Vol18 No.4: 1112-1130
【Title】Multiscale characteristics of the wetting deformation of Malan loess in the Yan'an area, China
【Author】NAN Jing-jing1,2, PENG Jian-bing1,2 *, ZHU Feng-ji3, ZHAO Jun-yan1,2, LENG Yan-qiu1,2
【Addresses】1 Department of Geological Engineering, Chang'an University, Xi'an 710054, China; 2 Key Laboratory of Western China Mineral Resources and Geological Engineering, Ministry of Education, Xi'an 710054, China; 3 China JIKAN Research Institute of Engineering Investigations and Design Co., Ltd., Xi'an 710043, China
【Corresponding author】PENG Jian-bing
【Citation】Nan JJ, Peng JB, Zhu FJ, et al. (2021) Multiscale characteristics of the wetting deformation of Malan loess in the Yan'an area, China. Journal of Mountain Science 18(4). https://doi.org/10.1007/s11629-020-6490-8
【Abstract】Loess is prone to collapse upon wetting due to its open metastable structure, which poses a considerable threat to the environment, construction processes and human life. In this study, double oedometer tests and scanning electron microscopy and mercury intrusion porosimetry analyses were conducted on loess from Yan'an to study the macroscopicand microscopiccharacteristics of loess wetting deformation and the underlying mechanism.The wetting collapse of loess under loading depends on the changes in different microstructure levels and elements. This collapse chain reaction is manifested by the dissipation, scatteringand recombinationof the cementation, deformation and reorganization of the particles, blocking of the pore channels, decrease in the dominant size and volume of unstable macropores (>14 µm) and abundant mesopores (2.5-14 µm), increase in the volume of small pores (0.05–2.5 µm), and volume contraction at the macroscale. This process is dependent on the initial water content, stress leveland wetting degree. These findings can facilitate collapsible loess hazard prevention and geological engineering construction.
【Keywords】Loess; Macroscopic wetting deformation; Wetting collapse mechanism; Microstructure; Pore change