- Title
- Experimental study of the microstructure of loess on its macroscopic geotechnical properties of the Baozhong railway subgrade in Ningxia, China
- Creator
- Meng, Zhao; Liyi, Chen; Shanyong, Wang; Honggang, Wu
- Relation
- Bulletin of Engineering Geology and the Environment Vol. 79, Issue 9, p. 4829-4840
- Publisher Link
- http://dx.doi.org/10.1007/s10064-020-01816-9
- Publisher
- Springer
- Resource Type
- journal article
- Date
- 2020
- Description
- Loess is found all over the world, accounting for about 10 % of the world’s total land area. This soil exhibits a distinctive behavior that is related to their formation history, mineralogy, and microstructure, which can cause serious geotechnical engineering problems. This paper presents the microstructural evolution of the subgrade loess of the Baozhong railway in Guyuan. Particularly, the collapse potential, shear behavior, and the influence of microstructure on them are experimentally studied. The results reveal that the top loess contains more clay content, and the grains with a size of 1–20 μm are significantly more than those of the middle loess and the bottom loess. These particles usually have the effect of combining quartz, feldspar, and other particles. In addition, the macroscopic mechanical properties of top loess are more influenced by intergrains cementation bonds and are more sensitive to water. As a comparison, the middle and bottom loess are more influenced by its loose interstructure and are more sensitive to compression. Based on the analysis of microstructure, a cyclic process model which link the pore change and particle packing is proposed. It is demonstrated that the particle packing is closely related to the change of pores. While the pores decrease to a minimum, the particle packing changes to a bridged random close packing. This mechanism can be used to explain the uneven settlement of the Baozhong railway subgrade in Ningxia.
- Subject
- collapsible loess; microstructure; geotechnical properties; pore change; particle packing
- Identifier
- http://hdl.handle.net/1959.13/1464997
- Identifier
- uon:47184
- Identifier
- ISSN:1435-9529
- Language
- eng
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