Core size effect on the dry and saturated ultrasonic pulse velocity of limestone samples


ERÇIKDI B., KARAMAN K., CİHANGİR F., YILMAZ T., ALIYAZICIOGLU S., KESİMAL A.

ULTRASONICS, vol.72, pp.143-149, 2016 (SCI-Expanded) identifier identifier identifier

  • Publication Type: Article / Article
  • Volume: 72
  • Publication Date: 2016
  • Doi Number: 10.1016/j.ultras.2016.08.006
  • Journal Name: ULTRASONICS
  • Journal Indexes: Science Citation Index Expanded (SCI-EXPANDED), Scopus
  • Page Numbers: pp.143-149
  • Keywords: P-wave velocity, Core sample length, Calcite minerals, Water effect, P-WAVE VELOCITY, MECHANICAL-PROPERTIES, COMPRESSIVE STRENGTH, ROCK
  • Karadeniz Technical University Affiliated: Yes

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 (25-125 mm) at a constant diameter (54.7 mm). 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 125 mm 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 75 mm sample lengths, thereafter, a trend of stabilization was observed. The maximum variation of UPV values between the sample length of 75 mm and 125 mm was only 7.3%. Therefore, the threshold core sample length was interpreted as 75 mm for UPV measurement in biomicritic limestone samples used in this study. (C) 2016 Elsevier B.V. All rights reserved.