Physical modeling of deformation failure mechanism of surrounding rocks for the deep-buried tunnel in soft rock strata during the excavation

A physical modeling experiment was carried out to study deformation mechanism of tunnel excavated in the deep-buried soft rock strata. During the process of excavation, an infrared camera and a full-field strain measurement system were employed to obtain the thermal response and deformation of surrounding rock. Meanwhile, strain rosettes were used to measuring the strain of surrounding rocks, which were installed with a circular layout pattern in the surrounding rocks. Deformation failure mechanism of surrounding rocks was investigated by synthetic analysis of the infrared images, experimental pictures, and displacement field images. A numerical model was implemented to compare the displacement results of the physical model. The results showed that driving footage produced an effect on the deformation of surrounding rock, the bedding plane had an inevitable influence on the deformation of surrounding rock during the excavation processes and temperature variations of surrounding rock can reflect the behavior change of surrounding rock.