compacted Loess and the associated Microscopic Mechanism

Contact Info

Product

Resources

About