Modified kastner formula for cylindrical cavity contraction in mohr-coulomb medium for circular tunnel in isotropic medium

Yung Ming Cheng

Research output: Journal article publicationJournal articleAcademic researchpeer-review

15 Citations (Scopus)


The Kastner formula for cavity contraction is one of the commonly used formulae for the cavity contraction problem in tunnel excavation, and it is based on the assumption of small displacement around the cavity with no volume change in the plastic zone. In this paper, the errors arising from these assumptions are discussed, and the volume change of the plastic zone is considered. It can be seen that this assumption is reasonable for normal situations, but for rock with weak shear strength, the Kastner formula should be used with care, especially in situations where there will be relatively large volume changes in the plastic zone. 2012.
Original languageEnglish
Pages (from-to)163-169
Number of pages7
JournalJournal of Mechanics
Issue number1
Publication statusPublished - 1 Mar 2012


  • Cavity contraction
  • Cavity expansion
  • Kastner formula

ASJC Scopus subject areas

  • Condensed Matter Physics
  • Mechanical Engineering
  • Applied Mathematics

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