Size effects in the uniaxial compressive properties of 3D printed models of rocks: an experimental investigation

Abstract

Transparent physical models of real rocks fabricated using three-dimensional (3D) printing technology are used in photoelastic experiments to quantify the evolution of the internal stress and deformation fields of rocks. Therefore, they are rendered as an emerging powerful technique to quantitatively reveal the intrinsic mechanisms of rock failure. The mechanical behavior of natural rocks exhibits a significant size effect; however, limited research has been conducted on whether transparent physical models observe similar size effects. In this study, to make the transparent printed models accurately demonstrate the mechanical behavior of natural rocks and reveal the internal mechanism of the size effect in rock mechanical behavior, the size effect in 3D printed models of fractured and porous rocks under uniaxial compressive loading was investigated. Transparent cylindrical models with different sizes that contained different fractured and porous structures were printed using the fracture and porous characteristics extracted from natural coal and sandstone. The variation in uniaxial compressive strength and elastic modulus of fractured and porous models for increasing model sizes were obtained through uniaxial compression experiments. Finally, the influence of internal discontinuous structural features, such as fractures and pores, on the size effect pertaining to the mechanical behavior of the model was analyzed and elaborated by comparing it with the mechanical properties of the continuous homogeneous model without fractures and pores. The findings provided support and reference to analyze the size effect of rock mechanical behavior and the effect of the internal discontinuous structure using 3D printed transparent models.

Appraisal of Different Artificial Intelligence Techniques for the Prediction of Marble Strength

“…Uniaxial compressive strength (UCS) is an integral parameter significantly used in the effective and sustainable design of tunnels and other engineering structures in civil and mining engineering [1][2][3][4][5][6][7][8][9][10][11][12]. UCS is determined using direct and indirect methods.…”

Scale Effect on Uniaxial Compressive Properties of the Outburst-Prone Coal

“…A coal and gas outburst is a kind of dynamic disaster occurring underground in coal mines, and the process of outburst is accompanied by a large amount of coal rock being broken and gas ejected, causing equipment damage and casualties. , Soft outburst coal is easy to cause coal and gas outbursts, so mastering the strength of outburst coal is the basis for revealing the causes of outbursts and preventing them . However, as a brittle and semibrittle material, the strength of coal rock depends on the variation of the sample scale, namely, the scale effect . Although large-scale field tests can accurately estimate the strength and deformation characteristics of coal rock around underground projects such as coal mining and tunneling, these tests are not always practical or economical considering the difficulty of conducting such tests or the time and economic costs that result .…”

“… 3 However, as a brittle and semibrittle material, the strength of coal rock depends on the variation of the sample scale, namely, the scale effect. 4 Although large-scale field tests can accurately estimate the strength and deformation characteristics of coal rock around underground projects such as coal mining and tunneling, these tests are not always practical or economical considering the difficulty of conducting such tests or the time and economic costs that result. 5 A particularly promising alternative is to amplify the strength and elastic properties of laboratory-tested intact coal to match coal rock in practical engineering.…”

Assessing the Scale Effect on Bearing Capacity of Undrained Subsoil: Implications for Seismic Resilience of Shallow Foundations

“…In a recent study by Wu et al [ 41 ], the investigation extended to 3D printed models of rocks illuminated the intriguing size effects present in their uniaxial compressive properties. Furthermore, efforts to encapsulate the in situ material behavior led to the formulation of a theoretical framework based on the concept of fracture energy [ 42 ].…”