Determination of Rock Tensile Strength Based on Arc Loading Splitting Test considering Modulus Effect

Abstract

Tensile strength is an important control parameter for the design and stability analysis in rock engineering. In order to reveal the influence of elastic modulus on tensile strength test results, Brazilian splitting tests were carried out on specimens with different strengths, such as mudstone, white sandstone, green sandstone, red sandstone, and marble. Longitudinal and transverse strains were monitored to analyze the influence of elastic modulus on the maximum contact angle and peak contact load between head and disc. A numerical model of Brazilian splitting tests was built, and the contact load between the head and rock disc were detailed revealed. Based on the experimental and numerical results, a modified formula to calculate tensile strength considering the modulus effect was proposed theoretically. Results show that the maximum pressure between the head and disc increases and the contact angle decreases with the increasing of elastic modulus, which show great influence on the splitting failure; the distribution of contact load can be divided into three types: parabolic I, sinusoidal, and parabolic II, which are suitable for soft rock, medium-hard rock, and hard rock, respectively; the new models can improve the calculation accuracy of rock tensile strength.