JOURNAL OF ROCK MECHANICS

JOURNAL OF ROCK MECHANICS

Investigation of shear behavior of rock sample which have discontinuities system made by 3D printer

Document Type : Original Article

Authors
1 MSc. in Rock Mechanics, Mining Dept., Eng. Faculty, Tarbiat Modares Uni., Tehran, Iran
2 Associate Prof., Mining Dept., Eng. Faculty, Tarbiat Modares Uni., Tehran, Iran
3 Prof. of Rock Mechanics, Mining Dept., Eng. Faculty, Tarbiat Modares Uni., Tehran, Iran
Abstract
The presence of discontinuities such as joints, has effect on behavior of rock mass and as a result affects stability of structures built within rock mass. Therefore, it is imperative to assess the behavior of the rock mass before designing and constructing structures within it. Performing in situ tests is the most accurate method for estimating the geomechanical properties of rock masses, but it is expensive and time-consuming. As a result, researchers often decide to produce laboratory-based rock mass samples. In recent years, in rock mechanics science has been used 3D printing technology for preparation of rock samples. The objective of this research was to model discontinuities systems within rock sample to investigate the shear behavior of jointed rock. This study started by reviewing the limitations of conventional rock mechanics tests when applied to jointed rock. Subsequently, jointed rock samples were prepared using a 3D printer. Direct shear tests were conducted on artificial samples which were designed to simulate rock mass. The results clearly demonstrate the capability of 3D printing technology to produce rock mass. It was observed that the shear strength of the 3D-printed rock samples was lower than that of intact rock samples. The use of polyvinyl alcohol materials in constructing the discontinuities system proved to be suitable. These materials dissolve easily in water. The 3D-printed network is placed inside a mold and filled with a slurry with the appropriate ratio of water, sand and cement. This block is placed in water, resulting the network dissolve and do not influence on geomechanical parameters of sample. Furthermore, the cohesion of the rock mass was found to be directly influenced by the orientation of the discontinuities systems. Aligning the shearing surface with the discontinuities system reduced cohesion.
Keywords
Subjects

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