Damage constitutive model of single flaw sandstone under freeze-thaw and load

• Published in: Cold regions science and technology 2019-03, Vol.159, p.20-28
• Main Authors: Lu, Yani, Li, Xinping, Chan, Andrew
• Format: Article
• Language: English
• Subjects: Constitutive model; Damage mechanism; Freeze-thaw action; Single flaw rock masses; Triaxial compression tests
• ISSN: 0165-232X; 1872-7441
• DOI: 10.1016/j.coldregions.2018.11.017

The deterioration of mechanical properties subjected to freeze-thaw action is a determining factor for natural rock masses in cold region engineering. Taking four cases of flaw sandstone as the research object, freeze-thaw cycles experiments and triaxial compression tests were conducted to analyze the mechanical properties after 0, 20, 40 and 60 freeze-thaw cycles. The damage evolution equation of freeze-thaw sandstone under load is established based on the Lemaitre strain equivalent principle and continuum damage mechanics theory. In this regard, the damage model was developed to predict the degradation of triaxial compression strength for single flaw sandstone samples, it takes into account pre-existing cracks, confining pressure, freeze-thaw action and load. The results show that the sandstone damage consists of factors mentioned above, the coupled damage variable acquired from the proposed method well agree with the actual condition, and the damage constitutive model validations are given through comparisons between the calculated and the measured. •A series of freeze-thaw experiments and triaxial compression tests were conducted on four cases of jointed rockmass.•The deterioration of mechanical properties subjected to freeze-thaw action were studied.•A damage model was developed to predict the degradation of triaxial compression strength for fissured rock.