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Öğe A brittleness index to estimate the sawability of carbonate rocks(A A BALKEMA PUBLISHERS, 2005) Kahraman, S.; Fener, M.; Gunaydin, O.; Konecny, PPerformance measurements of large-diameter circular diamond saws were conducted on eight different carbonate rocks in marble factories located in some areas of Turkey and hourly slab productions were calculated. Rock samples were collected from these factories for laboratory tests. Triaxial compressive strength test were carried out on each rock type and a brittleness index determined from Mohr's envelope. Slab productions of circular diamond saws and the brittleness index evaluated using both linear and exponential regression analysis. The both regression analysis produced strong correlations between the slab production and the brittleness index. Concluding remark is that the sawability of carbonate rocks can be predicted from the brittleness index determined from Mohr's envelope. However, the validity of the derived equations must be checked for the other rock types.Öğe A quality classification of building stones from P-wave velocity and its application to stone cutting with gang saws(SOUTH AFRICAN INST MINING METALLURGY, 2007) Kahraman, S.; Ulker, U.; Delibalta, M. S.P-wave velocity measurements were carried out on 22 large limestone blocks in a stone processing plant. In the laboratory, P-wave velocity of core samples was measured to obtain intact rock velocity. The square root of the ratio of the velocity of the large stone block to the velocity of the core specimen was called the velocity ratio index (VRI) and a quality classification for large building stones was suggested. in addition, the applicability of the established classification to stone cutting with gang saws was checked. it was concluded that the quality classification and estimation of slab production efficiency of the building stones can easily be made by ultrasonic measurements. However, the study was carried out only in limestone. Further study must be conducted to check the validity of the obtained results for the other rock types.Öğe Analyses of acoustic emission response of a fault breccia in uniaxial deformation(SPRINGER HEIDELBERG, 2010) Slatalla, N.; Alber, M.; Kahraman, S.Interpretation of mechanical tests on block-in-matrix rocks (bimrocks) is difficult and often open to dispute as, with deformation, the interactions between blocks, matrix and pores are complex, reflecting the influence of their different shape, size, strength and stiffness. The acoustic emission (AE) technique can be used to record an ultrasound pulse emitted by a defect within the sample at the moment of its occurrence. Typically several deformations occur, such as crack closure, crack initiation or permanent crack damage, but they may be difficult to visualize with a fault breccia. Consequently, with fault breccia it is advisable to focus on the primary stage of deformation where the acoustic emission response may be traced to properties of the breccia, such as block proportions. The paper shows that the different geometrical properties, particularly the volumetric block proportions, are reflected by stress concentrations which in turn trigger specific AE signatures.Öğe Determination of fracture depth of rock blocks from P-wave velocity(SPRINGER HEIDELBERG, 2008) Kahraman, S.; Soylemez, M.; Fener, M.The quality of large rock blocks produced from quarries depends significantly on the fractures and the extent to which they penetrate into the rock. The paper reports a laboratory study to evaluate the possibility of the determining fracture depth in rock blocks from P-wave velocity. Three igneous, three sedimentary and three metamorphic rocks were studied. Inverse linear relations were found between the fracture depths and the P-wave velocities. Although, the slope of the regression lines is approximately the same for the rocks belonging to one rock class, different trends are seen for the different rock types. In addition, some correlation was found between the slopes of the regression lines and the physical properties of the rocks.Öğe Estimating unconfined compressive strength and elastic modulus of a fault breccia mixture of weak blocks and strong matrix(PERGAMON-ELSEVIER SCIENCE LTD, 2006) Kahraman, S.; Alber, M.[Abstract Not Available]Öğe Evaluating the geomechanical properties of Misis fault breccia (Turkey)(PERGAMON-ELSEVIER SCIENCE LTD, 2008) Kahraman, S.; Alber, M.; Fener, M.; Gunaydin, O.This study investigated the correlations between the uniaxial compressive strength (UCS), elastic modulus (E) or the differential stress (Delta sigma) and density, P- and S-wave velocity, volumetric block proportion (VBP), average block diameter (($) over bar (block)), average block diameter factor (ABD(F)), aspect ratio and roundness. The results were evaluated by both simple and multiple regression analysis. Simple regression analysis results show no correlation between UCS, E or Delta sigma and the other examined parameters, except S-wave velocity. A correlation was, however, found between UCS and S-wave