The 3D-Printing Technology of Geological Models Using Rock-Like Materials

The common practice in understanding some puzzling geotechnical and geomechanical issues by large-scale three-dimensional physical model tests is recently much improved by the introduction of 3D-printing technology which can realize the reconstruction of complex geological structures. However, during 3D printing process, the regular rock-like material suffers from some general problems such as short initial setting time, water segregation, decreasing fluidity induced by chemical reaction, and some other unclear influencing factors. To promote further development of physical model via 3D printing method and to fabricate large-scale high-precision 3D geological models, in this paper, the flow characteristics of rock-like materials were first investigated using a new fluidity testing apparatus. Based on the test results, a novel 3D-printing technology of geological material was formulated. Then, the technologies of fabricating the desired structural specimens, acquiring samples with mechanical properties and cracking behaviors similar to natural rock, printing large-scale complex geological models were formulated. The results show that the 3D-printing technology of geological materials had a principle: no losing fluidity during printing time. The parameters of print head diameter, line width, line span, and line slump were the four key factors affecting desired structural samples. From the enlightenment of printing small-scale sample, the printing methods of complex large-scale geological models including decreasing printing time, acquiring heterogeneous geological model with inner structures, desired density, and surrounding smooth surface were proposed.