ISSN - ISRM

12 ISRM (India) JournalTable 6 : Percentage change for properties given in Table 5Sample Change in values from dry to saturation (%)V pV sμ dE dD1 19 -3 262 17D2 20 -2 360 29D3 8 -3 49 12D4 17 0.03 83 25D5 17 -0.34 107 25D6 14 0.31 80 23D7 8 -4 125 11D8 16 -0.3 45 21D9 11 -3 28 76.1 Relationship between P-and S-Wave VelocitiesFirstly, the data related to P- and S-wave velocities thatwere obtained from measurements on 37 rockspecimens, representing all kinds of rock samples fromborehole Darkov 265-01, in dry and saturated conditions,are analysed. Relationship between V pand V sis shownin Figs. 4 and 5. From these figures, the linear relationshipbetween P- and S-wave velocities is clearly visible.Because of a high regression coefficient between theseparameters, it is easily possible to estimate one velocitywhen knowing the other.6.2 Relationship between Geophysical and PhysicalPropertiesThe relationship between different P- and S-wavevelocities and with that of physical properties is tried.The relationship between dry density and dry P-wavevelocity is shown in Fig. 6. An increase in P-wave velocitywith increasing density is observed. This is obvious sincewave velocities generally increase with increasingspecimen density. Fig. 7 shows the relationship betweenwater absorption and dry P-wave velocity. It shows anincrease in dry P-wave velocity with decrease in waterabsorption. Water absorption depends on mineralogy andporosity of rock. The ultra-sound velocity depends onthe same factors. Therefore, it would be possible to finda relationship between water absorption and velocity. Thescatter in the data and poor correlation could beassociated with sample extraction, disturbance, samplepreparation and measurements.Fig. 6 : Relationship between dry density and dry P-wave velocityFig. 4 : Relationship between dry P-and S-wave velocitiesFig. 7 : Relationship between water absorptionand dry P-wave velocityFig. 5 : Relationship between saturated P-and S-wavevelocities7.0 RELATIONSHIP BETWEEN FATIGUE ANDPHYSICAL AND GEOPHYSICAL PROPERTIESTo find out possible relations with geophysical andphysical properties and with fatigue properties of the rock,all these specimens (37 in total) were tested under thesame dynamic cyclic loading conditions. Simulatedloading frequency was 1 Hz, and amplitude was 0.1 mm,using ramp waveform. For more detail about the testingequipment and loading condition kindly see author’sVolume 1 v No. 1 v January 2012