velocity for 25% and 75% VBP. Other significant models including density, P- and S-wave velocity and textural properties for the prediction of UCS and Ds were found by multiple regression analysis. From these results it is concluded that the strength of the Misis fault breccia cannot be defined by a single parameter such as VBP as is the case for some bimrocks. It is also concluded that the models developed by multiple regression analysis can be used to predict the UCS and Ds of the Misis fault breccia. The multiple regression models including two or three independent variables are the most practical equations. Using these equations to predict the UCS and Ds of the fault breccia is easier, faster and cheaper than conducting triaxial or uniaxial compressive strength tests. (C) 2008 Elsevier Ltd. All rights reserved.Öğe Evaluating the strength and deformability properties of Misis fault breccia using artificial neural networks(PERGAMON-ELSEVIER SCIENCE LTD, 2009) Kahraman, S.; Gunaydin, O.; Alber, M.; Fener, M.Since the preparation of smooth specimens from the fault breccias are usually difficult and expensive, the development of some predictive models for the geomechanical properties of fault breccias will be useful. In this study, artificial neural networks (ANNs) analysis was applied on the data pertaining to Misis fault breccia to develop some predictive models for the uniaxial compressive strength (UCS) and elastic modulus (E) from the indirect methods. The developed ANNs models were also compared with the regression models. As a result of ANNs analysis, very good models were derived for both UCS and E estimation. It was shown that ANNs models were more reliable than the regression models. Concluding remark is that UCS and E values of Misis fault breccia can reliably be estimated from the indirect methods using ANNs analysis. (c) 2008 Elsevier Ltd. All rights reserved.Öğe Indentation hardness test to estimate the sawability of carbonate rocks(SPRINGER HEIDELBERG, 2008) Kahraman, S.; Gunaydin, O.The performance of large-diameter circular saws on eight carbonate rocks was recorded and indentation hardness, density and porosity tests were undertaken on the five travertines, two limestone and one dolomitic limestone samples returned to the laboratory. A strong linear correlation between indentation hardness index values and the hourly production of the circular saws was found. The slab production was slowest for the dolomitic limestone rocks with the highest indentation hardness, lowest porosity and highest density values.Öğe NOISE LEVEL MEASUREMENT TEST TO PREDICT THE ABRASION RESISTANCE OF ROCK AGGREGATES(WORLD SCIENTIFIC PUBL CO PTE LTD, 2013) Kahraman, S.; Delibalta, M. S.; Comakli, R.Compared to the indirect tests, the determination of the Los Angeles abrasion loss is time consuming and expensive, and requires a large amount of samples. For this reason, the prediction of Los Angeles abrasion loss from some indirect tests is useful for preliminary studies. In this study, Los Angeles abrasion, noise level (NL) measurement, density, and porosity tests were carried out on 27 different rock types such as igneous, metamorphic, and sedimentary. The test results were evaluated using the simple and multiple regression analysis. A good relation was found between the Los Angeles abrasion loss and the NL. In order to check the possibility of obtaining more significant relations, multiple regression analysis was performed by including density and porosity values. However, the regression analysis showed that the correlation coefficients of the multiple regression equations were slightly higher than that of the simple regression equation. Since the simple regression equation is practical and statistically significant, it is suggested for estimation purpose. In conclusion, it can be said that Los Angeles abrasion loss of aggregates can be reliably estimated from NL measurement.Öğe Predicting Los Angeles abrasion loss of rock aggregates from crushability index(SPRINGER, 2008) Kahraman, S.; Toraman, O. Y.Predicting Los Angeles abrasion loss of aggregate material from some simpler tests will be useful for especially preliminary studies. For this reason, to investigate the possibility of predicting the Los Angeles abrasion loss from the crushability index, Los Angeles abrasion, crushability, density and porosity tests were performed on 11 different rock types collected from different areas of Turkey. The results of the tests were analysed using simple and multiple regression analyses. Generally significant correlations were obtained from both simple and multiple regression analyses. The correlation coefficients and estimation capabilities of the two multiple regression equations are slightly higher than that of the simple regression equation. It was concluded that the simple regression equation is practical and reliable enough for estimation purposes. However, the two multiple regression equations can be used for a more accurate estimation.