Mechanical behavior of sandstone during post-peak cyclic loading and unloading under hydromechanical coupling

Yanlin Zhao, Jinhai Liu, Chunshun Zhang, Houquan Zhang, Jian Liao, Sitao Zhu, Lianyang Zhang

Research output: Contribution to journalArticlepeer-review

28 Scopus citations

Abstract

This paper investigates mechanical behaviours of sandstone during post-peak cyclic loading and unloading subjected to hydromechanical coupling effect, confirming the peak and residual strengths reduction laws of sandstone with water pressure, and revealing the influence of water pressure on the upper limit stress and deformation characteristics of sandstone during post-peak cyclic loading and unloading. Regarding the rock strength, the experimental study confirms that the peak strength σp and residual strength σr decrease as water pressure P increases. Especially, the normalized strength parameters σppk and σrre was negatively and linearly correlated with the P/σ3. Moreover, the Hoek-Brown strength criterion can be applied to describe the relationship between effective peak strength and effective confining stress. During post-peak cyclic loading and unloading, both the upper limit stress σp(i) and crack damage threshold stress σcd(i) of each cycle tend to decrease with the increasing cycle number. A hysteresis loop exists among the loading and unloading stress–strain curves, indicating the unloading deformation modulus Eunload is larger than the loading deformation modulus Eload. Based on experimental results, a post-peak strength prediction model related to water pressure and plastic shear strain is established.

Original languageEnglish (US)
Pages (from-to)927-947
Number of pages21
JournalInternational Journal of Mining Science and Technology
Volume33
Issue number8
DOIs
StatePublished - Aug 2023
Externally publishedYes

Keywords

  • Cyclic loading and unloading
  • Hydromechanical coupling
  • Post-peak stage
  • Sandstone
  • Water pressure

ASJC Scopus subject areas

  • Geotechnical Engineering and Engineering Geology
  • Energy Engineering and Power Technology
  • Geochemistry and Petrology

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