Abstract: Geotechnical engineering often encounters high temperature environment. It is important to study the mechanical properties of rock samples printed in 3D subjected to high temperature treatment to promote the application of 3D printing technology in engineering field. Using GS19 sand and furan resin as printing substrates, rock samples with highly consistent internal structure were prepared by 3D printing technology and the mechanical properties of rock samples printed in 3D subjected to different temperature treatments were studied. The reasons for the change in mechanical properties of rock samples printed in 3D at different temperatures were analyzed from the microscopic level by scanning electron microscopy. The optimal temperature of 3D printed rock samples are proposed and the failure characteristics of 3D printing rock samples with prefabricated cracks after optical mechanical temperature action are studied. The uniaxial compressive strength and splitting tensile strength of 3D printed rock samples increase first and then decrease with increasing temperature. The optical mechanical temperature is 150 ℃. After the optical mechanical temperature effect, the failure process of 3D printed rock samples with different inclined cracks includes four stages, i.e. compaction, micro-crack initiation, stable crack propagation and penetration failure. The initial crack initiation locations appear at the prefabricated cracks, but with the change in inclination of prefabricated cracks, the propagation path always tends to the direction of load loading and is approximately centrosymmetrical.

Key words: geotechnical engineering, 3D printing, high temperature, mechanical properties, prefabricated cracks