Correlation of Schmidt Rebound Hardness with Uniaxial Compressive Strength and P-Wave Velocity of Rock Materials

The Schmidt hammer is widely used for various applications since 1950s due to its simplicity and portability. The purpose of this study was to compare two Schmidt hammer test methods: earlier (RISRM-EV) and revised version (RISRM-RV) of ISRM in terms of estimation capabilities of uniaxial compressive strength (UCS) and ultrasonic P-wave velocity (UPV). Multiple regression analysis was also performed between Schmidt hardness (R) and the ratio of UPV/UCS. A total of 46 rocks [28 volcanic, 8 metamorphic (metabasalt) and 10 sedimentary (carbonate rocks)] were sampled and tested. The validity of obtained coefficients of correlation was confirmed using the correlation analyses. In the present study, the result of the correlation analysis indicated strong relationships between R with UCS, UPV and UPV/UCS ratio. Relationships between RISRM-RV and UCS, RISRM-EV and UPV/UCS ratio, RISRM-RV and UPV/UCS ratio are not significant at a 95 % confidence limit for metamorphic rocks due to the presence of micro-cracks that cause fluctuations in the test results. Other relations are statistically significant according to the correlation analyses with 95 % confidence limit. This study also revealed that UPV/UCS ratios decrease exponentially with increasing R values. It was shown that the ratio of UPV/UCS would be dependent on R for rocks.

[1]  Isrm.  Suggested methods for determining hardness and abrasiveness of rocks , 1978 .

[2]  I. W. Farmer,et al.  Consistency and repeatability of Schmidt Hammer rebound data during field testing , 1980 .

[3]  J. C. Fernandes,et al.  Determination of Schmidt rebound hardness consistency in granite , 1999 .

[4]  Saffet Yagiz,et al.  P-wave velocity test for assessment of geotechnical properties of some rock materials , 2011 .

[5]  M. Ataei,et al.  Application of Schmidt rebound number for estimating rock strength under specific geological conditions , 2011 .

[6]  F. Ren,et al.  Hardness of metallic crystals , 2011 .

[7]  Mohammad Ataei,et al.  Comparison of Some Rock Hardness Scales Applied in Drillability Studies , 2012 .

[8]  R J Fowell,et al.  ASSESSING ROCK DISCONTINUITIES , 1978 .

[9]  Oded Katz,et al.  Evaluation of mechanical rock properties using a Schmidt Hammer , 2000 .

[10]  C. Gokceoğlu,et al.  New approaches to the characterization of clay-bearing, densely jointed and weak rock masses , 2000 .

[11]  R. M. Goktan,et al.  A comparative study of Schmidt hammer testing procedures with reference to rock cutting machine performance prediction , 2005 .

[12]  Nuh Bilgin,et al.  ROADHEADERS GLEAN VALUABLE TIPS FOR ISTANBUL METRO , 1990 .

[13]  Saffet Yagiz,et al.  Predicting uniaxial compressive strength, modulus of elasticity and index properties of rocks using the Schmidt hammer , 2009 .

[14]  E. Schmidt,et al.  A non-destructive concrete tester , 1951 .

[15]  R. M. Göktan,et al.  A SUGGESTED IMPROVEMENT TO THE SCHMIDT REBOUND HARDNESS ISRM SUGGESTED METHOD WITH PARTICULAR REFERENCE TO ROCK MACHINEABILITY , 1993 .

[16]  S. Kahraman,et al.  Dominant rock properties affecting the penetration rate of percussive drills , 2003 .

[17]  Adnan Aydin,et al.  The Schmidt hammer in rock material characterization , 2005 .

[18]  Avni Guney,et al.  Performance Prediction of Large-Diameter Circular Saws Based on Surface Hardness Tests for Mugla (Turkey) Marbles , 2011 .

[19]  A. Kidybiński.  Rebound number and the quality of mine roof strata , 1968 .

[20]  A. Aydin.  ISRM Suggested method for determination of the Schmidt hammer rebound hardness: Revised version ☆ , 2009 .

[21]  C. Karpuz.  A classification system for excavation of surface coal measures , 1990 .

[22]  W. Nel,et al.  The effect of rock moisture on Schmidt hammer rebound: tests on rock samples from Marion Island and South Africa , 2002 .

[23]  Edward J. Cording,et al.  Estimation of rock engineering properties using hardness tests , 2007 .

[24]  R. Altindag,et al.  The effect of sample size on Schmidt rebound hardness value of rocks , 2009 .

[25]  Kaveh Ahangari,et al.  Estimation of uniaxial compressive strength based on P-wave and Schmidt hammer rebound using statistical method , 2013, Arabian Journal of Geosciences.

[26]  Manoj Khandelwal,et al.  Correlating P-wave Velocity with the Physico-Mechanical Properties of Different Rocks , 2013, Pure and Applied Geophysics.

[27]  Allen W. Hatheway,et al.  The Complete ISRM Suggested Methods for Rock Characterization, Testing and Monitoring; 1974–2006 , 2009 .

[28]  R. M. Goktan,et al.  The effect of Schmidt hammer type on uniaxial compressive strength prediction of rock , 2007 .

[29]  R. Altindag,et al.  P-wave velocity and Schmidt rebound hardness value of rocks under uniaxial compressional loading , 2011 .

[30]  V. Hucka,et al.  A rapid method of determining the strength of rocks in situ , 1965 .

[31]  A. Kesimal,et al.  Evaluation of the influence of porosity on the engineering properties of volcanic rocks from the Eastern Black Sea Region: NE Turkey , 2013, Arabian Journal of Geosciences.

[32]  Celal Karpuz,et al.  Field characterisation of weathered Ankara andesites , 1997 .

[33]  E. Yaşar,et al.  Estimation of rock physicomechanical properties using hardness methods , 2004 .

[34]  Bhawani Singh,et al.  Schmidt hammer rebound data for estimation of large scale in situ coal strength , 1984 .

[35]  A. Goudie.  The Schmidt Hammer in geomorphological research , 2006 .