Öğe Predicting the brittleness of rocks from a crushability index(European Association of Geoscientists and Engineers, EAGE, 2015) Kahraman, S.; Toraman, O.Y.The determination of brittleness, an important mechanical property of rocks, requires some standard tests which are time consuming and expensive. The sample preparation and testing methods are easy in the crushability test suggested in this study and a small amount of crushed rock is enough for testing. That the crushability test can be applied on the drill cuttings is another important advantage. The prediction of brittleness from the crushability test will be useful for some cases. 500 g oven-dried crushed samples, in the size range of 19.0-9.52 mm, were prepared from twenty four different rock types. After charging the samples to a jaw crusher, the crushed materials were passed through the 9.52 mm mesh and the percentage of oversized material was described as the crushability index (CI). The brittleness B1 determined from the Protodyakonov impact test and the brittleness B2 determined from compressive and tensile strength were evaluated in this study. A significant strong correlation was found between the CI and the brittleness B2. Because the tested rocks cover sedimentary, igneous, and metamorphic rocks, the derived relation can be generalized. It can be concluded that the crushability test is a practical and easy method for the prediction of brittleness B2.Öğe Predicting the compressive and tensile strength of rocks from indentation hardness index(SOUTH AFRICAN INST MINING METALLURGY, 2012) Kahraman, S.; Fener, M.; Kozman, E.The prediction of rock properties from indirect testing methods is important, particularly for preliminary investigations since indirect tests are easier and cheaper than the direct tests. In this study, we investigate the predictability of the uniaxial compressive strength (UCS) and Brazilian tensile strength (BTS) of rocks from the indentation hardness index (IHI) obtained using point load apparatus. Forty-six different rock types, 14 of which were igneous, 15 were metamorphic, and 17 were sedimentary were tested in the laboratory. The UCS and BTS values were correlated with the corresponding IHI values and the results were statistically analysed. The influence of rock classes on the relationships was also investigated. A strong correlation between UCS and IHI was found for all data. The correlation between BTS and IHI is not as strong as the correlation between UCS and IHI.However, it is in the acceptable limits. When the regression analyses were repeated for igneous, metamorphic, and sedimentary rocks, the correlation coefficients were generally increased. The results show the UCS and BTS can be estimated from IHI. In addition, the effect of rock classes on the relationships between IHI and both UCS and BTS is important.Öğe Predicting the crushability of rocks from the impact strength index(PERGAMON-ELSEVIER SCIENCE LTD, 2010) Toraman, O. Y.; Kahraman, S.; Cayirli, S.To investigate the possibility of predicting the crushability of rocks from impact strength index, twenty-four different rock types were tested in the laboratory. The crushability results were correlated with the results of impact strength test and regression analysis was performed. A strong inverse linear relation between the crushability index and the impact strength index was found. The effect of porosity and density on the correlation was also shown. In addition, multiple regression analysis including porosity and density was carried out. The significances of the derived models were statistically tested. It was concluded that the crushability of rocks can practically be estimated from the impact strength index using the simple regression model. (C) 2010 Elsevier Ltd. All rights reserved.Öğe Predicting the Los Angeles abrasion loss of rock aggregates from the uniaxial compressive strength(ELSEVIER SCIENCE BV, 2007) Kahraman, S.; Fener, M.Los Angeles abrasion, Uniaxial compression, and porosity tests were performed on 35 different rock types collected from different areas of Turkey, nine of which were igneous, eleven of which were metamorphic and fifteen of which were sedimentary. To investigate the possibility of predicting the Los Angeles (LA) abrasion loss from the uniaxial compressive strength (UCS), the results of the tests were analyzed using regression analysis. A good correlation between L.A. abrasion loss and UCS was found. In addition, it was seen that when the rocks were classified into classes according to porosity, the correlation coefficients were increased. Concluding remark is that derived equations can reliably be used for the prediction of L.A. abrasion loss from the UCS. (c) 2007 Elsevier B.V All rights reserved.