Ahmadi sheshdeh E, Cheshomi A. Estimation the Uniaxial Compressive Strength of Microcrystalline Limestones Using Indentation Test. Journal of Engineering Geology 2015; 9 (3) :2891-2916
URL:
http://jeg.khu.ac.ir/article-1-1713-en.html
1- , a.cheshomi@ut.ac.ir
Abstract: (10195 Views)
Measuring of uniaxial compressive strength (UCS) of intact rocks is required in many engineering projects. In deep well drilling for petroleum production or exploration drilling in deep tunnels, because of depth of wells, obtaining suitable core samples for UCS test is too expensive and sometimes impossible. Therefore, indirect methods for determine UCS (for example using rock particles) are common. One of these methods is known as indentation test. In this test an indenter that is hard penetrates into rock particle which is surrounded by resin used. In this paper, 11 microcrystalline limestone block samples from carbonate Zagros formation outcrops were prepared and UCS test in laboratory was performed. Then cores are crushed and 720 rock particle samples with 2, 3 and 4 millimeter size was prepared. Indentation test with indenter 0.6, 0.8 and 1 millimeter diameter was done and critical transitional force (CTF) for each particles was determined. Empirical equation between UCS and CTF for different samples and has been provided. Based on the obtained results it is suggestedto utilize indenter with a R2&ge0.78. Using multiple regression general equation between UCS, CFT, particle size (D) indenter diameter (I), R2=0.85 is proposed. 135 indentation tests were performed on 3 microcrystalline limestone samples with the aim of verification of obtained empirical equations. Comparing measured UCS in laboratory and estimated UCS values showed 88% similarity
Type of Study:
Original Research |
Subject:
En. Geology Accepted: 2016/10/5 | Published: 2016/10/5