Advanced physical modeling of tunnel behavior in stratified strata: Insights from 3D printing and gypsum-based materials

This study proposed and applied innovative methods for constructing elaborated tunnel models and stratified rock masses, utilizing 3D printing technology and gypsum-based materials. In the test, three types of elaborated tunnel models and a traditional model are constructed and their application effects are compared in physical model tests. Experimental results indicate that elaborated models with base structures, such as inverted arch filling, more accurately represent the deformation and damage observed in actual tunnels. The precision of these elaborated models is enhanced by 3D printing technology, while gypsum-based materials effectively simulate the failure of tunnel structures under high in-situ stress. Additionally, horizontally soft-hard stratified rock masses are well replicated by employing the self-leveling characteristics of the slurry of gypsum-based similar materials. Furthermore, the failure characteristics of tunnel structures and stratified rock masses are investigated in the test. Under high horizontal in-situ stress, cracks in tunnel structures and failures in surrounding stratified rocks are concentrated in the vault and base of the tunnel, and the damage to the surrounding rocks manifests as the bending of rock layers and shear-slip failure of the rock mass. Therefore, to prevent damage to tunnels in nearly horizontally stratified strata subjected to high in-situ stress, it is crucial to reinforce the structures and surrounding rocks at both the bottom and vault of the tunnel. • Advanced physical modeling of tunnels are proposed and applied using 3D printing technology and cast-in-place process. • Elaborated stratified rock masses are created with gypsum-based similar materials. • Failure characteristics of tunnels in stratified rock masses under high in-situ stress are investigated.