Comparison of Averaging Procedures for Point Load Testing of Rock

This paper presents the experimental results of a laboratory point load testing program carried out to analyze the effect of two different point load mean value calculation procedures on the prediction accuracy of uniaxial compressive strength of rocks. Apart from the calculation procedure corresponding to the one suggested by ASTM and ISRM, a second calculation procedure involving the ordinary arithmetic mean value was used in the analyses. Axial point load tests were conducted on a total of 19 rocks having two different thickness-to-diameter ratios. Finally, the results of the point load tests were correlated with those of the standard uniaxial compressive strength tests, and some test statistics were employed to determine the relative effectiveness of the considered calculation procedures. Valid for axial testing method and the tested rock types, it was concluded that the suggested mean value calculation procedure by the ASTM and ISRM has no significant advantage compared with the traditional statistical procedure that involves ordinary arithmetic mean.

[1]  Guidicini G.,et al.  Analysis of point load test as a method for preliminary geotechnical classification of rocks , 1973 .

[2]  F. Kulhawy,et al.  A comparative evaluation of rock strength measures , 1984 .

[3]  G. Tsiambaos,et al.  Considerations on strength of intact sedimentary rocks , 2004 .

[4]  A. Tugrul,et al.  Correlation of mineralogical and textural characteristics with engineering properties of selected granitic rocks from Turkey , 1999 .

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

[6]  A. Shakoor,et al.  Evaluation of empirical methods for measuring the uniaxial compressive strength of rock , 1990 .

[7]  S. Kahraman.  Evaluation of simple methods for assessing the uniaxial compressive strength of rock , 2001 .

[8]  Adnan Aydin,et al.  Predicting Uniaxial Compressive Strength by Point Load Test: Significance of Cone Penetration , 2006 .

[9]  Jrl Read,et al.  A rational approach to the point load test , 1980 .

[10]  J. A. Franklin,et al.  Suggested method for determining point load strength , 1985 .

[11]  S. Kahraman,et al.  A Comparative Evaluation of Indirect Methods to Estimate the Compressive Strength of Rocks , 2005 .

[12]  R. Ulusay,et al.  Prediction of engineering properties of a selected litharenite sandstone from its petrographic characteristics using correlation and multivariate statistical techniques , 1994 .

[13]  E. T. Brown.  Rock characterization, testing & monitoring: ISRM suggested methods , 1981 .

[14]  M. Karakus,et al.  Fuzzy and Multiple Regression Modelling for Evaluation of Intact Rock Strength Based on Point Load, Schmidt Hammer and Sonic Velocity , 2006 .

[15]  S. Kahraman,et al.  The effect of porosity on the relation between uniaxial compressive strength and point load index , 2005 .