Physical modeling experimental study on failure mechanism of surrounding rock of deep-buried soft tunnel based on digital image correlation technology

In this paper, a physical model experiment was conducted to study the deformation and failure mechanism of surrounding rock of deep-buried soft tunnel. With the help of noncontact displacement monitoring system, strain data acquisition system, and high-definition camera, the displacement field data, the strain field data, and the deformation and failure process of surrounding rock were obtained during the experiment. The results of study showed that the excavation footage and horizontal stress had a significant influence on the deformation of surrounding rock of deep-buried soft rock tunnel; the surrounding rock had obvious asymmetrical deformation, and the key position of failure was located at the top and right side of tunnel; the uncoordinated deformation areas were the potential dangerous destruction areas of surrounding rock; and the surrounding rock of tunnel was destroyed under the combined action of tension and compression stress.