Distinct element method based stability analysis of tunnels in a deep coal mine in China

S. Shreedharan, Pinnaduwa Kulatilake

Research output: Chapter in Book/Report/Conference proceedingConference contribution

Abstract

Stability studies on two tunnels, a horseshoe-shaped and an inverted arch-shaped tunnel, in a deep coal mine in China, have been performed using the 3DEC distinct element code and presented in this study. A pseudo time-dependent support installation procedure has been developed to incorporate the stress relaxation and deformation due to time gap between excavation and support installation. The utility of incorporating stress relaxation before support installation has been explored through observation of support factors of safety and grout failures. The numerical models have been analyzed for different support configurations and unsupported situations. The reinforcement provided by the supports has been demonstrated using changes in tunnel deformations and sizes of yield zones around the tunnels, in addition to observations of support factors of safety and grout failures. Results indicate that using longer supports and floor bolting would provide higher stability for the rock masses around the tunnels. A comparison between the closure strains in the two tunnels indicates that the inverted arch tunnel may be more stable under the existing geo-mining conditions at the site. Finally, parametric studies point to the importance of cohesion and friction angle estimation for intact rock, and basic friction angle estimation for the rock mass, to ensure robust numerical results.

Original languageEnglish (US)
Title of host publication50th US Rock Mechanics / Geomechanics Symposium 2016
PublisherAmerican Rock Mechanics Association (ARMA)
Pages1477-1487
Number of pages11
Volume2
ISBN (Electronic)9781510828025
StatePublished - 2016
Event50th US Rock Mechanics / Geomechanics Symposium 2016 - Houston, United States
Duration: Jun 26 2016Jun 29 2016

Other

Other50th US Rock Mechanics / Geomechanics Symposium 2016
CountryUnited States
CityHouston
Period6/26/166/29/16

ASJC Scopus subject areas

  • Geochemistry and Petrology
  • Geophysics

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  • Cite this

    Shreedharan, S., & Kulatilake, P. (2016). Distinct element method based stability analysis of tunnels in a deep coal mine in China. In 50th US Rock Mechanics / Geomechanics Symposium 2016 (Vol. 2, pp. 1477-1487). American Rock Mechanics Association (ARMA).