MICROSTRUCTURE OF LOESS SOIL IN CHINA RELATIVE TO GEOGRAPHIC AND GEOLOGIC ENVIRONMENT
Gao Guorui (Geotechnical Investigation Corporation, Ministry of Chemical Industry)
In this paper the distribution, thickness, stratum, composition, collapsibility and climate conditions as well as geographical environment of loess soils in China are described. After studing the microstructure features of loess soil in many parts of China with scanning electron microscope, the following considerations are suggested. First of all, the spaced granular structure in loess soil is the basic reason for collapsibility. Secondly, the microstructure features of loess soil vary regionally with regional climate conditions, this variation conforms to collapsing tendency of gradually decreasing from the northwest to the southeast of the loess region in China found in engineering practice. Thirdly, from regional variation of loess soil microstructure features, it can be considered that its formation and development have undegone four stages: the loessization stage, the formation stage, the development stage and the clayization stage. And finally, even though under the modern climate conditions, the loess in the northwest of the Loess Plateau of China is still developing, however, the feature of loess is gradually disappearing in southeast of the loess plateau of China.