• Fulltext

       

        Click here to view fulltext PDF


      Permanent link:
      https://www.ias.ac.in/article/fulltext/jess/131/0118

    • Keywords

       

      Analogue-experiments; persistence ratio; strength of rocks; tensile wing crack.

    • Abstract

       

      We investigated the effects of displacement rates on the strength and mechanisms of fracturing by conducting three series of compressive experiments with synthetic samples analogous to soft-porous rocks. The three series correspond to (i) intact samples (without joints), (ii) samples with single joint of different lengths (10, 15, 20 and 25 mm) and (iii) samples with double joint-segments (15 mm each separated by a bridge), respectively. The samples were deformed under variable displacement rates (0.048, 0.12, 3, 4.45 and 6 mm/min). We found that the material-strength enhanced with increasing displacement rates for intact and samples with single joint-segment with limited persistent ratio; however, the strength declined substantially for samples with persistent ratio above a threshold (${\sim}$0.20) and beyond a critical window of displacement rates (3–4.45 mm/min) for both the samples with single- and double-joint-segment(s). The fractures were dominated by tensile wing cracks, however, the location, timing and corresponding displacement rates concerning the appearance of secondary shearing confirmed that the extent of shearing mechanism enhanced at fast-displacement rates when the persistent ratio crossed a critical value (${\sim}$0.20). Overall, the strength of material considerably reduced and the potential of damage further accelerate at faster displacement rates when the persistent ratio of non-persistent joint(s) crossed a pedantic threshold.

    • Author Affiliations

       

      GAURAV KUMAR MATHUR1 VIKRAM MAJI1 SANTANU MISRA1 GAURAV TIWARI2

      1. Experimental Rock Deformation Laboratory, Department of Earth Sciences, Indian Institute of Technology Kanpur, Kanpur, Uttar Pradesh 208 016, India.
      2. Department of Civil Engineering, Indian Institute of Technology Kanpur, Kanpur, Uttar Pradesh 208 016, India.
    • Dates

       
  • Journal of Earth System Science | News

    • Editorial Note on Continuous Article Publication

      Posted on July 25, 2019

      Click here for Editorial Note on CAP Mode

© 2021-2022 Indian Academy of Sciences, Bengaluru.