Correlation between uniaxial compressive strength and brittleness of selected rock types

The purpose of this study is to investigate the relationship between uniaxial compressive strength and brittles of selected rock types. Intact rock tests including Uniaxial compressive and Brazilian tensile strength and punch penetration tests were performed in the laboratory on selected rock samples collected along the tunnel excavated in New York City. Uniaxial and Brazilian compressive strength tests are performed according to ASTM standards, however punch penetration tests do not have any academic/institutional standard at this moment; therefore, the test was performed according to United States of America industrial standard. Along the tunnel from 100 different locations, rock samples are collected and from each data point, at least 3 tests were performed and average values were recorded for establishing database. Finally, multiple regression analysis was performed to achieve correlation between the brittleness values (b1, b2, b3, gathered from punch penetration tests, and uniaxial compressive to Brazilian tensile test ratios) and uniaxial compressive strength of selected rock types. Good correlation was achieved between the uniaxial compressive strength to punch penetration tests results as well as correlation between the brittleness values themselves.