Öğe Predicting the physico-mechanical properties of igneous rocks from electrical resistivity measurements(TAYLOR & FRANCIS LTD, 2006) Kahraman, S.; Ogretici, E.; Fener, M.; Yeken, T.; Cotthem, AV; Charlier, R; Thimus, JF; Tshibangu, JPElectrical resistivity values of eight different igneous rocks were measured on core samples using a resistivity meter in the laboratory. The resistivity tests were conducted on the samples fully saturated with brine (NaCl solution) and uniaxial compressive strength, Brazilian tensile strength, density and porosity values of the samples were determined in the laboratory. Resistivity values were correlated with the corresponding physico-mechanical properties using simple regression analysis methods. Generally strong correlations obtained from regression analysis. Concluding remark is that electrical resistivity may be a representative measure of properties of igneous rocks. However, further research is necessary to check how the stronger and different igneous rocks affect the correlations.Öğe Predicting the strength and brittleness of rocks from a crushability index(SPRINGER HEIDELBERG, 2018) Kahraman, S.; Toraman, O. Y.; Cayirli, S.Uniaxial compressive strength (UCS), Brazilian tensile strength (BTS), and brittleness are widely used in rock engineering applications. However, preparing the test samples for the standard tests may not always be possible for weak or soft rocks. On the other hand, only rock fragments may be available to estimate the rock strength in some cases such as drilling. Therefore, developing some models for estimating the rock strength and brittleness from rock fragments will be useful. In this study, a crushability index (CI) was described from the crushing test, and the possibility of predicting UCS, BTS, and brittleness from this index was investigated. Strong and significant linear correlations were found between the CI and UCS, BTS, and one of the brittleness concepts. It was concluded that the UCS, BTS, and some brittleness concepts of rock could be estimated from the CI. The suggested method is especially useful for the drilling industry and for the cases where there are not enough samples for the standard tests. However, the study is a preliminary study on limited rock types and further study is required by including the number of different rock types.Öğe Predicting the uniaxial compressive strength and elastic modulus of a fault breccia from texture coefficient(SPRINGER WIEN, 2009) Alber, M.; Kahraman, S.[Abstract Not Available]Öğe Prediction of physico-mechanical rock characteristics from electrical resistivity tests(Southern African Inst Mining Metallurgy, 2024) Kahraman, S.; Ogretici, E.The indirect estimation of intact rock properties is particularly useful for preliminary investigations in engineering projects. In this paper we examine the usability of electrical resistivity, a nondestructive measurement, for the prediction of physical and mechanical rock characteristics. Physico-mechanical tests (uniaxial compression, Brazilian tensile, density, and porosity tests) and electrical resistivity measurements were performed on specimens of 36 rock types. Before the resistivity tests, the specimens were completely saturated with saline solution. Evaluation of the test results showed that there are medium or strong correlations between resistivity and rock properties. There are also strong or stronger correlations between the two parameters for the rock classes. The regression equations developed were statistically tested, and their validity was confirmed. The results were also compared with previous studies. The conclusion is that electrical resistivity measurement can be used for reliably estimating physical and mechanical rock characteristics.Öğe Reply to Yagiz's discussion on Kahraman and Gunaydin (2008) indentation hardness test to estimate the sawability of carbonate rocks. Bull Eng Geol Environ 67:507-511(SPRINGER HEIDELBERG, 2009) Kahraman, S.; Gunaydin, O.[Abstract Not Available]Öğe The correlations between the saturated and dry P-wave velocity of rocks(ELSEVIER SCIENCE BV, 2007) Kahraman, S.Sometimes engineers need to estimate the wet-rock P-wave velocity from the dry-rock P-wave velocity. An estimation equation embracing all rock classes will be useful for the rock engineers. To investigate the predictability of wet-rock P-wave velocity from the dry-rock P-wave velocity, P-wave velocity measurements were performed on 41 different rock types, 11 of which were igneous, 15 of which were sedimentary and 15 of which was metamorphic. In addition to the dry- and wet-rock P-wave velocity measurements, the P-wave velocity changing as a function of saturation degree was studied. Moreover, dry- rock S-wave velocity measurements were conducted. The test results were modeled using Gassmann's and Wood's theory and it was seen that the measured data did not fit the theories. The unconformity is due to the fact that the theories are valid for high-porosity unconsolidated sediments at low frequencies. Gassmann's equation was modified for the rocks except high-porosity unconsolidated sediments. The dry- and wet-rock P-wave velocity values were evaluated using regression analysis. A strong linear correlation between the dry- and wet-rock P-wave velocities was found. Regression analyses were repeated for the rock classes and it was shown that correlation coefficients were increased. Concluding remark is that the derived equations can be used for the prediction of wet-rock P-wave velocity from the dry- rock P-wave velocity. (c) 2007 Elsevier B. V. All rights reserved.
