Development and Application of Micro Automatic Excavation Device for Model Test of Underground Engineering

In the model test of underground engineering, how to carry out the automatic excavation of different types of tunnel and small caverns is still a technical challenge at present. In this paper, we designed and developed the micro automatic excavation device, including the cutting type automatic excavation device and the crushing type automatic excavation device for model test of underground engineering by using servo electric control technology. The device has high excavation accuracy. With the aid of this device, the excavation of cavern with any shape can be conducted. This device can carry out not only full section automatic excavation, but also bench method automatic excavation. The device has been successfully applied in the three-dimensional geomechanical model test of the excavation for the cavern groups in an underground laboratory. After the excavation of the model cavern, the wall of the cavern is smooth, and the intersection position and angle between the caverns are accurate. Compared with the design size, the excavation error of all caverns is within ± 5 ‰, which meets the design requirements. It provides technical support for accurate excavation test of model test meanwhile provides a strong technical guarantee for the fine simulation of the deformation characteristics and failure laws of deep underground caverns.