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Grain size composition change after feldspathic sandstone and aeolian sandy soil compounding |
Zhang Lu, Han Jichang, Wang Huanyuan, Ma Zenghui |
Shaanxi Land Construction Group, Key Laboratory of Degraded and Unused Land Consolidation Engineering the Ministry of Land and Resources of China, 710075, Xi'an, China |
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Abstract The purpose of this research was to explore the possibility of feldspathic sandstone as a kind of new sand-fixing material from the grain size composition change statistics and particle size distribution charactertistics, to provide a scientific support for desertification control, soil and water conservation and development of farming in Mu Us Sandy Land, and at the same time, to improve the living standards of local people. Methods of mixing feldspathic sandstone and aeolian sandy soil according to the kinds of mass ratios of mf:ms =1:0,1:1,1:2,1:5,and 0:1(where mf is the quality of the feldspathic sandstone, ms is the quality of the aeolian sandy soil) were used, then, the particle graded composition and particle size distribution characteristics of feldspathic sandstone and aeolian sandy soil compound soil were studied with Malvern 2000 laser particle size analyzer. The results showed that after feldspathic sandstone and aeolian sandy soil compounding, the texture characteristics of compound soil changed for the better. These features of sand-based, loose structure, easy to wind erosion of aeolian sandy soil were improved gradually after feldspathic sandstone and aeolian sandy soil compounding. The mass content of < 0.05 mm particle increased with feldspathic sandstone mass increasing and the mass content of > 0.05 mm particle decreased with feldspathic sandstone mass increasing. The texture presented this kind of change trend from sand to sandy loam to loam to silt loam. The small particle size distribution, good particle homogeneity and other shortcoming of aeolian sandy soil were improved to a certain degree, and the particle size distribution became broad after feldspathic sandstone and aeolian sandy soil compounding. The grain grading was continuous and the particle grading characteristics were good when the mass ratio of feldspathic sandstone and aeolian sandy soil compound soil was 1:5(the nonuniform coefficient was 54.71 and the curvature coefficient was 2.54) or 1:2(the nonuniform coefficient was 76.21,the curvature coefficient was 1:12). After feldspathic sandstone and aeolian sandy soil compounding, not only the shortcoming of particle size composition of aeolian sandy soil was improved, but also this problem of high clay content of feldspathic sandstone was resolved, which effectively prevented the soil compaction problem of feldspathic sandstone. After feldspathic sandstone and aeolian sandy soil compounding, and particles of various sizes were mixed, the grain grading was continuous from microscopic particles of view, which provided a scientific base for land desertification control. Consequently, feldspathic sandstone has the possibility of sand-fixing from grain size composition of view. The texture characteristics changes for better with feldspathic sandstone mass increasing, and when the mass ratio of feldspathic sandstone and aeolian sandy soil is 1:2 or 1:5 which compound better for particle grading characteristics.
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Received: 02 July 2014
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