Additive manufacturing of hybrid straw-soil-cement materials for enhanced mine models

The deployment of 3D printing technology for the construction of mine physical models represents a promising method for improving precision and providing reliable suggestions for engineering problems. This study proposes the use of wheat straw as a component in a composite material with soil and cement. The composite was used as the 3D printing material for the construction of a physical model of a coal mine. The optimal ratio of straw, soil, cement, and water was determined, and the printability of the material was adjusted to achieve the desired mechanical characteristics for a 3D-printed coal mine engineering model. The model comprises supporting components that were manufactured using 3D printing technology. Two distinct techniques were proposed for the fabrication of rock bolts and U-shaped arches: stainless steel-based printing and PLA-based printing, respectively. A scaled model was then manufactured with the hybrid straw-soil-cement composite material, with a precise scale to consider the gob-side entry driving system. The mechanical characterization of the model demonstrated that the damage scenario and the collapse mechanism could mimic the real engineering case under extreme loading conditions. Furthermore, the proposed method for 3D printing of coal mine models can also be considered suitable for constructing other physical models for engineering cases.