An innovative index to assess clogging potential

• Author / Creator

  Zhou, Yang

• Clogging frequently occurs during underground excavation using tunnel boring machines (TBMs), and can cause severe schedule delays and cost overruns on projects. However, an index to quantitatively describe clogging potential has not been standardized. This paper presents a new index to indicate clogging potential based on the results of a mixing test, and the authors have also conducted sensitivity analysis to understand the effect of different types and weights of soil and different size of beater on the variability of the index. The new index is also compared with the stickiness ratio based on standard deviation of the weight of soil stuck on the beater over W/Ac and stickiness ratio, respectively, to show the advantage of using the new index. The results show that although the mass of soil that sticks to the mixing tool varies, assessing clogging potential using the new index, W/Ac, can give more repeatable results, since it eliminates the impact of beater size and mass of soil. In addition, the clogging potential of different types of soil can be differentiated using W/Ac, and the average standard deviation of the test using different beater sizes and masses of soil are smaller using the index W/Ac compared to using the stickiness ratio. This paper provides a reliable and straightforward index to assess clogging potential easily and simply based on the results of a mixing test.

• Subjects / Keywords

  • tunnel boring machine
  • stickiness ratio
  • mixing test
  • clogging potential

• Graduation date

  Fall 2020

• Type of Item

  Thesis

• Degree

  Master of Science

• DOI

  https://doi.org/10.7939/r3-4nq5-tb72

• License

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