Numerical Assessment of Factors Influencing the Tensile Strength of Rocks via Pull-Off Test

Abstract

The pull-off test (POT) is a tensile strength testing method that is widely used in concrete/mortar and was recently applied to rock mechanics. The POT can be easily performed in both the field and the laboratory. This study uses the extended finite-element method to analyze the POT fracture mechanism under different test conditions and to assess the factors influencing the tensile strength of homogeneous rock. The numerical results were validated with experimental data, and a good agreement was obtained. An ideal test geometry was proposed (the depth and the width of the partial core were 2.5 and 0.4 cm, respectively). The POT can overestimate or underestimate the tensile strength of the rock, depending on the cohesive fracture energy, and a correction equation was proposed for visually homogeneous rocks and concrete.