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Landslides

, Volume 13, Issue 5, pp 1261–1272 | Cite as

Research on mechanical parameters of coarse-grained sliding soil based on CT scanning and numerical tests

  • Jiwei JiangEmail author
  • Wei Xiang
  • Joachim Rohn
  • Markus Schleier
  • Jiajun Pan
  • Wei Zhang
Original Paper

Abstract

The inner structure of sliding soil is quite inhomogeneous, which makes it very hard to investigate the mechanical properties. In this paper, intact sliding soil samples collected from the Huangtupo landslide is verified to be rock and soil aggregates (RSA) firstly. Because of the grain-size limitations for general indoor shear tests and the unpredictability of test data obtained by reshaped sample, a new method which combines CT scanning for undisturbed samples, mechanical tests for fine-grained subdomain and numerical test is proposed. With the advantages of repeatability and parallel comparison, deep research into the mechanical properties and deformation mechanisms for sliding soil is carried out. The research shows that, for the RSA in this paper, which the coarse particles content is about 30 %, fine-grained subdomain is still the frame part of RSA, compared with pure fine-grained soil, the internal friction angle does not obviously increase, but the cohesion increased by at least 80 %. Meanwhile, coupling deformation between coarse particles and fine-grained subdomain is a complex mechanical process; coarse particles will support an effective resistance to the fine fraction, and in Mohr-Coulomb model, it is reflected by obvious increase of cohesion. Based on the mechanical trace preservations on a block of gravel, this external friction effect is verified. Then, by seven groups of large-size stacked ring shear test for the RSA samples, these analyses and judgements are verified. The comprehensive research method can also be widely used in achieving the mechanical and failure characteristic of RSA.

Keywords

Sliding soil CT scanning Numerical test Mechanical parameters Nondestructive testing Rock and soil aggregates (RSA) 

Notes

Acknowledgments

This work is supported by cooperation frame of the International Bureau of the German Federal Ministry of Education and the Three Gorges Research Center for Geo-hazard, Ministry of Education. The research is sponsored by National Natural Science Foundation of China (NSFC, Grant No. 51409011) and the Basic Scientific Research Operating Expenses of Central-Level Public Academies and Institutes (Grant No. CKSF2014057/YT and CKSF2015051/YT)

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Copyright information

© Springer-Verlag Berlin Heidelberg 2015

Authors and Affiliations

  • Jiwei Jiang
    • 1
    Email author
  • Wei Xiang
    • 2
  • Joachim Rohn
    • 3
  • Markus Schleier
    • 3
  • Jiajun Pan
    • 1
  • Wei Zhang
    • 1
  1. 1.Key Laboratory of Geotechnical Mechanics and Engineering of Ministry of Water ResourcesYangtze River Scientific Research InstituteWuhanChina
  2. 2.Faculty of EngineeringChina University of GeosciencesWuhanChina
  3. 3.Department of Applied GeologyUniversity of Erlangen-NurembergErlangenGermany

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