Journal of Guangdong University of Technology ›› 2018, Vol. 35 ›› Issue (06): 49-56.doi: 10.12052/gdutxb.180065

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Experiment Study on Microstructure of Soft Soil in Nansha District Based on NMR and SEM Test

Liu Yong-jian, Wu Jian-sheng, Xie Zhi-kun   

  1. Institute of Geotechnical Engineering, Guangdong University of Technology, Guangzhou 510006, China
  • Received:2018-03-30 Online:2018-11-23 Published:2018-11-05

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Abstract: The moisture characteristics and microstructure of soft soil are the key factors in determining the physical and mechanical properties of soil. The relaxation time T2 spectra and scanning electron microscope images of soft soil from Nansha District were obtained by means of nuclear magnetic resonance (NMR) and scanning electron microscopy (SEM). The water phase and pore size distribution of two types of soft soils were summarized based on SEM and NMR test results. The results show that the relaxation time T2 distribution curve of Nansha soft soil is bimodal with two kinds of water in soil, the first state water being over 99% of the total water quality, and muck and mucky soil having many small pores mainly concentrated in the range of 0.1 μm to 20 μm. SEM images show that the three microstructure types of Nansha soft soil are in flocculent microstructure, honeycomb microstructure and clot microstructure. These methods also can calculate the microstructure parameters such as average pore radius, average pore area, surface porosity, pore shape factor and pore fractal dimension. The results of pore sizes obtained by the two methods are basically the same, but not completely consistent. Finally, the characteristics of the two methods and several issues in the application of SEM and NMR test are discussed.

Key words: soft soil, moisture characteristics, microstructure, nuclear magnetic resonance test, scanning electron microscopy test

CLC Number: 

  • TU431
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