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Acta Mechanica Solida Sinica

, Volume 22, Issue 3, pp 240–250 | Cite as

Zonal disintegration mechanism of deep crack-weakened rock masses under dynamic unloading

  • Xiaoping Zhou
  • Qihu Qian
  • Bohu Zhang
Article

Abstract

Size and quantity of fractured zone and non-fractured zone are controlled by cracks contained in deep rock masses. Zonal disintegration mechanism is strongly dependent on the interaction among cracks. The strong interaction among cracks is investigated using stress superposition principle and the Chebyshev polynomials expansion of the pseudo-traction. It is found from numerical results that crack nucleation, growth and coalescence lead to failure of deep crack-weakened rock masses. The stress redistribution around the surrounding rock mass induced by unloading excavation is studied. The effect of the excavation time on nucleation, growth, interaction and coalescence of cracks was analyzed. Moreover, the influence of the excavation time on the size and quantity of fractured zone and non-fractured zone was given. When the excavation time is short, zonal disintegration phenomenon may occur in deep rock masses. It is shown from numerical results that the size and quantity of fractured zone increase with decreasing excavation time, and the size and quantity of fractured zone increase with the increasing value of in-situ geostress.

Key words

deep crack-weakened rock masses interaction among cracks stress superposition principle zonal disintegration mechanism dynamic unloading 

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Copyright information

© The Chinese Society of Theoretical and Applied Mechanics and Technology 2009

Authors and Affiliations

  1. 1.School of Civil EngineeringChongqing UniversityChongqingChina
  2. 2.PLA University of Science and TechnologyNanjingChina
  3. 3.School of Civil Engineering and ArchitectureSouthwest Petroleum UniversityChengduChina

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