Size effects in cavern model tests based on 3D printing

Similar model test is one of the most commonly used methods for studying the stability of underground caverns. 3D printing can conveniently create similar models of different sizes and study the size effect on test results. This study uses rock-like materials to 3D print cavern models of various sizes. The size effects on the strength, failure mechanisms, energy storage in model and cavern deformation are explored by experimental tests and corroborated by numerical simulations that consider material heterogeneity. The consistent experimental and numerical results show that the overall strength of test models decreases with the increase of model size. When model caverns fail, the larger test model has a more violent damage. There is a linear relationship between the allowable maximum deformation of the cavern and the model size. Material heterogeneity is the main factor causing the above size effect of the test models, and the large fractures in the large models also play a substantial role. The test models of underground engineering based on 3D printing provide support for stability evaluation and design.

Automated summary

This study uses 3D printing to create similar models of underground caverns in different sizes, and explores the size effect on strength, failure mechanisms, energy storage, and deformation through experimental tests and numerical simulations. The results show that larger test models have lower overall strength, more violent damages, and a linear relationship between allowable deformation and model size. Material heterogeneity is identified as the main factor causing the size effect, while large fractures in larger models also play a substantial role.