title: Core size effect on the dry and saturated ultrasonic pulse velocity of limestone samples.
abstract: This study presents the effect of core length on the saturated (UPVsat) and dry (UPVdry) P-wave velocities of four different biomicritic limestone samples, namely light grey (BL-LG), dark grey (BL-DG), reddish (BL-R) and yellow (BL-Y), using core samples having different lengths (25-125mm) at a constant diameter (54.7mm). The saturated P-wave velocity (UPVsat) of all core samples generally decreased with increasing the sample length. However, the dry P-wave velocity (UPVdry) of samples obtained from BL-LG and BL-Y limestones increased with increasing the sample length. In contrast to the literature, the dry P-wave velocity (UPVdry) values of core samples having a length of 75, 100 and 125mm were consistently higher (2.8-46.2%) than those of saturated (UPVsat). Chemical and mineralogical analyses have shown that the P wave velocity is very sensitive to the calcite and clay minerals potentially leading to the weakening/disintegration of rock samples in the presence of water. Severe fluctuations in UPV values were observed to occur between 25 and 75mm sample lengths, thereafter, a trend of stabilization was observed. The maximum variation of UPV values between the sample length of 75mm and 125mm was only 7.3%. Therefore, the threshold core sample length was interpreted as 75mm for UPV measurement in biomicritic limestone samples used in this study.
authors.affiliation: Department of Mining Eng., Karadeniz Technical University, 61080 Trabzon, Turkey. Electronic address: bercikdi@ktu.edu.tr.
authors.forename: Bayram
authors.initials: B
authors.lastname: Ercikdi
authors.affiliation: Department of Mining Eng., Karadeniz Technical University, 61080 Trabzon, Turkey.
authors.forename: Kadir
authors.initials: K
authors.lastname: Karaman
authors.affiliation: Department of Mining Eng., Karadeniz Technical University, 61080 Trabzon, Turkey.
authors.forename: Ferdi
authors.initials: F
authors.lastname: Cihangir
authors.affiliation: Department of Mining Eng., Karadeniz Technical University, 61080 Trabzon, Turkey.
authors.forename: Tekin
authors.initials: T
authors.lastname: Yılmaz
authors.affiliation: Department of Mining Eng., Karadeniz Technical University, 61080 Trabzon, Turkey.
authors.forename: Şener
authors.initials: Ş
authors.lastname: Aliyazıcıoğlu
authors.affiliation: Department of Mining Eng., Karadeniz Technical University, 61080 Trabzon, Turkey.
authors.forename: Ayhan
authors.initials: A
authors.lastname: Kesimal
keywords: Calcite minerals; Core sample length; P–wave velocity; Water effect