Table 1: Proposed correlations between UCS and Rock index tests.

Reference Correlation Reliability Rock Type
Kahraman et al. [52] UCS = 10.61BTS R2 = 0.54 Different rock types including limestone
Sari [5] UCS = 4.969exp(0.058RL) R2 = 0.575 Different rock types
Sari [5] UCS = 5.912VP1.741 R2 = 0.645 Different rock types
Altindag and Guney [53] UCS = 12.38BTS1.0725 R = 0.9 Different rock types including limestone
Gokceoglu and Zorlu [54] UCS = 6.8BTS +13.5 R = 0.65 -
Nazir et al. [3] UCS = 9.25BTS0.947 R2 = 0.90 20 Limestone samples
Karaman et al. [55] UCS = 24.301+4.874BTS R2 = 0.90 37 Rock samples including Basalt and limestone
Broch and Franklin [56] UCS = 23.7 Is(50) - -
Bieniawski [57] UCS = 23 Is(50) - Different type of rocks
Kahraman et al. [58] UCS = 10.22 Is(50) + 24.31 R2 = 0.75 38 Different rock samples
Basu and Aydin [59] UCS = 18 Is(50) R2 = 0.97 40 Granitic rock samples
Yilmaz and Yuksek [60] UCS = 12.4 Is(50) - 9.0859 R2 = 0.81 39 Sets of gypsum samples
Diamantis et al. [61] UCS = 19.79 Is(50) R2 = 0.74 32 Samples of serpentinite rock
Kahraman [62] UCS = 14.68Is(50) − 8.67 R = 0.88 32 Pyroclastic specimens
Sarkar et al. [63] UCS=0.038Vp-50 R2=0.93 13types of different rock
Kilic and Teymen [64] UCS=0.0137RL2.2721 R= 0.93 Different rock types
Cobanoglu and Selik [65] UCS=6.59 RL -212.6 R= 0.65 Limestone, sandstone, cement mortar
Tugrul and Zarif [66] UCS=8.36 RL -416 R= 0.87 19 Granite rock samples
Nazir et al. [4] UCS=12.83 e(0.0487 RL) R = 0.95 20 Limestone samples
Aydin and Basu [67] UCS=1.4459e0.0706 RL R = 0.92 Granitic rocks
Gupta [68] UCS=1.15 RL -15 R = 0.95 Granite
Sharma and Singh [69] UCS = 0.0642VP – 117.99 R2 = 0.90 49 samples in different rock types
Moradian and Behnia [70] UCS=165.05e(- .452/Vp) R2 = 0.7 64 different rock samples
Khandelwal [71] UCS = 0.033 VP – 34.83 R2 = 0.87 12 samples of a wide rock types
Diamantis et al. [61] UCS=0.11 VP - 515.56 R2 = 0.81 32 samples of serpentinite rock
Altindag [72] UCS = 12.743 VP1.194 R = 0.76 97 rock specimens (mainly limestone)
   Cobanoglu and Celik [65] UCS=56.71 VP - 192.93 R2 = 0.67 150 core samples of different rocks
   Xu et al. [73] UCS=2.98 e(0.06 RL) R = 0.95 Mica-schist
Jamshidi et al. [74] UCS=133.77 Ln Vp-1048 R= 0.90 Limestone
Entwisle et al. [75] UCS= 0.78 e 0.88VP R2 = 0.53 171 samples of Volcanic rock

*BTS: Brazilian Tensile Strength, Vp:P-wave velocity, Is(50): Point load index value, RL: Schmidt hammer rebound number.