Empirical estimation of the uniaxial compressive strength from the point load test in anisotropic rocks (schists and shales)

In this paper new empirical relationships are developed between uniaxial compressive strength and point load index Is(50) in anisotropic rocks, particularly in schists and shales. We have used data from 2015 point load tests and 229 uniaxial compressive strength tests performed in anisotropic rocks...

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Bibliographic Details
Authors: Burbano, Danny, García, Tania
Format: article
Status:Published version
Publication Date:2016
Country:Ecuador
Institution:Universidad Central del Ecuador
Repository:Revista FIGEMPA: Investigación y Desarrollo
Language:Spanish
OAI Identifier:oai:revistadigital.uce.edu.ec:article/862
Online Access:https://revistadigital.uce.edu.ec/index.php/RevFIG/article/view/862
Access Level:Open access
Keyword:anisotropía
ensayo de carga puntual
esquisto
mecánica de rocas
resistencia a compresión uniaxial
anisotropy
point load test
uniaxial compressive strength
rock mechanics
schists
Description
Summary:In this paper new empirical relationships are developed between uniaxial compressive strength and point load index Is(50) in anisotropic rocks, particularly in schists and shales. We have used data from 2015 point load tests and 229 uniaxial compressive strength tests performed in anisotropic rocks obtained during various stages of study of Paute-Cardenillo hydroelectric project, located in the eastern slopes of the northern Andes Cordillera (SE Ecuador). We have defined five anisotropic rocks types (schists and shales) for which the mean values of uniaxial compressive strength and point load index were obtained according to their orientation with respect to the planes of anisotropy. Finally, it is found that there is no direct relationship between uniaxial compressive strength and Is(50) so it is unreliable take traditional empirical linear regression models, which do not consider the effect of the planes of anisotropy in rock strength. Therefore, three new empirical relationships that estimate the uniaxial compressive strength from Is(50) in anisotropic rocks are proposed.